kubeadm - CLI tool to easily provision a secure Kubernetes cluster.
Components
kubelet - The
primary agent that runs on each node. The kubelet takes a set of PodSpecs
and ensures that the described containers are running and healthy.
kube-apiserver -
REST API that validates and configures data for API objects such as pods,
services, replication controllers.
kube-controller-manager -
Daemon that embeds the core control loops shipped with Kubernetes.
kube-proxy - Can
do simple TCP/UDP stream forwarding or round-robin TCP/UDP forwarding across
a set of back-ends.
kube-scheduler -
Scheduler that manages availability, performance, and capacity.
List of ports and protocols that
should be open on control plane and worker nodes
Config APIs
This section hosts the documentation for "unpublished" APIs which are used to
configure kubernetes components or tools. Most of these APIs are not exposed
by the API server in a RESTful way though they are essential for a user or an
operator to use or manage a cluster.
This section provides reference information for the Kubernetes API.
The REST API is the fundamental fabric of Kubernetes. All operations and
communications between components, and external user commands are REST API
calls that the API Server handles. Consequently, everything in the Kubernetes
platform is treated as an API object and has a corresponding entry in the
API.
The JSON and Protobuf serialization schemas follow the same guidelines for
schema changes. The following descriptions cover both formats.
The API versioning and software versioning are indirectly related.
The API and release versioning proposal
describes the relationship between API versioning and software versioning.
Different API versions indicate different levels of stability and support. You
can find more information about the criteria for each level in the
API Changes documentation.
Here's a summary of each level:
Alpha:
The version names contain alpha (for example, v1alpha1).
Built-in alpha API versions are disabled by default and must be explicitly enabled in the kube-apiserver configuration to be used.
The software may contain bugs. Enabling a feature may expose bugs.
Support for an alpha API may be dropped at any time without notice.
The API may change in incompatible ways in a later software release without notice.
The software is recommended for use only in short-lived testing clusters,
due to increased risk of bugs and lack of long-term support.
Beta:
The version names contain beta (for example, v2beta3).
Built-in beta API versions are disabled by default and must be explicitly enabled in the kube-apiserver configuration to be used
(except for beta versions of APIs introduced prior to Kubernetes 1.22, which were enabled by default).
Built-in beta API versions have a maximum lifetime of 9 months or 3 minor releases (whichever is longer) from introduction
to deprecation, and 9 months or 3 minor releases (whichever is longer) from deprecation to removal.
The software is well tested. Enabling a feature is considered safe.
The support for a feature will not be dropped, though the details may change.
The schema and/or semantics of objects may change in incompatible ways in
a subsequent beta or stable API version. When this happens, migration
instructions are provided. Adapting to a subsequent beta or stable API version
may require editing or re-creating API objects, and may not be straightforward.
The migration may require downtime for applications that rely on the feature.
The software is not recommended for production uses. Subsequent releases
may introduce incompatible changes. Use of beta API versions is
required to transition to subsequent beta or stable API versions
once the beta API version is deprecated and no longer served.
Note: Please try beta features and provide feedback. After the features exit beta, it
may not be practical to make more changes.
Stable:
The version name is vX where X is an integer.
Stable API versions remain available for all future releases within a Kubernetes major version,
and there are no current plans for a major version revision of Kubernetes that removes stable APIs.
API groups
API groups
make it easier to extend the Kubernetes API.
The API group is specified in a REST path and in the apiVersion field of a
serialized object.
There are several API groups in Kubernetes:
The core (also called legacy) group is found at REST path /api/v1.
The core group is not specified as part of the apiVersion field, for
example, apiVersion: v1.
The named groups are at REST path /apis/$GROUP_NAME/$VERSION and use
apiVersion: $GROUP_NAME/$VERSION (for example, apiVersion: batch/v1).
You can find the full list of supported API groups in
Kubernetes API reference.
Enabling or disabling API groups
Certain resources and API groups are enabled by default. You can enable or
disable them by setting --runtime-config on the API server. The
--runtime-config flag accepts comma separated <key>[=<value>] pairs
describing the runtime configuration of the API server. If the =<value>
part is omitted, it is treated as if =true is specified. For example:
to disable batch/v1, set --runtime-config=batch/v1=false
to enable batch/v2alpha1, set --runtime-config=batch/v2alpha1
to enable a specific version of an API, such as storage.k8s.io/v1beta1/csistoragecapacities, set --runtime-config=storage.k8s.io/v1beta1/csistoragecapacities
Note: When you enable or disable groups or resources, you need to restart the API
server and controller manager to pick up the --runtime-config changes.
Persistence
Kubernetes stores its serialized state in terms of the API resources by writing them into
etcd.
The Kubernetes API is a resource-based (RESTful) programmatic interface
provided via HTTP. It supports retrieving, creating, updating, and deleting
primary resources via the standard HTTP verbs (POST, PUT, PATCH, DELETE,
GET).
For some resources, the API includes additional subresources that allow
fine grained authorization (such as separate views for Pod details and
log retrievals), and can accept and serve those resources in different
representations for convenience or efficiency.
Kubernetes supports efficient change notifications on resources via watches.
Kubernetes also provides consistent list operations so that API clients can
effectively cache, track, and synchronize the state of resources.
You can view the API reference online,
or read on to learn about the API in general.
Kubernetes API terminology
Kubernetes generally leverages common RESTful terminology to describe the
API concepts:
A resource type is the name used in the URL (pods, namespaces, services)
All resource types have a concrete representation (their object schema) which is called a kind
A list of instances of a resource type is known as a collection
A single instance of a resource type is called a resource, and also usually represents an object
For some resource types, the API includes one or more sub-resources, which are represented as URI paths below the resource
Most Kubernetes API resource types are
objects –
they represent a concrete instance of a concept on the cluster, like a
pod or namespace. A smaller number of API resource types are virtual in
that they often represent operations on objects, rather than objects, such
as a permission check
(use a POST with a JSON-encoded body of SubjectAccessReview to the
subjectaccessreviews resource), or the eviction sub-resource of a Pod
(used to trigger
API-initiated eviction).
Object names
All objects you can create via the API have a unique object
name to allow idempotent creation and
retrieval, except that virtual resource types may not have unique names if they are
not retrievable, or do not rely on idempotency.
Within a namespace, only one object
of a given kind can have a given name at a time. However, if you delete the object,
you can make a new object with the same name. Some objects are not namespaced (for
example: Nodes), and so their names must be unique across the whole cluster.
API verbs
Almost all object resource types support the standard HTTP verbs - GET, POST, PUT, PATCH,
and DELETE. Kubernetes also uses its own verbs, which are often written lowercase to distinguish
them from HTTP verbs.
Kubernetes uses the term list to describe returning a collection of
resources to distinguish from retrieving a single resource which is usually called
a get. If you sent an HTTP GET request with the ?watch query parameter,
Kubernetes calls this a watch and not a get (see
Efficient detection of changes for more details).
For PUT requests, Kubernetes internally classifies these as either create or update
based on the state of the existing object. An update is different from a patch; the
HTTP verb for a patch is PATCH.
Resource URIs
All resource types are either scoped by the cluster (/apis/GROUP/VERSION/*) or to a
namespace (/apis/GROUP/VERSION/namespaces/NAMESPACE/*). A namespace-scoped resource
type will be deleted when its namespace is deleted and access to that resource type
is controlled by authorization checks on the namespace scope.
Note: core resources use /api instead of /apis and omit the GROUP path segment.
You can also access collections of resources (for example: listing all Nodes).
The following paths are used to retrieve collections and resources:
Cluster-scoped resources:
GET /apis/GROUP/VERSION/RESOURCETYPE - return the collection of resources of the resource type
GET /apis/GROUP/VERSION/RESOURCETYPE/NAME - return the resource with NAME under the resource type
Namespace-scoped resources:
GET /apis/GROUP/VERSION/RESOURCETYPE - return the collection of all instances of the resource type across all namespaces
GET /apis/GROUP/VERSION/namespaces/NAMESPACE/RESOURCETYPE - return collection of all instances of the resource type in NAMESPACE
GET /apis/GROUP/VERSION/namespaces/NAMESPACE/RESOURCETYPE/NAME - return the instance of the resource type with NAME in NAMESPACE
Since a namespace is a cluster-scoped resource type, you can retrieve the list
(“collection”) of all namespaces with GET /api/v1/namespaces and details about
a particular namespace with GET /api/v1/namespaces/NAME.
Cluster-scoped subresource: GET /apis/GROUP/VERSION/RESOURCETYPE/NAME/SUBRESOURCE
Namespace-scoped subresource: GET /apis/GROUP/VERSION/namespaces/NAMESPACE/RESOURCETYPE/NAME/SUBRESOURCE
The verbs supported for each subresource will differ depending on the object -
see the API reference for more information. It
is not possible to access sub-resources across multiple resources - generally a new
virtual resource type would be used if that becomes necessary.
Efficient detection of changes
The Kubernetes API allows clients to make an initial request for an object or a
collection, and then to track changes since that initial request: a watch. Clients
can send a list or a get and then make a follow-up watch request.
To make this change tracking possible, every Kubernetes object has a resourceVersion
field representing the version of that resource as stored in the underlying persistence
layer. When retrieving a collection of resources (either namespace or cluster scoped),
the response from the API server contains a resourceVersion value. The client can
use that resourceVersion to initiate a watch against the API server.
When you send a watch request, the API server responds with a stream of
changes. These changes itemize the outcome of operations (such as create, delete,
and update) that occurred after the resourceVersion you specified as a parameter
to the watch request. The overall watch mechanism allows a client to fetch
the current state and then subscribe to subsequent changes, without missing any events.
If a client watch is disconnected then that client can start a new watch from
the last returned resourceVersion; the client could also perform a fresh get /
list request and begin again. See Resource Version Semantics
for more detail.
For example:
List all of the pods in a given namespace.
GET /api/v1/namespaces/test/pods
---
200 OK
Content-Type: application/json
{
"kind": "PodList",
"apiVersion": "v1",
"metadata": {"resourceVersion":"10245"},
"items": [...]
}
Starting from resource version 10245, receive notifications of any API operations
(such as create, delete, patch or update) that affect Pods in the
test namespace. Each change notification is a JSON document. The HTTP response body
(served as application/json) consists a series of JSON documents.
A given Kubernetes server will only preserve a historical record of changes for a
limited time. Clusters using etcd 3 preserve changes in the last 5 minutes by default.
When the requested watch operations fail because the historical version of that
resource is not available, clients must handle the case by recognizing the status code
410 Gone, clearing their local cache, performing a new get or list operation,
and starting the watch from the resourceVersion that was returned.
For subscribing to collections, Kubernetes client libraries typically offer some form
of standard tool for this list-then-watch logic. (In the Go client library,
this is called a Reflector and is located in the k8s.io/client-go/tools/cache package.)
Watch bookmarks
To mitigate the impact of short history window, the Kubernetes API provides a watch
event named BOOKMARK. It is a special kind of event to mark that all changes up
to a given resourceVersion the client is requesting have already been sent. The
document representing the BOOKMARK event is of the type requested by the request,
but only includes a .metadata.resourceVersion field. For example:
As a client, you can request BOOKMARK events by setting the
allowWatchBookmarks=true query parameter to a watch request, but you shouldn't
assume bookmarks are returned at any specific interval, nor can clients assume that
the API server will send any BOOKMARK event even when requested.
Streaming lists
FEATURE STATE:Kubernetes v1.27 [alpha]
On large clusters, retrieving the collection of some resource types may result in
a significant increase of resource usage (primarily RAM) on the control plane.
In order to alleviate its impact and simplify the user experience of the list + watch
pattern, Kubernetes v1.27 introduces as an alpha feature the support
for requesting the initial state (previously requested via the list request) as part of
the watch request.
Provided that the WatchListfeature gate
is enabled, this can be achieved by specifying sendInitialEvents=true as query string parameter
in a watch request. If set, the API server starts the watch stream with synthetic init
events (of type ADDED) to build the whole state of all existing objects followed by a
BOOKMARK event
(if requested via allowWatchBookmarks=true option). The bookmark event includes the resource version
to which is synced. After sending the bookmark event, the API server continues as for any other watch
request.
When you set sendInitialEvents=true in the query string, Kubernetes also requires that you set
resourceVersionMatch to NotOlderThan value.
If you provided resourceVersion in the query string without providing a value or don't provide
it at all, this is interpreted as a request for consistent read;
the bookmark event is sent when the state is synced at least to the moment of a consistent read
from when the request started to be processed. If you specify resourceVersion (in the query string),
the bookmark event is sent when the state is synced at least to the provided resource version.
Example
An example: you want to watch a collection of Pods. For that collection, the current resource version
is 10245 and there are two pods: foo and bar. Then sending the following request (explicitly requesting
consistent read by setting empty resource version using resourceVersion=) could result
in the following sequence of events:
APIResponseCompression is an option that allows the API server to compress the responses for get
and list requests, reducing the network bandwidth and improving the performance of large-scale clusters.
It is enabled by default since Kubernetes 1.16 and it can be disabled by including
APIResponseCompression=false in the --feature-gates flag on the API server.
API response compression can significantly reduce the size of the response, especially for large resources or
collections.
For example, a list request for pods can return hundreds of kilobytes or even megabytes of data,
depending on the number of pods and their attributes. By compressing the response, the network bandwidth
can be saved and the latency can be reduced.
To verify if APIResponseCompression is working, you can send a get or list request to the
API server with an Accept-Encoding header, and check the response size and headers. For example:
GET /api/v1/pods
Accept-Encoding: gzip
---
200 OK
Content-Type: application/json
content-encoding: gzip
...
The content-encoding header indicates that the response is compressed with gzip.
Retrieving large results sets in chunks
FEATURE STATE:Kubernetes v1.9 [beta]
On large clusters, retrieving the collection of some resource types may result in
very large responses that can impact the server and client. For instance, a cluster
may have tens of thousands of Pods, each of which is equivalent to roughly 2 KiB of
encoded JSON. Retrieving all pods across all namespaces may result in a very large
response (10-20MB) and consume a large amount of server resources.
Provided that you don't explicitly disable the APIListChunkingfeature gate, the
Kubernetes API server supports the ability to break a single large collection request
into many smaller chunks while preserving the consistency of the total request. Each
chunk can be returned sequentially which reduces both the total size of the request and
allows user-oriented clients to display results incrementally to improve responsiveness.
You can request that the API server handles a list by serving single collection
using pages (which Kubernetes calls chunks). To retrieve a single collection in
chunks, two query parameters limit and continue are supported on requests against
collections, and a response field continue is returned from all list operations
in the collection's metadata field. A client should specify the maximum results they
wish to receive in each chunk with limit and the server will return up to limit
resources in the result and include a continue value if there are more resources
in the collection.
As an API client, you can then pass this continue value to the API server on the
next request, to instruct the server to return the next page (chunk) of results. By
continuing until the server returns an empty continue value, you can retrieve the
entire collection.
Like a watch operation, a continue token will expire after a short amount
of time (by default 5 minutes) and return a 410 Gone if more results cannot be
returned. In this case, the client will need to start from the beginning or omit the
limit parameter.
For example, if there are 1,253 pods on the cluster and you wants to receive chunks
of 500 pods at a time, request those chunks as follows:
List all of the pods on a cluster, retrieving up to 500 pods each time.
Continue the previous call, retrieving the last 253 pods.
GET /api/v1/pods?limit=500&continue=ENCODED_CONTINUE_TOKEN_2
---
200 OK
Content-Type: application/json
{
"kind": "PodList",
"apiVersion": "v1",
"metadata": {
"resourceVersion":"10245",
"continue": "", // continue token is empty because we have reached the end of the list
...
},
"items": [...] // returns pods 1001-1253
}
Notice that the resourceVersion of the collection remains constant across each request,
indicating the server is showing you a consistent snapshot of the pods. Pods that
are created, updated, or deleted after version 10245 would not be shown unless
you make a separate list request without the continue token. This allows you
to break large requests into smaller chunks and then perform a watch operation
on the full set without missing any updates.
remainingItemCount is the number of subsequent items in the collection that are not
included in this response. If the list request contained label or field
selectors then the number of
remaining items is unknown and the API server does not include a remainingItemCount
field in its response.
If the list is complete (either because it is not chunking, or because this is the
last chunk), then there are no more remaining items and the API server does not include a
remainingItemCount field in its response. The intended use of the remainingItemCount
is estimating the size of a collection.
Collections
In Kubernetes terminology, the response you get from a list is
a collection. However, Kubernetes defines concrete kinds for
collections of different types of resource. Collections have a kind
named for the resource kind, with List appended.
When you query the API for a particular type, all items returned by that query are
of that type.
For example, when you list Services, the collection response
has kind set to
ServiceList; each item in that collection represents a single Service. For example:
There are dozens of collection types (such as PodList, ServiceList,
and NodeList) defined in the Kubernetes API.
You can get more information about each collection type from the
Kubernetes API documentation.
Some tools, such as kubectl, represent the Kubernetes collection
mechanism slightly differently from the Kubernetes API itself.
Because the output of kubectl might include the response from
multiple list operations at the API level, kubectl represents
a list of items using kind: List. For example:
Keep in mind that the Kubernetes API does not have a kind named List.
kind: List is a client-side, internal implementation detail for processing
collections that might be of different kinds of object. Avoid depending on
kind: List in automation or other code.
Receiving resources as Tables
When you run kubectl get, the default output format is a simple tabular
representation of one or more instances of a particular resource type. In the past,
clients were required to reproduce the tabular and describe output implemented in
kubectl to perform simple lists of objects.
A few limitations of that approach include non-trivial logic when dealing with
certain objects. Additionally, types provided by API aggregation or third party
resources are not known at compile time. This means that generic implementations
had to be in place for types unrecognized by a client.
In order to avoid potential limitations as described above, clients may request
the Table representation of objects, delegating specific details of printing to the
server. The Kubernetes API implements standard HTTP content type negotiation: passing
an Accept header containing a value of application/json;as=Table;g=meta.k8s.io;v=v1
with a GET call will request that the server return objects in the Table content
type.
For example, list all of the pods on a cluster in the Table format.
GET /api/v1/pods
Accept: application/json;as=Table;g=meta.k8s.io;v=v1
---
200 OK
Content-Type: application/json
{
"kind": "Table",
"apiVersion": "meta.k8s.io/v1",
...
"columnDefinitions": [
...
]
}
For API resource types that do not have a custom Table definition known to the control
plane, the API server returns a default Table response that consists of the resource's
name and creationTimestamp fields.
Not all API resource types support a Table response; for example, a
CustomResourceDefinitions
might not define field-to-table mappings, and an APIService that
extends the core Kubernetes API
might not serve Table responses at all. If you are implementing a client that
uses the Table information and must work against all resource types, including
extensions, you should make requests that specify multiple content types in the
Accept header. For example:
By default, Kubernetes returns objects serialized to JSON with content type
application/json. This is the default serialization format for the API. However,
clients may request the more efficient
Protobuf representation of these objects for better performance at scale.
The Kubernetes API implements standard HTTP content type negotiation: passing an
Accept header with a GET call will request that the server tries to return
a response in your preferred media type, while sending an object in Protobuf to
the server for a PUT or POST call means that you must set the Content-Type
header appropriately.
The server will return a response with a Content-Type header if the requested
format is supported, or the 406 Not acceptable error if none of the media types you
requested are supported. All built-in resource types support the application/json
media type.
See the Kubernetes API reference for a list of
supported content types for each API.
For example:
List all of the pods on a cluster in Protobuf format.
GET /api/v1/pods
Accept: application/vnd.kubernetes.protobuf
---
200 OK
Content-Type: application/vnd.kubernetes.protobuf
... binary encoded PodList object
Create a pod by sending Protobuf encoded data to the server, but request a response
in JSON.
POST /api/v1/namespaces/test/pods
Content-Type: application/vnd.kubernetes.protobuf
Accept: application/json
... binary encoded Pod object
---
200 OK
Content-Type: application/json
{
"kind": "Pod",
"apiVersion": "v1",
...
}
Not all API resource types support Protobuf; specifically, Protobuf isn't available for
resources that are defined as
CustomResourceDefinitions
or are served via the
aggregation layer.
As a client, if you might need to work with extension types you should specify multiple
content types in the request Accept header to support fallback to JSON.
For example:
Kubernetes uses an envelope wrapper to encode Protobuf responses. That wrapper starts
with a 4 byte magic number to help identify content in disk or in etcd as Protobuf
(as opposed to JSON), and then is followed by a Protobuf encoded wrapper message, which
describes the encoding and type of the underlying object and then contains the object.
The wrapper format is:
A four byte magic number prefix:
Bytes 0-3: "k8s\x00" [0x6b, 0x38, 0x73, 0x00]
An encoded Protobuf message with the following IDL:
message Unknown {
// typeMeta should have the string values for "kind" and "apiVersion" as set on the JSON object
optional TypeMeta typeMeta = 1;
// raw will hold the complete serialized object in protobuf. See the protobuf definitions in the client libraries for a given kind.
optional bytes raw = 2;
// contentEncoding is encoding used for the raw data. Unspecified means no encoding.
optional string contentEncoding = 3;
// contentType is the serialization method used to serialize 'raw'. Unspecified means application/vnd.kubernetes.protobuf and is usually
// omitted.
optional string contentType = 4;
}
message TypeMeta {
// apiVersion is the group/version for this type
optional string apiVersion = 1;
// kind is the name of the object schema. A protobuf definition should exist for this object.
optional string kind = 2;
}
Note: Clients that receive a response in application/vnd.kubernetes.protobuf that does
not match the expected prefix should reject the response, as future versions may need
to alter the serialization format in an incompatible way and will do so by changing
the prefix.
Resource deletion
When you delete a resource this takes place in two phases.
When a client first sends a delete to request removal of a resource, the .metadata.deletionTimestamp is set to the current time.
Once the .metadata.deletionTimestamp is set, external controllers that act on finalizers
may start performing their cleanup work at any time, in any order.
Order is not enforced between finalizers because it would introduce significant
risk of stuck .metadata.finalizers.
The .metadata.finalizers field is shared: any actor with permission can reorder it.
If the finalizer list were processed in order, then this might lead to a situation
in which the component responsible for the first finalizer in the list is
waiting for some signal (field value, external system, or other) produced by a
component responsible for a finalizer later in the list, resulting in a deadlock.
Without enforced ordering, finalizers are free to order amongst themselves and are
not vulnerable to ordering changes in the list.
Once the last finalizer is removed, the resource is actually removed from etcd.
Single resource API
The Kubernetes API verbs get, create, update, patch,
delete and proxy support single resources only.
These verbs with single resource support have no support for submitting multiple
resources together in an ordered or unordered list or transaction.
When clients (including kubectl) act on a set of resources, the client makes a series
of single-resource API requests, then aggregates the responses if needed.
By contrast, the Kubernetes API verbs list and watch allow getting multiple
resources, and deletecollection allows deleting multiple resources.
Field validation
Kubernetes always validates the type of fields. For example, if a field in the
API is defined as a number, you cannot set the field to a text value. If a field
is defined as an array of strings, you can only provide an array. Some fields
allow you to omit them, other fields are required. Omitting a required field
from an API request is an error.
If you make a request with an extra field, one that the cluster's control plane
does not recognize, then the behavior of the API server is more complicated.
By default, the API server drops fields that it does not recognize
from an input that it receives (for example, the JSON body of a PUT request).
There are two situations where the API server drops fields that you supplied in
an HTTP request.
These situations are:
The field is unrecognized because it is not in the resource's OpenAPI schema. (One
exception to this is for CRDs that explicitly choose not to prune unknown
fields via x-kubernetes-preserve-unknown-fields).
The field is duplicated in the object.
Validation for unrecognized or duplicate fields
FEATURE STATE:Kubernetes v1.27 [stable]
From 1.25 onward, unrecognized or duplicate fields in an object are detected via
validation on the server when you use HTTP verbs that can submit data (POST, PUT, and PATCH). Possible levels of
validation are Ignore, Warn (default), and Strict.
Ignore
The API server succeeds in handling the request as it would without the erroneous fields
being set, dropping all unknown and duplicate fields and giving no indication it
has done so.
Warn
(Default) The API server succeeds in handling the request, and reports a
warning to the client. The warning is sent using the Warning: response header,
adding one warning item for each unknown or duplicate field. For more
information about warnings and the Kubernetes API, see the blog article
Warning: Helpful Warnings Ahead.
Strict
The API server rejects the request with a 400 Bad Request error when it
detects any unknown or duplicate fields. The response message from the API
server specifies all the unknown or duplicate fields that the API server has
detected.
The field validation level is set by the fieldValidation query parameter.
Note:
If you submit a request that specifies an unrecognized field, and that is also invalid for
a different reason (for example, the request provides a string value where the API expects
an integer for a known field), then the API server responds with a 400 Bad Request error, but will
not provide any information on unknown or duplicate fields (only which fatal
error it encountered first).
You always receive an error response in this case, no matter what field validation level you requested.
Tools that submit requests to the server (such as kubectl), might set their own
defaults that are different from the Warn validation level that the API server uses
by default.
The kubectl tool uses the --validate flag to set the level of field
validation. It accepts the values ignore, warn, and strict while
also accepting the values true (equivalent to strict) and false
(equivalent to ignore). The default validation setting for kubectl is
--validate=true, which means strict server-side field validation.
When kubectl cannot connect to an API server with field validation (API servers
prior to Kubernetes 1.27), it will fall back to using client-side validation.
Client-side validation will be removed entirely in a future version of kubectl.
Note: Prior to Kubernetes 1.25 kubectl --validate was used to toggle client-side validation on or off as
a boolean flag.
Dry-run
FEATURE STATE:Kubernetes v1.18 [stable]
When you use HTTP verbs that can modify resources (POST, PUT, PATCH, and
DELETE), you can submit your request in a dry run mode. Dry run mode helps to
evaluate a request through the typical request stages (admission chain, validation,
merge conflicts) up until persisting objects to storage. The response body for the
request is as close as possible to a non-dry-run response. Kubernetes guarantees that
dry-run requests will not be persisted in storage or have any other side effects.
Make a dry-run request
Dry-run is triggered by setting the dryRun query parameter. This parameter is a
string, working as an enum, and the only accepted values are:
[no value set]
Allow side effects. You request this with a query string such as ?dryRun
or ?dryRun&pretty=true. The response is the final object that would have been
persisted, or an error if the request could not be fulfilled.
All
Every stage runs as normal, except for the final storage stage where side effects
are prevented.
When you set ?dryRun=All, any relevant
admission controllers
are run, validating admission controllers check the request post-mutation, merge is
performed on PATCH, fields are defaulted, and schema validation occurs. The changes
are not persisted to the underlying storage, but the final object which would have
been persisted is still returned to the user, along with the normal status code.
If the non-dry-run version of a request would trigger an admission controller that has
side effects, the request will be failed rather than risk an unwanted side effect. All
built in admission control plugins support dry-run. Additionally, admission webhooks can
declare in their
configuration object
that they do not have side effects, by setting their sideEffects field to None.
Note: If a webhook actually does have side effects, then the sideEffects field should be
set to "NoneOnDryRun". That change is appropriate provided that the webhook is also
be modified to understand the DryRun field in AdmissionReview, and to prevent side
effects on any request marked as dry runs.
Here is an example dry-run request that uses ?dryRun=All:
POST /api/v1/namespaces/test/pods?dryRun=All
Content-Type: application/json
Accept: application/json
The response would look the same as for non-dry-run request, but the values of some
generated fields may differ.
Generated values
Some values of an object are typically generated before the object is persisted. It
is important not to rely upon the values of these fields set by a dry-run request,
since these values will likely be different in dry-run mode from when the real
request is made. Some of these fields are:
name: if generateName is set, name will have a unique random name
creationTimestamp / deletionTimestamp: records the time of creation/deletion
UID: uniquely identifies the object and is randomly generated (non-deterministic)
resourceVersion: tracks the persisted version of the object
Any field set by a mutating admission controller
For the Service resource: Ports or IP addresses that the kube-apiserver assigns to Service objects
Dry-run authorization
Authorization for dry-run and non-dry-run requests is identical. Thus, to make
a dry-run request, you must be authorized to make the non-dry-run request.
For example, to run a dry-run patch for a Deployment, you must be authorized
to perform that patch. Here is an example of a rule for Kubernetes
RBAC that allows patching
Deployments:
Kubernetes provides several ways to update existing objects.
You can read choosing an update mechanism to
learn about which approach might be best for your use case.
You can overwrite (update) an existing resource - for example, a ConfigMap -
using an HTTP PUT. For a PUT request, it is the client's responsibility to specify
the resourceVersion (taking this from the object being updated). Kubernetes uses
that resourceVersion information so that the API server can detect lost updates
and reject requests made by a client that is out of date with the cluster.
In the event that the resource has changed (the resourceVersion the client
provided is stale), the API server returns a 409 Conflict error response.
Instead of sending a PUT request, the client can send an instruction to the API
server to patch an existing resource. A patch is typically appropriate
if the change that the client wants to make isn't conditional on the existing data. Clients that need effective detection of lost updates should consider
making their request conditional on the existing resourceVersion (either HTTP PUT or HTTP PATCH),
and then handle any retries that are needed in case there is a conflict.
The Kubernetes API supports four different PATCH operations, determined by their
corresponding HTTP Content-Type header:
application/apply-patch+yaml
Server Side Apply YAML (a Kubernetes-specific extension, based on YAML).
All JSON documents are valid YAML, so you can also submit JSON using this
media type. See Server Side Apply serialization
for more details.
To Kubernetes, this is a create operation if the object does not exist,
or a patch operation if the object already exists.
application/json-patch+json
JSON Patch, as defined in RFC6902.
A JSON patch is a sequence of operations that are executed on the resource;
for example {"op": "add", "path": "/a/b/c", "value": [ "foo", "bar" ]}.
To Kubernetes, this is a patch operation.
A patch using application/json-patch+json can include conditions to
validate consistency, allowing the operation to fail if those conditions
are not met (for example, to avoid a lost update).
application/merge-patch+json
JSON Merge Patch, as defined in RFC7386.
A JSON Merge Patch is essentially a partial representation of the resource.
The submitted JSON is combined with the current resource to create a new one,
then the new one is saved.
To Kubernetes, this is a patch operation.
application/strategic-merge-patch+json
Strategic Merge Patch (a Kubernetes-specific extension based on JSON).
Strategic Merge Patch is a custom implementation of JSON Merge Patch.
You can only use Strategic Merge Patch with built-in APIs, or with aggregated
API servers that have special support for it. You cannot use
application/strategic-merge-patch+json with any API
defined using a CustomResourceDefinition.
Note: The Kubernetes server side apply mechanism has superseded Strategic Merge
Patch.
Kubernetes' Server Side Apply
feature allows the control plane to track managed fields for newly created objects.
Server Side Apply provides a clear pattern for managing field conflicts,
offers server-side apply and update operations, and replaces the
client-side functionality of kubectl apply.
For Server-Side Apply, Kubernetes treats the request as a create if the object
does not yet exist, and a patch otherwise. For other requests that use PATCH
at the HTTP level, the logical Kubernetes operation is always patch.
The update (HTTP PUT) operation is simple to implement and flexible,
but has drawbacks:
You need to handle conflicts where the resourceVersion of the object changes
between your client reading it and trying to write it back. Kubernetes always
detects the conflict, but you as the client author need to implement retries.
You might accidentally drop fields if you decode an object locally (for example,
using client-go, you could receive fields that your client does not know how to
handle - and then drop them as part of your update.
If there's a lot of contention on the object (even on a field, or set of fields,
that you're not trying to edit), you might have trouble sending the update.
The problem is worse for larger objects and for objects with many fields.
HTTP PATCH using JSON Patch
A patch update is helpful, because:
As you're only sending differences, you have less data to send in the PATCH
request.
You can make changes that rely on existing values, such as copying the
value of a particular field into an annotation.
Unlike with an update (HTTP PUT), making your change can happen right away
even if there are frequent changes to unrelated fields): you usually would
not need to retry.
You might still need to specify the resourceVersion (to match an existing object)
if you want to be extra careful to avoid lost updates
It's still good practice to write in some retry logic in case of errors.
You can use test conditions to careful craft specific update conditions.
For example, you can increment a counter without reading it if the existing
value matches what you expect. You can do this with no lost update risk,
even if the object has changed in other ways since you last wrote to it.
(If the test condition fails, you can fall back to reading the current value
and then write back the changed number).
However:
you need more local (client) logic to build the patch; it helps a lot if you have
a library implementation of JSON Patch, or even for making a JSON Patch specifically against Kubernetes
as the author of client software, you need to be careful when building the patch
(the HTTP request body) not to drop fields (the order of operations matters)
HTTP PATCH using Server-Side Apply
Server-Side Apply has some clear benefits:
A single round trip: it rarely requires making a GET request first.
and you can still detect conflicts for unexpected changes
you have the option to force override a conflict, if appropriate
Client implementations are easy to make
You get an atomic create-or-update operation without extra effort
(similar to UPSERT in some SQL dialects)
However:
Server-Side Apply does not work at all for field changes that depend on a current value of the object
You can only apply updates to objects. Some resources in the Kubernetes HTTP API are
not objects (they do not have a .metadata field), and Server-Side Apply
is only relevant for Kubernetes objects.
Resource versions
Resource versions are strings that identify the server's internal version of an
object. Resource versions can be used by clients to determine when objects have
changed, or to express data consistency requirements when getting, listing and
watching resources. Resource versions must be treated as opaque by clients and passed
unmodified back to the server.
You must not assume resource versions are numeric or collatable. API clients may
only compare two resource versions for equality (this means that you must not compare
resource versions for greater-than or less-than relationships).
resourceVersion fields in metadata
Clients find resource versions in resources, including the resources from the response
stream for a watch, or when using list to enumerate resources.
v1.meta/ObjectMeta - The metadata.resourceVersion of a resource instance identifies the resource version the instance was last modified at.
v1.meta/ListMeta - The metadata.resourceVersion of a resource collection (the response to a list) identifies the resource version at which the collection was constructed.
resourceVersion parameters in query strings
The get, list, and watch operations support the resourceVersion parameter.
From version v1.19, Kubernetes API servers also support the resourceVersionMatch
parameter on list requests.
The API server interprets the resourceVersion parameter differently depending
on the operation you request, and on the value of resourceVersion. If you set
resourceVersionMatch then this also affects the way matching happens.
Semantics for get and list
For get and list, the semantics of resourceVersion are:
get:
resourceVersion unset
resourceVersion="0"
resourceVersion="{value other than 0}"
Most Recent
Any
Not older than
list:
From version v1.19, Kubernetes API servers support the resourceVersionMatch parameter
on list requests. If you set both resourceVersion and resourceVersionMatch, the
resourceVersionMatch parameter determines how the API server interprets
resourceVersion.
You should always set the resourceVersionMatch parameter when setting
resourceVersion on a list request. However, be prepared to handle the case
where the API server that responds is unaware of resourceVersionMatch
and ignores it.
Unless you have strong consistency requirements, using resourceVersionMatch=NotOlderThan and
a known resourceVersion is preferable since it can achieve better performance and scalability
of your cluster than leaving resourceVersion and resourceVersionMatch unset, which requires
quorum read to be served.
Setting the resourceVersionMatch parameter without setting resourceVersion is not valid.
This table explains the behavior of list requests with various combinations of
resourceVersion and resourceVersionMatch:
resourceVersionMatch and paging parameters for list
resourceVersionMatch param
paging params
resourceVersion not set
resourceVersion="0"
resourceVersion="{value other than 0}"
unset
limit unset
Most Recent
Any
Not older than
unset
limit=<n>, continue unset
Most Recent
Any
Exact
unset
limit=<n>, continue=<token>
Continue Token, Exact
Invalid, treated as Continue Token, Exact
Invalid, HTTP 400 Bad Request
resourceVersionMatch=Exact
limit unset
Invalid
Invalid
Exact
resourceVersionMatch=Exact
limit=<n>, continue unset
Invalid
Invalid
Exact
resourceVersionMatch=NotOlderThan
limit unset
Invalid
Any
Not older than
resourceVersionMatch=NotOlderThan
limit=<n>, continue unset
Invalid
Any
Not older than
Note: If your cluster's API server does not honor the resourceVersionMatch parameter,
the behavior is the same as if you did not set it.
The meaning of the get and list semantics are:
Any
Return data at any resource version. The newest available resource version is preferred,
but strong consistency is not required; data at any resource version may be served. It is possible
for the request to return data at a much older resource version that the client has previously
observed, particularly in high availability configurations, due to partitions or stale
caches. Clients that cannot tolerate this should not use this semantic.
Most recent
Return data at the most recent resource version. The returned data must be
consistent (in detail: served from etcd via a quorum read).
Not older than
Return data at least as new as the provided resourceVersion. The newest
available data is preferred, but any data not older than the provided resourceVersion may be
served. For list requests to servers that honor the resourceVersionMatch parameter, this
guarantees that the collection's .metadata.resourceVersion is not older than the requested
resourceVersion, but does not make any guarantee about the .metadata.resourceVersion of any
of the items in that collection.
Exact
Return data at the exact resource version provided. If the provided resourceVersion is
unavailable, the server responds with HTTP 410 "Gone". For list requests to servers that honor the
resourceVersionMatch parameter, this guarantees that the collection's .metadata.resourceVersion
is the same as the resourceVersion you requested in the query string. That guarantee does
not apply to the .metadata.resourceVersion of any items within that collection.
Continue Token, Exact
Return data at the resource version of the initial paginated list call. The returned continue
tokens are responsible for keeping track of the initially provided resource version for all paginated
list calls after the initial paginated list.
Note: When you list resources and receive a collection response, the response includes the
list metadata
of the collection as well as
object metadata
for each item in that collection. For individual objects found within a collection response,
.metadata.resourceVersion tracks when that object was last updated, and not how up-to-date
the object is when served.
When using resourceVersionMatch=NotOlderThan and limit is set, clients must
handle HTTP 410 "Gone" responses. For example, the client might retry with a
newer resourceVersion or fall back to resourceVersion="".
When using resourceVersionMatch=Exact and limit is unset, clients must
verify that the collection's .metadata.resourceVersion matches
the requested resourceVersion, and handle the case where it does not. For
example, the client might fall back to a request with limit set.
Semantics for watch
For watch, the semantics of resource version are:
watch:
resourceVersion for watch
resourceVersion unset
resourceVersion="0"
resourceVersion="{value other than 0}"
Get State and Start at Most Recent
Get State and Start at Any
Start at Exact
The meaning of those watch semantics are:
Get State and Start at Any
Caution: Watches initialized this way may return arbitrarily stale
data. Please review this semantic before using it, and favor the other semantics
where possible.
Start a watch at any resource version; the most recent resource version
available is preferred, but not required. Any starting resource version is
allowed. It is possible for the watch to start at a much older resource
version that the client has previously observed, particularly in high availability
configurations, due to partitions or stale caches. Clients that cannot tolerate
this apparent rewinding should not start a watch with this semantic. To
establish initial state, the watch begins with synthetic "Added" events for
all resource instances that exist at the starting resource version. All following
watch events are for all changes that occurred after the resource version the
watch started at.
Get State and Start at Most Recent
Start a watch at the most recent resource version, which must be consistent
(in detail: served from etcd via a quorum read). To establish initial state,
the watch begins with synthetic "Added" events of all resources instances
that exist at the starting resource version. All following watch events are for
all changes that occurred after the resource version the watch started at.
Start at Exact
Start a watch at an exact resource version. The watch events are for all changes
after the provided resource version. Unlike "Get State and Start at Most Recent"
and "Get State and Start at Any", the watch is not started with synthetic
"Added" events for the provided resource version. The client is assumed to already
have the initial state at the starting resource version since the client provided
the resource version.
"410 Gone" responses
Servers are not required to serve all older resource versions and may return a HTTP
410 (Gone) status code if a client requests a resourceVersion older than the
server has retained. Clients must be able to tolerate 410 (Gone) responses. See
Efficient detection of changes for details on
how to handle 410 (Gone) responses when watching resources.
If you request a resourceVersion outside the applicable limit then, depending
on whether a request is served from cache or not, the API server may reply with a
410 Gone HTTP response.
Unavailable resource versions
Servers are not required to serve unrecognized resource versions. If you request
list or get for a resource version that the API server does not recognize,
then the API server may either:
wait briefly for the resource version to become available, then timeout with a
504 (Gateway Timeout) if the provided resource versions does not become available
in a reasonable amount of time;
respond with a Retry-After response header indicating how many seconds a client
should wait before retrying the request.
If you request a resource version that an API server does not recognize, the
kube-apiserver additionally identifies its error responses with a "Too large resource
version" message.
If you make a watch request for an unrecognized resource version, the API server
may wait indefinitely (until the request timeout) for the resource version to become
available.
2.2 - Server-Side Apply
FEATURE STATE:Kubernetes v1.22 [stable]
Kubernetes supports multiple appliers collaborating to manage the fields
of a single object.
Server-Side Apply provides an optional mechanism for your cluster's control plane to track
changes to an object's fields. At the level of a specific resource, Server-Side
Apply records and tracks information about control over the fields of that object.
Server-Side Apply helps users and controllers
manage their resources through declarative configuration. Clients can create and modify
objects
declaratively by submitting their fully specified intent.
A fully specified intent is a partial object that only includes the fields and
values for which the user has an opinion. That intent either creates a new
object (using default values for unspecified fields), or is
combined, by the API server, with the existing object.
Comparison with Client-Side Apply explains
how Server-Side Apply differs from the original, client-side kubectl apply
implementation.
Field management
The Kubernetes API server tracks managed fields for all newly created objects.
When trying to apply an object, fields that have a different value and are owned by
another manager will result in a conflict. This is done
in order to signal that the operation might undo another collaborator's changes.
Writes to objects with managed fields can be forced, in which case the value of any
conflicted field will be overridden, and the ownership will be transferred.
Whenever a field's value does change, ownership moves from its current manager to the
manager making the change.
Apply checks if there are any other field managers that also own the
field. If the field is not owned by any other field managers, that field is
set to its default value (if there is one), or otherwise is deleted from the
object.
The same rule applies to fields that are lists, associative lists, or maps.
For a user to manage a field, in the Server-Side Apply sense, means that the
user relies on and expects the value of the field not to change. The user who
last made an assertion about the value of a field will be recorded as the
current field manager. This can be done by changing the field manager
details explicitly using HTTP POST (create), PUT (update), or non-apply
PATCH (patch). You can also declare and record a field manager
by including a value for that field in a Server-Side Apply operation.
A Server-Side Apply patch request requires the client to provide its identity
as a field manager. When using Server-Side Apply, trying to change a
field that is controlled by a different manager results in a rejected
request unless the client forces an override.
For details of overrides, see Conflicts.
When two or more appliers set a field to the same value, they share ownership of
that field. Any subsequent attempt to change the value of the shared field, by any of
the appliers, results in a conflict. Shared field owners may give up ownership
of a field by making a Server-Side Apply patch request that doesn't include
that field.
Field management details are stored in a managedFields field that is part of an
object's metadata.
If you remove a field from a manifest and apply that manifest, Server-Side
Apply checks if there are any other field managers that also own the field.
If the field is not owned by any other field managers, it is either deleted
from the live object or reset to its default value, if it has one.
The same rule applies to associative list or map items.
Compared to the (legacy)
kubectl.kubernetes.io/last-applied-configuration
annotation managed by kubectl, Server-Side Apply uses a more declarative
approach, that tracks a user's (or client's) field management, rather than
a user's last applied state. As a side effect of using Server-Side Apply,
information about which field manager manages each field in an object also
becomes available.
Example
A simple example of an object created using Server-Side Apply could look like this:
---apiVersion:v1kind:ConfigMapmetadata:name:test-cmnamespace:defaultlabels:test-label:testmanagedFields:- manager:kubectloperation: Apply # note capitalization:"Apply"(or "Update")apiVersion:v1time:"2010-10-10T0:00:00Z"fieldsType:FieldsV1fieldsV1:f:metadata:f:labels:f:test-label:{}f:data:f:key:{}data:key:some value
That example ConfigMap object contains a single field management record in
.metadata.managedFields. The field management record consists of basic information
about the managing entity itself, plus details about the fields being managed and
the relevant operation (Apply or Update). If the request that last changed that
field was a Server-Side Apply patch then the value of operation is Apply;
otherwise, it is Update.
There is another possible outcome. A client could submit an invalid request
body. If the fully specified intent does not produce a valid object, the
request fails.
It is however possible to change .metadata.managedFields through an
update, or through a patch operation that does not use Server-Side Apply.
Doing so is highly discouraged, but might be a reasonable option to try if,
for example, the .metatadata.managedFields get into an inconsistent state
(which should not happen in normal operations).
The format of managedFields is described
in the Kubernetes API reference.
Caution: The .metadata.managedFields field is managed by the API server.
You should avoid updating it manually.
Conflicts
A conflict is a special status error that occurs when an Apply operation tries
to change a field that another manager also claims to manage. This prevents an
applier from unintentionally overwriting the value set by another user. When
this occurs, the applier has 3 options to resolve the conflicts:
Overwrite value, become sole manager: If overwriting the value was
intentional (or if the applier is an automated process like a controller) the
applier should set the force query parameter to true (for kubectl apply,
you use the --force-conflicts command line parameter), and make the request
again. This forces the operation to succeed, changes the value of the field,
and removes the field from all other managers' entries in managedFields.
Don't overwrite value, give up management claim: If the applier doesn't
care about the value of the field any more, the applier can remove it from their
local model of the resource, and make a new request with that particular field
omitted. This leaves the value unchanged, and causes the field to be removed
from the applier's entry in managedFields.
Don't overwrite value, become shared manager: If the applier still cares
about the value of a field, but doesn't want to overwrite it, they can
change the value of that field in their local model of the resource so as to
match the value of the object on the server, and then make a new request that
takes into account that local update. Doing so leaves the value unchanged,
and causes that field's management to be shared by the applier along with all
other field managers that already claimed to manage it.
Field managers
Managers identify distinct workflows that are modifying the object (especially
useful on conflicts!), and can be specified through the
fieldManager
query parameter as part of a modifying request. When you Apply to a resource,
the fieldManager parameter is required
For other updates, the API server infers a field manager identity from the
"User-Agent:" HTTP header (if present).
When you use the kubectl tool to perform a Server-Side Apply operation, kubectl
sets the manager identity to "kubectl" by default.
Serialization
At the protocol level, Kubernetes represents Server-Side Apply message bodies
as YAML, with the media type application/apply-patch+yaml.
Note:
Whether you are submitting JSON data or YAML data, use
application/apply-patch+yaml as the Content-Type header value.
All JSON documents are valid YAML.
The serialization is the same as for Kubernetes objects, with the exception that
clients are not required to send a complete object.
Here's an example of a Server-Side Apply message body (fully specified intent):
{"apiVersion": "v1","kind": "ConfigMap"}
(this would make a no-change update, provided that it was sent as the body
of a patch request to a valid v1/configmaps resource, and with the
appropriate request Content-Type).
Operations in scope for field management
The Kubernetes API operations where field management is considered are:
Server-Side Apply (HTTP PATCH, with content type application/apply-patch+yaml)
Replacing an existing object (update to Kubernetes; PUT at the HTTP level)
Both operations update .metadata.managedFields, but behave a little differently.
Unless you specify a forced override, an apply operation that encounters field-level
conflicts always fails; by contrast, if you make a change using update that would
affect a managed field, a conflict never provokes failure of the operation.
All Server-Side Apply patch requests are required to identify themselves by providing a
fieldManager query parameter, while the query parameter is optional for update
operations. Finally, when using the Apply operation you cannot define managedFields in
the body of the request that you submit.
An example object with multiple managers could look like this:
---apiVersion:v1kind:ConfigMapmetadata:name:test-cmnamespace:defaultlabels:test-label:testmanagedFields:- manager:kubectloperation:ApplyapiVersion:v1fields:f:metadata:f:labels:f:test-label:{}- manager:kube-controller-manageroperation:UpdateapiVersion:v1time:'2019-03-30T16:00:00.000Z'fields:f:data:f:key:{}data:key:new value
In this example, a second operation was run as an update by the manager called
kube-controller-manager. The update request succeeded and changed a value in the data
field, which caused that field's management to change to the kube-controller-manager.
If this update has instead been attempted using Server-Side Apply, the request
would have failed due to conflicting ownership.
Merge strategy
The merging strategy, implemented with Server-Side Apply, provides a generally
more stable object lifecycle. Server-Side Apply tries to merge fields based on
the actor who manages them instead of overruling based on values. This way
multiple actors can update the same object without causing unexpected interference.
When a user sends a fully-specified intent object to the Server-Side Apply
endpoint, the server merges it with the live object favoring the value from the
request body if it is specified in both places. If the set of items present in
the applied config is not a superset of the items applied by the same user last
time, each missing item not managed by any other appliers is removed. For
more information about how an object's schema is used to make decisions when
merging, see
sigs.k8s.io/structured-merge-diff.
The Kubernetes API (and the Go code that implements that API for Kubernetes) allows
defining merge strategy markers. These markers describe the merge strategy supported
for fields within Kubernetes objects.
For a CustomResourceDefinition,
you can set these markers when you define the custom resource.
Golang marker
OpenAPI extension
Possible values
Description
//+listType
x-kubernetes-list-type
atomic/set/map
Applicable to lists. set applies to lists that include only scalar elements. These elements must be unique. map applies to lists of nested types only. The key values (see listMapKey) must be unique in the list. atomic can apply to any list. If configured as atomic, the entire list is replaced during merge. At any point in time, a single manager owns the list. If set or map, different managers can manage entries separately.
//+listMapKey
x-kubernetes-list-map-keys
List of field names, e.g. ["port", "protocol"]
Only applicable when +listType=map. A list of field names whose values uniquely identify entries in the list. While there can be multiple keys, listMapKey is singular because keys need to be specified individually in the Go type. The key fields must be scalars.
//+mapType
x-kubernetes-map-type
atomic/granular
Applicable to maps. atomic means that the map can only be entirely replaced by a single manager. granular means that the map supports separate managers updating individual fields.
//+structType
x-kubernetes-map-type
atomic/granular
Applicable to structs; otherwise same usage and OpenAPI annotation as //+mapType.
If listType is missing, the API server interprets a
patchStrategy=merge marker as a listType=map and the
corresponding patchMergeKey marker as a listMapKey.
The atomic list type is recursive.
(In the Go code for Kubernetes, these markers are specified as
comments and code authors need not repeat them as field tags).
Custom resources and Server-Side Apply
By default, Server-Side Apply treats custom resources as unstructured data. All
keys are treated the same as struct fields, and all lists are considered atomic.
If the CustomResourceDefinition defines a
schema
that contains annotations as defined in the previous Merge Strategy
section, these annotations will be used when merging objects of this
type.
Compatibility across topology changes
On rare occurrences, the author for a CustomResourceDefinition (CRD) or built-in
may want to change the specific topology of a field in their resource,
without incrementing its API version. Changing the topology of types,
by upgrading the cluster or updating the CRD, has different consequences when
updating existing objects. There are two categories of changes: when a field goes from
map/set/granular to atomic, and the other way around.
When the listType, mapType, or structType changes from
map/set/granular to atomic, the whole list, map, or struct of
existing objects will end-up being owned by actors who owned an element
of these types. This means that any further change to these objects
would cause a conflict.
When a listType, mapType, or structType changes from atomic to
map/set/granular, the API server is unable to infer the new
ownership of these fields. Because of that, no conflict will be produced
when objects have these fields updated. For that reason, it is not
recommended to change a type from atomic to map/set/granular.
Before spec.data gets changed from atomic to granular,
manager-one owns the field spec.data, and all the fields within it
(key1 and key2). When the CRD gets changed to make spec.datagranular, manager-one continues to own the top-level field
spec.data (meaning no other managers can delete the map called data
without a conflict), but it no longer owns key1 and key2, so another
manager can then modify or delete those fields without conflict.
Using Server-Side Apply in a controller
As a developer of a controller, you can use Server-Side Apply as a way to
simplify the update logic of your controller. The main differences with a
read-modify-write and/or patch are the following:
the applied object must contain all the fields that the controller cares about.
there is no way to remove fields that haven't been applied by the controller
before (controller can still send a patch or update for these use-cases).
the object doesn't have to be read beforehand; resourceVersion doesn't have
to be specified.
It is strongly recommended for controllers to always force conflicts on objects that
they own and manage, since they might not be able to resolve or act on these conflicts.
Transferring ownership
In addition to the concurrency controls provided by conflict resolution,
Server-Side Apply provides ways to perform coordinated
field ownership transfers from users to controllers.
This is best explained by example. Let's look at how to safely transfer
ownership of the replicas field from a user to a controller while enabling
automatic horizontal scaling for a Deployment, using the HorizontalPodAutoscaler
resource and its accompanying controller.
Say a user has defined Deployment with replicas set to the desired value:
Now, the user would like to remove replicas from their configuration, so they
don't accidentally fight with the HorizontalPodAutoscaler (HPA) and its controller.
However, there is a race: it might take some time before the HPA feels the need
to adjust .spec.replicas; if the user removes .spec.replicas before the HPA writes
to the field and becomes its owner, then the API server would set .spec.replicas to
1 (the default replica count for Deployment).
This is not what the user wants to happen, even temporarily - it might well degrade
a running workload.
There are two solutions:
(basic) Leave replicas in the configuration; when the HPA eventually writes to that
field, the system gives the user a conflict over it. At that point, it is safe
to remove from the configuration.
(more advanced) If, however, the user doesn't want to wait, for example
because they want to keep the cluster legible to their colleagues, then they
can take the following steps to make it safe to remove replicas from their
configuration:
First, the user defines a new manifest containing only the replicas field:
# Save this file as 'nginx-deployment-replicas-only.yaml'.apiVersion:apps/v1kind:Deploymentmetadata:name:nginx-deploymentspec:replicas:3
Note: The YAML file for SSA in this case only contains the fields you want to change.
You are not supposed to provide a fully compliant Deployment manifest if you only
want to modify the spec.replicas field using SSA.
The user applies that manifest using a private field manager name. In this example,
the user picked handover-to-hpa:
If the apply results in a conflict with the HPA controller, then do nothing. The
conflict indicates the controller has claimed the field earlier in the
process than it sometimes does.
At this point the user may remove the replicas field from their manifest:
Note that whenever the HPA controller sets the replicas field to a new value,
the temporary field manager will no longer own any fields and will be
automatically deleted. No further clean up is required.
Transferring ownership between managers
Field managers can transfer ownership of a field between each other by setting the field
to the same value in both of their applied configurations, causing them to share
ownership of the field. Once the managers share ownership of the field, one of them
can remove the field from their applied configuration to give up ownership and
complete the transfer to the other field manager.
Comparison with Client-Side Apply
Server-Side Apply is meant both as a replacement for the original client-side
implementation of the kubectl apply subcommand, and as simple and effective
mechanism for controllers
to enact their changes.
Compared to the last-applied annotation managed by kubectl, Server-Side
Apply uses a more declarative approach, which tracks an object's field management,
rather than a user's last applied state. This means that as a side effect of
using Server-Side Apply, information about which field manager manages each
field in an object also becomes available.
A consequence of the conflict detection and resolution implemented by Server-Side
Apply is that an applier always has up to date field values in their local
state. If they don't, they get a conflict the next time they apply. Any of the
three options to resolve conflicts results in the applied configuration being an
up to date subset of the object on the server's fields.
This is different from Client-Side Apply, where outdated values which have been
overwritten by other users are left in an applier's local config. These values
only become accurate when the user updates that specific field, if ever, and an
applier has no way of knowing whether their next apply will overwrite other
users' changes.
Another difference is that an applier using Client-Side Apply is unable to
change the API version they are using, but Server-Side Apply supports this use
case.
Migration between client-side and server-side apply
Upgrading from client-side apply to server-side apply
Client-side apply users who manage a resource with kubectl apply can start
using server-side apply with the following flag.
kubectl apply --server-side [--dry-run=server]
By default, field management of the object transfers from client-side apply to
kubectl server-side apply, without encountering conflicts.
Caution:
Keep the last-applied-configuration annotation up to date.
The annotation infers client-side applies managed fields.
Any fields not managed by client-side apply raise conflicts.
For example, if you used kubectl scale to update the replicas field after
client-side apply, then this field is not owned by client-side apply and
creates conflicts on kubectl apply --server-side.
This behavior applies to server-side apply with the kubectl field manager.
As an exception, you can opt-out of this behavior by specifying a different,
non-default field manager, as seen in the following example. The default field
manager for kubectl server-side apply is kubectl.
Downgrading from server-side apply to client-side apply
If you manage a resource with kubectl apply --server-side,
you can downgrade to client-side apply directly with kubectl apply.
Downgrading works because kubectl Server-Side Apply keeps the
last-applied-configuration annotation up-to-date if you use
kubectl apply.
This behavior applies to Server-Side Apply with the kubectl field manager.
As an exception, you can opt-out of this behavior by specifying a different,
non-default field manager, as seen in the following example. The default field
manager for kubectl server-side apply is kubectl.
The PATCH verb for a resource that supports Server-Side Apply can accepts the
unofficial application/apply-patch+yaml content type. Users of Server-Side
Apply can send partially specified objects as YAML as the body of a PATCH request
to the URI of a resource. When applying a configuration, you should always include all the
fields that are important to the outcome (such as a desired state) that you want to define.
All JSON messages are valid YAML. Some clients specify Server-Side Apply requests using YAML
request bodies that are also valid JSON.
Access control and permissions
Since Server-Side Apply is a type of PATCH, a principal (such as a Role for Kubernetes
RBAC) requires the patch permission to
edit existing resources, and also needs the create verb permission in order to create
new resources with Server-Side Apply.
Clearing managedFields
It is possible to strip all managedFields from an object by overwriting them
using a patch (JSON Merge Patch, Strategic Merge Patch, JSON Patch), or
through an update (HTTP PUT); in other words, through every write operation
other than apply. This can be done by overwriting the managedFields field
with an empty entry. Two examples are:
This will overwrite the managedFields with a list containing a single empty
entry that then results in the managedFields being stripped entirely from the
object. Note that setting the managedFields to an empty list will not
reset the field. This is on purpose, so managedFields never get stripped by
clients not aware of the field.
In cases where the reset operation is combined with changes to other fields
than the managedFields, this will result in the managedFields being reset
first and the other changes being processed afterwards. As a result the
applier takes ownership of any fields updated in the same request.
Note: Server-Side Apply does not correctly track ownership on
sub-resources that don't receive the resource object type. If you are
using Server-Side Apply with such a sub-resource, the changed fields
may not be tracked.
What's next
You can read about managedFields within the Kubernetes API reference for the
metadata
top level field.
2.3 - Client Libraries
This page contains an overview of the client libraries for using the Kubernetes
API from various programming languages.
To write applications using the Kubernetes REST API,
you do not need to implement the API calls and request/response types yourself.
You can use a client library for the programming language you are using.
Client libraries often handle common tasks such as authentication for you.
Most client libraries can discover and use the Kubernetes Service Account to
authenticate if the API client is running inside the Kubernetes cluster, or can
understand the kubeconfig file
format to read the credentials and the API Server address.
Note:
This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.
The following Kubernetes API client libraries are provided and maintained by
their authors, not the Kubernetes team.
The Common Expression Language (CEL) is used
in the Kubernetes API to declare validation rules, policy rules, and other
constraints or conditions.
CEL expressions are evaluated directly in the
API server, making CEL a
convenient alternative to out-of-process mechanisms, such as webhooks, for many
extensibility use cases. Your CEL expressions continue to execute so long as the
control plane's API server component remains available.
Language overview
The CEL
language has a
straightforward syntax that is similar to the expressions in C, C++, Java,
JavaScript and Go.
CEL was designed to be embedded into applications. Each CEL "program" is a
single expression that evaluates to a single value. CEL expressions are
typically short "one-liners" that inline well into the string fields of Kubernetes
API resources.
Inputs to a CEL program are "variables". Each Kubernetes API field that contains
CEL declares in the API documentation which variables are available to use for
that field. For example, in the x-kubernetes-validations[i].rules field of
CustomResourceDefinitions, the self and oldSelf variables are available and
refer to the previous and current state of the custom resource data to be
validated by the CEL expression. Other Kubernetes API fields may declare
different variables. See the API documentation of the API fields to learn which
variables are available for that field.
Example CEL expressions:
Examples of CEL expressions and the purpose of each
In additional to the CEL community libraries, Kubernetes includes CEL libraries
that are available everywhere CEL is used in Kubernetes.
Kubernetes list library
The list library includes indexOf and lastIndexOf, which work similar to the
strings functions of the same names. These functions either the first or last
positional index of the provided element in the list.
The list library also includes min, max and sum. Sum is supported on all
number types as well as the duration type. Min and max are supported on all
comparable types.
isSorted is also provided as a convenience function and is supported on all
comparable types.
Examples:
Examples of CEL expressions using list library functions
CEL Expression
Purpose
names.isSorted()
Verify that a list of names is kept in alphabetical order
items.map(x, x.weight).sum() == 1.0
Verify that the "weights" of a list of objects sum to 1.0
In addition to the matches function provided by the CEL standard library, the
regex library provides find and findAll, enabling a much wider range of
regex operations.
Examples:
Examples of CEL expressions using regex library functions
For CEL expressions in the API where a variable of type Authorizer is available,
the authorizer may be used to perform authorization checks for the principal
(authenticated user) of the request.
API resource checks are performed as follows:
Specify the group and resource to check: Authorizer.group(string).resource(string) ResourceCheck
Optionally call any combination of the following builder functions to further narrow the authorization check.
Note that these functions return the receiver type and can be chained:
ResourceCheck.subresource(string) ResourceCheck
ResourceCheck.namespace(string) ResourceCheck
ResourceCheck.name(string) ResourceCheck
Call ResourceCheck.check(verb string) Decision to perform the authorization check.
Call allowed() bool or reason() string to inspect the result of the authorization check.
Non-resource authorization performed are used as follows:
specify only a path: Authorizer.path(string) PathCheck
Call PathCheck.check(httpVerb string) Decision to perform the authorization check.
Call allowed() bool or reason() string to inspect the result of the authorization check.
To perform an authorization check for a service account:
Authorizer.serviceAccount(namespace string, name string) Authorizer
Examples of CEL expressions using URL library functions
Some Kubernetes API fields contain partially type checked CEL expressions. A
partially type checked expression is an experessions where some of the variables
are statically typed but others are dynamically typed. For example, in the CEL
expressions of
ValidatingAdmissionPolicies
the request variable is typed, but the object variable is dynamically typed.
As a result, an expression containing request.namex would fail type checking
because the namex field is not defined. However, object.namex would pass
type checking even when the namex field is not defined for the resource kinds
that object refers to, because object is dynamically typed.
The has() macro in CEL may be used in CEL expressions to check if a field of a
dynamically typed variable is accessible before attempting to access the field's
value. For example:
Equality comparison for arrays with x-kubernetes-list-type of set or map ignores element
order. For example [1, 2] == [2, 1] if the arrays represent Kubernetes set values.
Concatenation on arrays with x-kubernetes-list-type use the semantics of the
list type:
set: X + Y performs a union where the array positions of all elements in
X are preserved and non-intersecting elements in Y are appended, retaining
their partial order.
map: X + Y performs a merge where the array positions of all keys in X
are preserved but the values are overwritten by values in Y when the key
sets of X and Y intersect. Elements in Y with non-intersecting keys are
appended, retaining their partial order.
Escaping
Only Kubernetes resource property names of the form
[a-zA-Z_.-/][a-zA-Z0-9_.-/]* are accessible from CEL. Accessible property
names are escaped according to the following rules when accessed in the
expression:
When you escape any of CEL's RESERVED keywords you need to match the exact property name
use the underscore escaping
(for example, int in the word sprint would not be escaped and nor would it need to be).
Examples on escaping:
Examples escaped CEL identifiers
property name
rule with escaped property name
namespace
self.__namespace__ > 0
x-prop
self.x__dash__prop > 0
redact__d
self.redact__underscores__d > 0
string
self.startsWith('kube')
Resource constraints
CEL is non-Turing complete and offers a variety of production safety controls to
limit execution time. CEL's resource constraint features provide feedback to
developers about expression complexity and help protect the API server from
excessive resource consumption during evaluation. CEL's resource constraint
features are used to prevent CEL evaluation from consuming excessive API server
resources.
A key element of the resource constraint features is a cost unit that CEL
defines as a way of tracking CPU utilization. Cost units are independent of
system load and hardware. Cost units are also deterministic; for any given CEL
expression and input data, evaluation of the expression by the CEL interpreter
will always result in the same cost.
Many of CEL's core operations have fixed costs. The simplest operations, such as
comparisons (e.g. <) have a cost of 1. Some have a higher fixed cost, for
example list literal declarations have a fixed base cost of 40 cost units.
Calls to functions implemented in native code approximate cost based on the time
complexity of the operation. For example: operations that use regular
expressions, such as match and find, are estimated using an approximated
cost of length(regexString)*length(inputString). The approximated cost
reflects the worst case time complexity of Go's RE2 implementation.
Runtime cost budget
All CEL expressions evaluated by Kubernetes are constrained by a runtime cost
budget. The runtime cost budget is an estimate of actual CPU utilization
computed by incrementing a cost unit counter while interpreting a CEL
expression. If the CEL interpreter executes too many instructions, the runtime
cost budget will be exceeded, execution of the expressions will be halted, and
an error will result.
Some Kubernetes resources define an additional runtime cost budget that bounds
the execution of multiple expressions. If the sum total of the cost of
expressions exceed the budget, execution of the expressions will be halted, and
an error will result. For example the validation of a custom resource has a
per-validation runtime cost budget for all
Validation Rules
evaluated to validate the custom resource.
Estimated cost limits
For some Kubernetes resources, the API server may also check if worst case
estimated running time of CEL expressions would be prohibitively expensive to
execute. If so, the API server prevent the CEL expression from being written to
API resources by rejecting create or update operations containing the CEL
expression to the API resources. This feature offers a stronger assurance that
CEL expressions written to the API resource will be evaluate at runtime without
exceeding the runtime cost budget.
2.5 - Kubernetes Deprecation Policy
This document details the deprecation policy for various facets of the system.
Kubernetes is a large system with many components and many contributors. As
with any such software, the feature set naturally evolves over time, and
sometimes a feature may need to be removed. This could include an API, a flag,
or even an entire feature. To avoid breaking existing users, Kubernetes follows
a deprecation policy for aspects of the system that are slated to be removed.
Deprecating parts of the API
Since Kubernetes is an API-driven system, the API has evolved over time to
reflect the evolving understanding of the problem space. The Kubernetes API is
actually a set of APIs, called "API groups", and each API group is
independently versioned. API versions fall
into 3 main tracks, each of which has different policies for deprecation:
Example
Track
v1
GA (generally available, stable)
v1beta1
Beta (pre-release)
v1alpha1
Alpha (experimental)
A given release of Kubernetes can support any number of API groups and any
number of versions of each.
The following rules govern the deprecation of elements of the API. This
includes:
REST resources (aka API objects)
Fields of REST resources
Annotations on REST resources, including "beta" annotations but not
including "alpha" annotations.
Enumerated or constant values
Component config structures
These rules are enforced between official releases, not between
arbitrary commits to master or release branches.
Rule #1: API elements may only be removed by incrementing the version of the
API group.
Once an API element has been added to an API group at a particular version, it
can not be removed from that version or have its behavior significantly
changed, regardless of track.
Note: For historical reasons, there are 2 "monolithic" API groups - "core" (no
group name) and "extensions". Resources will incrementally be moved from these
legacy API groups into more domain-specific API groups.
Rule #2: API objects must be able to round-trip between API versions in a given
release without information loss, with the exception of whole REST resources
that do not exist in some versions.
For example, an object can be written as v1 and then read back as v2 and
converted to v1, and the resulting v1 resource will be identical to the
original. The representation in v2 might be different from v1, but the system
knows how to convert between them in both directions. Additionally, any new
field added in v2 must be able to round-trip to v1 and back, which means v1
might have to add an equivalent field or represent it as an annotation.
Rule #3: An API version in a given track may not be deprecated in favor of a less stable API version.
GA API versions can replace beta and alpha API versions.
Beta API versions can replace earlier beta and alpha API versions, but may not replace GA API versions.
Alpha API versions can replace earlier alpha API versions, but may not replace GA or beta API versions.
Rule #4a: API lifetime is determined by the API stability level
GA API versions may be marked as deprecated, but must not be removed within a major version of Kubernetes
Beta API versions are deprecated no more than 9 months or 3 minor releases after introduction (whichever is longer),
and are no longer served 9 months or 3 minor releases after deprecation (whichever is longer)
Alpha API versions may be removed in any release without prior deprecation notice
This ensures beta API support covers the maximum supported version skew of 2 releases,
and that APIs don't stagnate on unstable beta versions, accumulating production usage that will be disrupted when support for the beta API ends.
Note: There are no current plans for a major version revision of Kubernetes that removes GA APIs.
Note: Until #52185 is
resolved, no API versions that have been persisted to storage may be removed.
Serving REST endpoints for those versions may be disabled (subject to the
deprecation timelines in this document), but the API server must remain capable
of decoding/converting previously persisted data from storage.
Rule #4b: The "preferred" API version and the "storage version" for a given
group may not advance until after a release has been made that supports both the
new version and the previous version
Users must be able to upgrade to a new release of Kubernetes and then roll back
to a previous release, without converting anything to the new API version or
suffering breakages (unless they explicitly used features only available in the
newer version). This is particularly evident in the stored representation of
objects.
All of this is best illustrated by examples. Imagine a Kubernetes release,
version X, which introduces a new API group. A new Kubernetes release is made
every approximately 4 months (3 per year). The following table describes which
API versions are supported in a series of subsequent releases.
Consider a hypothetical REST resource named Widget, which was present in API v1
in the above timeline, and which needs to be deprecated. We document and
announce the
deprecation in sync with release X+1. The Widget resource still exists in API
version v1 (deprecated) but not in v2alpha1. The Widget resource continues to
exist and function in releases up to and including X+8. Only in release X+9,
when API v1 has aged out, does the Widget resource cease to exist, and the
behavior get removed.
Starting in Kubernetes v1.19, making an API request to a deprecated REST API endpoint:
Returns a Warning header (as defined in RFC7234, Section 5.5) in the API response.
Adds a "k8s.io/deprecated":"true" annotation to the audit event recorded for the request.
Sets an apiserver_requested_deprecated_apis gauge metric to 1 in the kube-apiserver
process. The metric has labels for group, version, resource, subresource that can be joined
to the apiserver_request_total metric, and a removed_release label that indicates the
Kubernetes release in which the API will no longer be served. The following Prometheus query
returns information about requests made to deprecated APIs which will be removed in v1.22:
As with whole REST resources, an individual field which was present in API v1
must exist and function until API v1 is removed. Unlike whole resources, the
v2 APIs may choose a different representation for the field, as long as it can
be round-tripped. For example a v1 field named "magnitude" which was
deprecated might be named "deprecatedMagnitude" in API v2. When v1 is
eventually removed, the deprecated field can be removed from v2.
Enumerated or constant values
As with whole REST resources and fields thereof, a constant value which was
supported in API v1 must exist and function until API v1 is removed.
Component config structures
Component configs are versioned and managed similar to REST resources.
Future work
Over time, Kubernetes will introduce more fine-grained API versions, at which
point these rules will be adjusted as needed.
Deprecating a flag or CLI
The Kubernetes system is comprised of several different programs cooperating.
Sometimes, a Kubernetes release might remove flags or CLI commands
(collectively "CLI elements") in these programs. The individual programs
naturally sort into two main groups - user-facing and admin-facing programs,
which vary slightly in their deprecation policies. Unless a flag is explicitly
prefixed or documented as "alpha" or "beta", it is considered GA.
CLI elements are effectively part of the API to the system, but since they are
not versioned in the same way as the REST API, the rules for deprecation are as
follows:
Rule #5a: CLI elements of user-facing components (e.g. kubectl) must function
after their announced deprecation for no less than:
GA: 12 months or 2 releases (whichever is longer)
Beta: 3 months or 1 release (whichever is longer)
Alpha: 0 releases
Rule #5b: CLI elements of admin-facing components (e.g. kubelet) must function
after their announced deprecation for no less than:
GA: 6 months or 1 release (whichever is longer)
Beta: 3 months or 1 release (whichever is longer)
Alpha: 0 releases
Rule #6: Deprecated CLI elements must emit warnings (optionally disable)
when used.
Deprecating a feature or behavior
Occasionally a Kubernetes release needs to deprecate some feature or behavior
of the system that is not controlled by the API or CLI. In this case, the
rules for deprecation are as follows:
Rule #7: Deprecated behaviors must function for no less than 1 year after their
announced deprecation.
This does not imply that all changes to the system are governed by this policy.
This applies only to significant, user-visible behaviors which impact the
correctness of applications running on Kubernetes or that impact the
administration of Kubernetes clusters, and which are being removed entirely.
An exception to the above rule is feature gates. Feature gates are key=value
pairs that allow for users to enable/disable experimental features.
Feature gates are intended to cover the development life cycle of a feature - they
are not intended to be long-term APIs. As such, they are expected to be deprecated
and removed after a feature becomes GA or is dropped.
As a feature moves through the stages, the associated feature gate evolves.
The feature life cycle matched to its corresponding feature gate is:
Alpha: the feature gate is disabled by default and can be enabled by the user.
Beta: the feature gate is enabled by default and can be disabled by the user.
GA: the feature gate is deprecated (see "Deprecation") and becomes
non-operational.
GA, deprecation window complete: the feature gate is removed and calls to it are
no longer accepted.
Deprecation
Features can be removed at any point in the life cycle prior to GA. When features are
removed prior to GA, their associated feature gates are also deprecated.
When an invocation tries to disable a non-operational feature gate, the call fails in order
to avoid unsupported scenarios that might otherwise run silently.
In some cases, removing pre-GA features requires considerable time. Feature gates can remain
operational until their associated feature is fully removed, at which point the feature gate
itself can be deprecated.
When removing a feature gate for a GA feature also requires considerable time, calls to
feature gates may remain operational if the feature gate has no effect on the feature,
and if the feature gate causes no errors.
Features intended to be disabled by users should include a mechanism for disabling the
feature in the associated feature gate.
Versioning for feature gates is different from the previously discussed components,
therefore the rules for deprecation are as follows:
Rule #8: Feature gates must be deprecated when the corresponding feature they control
transitions a lifecycle stage as follows. Feature gates must function for no less than:
Beta feature to GA: 6 months or 2 releases (whichever is longer)
Beta feature to EOL: 3 months or 1 release (whichever is longer)
Alpha feature to EOL: 0 releases
Rule #9: Deprecated feature gates must respond with a warning when used. When a feature gate
is deprecated it must be documented in both in the release notes and the corresponding CLI help.
Both warnings and documentation must indicate whether a feature gate is non-operational.
Deprecating a metric
Each component of the Kubernetes control-plane exposes metrics (usually the
/metrics endpoint), which are typically ingested by cluster administrators.
Not all metrics are the same: some metrics are commonly used as SLIs or used
to determine SLOs, these tend to have greater import. Other metrics are more
experimental in nature or are used primarily in the Kubernetes development
process.
Accordingly, metrics fall under three stability classes (ALPHA, BETASTABLE);
this impacts removal of a metric during a Kubernetes release. These classes
are determined by the perceived importance of the metric. The rules for
deprecating and removing a metric are as follows:
Rule #9a: Metrics, for the corresponding stability class, must function for no less than:
STABLE: 4 releases or 12 months (whichever is longer)
BETA: 2 releases or 8 months (whichever is longer)
ALPHA: 0 releases
Rule #9b: Metrics, after their announced deprecation, must function for no less than:
STABLE: 3 releases or 9 months (whichever is longer)
BETA: 1 releases or 4 months (whichever is longer)
ALPHA: 0 releases
Deprecated metrics will have their description text prefixed with a deprecation notice
string '(Deprecated from x.y)' and a warning log will be emitted during metric
registration. Like their stable undeprecated counterparts, deprecated metrics will
be automatically registered to the metrics endpoint and therefore visible.
On a subsequent release (when the metric's deprecatedVersion is equal to
current_kubernetes_version - 3)), a deprecated metric will become a hidden metric.
Unlike their deprecated counterparts, hidden metrics will no longer be
automatically registered to the metrics endpoint (hence hidden). However, they
can be explicitly enabled through a command line flag on the binary
(--show-hidden-metrics-for-version=). This provides cluster admins an
escape hatch to properly migrate off of a deprecated metric, if they were not
able to react to the earlier deprecation warnings. Hidden metrics should be
deleted after one release.
Exceptions
No policy can cover every possible situation. This policy is a living
document, and will evolve over time. In practice, there will be situations
that do not fit neatly into this policy, or for which this policy becomes a
serious impediment. Such situations should be discussed with SIGs and project
leaders to find the best solutions for those specific cases, always bearing in
mind that Kubernetes is committed to being a stable system that, as much as
possible, never breaks users. Exceptions will always be announced in all
relevant release notes.
2.6 - Deprecated API Migration Guide
As the Kubernetes API evolves, APIs are periodically reorganized or upgraded.
When APIs evolve, the old API is deprecated and eventually removed.
This page contains information you need to know when migrating from
deprecated API versions to newer and more stable API versions.
Removed APIs by release
v1.29
The v1.29 release will stop serving the following deprecated API versions:
Flow control resources
The flowcontrol.apiserver.k8s.io/v1beta2 API version of FlowSchema and PriorityLevelConfiguration will no longer be served in v1.29.
Migrate manifests and API clients to use the flowcontrol.apiserver.k8s.io/v1beta3 API version, available since v1.26.
All existing persisted objects are accessible via the new API
Notable changes in flowcontrol.apiserver.k8s.io/v1beta3:
The PriorityLevelConfiguration spec.limited.assuredConcurrencyShares field is renamed to spec.limited.nominalConcurrencyShares
v1.27
The v1.27 release stopped serving the following deprecated API versions:
CSIStorageCapacity
The storage.k8s.io/v1beta1 API version of CSIStorageCapacity will no longer be served in v1.27.
Migrate manifests and API clients to use the storage.k8s.io/v1 API version, available since v1.24.
All existing persisted objects are accessible via the new API
No notable changes
v1.26
The v1.26 release stopped serving the following deprecated API versions:
Flow control resources
The flowcontrol.apiserver.k8s.io/v1beta1 API version of FlowSchema and PriorityLevelConfiguration is no longer served as of v1.26.
Migrate manifests and API clients to use the flowcontrol.apiserver.k8s.io/v1beta3 API version, available since v1.26.
All existing persisted objects are accessible via the new API
No notable changes
HorizontalPodAutoscaler
The autoscaling/v2beta2 API version of HorizontalPodAutoscaler is no longer served as of v1.26.
Migrate manifests and API clients to use the autoscaling/v2 API version, available since v1.23.
All existing persisted objects are accessible via the new API
v1.25
The v1.25 release stopped serving the following deprecated API versions:
CronJob
The batch/v1beta1 API version of CronJob is no longer served as of v1.25.
Migrate manifests and API clients to use the batch/v1 API version, available since v1.21.
All existing persisted objects are accessible via the new API
No notable changes
EndpointSlice
The discovery.k8s.io/v1beta1 API version of EndpointSlice is no longer served as of v1.25.
Migrate manifests and API clients to use the discovery.k8s.io/v1 API version, available since v1.21.
All existing persisted objects are accessible via the new API
Notable changes in discovery.k8s.io/v1:
use per Endpoint nodeName field instead of deprecated topology["kubernetes.io/hostname"] field
use per Endpoint zone field instead of deprecated topology["topology.kubernetes.io/zone"] field
topology is replaced with the deprecatedTopology field which is not writable in v1
Event
The events.k8s.io/v1beta1 API version of Event is no longer served as of v1.25.
Migrate manifests and API clients to use the events.k8s.io/v1 API version, available since v1.19.
All existing persisted objects are accessible via the new API
Notable changes in events.k8s.io/v1:
type is limited to Normal and Warning
involvedObject is renamed to regarding
action, reason, reportingController, and reportingInstance are required
when creating new events.k8s.io/v1 Events
use eventTime instead of the deprecated firstTimestamp field (which is renamed
to deprecatedFirstTimestamp and not permitted in new events.k8s.io/v1 Events)
use series.lastObservedTime instead of the deprecated lastTimestamp field
(which is renamed to deprecatedLastTimestamp and not permitted in new events.k8s.io/v1 Events)
use series.count instead of the deprecated count field
(which is renamed to deprecatedCount and not permitted in new events.k8s.io/v1 Events)
use reportingController instead of the deprecated source.component field
(which is renamed to deprecatedSource.component and not permitted in new events.k8s.io/v1 Events)
use reportingInstance instead of the deprecated source.host field
(which is renamed to deprecatedSource.host and not permitted in new events.k8s.io/v1 Events)
HorizontalPodAutoscaler
The autoscaling/v2beta1 API version of HorizontalPodAutoscaler is no longer served as of v1.25.
Migrate manifests and API clients to use the autoscaling/v2 API version, available since v1.23.
All existing persisted objects are accessible via the new API
PodDisruptionBudget
The policy/v1beta1 API version of PodDisruptionBudget is no longer served as of v1.25.
Migrate manifests and API clients to use the policy/v1 API version, available since v1.21.
All existing persisted objects are accessible via the new API
Notable changes in policy/v1:
an empty spec.selector ({}) written to a policy/v1 PodDisruptionBudget selects all
pods in the namespace (in policy/v1beta1 an empty spec.selector selected no pods).
An unset spec.selector selects no pods in either API version.
PodSecurityPolicy
PodSecurityPolicy in the policy/v1beta1 API version is no longer served as of v1.25,
and the PodSecurityPolicy admission controller will be removed.
RuntimeClass in the node.k8s.io/v1beta1 API version is no longer served as of v1.25.
Migrate manifests and API clients to use the node.k8s.io/v1 API version, available since v1.20.
All existing persisted objects are accessible via the new API
No notable changes
v1.22
The v1.22 release stopped serving the following deprecated API versions:
Webhook resources
The admissionregistration.k8s.io/v1beta1 API version of MutatingWebhookConfiguration
and ValidatingWebhookConfiguration is no longer served as of v1.22.
Migrate manifests and API clients to use the admissionregistration.k8s.io/v1 API version, available since v1.16.
All existing persisted objects are accessible via the new APIs
Notable changes:
webhooks[*].failurePolicy default changed from Ignore to Fail for v1
webhooks[*].matchPolicy default changed from Exact to Equivalent for v1
webhooks[*].timeoutSeconds default changed from 30s to 10s for v1
webhooks[*].sideEffects default value is removed, and the field made required,
and only None and NoneOnDryRun are permitted for v1
webhooks[*].admissionReviewVersions default value is removed and the field made
required for v1 (supported versions for AdmissionReview are v1 and v1beta1)
webhooks[*].name must be unique in the list for objects created via admissionregistration.k8s.io/v1
CustomResourceDefinition
The apiextensions.k8s.io/v1beta1 API version of CustomResourceDefinition is no longer served as of v1.22.
Migrate manifests and API clients to use the apiextensions.k8s.io/v1 API version, available since v1.16.
All existing persisted objects are accessible via the new API
Notable changes:
spec.scope is no longer defaulted to Namespaced and must be explicitly specified
spec.version is removed in v1; use spec.versions instead
spec.validation is removed in v1; use spec.versions[*].schema instead
spec.subresources is removed in v1; use spec.versions[*].subresources instead
spec.additionalPrinterColumns is removed in v1; use spec.versions[*].additionalPrinterColumns instead
spec.conversion.webhookClientConfig is moved to spec.conversion.webhook.clientConfig in v1
spec.conversion.conversionReviewVersions is moved to spec.conversion.webhook.conversionReviewVersions in v1
spec.versions[*].schema.openAPIV3Schema is now required when creating v1 CustomResourceDefinition objects,
and must be a structural schema
spec.preserveUnknownFields: true is disallowed when creating v1 CustomResourceDefinition objects;
it must be specified within schema definitions as x-kubernetes-preserve-unknown-fields: true
In additionalPrinterColumns items, the JSONPath field was renamed to jsonPath in v1
(fixes #66531)
APIService
The apiregistration.k8s.io/v1beta1 API version of APIService is no longer served as of v1.22.
Migrate manifests and API clients to use the apiregistration.k8s.io/v1 API version, available since v1.10.
All existing persisted objects are accessible via the new API
No notable changes
TokenReview
The authentication.k8s.io/v1beta1 API version of TokenReview is no longer served as of v1.22.
Migrate manifests and API clients to use the authentication.k8s.io/v1 API version, available since v1.6.
No notable changes
SubjectAccessReview resources
The authorization.k8s.io/v1beta1 API version of LocalSubjectAccessReview,
SelfSubjectAccessReview, SubjectAccessReview, and SelfSubjectRulesReview is no longer served as of v1.22.
Migrate manifests and API clients to use the authorization.k8s.io/v1 API version, available since v1.6.
Notable changes:
spec.group was renamed to spec.groups in v1 (fixes #32709)
CertificateSigningRequest
The certificates.k8s.io/v1beta1 API version of CertificateSigningRequest is no longer served as of v1.22.
Migrate manifests and API clients to use the certificates.k8s.io/v1 API version, available since v1.19.
All existing persisted objects are accessible via the new API
Notable changes in certificates.k8s.io/v1:
For API clients requesting certificates:
spec.signerName is now required
(see known Kubernetes signers),
and requests for kubernetes.io/legacy-unknown are not allowed to be created via the certificates.k8s.io/v1 API
spec.usages is now required, may not contain duplicate values, and must only contain known usages
For API clients approving or signing certificates:
status.conditions may not contain duplicate types
status.conditions[*].status is now required
status.certificate must be PEM-encoded, and contain only CERTIFICATE blocks
Lease
The coordination.k8s.io/v1beta1 API version of Lease is no longer served as of v1.22.
Migrate manifests and API clients to use the coordination.k8s.io/v1 API version, available since v1.14.
All existing persisted objects are accessible via the new API
No notable changes
Ingress
The extensions/v1beta1 and networking.k8s.io/v1beta1 API versions of Ingress is no longer served as of v1.22.
Migrate manifests and API clients to use the networking.k8s.io/v1 API version, available since v1.19.
All existing persisted objects are accessible via the new API
Notable changes:
spec.backend is renamed to spec.defaultBackend
The backend serviceName field is renamed to service.name
Numeric backend servicePort fields are renamed to service.port.number
String backend servicePort fields are renamed to service.port.name
pathType is now required for each specified path. Options are Prefix,
Exact, and ImplementationSpecific. To match the undefined v1beta1 behavior, use ImplementationSpecific.
IngressClass
The networking.k8s.io/v1beta1 API version of IngressClass is no longer served as of v1.22.
Migrate manifests and API clients to use the networking.k8s.io/v1 API version, available since v1.19.
All existing persisted objects are accessible via the new API
No notable changes
RBAC resources
The rbac.authorization.k8s.io/v1beta1 API version of ClusterRole, ClusterRoleBinding,
Role, and RoleBinding is no longer served as of v1.22.
Migrate manifests and API clients to use the rbac.authorization.k8s.io/v1 API version, available since v1.8.
All existing persisted objects are accessible via the new APIs
No notable changes
PriorityClass
The scheduling.k8s.io/v1beta1 API version of PriorityClass is no longer served as of v1.22.
Migrate manifests and API clients to use the scheduling.k8s.io/v1 API version, available since v1.14.
All existing persisted objects are accessible via the new API
No notable changes
Storage resources
The storage.k8s.io/v1beta1 API version of CSIDriver, CSINode, StorageClass, and VolumeAttachment is no longer served as of v1.22.
Migrate manifests and API clients to use the storage.k8s.io/v1 API version
CSIDriver is available in storage.k8s.io/v1 since v1.19.
CSINode is available in storage.k8s.io/v1 since v1.17
StorageClass is available in storage.k8s.io/v1 since v1.6
VolumeAttachment is available in storage.k8s.io/v1 v1.13
All existing persisted objects are accessible via the new APIs
No notable changes
v1.16
The v1.16 release stopped serving the following deprecated API versions:
NetworkPolicy
The extensions/v1beta1 API version of NetworkPolicy is no longer served as of v1.16.
Migrate manifests and API clients to use the networking.k8s.io/v1 API version, available since v1.8.
All existing persisted objects are accessible via the new API
DaemonSet
The extensions/v1beta1 and apps/v1beta2 API versions of DaemonSet are no longer served as of v1.16.
Migrate manifests and API clients to use the apps/v1 API version, available since v1.9.
All existing persisted objects are accessible via the new API
Notable changes:
spec.templateGeneration is removed
spec.selector is now required and immutable after creation; use the existing
template labels as the selector for seamless upgrades
spec.updateStrategy.type now defaults to RollingUpdate
(the default in extensions/v1beta1 was OnDelete)
Deployment
The extensions/v1beta1, apps/v1beta1, and apps/v1beta2 API versions of Deployment are no longer served as of v1.16.
Migrate manifests and API clients to use the apps/v1 API version, available since v1.9.
All existing persisted objects are accessible via the new API
Notable changes:
spec.rollbackTo is removed
spec.selector is now required and immutable after creation; use the existing
template labels as the selector for seamless upgrades
spec.progressDeadlineSeconds now defaults to 600 seconds
(the default in extensions/v1beta1 was no deadline)
spec.revisionHistoryLimit now defaults to 10
(the default in apps/v1beta1 was 2, the default in extensions/v1beta1 was to retain all)
maxSurge and maxUnavailable now default to 25%
(the default in extensions/v1beta1 was 1)
StatefulSet
The apps/v1beta1 and apps/v1beta2 API versions of StatefulSet are no longer served as of v1.16.
Migrate manifests and API clients to use the apps/v1 API version, available since v1.9.
All existing persisted objects are accessible via the new API
Notable changes:
spec.selector is now required and immutable after creation;
use the existing template labels as the selector for seamless upgrades
spec.updateStrategy.type now defaults to RollingUpdate
(the default in apps/v1beta1 was OnDelete)
ReplicaSet
The extensions/v1beta1, apps/v1beta1, and apps/v1beta2 API versions of ReplicaSet are no longer served as of v1.16.
Migrate manifests and API clients to use the apps/v1 API version, available since v1.9.
All existing persisted objects are accessible via the new API
Notable changes:
spec.selector is now required and immutable after creation; use the existing template labels as the selector for seamless upgrades
PodSecurityPolicy
The extensions/v1beta1 API version of PodSecurityPolicy is no longer served as of v1.16.
Migrate manifests and API client to use the policy/v1beta1 API version, available since v1.10.
Note that the policy/v1beta1 API version of PodSecurityPolicy will be removed in v1.25.
What to do
Test with deprecated APIs disabled
You can test your clusters by starting an API server with specific API versions disabled
to simulate upcoming removals. Add the following flag to the API server startup arguments:
This conversion may use non-ideal default values. To learn more about a specific
resource, check the Kubernetes API reference.
Note:
The kubectl convert tool is not installed by default, although
in fact it once was part of kubectl itself. For more details, you can read the
deprecation and removal issue
for the built-in subcommand.
To learn how to set up kubectl convert on your computer, visit the page that is right for your
operating system:
Linux,
macOS, or
Windows.
2.7 - Kubernetes API health endpoints
The Kubernetes API server provides API endpoints to indicate the current status of the API server.
This page describes these API endpoints and explains how you can use them.
API endpoints for health
The Kubernetes API server provides 3 API endpoints (healthz, livez and readyz) to indicate the current status of the API server.
The healthz endpoint is deprecated (since Kubernetes v1.16), and you should use the more specific livez and readyz endpoints instead.
The livez endpoint can be used with the --livez-grace-periodflag to specify the startup duration.
For a graceful shutdown you can specify the --shutdown-delay-durationflag with the /readyz endpoint.
Machines that check the healthz/livez/readyz of the API server should rely on the HTTP status code.
A status code 200 indicates the API server is healthy/live/ready, depending on the called endpoint.
The more verbose options shown below are intended to be used by human operators to debug their cluster or understand the state of the API server.
The following examples will show how you can interact with the health API endpoints.
For all endpoints, you can use the verbose parameter to print out the checks and their status.
This can be useful for a human operator to debug the current status of the API server, it is not intended to be consumed by a machine:
curl -k https://localhost:6443/livez?verbose
or from a remote host with authentication:
kubectl get --raw='/readyz?verbose'
The output will look like this:
[+]ping ok
[+]log ok
[+]etcd ok
[+]poststarthook/start-kube-apiserver-admission-initializer ok
[+]poststarthook/generic-apiserver-start-informers ok
[+]poststarthook/start-apiextensions-informers ok
[+]poststarthook/start-apiextensions-controllers ok
[+]poststarthook/crd-informer-synced ok
[+]poststarthook/bootstrap-controller ok
[+]poststarthook/rbac/bootstrap-roles ok
[+]poststarthook/scheduling/bootstrap-system-priority-classes ok
[+]poststarthook/start-cluster-authentication-info-controller ok
[+]poststarthook/start-kube-aggregator-informers ok
[+]poststarthook/apiservice-registration-controller ok
[+]poststarthook/apiservice-status-available-controller ok
[+]poststarthook/kube-apiserver-autoregistration ok
[+]autoregister-completion ok
[+]poststarthook/apiservice-openapi-controller ok
healthz check passed
The Kubernetes API server also supports to exclude specific checks.
The query parameters can also be combined like in this example:
[+]ping ok
[+]log ok
[+]etcd excluded: ok
[+]poststarthook/start-kube-apiserver-admission-initializer ok
[+]poststarthook/generic-apiserver-start-informers ok
[+]poststarthook/start-apiextensions-informers ok
[+]poststarthook/start-apiextensions-controllers ok
[+]poststarthook/crd-informer-synced ok
[+]poststarthook/bootstrap-controller ok
[+]poststarthook/rbac/bootstrap-roles ok
[+]poststarthook/scheduling/bootstrap-system-priority-classes ok
[+]poststarthook/start-cluster-authentication-info-controller ok
[+]poststarthook/start-kube-aggregator-informers ok
[+]poststarthook/apiservice-registration-controller ok
[+]poststarthook/apiservice-status-available-controller ok
[+]poststarthook/kube-apiserver-autoregistration ok
[+]autoregister-completion ok
[+]poststarthook/apiservice-openapi-controller ok
[+]shutdown ok
healthz check passed
Individual health checks
FEATURE STATE:Kubernetes v1.28 [alpha]
Each individual health check exposes an HTTP endpoint and can be checked individually.
The schema for the individual health checks is /livez/<healthcheck-name> where livez and readyz and be used to indicate if you want to check the liveness or the readiness of the API server.
The <healthcheck-name> path can be discovered using the verbose flag from above and take the path between [+] and ok.
These individual health checks should not be consumed by machines but can be helpful for a human operator to debug a system:
All Kubernetes clusters have two categories of users: service accounts managed
by Kubernetes, and normal users.
It is assumed that a cluster-independent service manages normal users in the following ways:
an administrator distributing private keys
a user store like Keystone or Google Accounts
a file with a list of usernames and passwords
In this regard, Kubernetes does not have objects which represent normal user
accounts. Normal users cannot be added to a cluster through an API call.
Even though a normal user cannot be added via an API call, any user that
presents a valid certificate signed by the cluster's certificate authority
(CA) is considered authenticated. In this configuration, Kubernetes determines
the username from the common name field in the 'subject' of the cert (e.g.,
"/CN=bob"). From there, the role based access control (RBAC) sub-system would
determine whether the user is authorized to perform a specific operation on a
resource. For more details, refer to the normal users topic in
certificate request
for more details about this.
In contrast, service accounts are users managed by the Kubernetes API. They are
bound to specific namespaces, and created automatically by the API server or
manually through API calls. Service accounts are tied to a set of credentials
stored as Secrets, which are mounted into pods allowing in-cluster processes
to talk to the Kubernetes API.
API requests are tied to either a normal user or a service account, or are treated
as anonymous requests. This means every process inside or outside the cluster, from
a human user typing kubectl on a workstation, to kubelets on nodes, to members
of the control plane, must authenticate when making requests to the API server,
or be treated as an anonymous user.
Authentication strategies
Kubernetes uses client certificates, bearer tokens, or an authenticating proxy to
authenticate API requests through authentication plugins. As HTTP requests are
made to the API server, plugins attempt to associate the following attributes
with the request:
Username: a string which identifies the end user. Common values might be kube-admin or jane@example.com.
UID: a string which identifies the end user and attempts to be more consistent and unique than username.
Groups: a set of strings, each of which indicates the user's membership in a named logical collection of users.
Common values might be system:masters or devops-team.
Extra fields: a map of strings to list of strings which holds additional information authorizers may find useful.
All values are opaque to the authentication system and only hold significance
when interpreted by an authorizer.
You can enable multiple authentication methods at once. You should usually use at least two methods:
service account tokens for service accounts
at least one other method for user authentication.
When multiple authenticator modules are enabled, the first module
to successfully authenticate the request short-circuits evaluation.
The API server does not guarantee the order authenticators run in.
The system:authenticated group is included in the list of groups for all authenticated users.
Integrations with other authentication protocols (LDAP, SAML, Kerberos, alternate x509 schemes, etc)
can be accomplished using an authenticating proxy or the
authentication webhook.
X509 client certificates
Client certificate authentication is enabled by passing the --client-ca-file=SOMEFILE
option to API server. The referenced file must contain one or more certificate authorities
to use to validate client certificates presented to the API server. If a client certificate
is presented and verified, the common name of the subject is used as the user name for the
request. As of Kubernetes 1.4, client certificates can also indicate a user's group memberships
using the certificate's organization fields. To include multiple group memberships for a user,
include multiple organization fields in the certificate.
For example, using the openssl command line tool to generate a certificate signing request:
The API server reads bearer tokens from a file when given the --token-auth-file=SOMEFILE option
on the command line. Currently, tokens last indefinitely, and the token list cannot be
changed without restarting the API server.
The token file is a csv file with a minimum of 3 columns: token, user name, user uid,
followed by optional group names.
Note:
If you have more than one group the column must be double quoted e.g.
token,user,uid,"group1,group2,group3"
Putting a bearer token in a request
When using bearer token authentication from an http client, the API
server expects an Authorization header with a value of Bearer <token>. The bearer token must be a character sequence that can be
put in an HTTP header value using no more than the encoding and
quoting facilities of HTTP. For example: if the bearer token is
31ada4fd-adec-460c-809a-9e56ceb75269 then it would appear in an HTTP
header as shown below.
To allow for streamlined bootstrapping for new clusters, Kubernetes includes a
dynamically-managed Bearer token type called a Bootstrap Token. These tokens
are stored as Secrets in the kube-system namespace, where they can be
dynamically managed and created. Controller Manager contains a TokenCleaner
controller that deletes bootstrap tokens as they expire.
The tokens are of the form [a-z0-9]{6}.[a-z0-9]{16}. The first component is a
Token ID and the second component is the Token Secret. You specify the token
in an HTTP header as follows:
Authorization: Bearer 781292.db7bc3a58fc5f07e
You must enable the Bootstrap Token Authenticator with the
--enable-bootstrap-token-auth flag on the API Server. You must enable
the TokenCleaner controller via the --controllers flag on the Controller
Manager. This is done with something like --controllers=*,tokencleaner.
kubeadm will do this for you if you are using it to bootstrap a cluster.
The authenticator authenticates as system:bootstrap:<Token ID>. It is
included in the system:bootstrappers group. The naming and groups are
intentionally limited to discourage users from using these tokens past
bootstrapping. The user names and group can be used (and are used by kubeadm)
to craft the appropriate authorization policies to support bootstrapping a
cluster.
Please see Bootstrap Tokens for in depth
documentation on the Bootstrap Token authenticator and controllers along with
how to manage these tokens with kubeadm.
Service account tokens
A service account is an automatically enabled authenticator that uses signed
bearer tokens to verify requests. The plugin takes two optional flags:
--service-account-key-file File containing PEM-encoded x509 RSA or ECDSA
private or public keys, used to verify ServiceAccount tokens. The specified file
can contain multiple keys, and the flag can be specified multiple times with
different files. If unspecified, --tls-private-key-file is used.
--service-account-lookup If enabled, tokens which are deleted from the API will be revoked.
Service accounts are usually created automatically by the API server and
associated with pods running in the cluster through the ServiceAccountAdmission Controller. Bearer tokens are
mounted into pods at well-known locations, and allow in-cluster processes to
talk to the API server. Accounts may be explicitly associated with pods using the
serviceAccountName field of a PodSpec.
Note:serviceAccountName is usually omitted because this is done automatically.
apiVersion:apps/v1# this apiVersion is relevant as of Kubernetes 1.9kind:Deploymentmetadata:name:nginx-deploymentnamespace:defaultspec:replicas:3template:metadata:# ...spec:serviceAccountName:bob-the-botcontainers:- name:nginximage:nginx:1.14.2
Service account bearer tokens are perfectly valid to use outside the cluster and
can be used to create identities for long standing jobs that wish to talk to the
Kubernetes API. To manually create a service account, use the kubectl create serviceaccount (NAME) command. This creates a service account in the current
namespace.
kubectl create serviceaccount jenkins
serviceaccount/jenkins created
Create an associated token:
kubectl create token jenkins
eyJhbGciOiJSUzI1NiIsImtp...
The created token is a signed JSON Web Token (JWT).
The signed JWT can be used as a bearer token to authenticate as the given service
account. See above for how the token is included
in a request. Normally these tokens are mounted into pods for in-cluster access to
the API server, but can be used from outside the cluster as well.
Service accounts authenticate with the username system:serviceaccount:(NAMESPACE):(SERVICEACCOUNT),
and are assigned to the groups system:serviceaccounts and system:serviceaccounts:(NAMESPACE).
Warning: Because service account tokens can also be stored in Secret API objects, any user with
write access to Secrets can request a token, and any user with read access to those
Secrets can authenticate as the service account. Be cautious when granting permissions
to service accounts and read or write capabilities for Secrets.
OpenID Connect Tokens
OpenID Connect is a flavor of OAuth2 supported by
some OAuth2 providers, notably Azure Active Directory, Salesforce, and Google.
The protocol's main extension of OAuth2 is an additional field returned with
the access token called an ID Token.
This token is a JSON Web Token (JWT) with well known fields, such as a user's
email, signed by the server.
To identify the user, the authenticator uses the id_token (not the access_token)
from the OAuth2 token response
as a bearer token. See above for how the token
is included in a request.
sequenceDiagram
participant user as User
participant idp as Identity Provider
participant kube as Kubectl
participant api as API Server
user ->> idp: 1. Log in to IdP
activate idp
idp -->> user: 2. Provide access_token, id_token, and refresh_token
deactivate idp
activate user
user ->> kube: 3. Call Kubectl with --token being the id_token OR add tokens to .kube/config
deactivate user
activate kube
kube ->> api: 4. Authorization: Bearer...
deactivate kube
activate api
api ->> api: 5. Is JWT signature valid?
api ->> api: 6. Has the JWT expired? (iat+exp)
api ->> api: 7. User authorized?
api -->> kube: 8. Authorized: Perform action and return result
deactivate api
activate kube
kube --x user: 9. Return result
deactivate kube
Log in to your identity provider
Your identity provider will provide you with an access_token, id_token and a refresh_token
When using kubectl, use your id_token with the --token flag or add it directly to your kubeconfig
kubectl sends your id_token in a header called Authorization to the API server
The API server will make sure the JWT signature is valid by checking against the certificate named in the configuration
Check to make sure the id_token hasn't expired
Make sure the user is authorized
Once authorized the API server returns a response to kubectl
kubectl provides feedback to the user
Since all of the data needed to validate who you are is in the id_token, Kubernetes doesn't need to
"phone home" to the identity provider. In a model where every request is stateless this provides a
very scalable solution for authentication. It does offer a few challenges:
Kubernetes has no "web interface" to trigger the authentication process. There is no browser or
interface to collect credentials which is why you need to authenticate to your identity provider first.
The id_token can't be revoked, it's like a certificate so it should be short-lived (only a few minutes)
so it can be very annoying to have to get a new token every few minutes.
To authenticate to the Kubernetes dashboard, you must use the kubectl proxy command or a reverse proxy
that injects the id_token.
Configuring the API Server
To enable the plugin, configure the following flags on the API server:
Parameter
Description
Example
Required
--oidc-issuer-url
URL of the provider that allows the API server to discover public signing keys. Only URLs that use the https:// scheme are accepted. This is typically the provider's discovery URL, changed to have an empty path
If the issuer's OIDC discovery URL is https://accounts.provider.example/.well-known/openid-configuration, the value should be https://accounts.provider.example
Yes
--oidc-client-id
A client id that all tokens must be issued for.
kubernetes
Yes
--oidc-username-claim
JWT claim to use as the user name. By default sub, which is expected to be a unique identifier of the end user. Admins can choose other claims, such as email or name, depending on their provider. However, claims other than email will be prefixed with the issuer URL to prevent naming clashes with other plugins.
sub
No
--oidc-username-prefix
Prefix prepended to username claims to prevent clashes with existing names (such as system: users). For example, the value oidc: will create usernames like oidc:jane.doe. If this flag isn't provided and --oidc-username-claim is a value other than email the prefix defaults to ( Issuer URL )# where ( Issuer URL ) is the value of --oidc-issuer-url. The value - can be used to disable all prefixing.
oidc:
No
--oidc-groups-claim
JWT claim to use as the user's group. If the claim is present it must be an array of strings.
groups
No
--oidc-groups-prefix
Prefix prepended to group claims to prevent clashes with existing names (such as system: groups). For example, the value oidc: will create group names like oidc:engineering and oidc:infra.
oidc:
No
--oidc-required-claim
A key=value pair that describes a required claim in the ID Token. If set, the claim is verified to be present in the ID Token with a matching value. Repeat this flag to specify multiple claims.
claim=value
No
--oidc-ca-file
The path to the certificate for the CA that signed your identity provider's web certificate. Defaults to the host's root CAs.
/etc/kubernetes/ssl/kc-ca.pem
No
--oidc-signing-algs
The signing algorithms accepted. Default is "RS256".
RS512
No
Importantly, the API server is not an OAuth2 client, rather it can only be
configured to trust a single issuer. This allows the use of public providers,
such as Google, without trusting credentials issued to third parties. Admins who
wish to utilize multiple OAuth clients should explore providers which support the
azp (authorized party) claim, a mechanism for allowing one client to issue
tokens on behalf of another.
Kubernetes does not provide an OpenID Connect Identity Provider.
You can use an existing public OpenID Connect Identity Provider (such as Google, or
others).
Or, you can run your own Identity Provider, such as dex,
Keycloak,
CloudFoundry UAA, or
Tremolo Security's OpenUnison.
For an identity provider to work with Kubernetes it must:
Have a CA signed certificate (even if the CA is not a commercial CA or is self signed)
A note about requirement #3 above, requiring a CA signed certificate. If you deploy your own
identity provider (as opposed to one of the cloud providers like Google or Microsoft) you MUST
have your identity provider's web server certificate signed by a certificate with the CA flag
set to TRUE, even if it is self signed. This is due to GoLang's TLS client implementation
being very strict to the standards around certificate validation. If you don't have a CA handy,
you can use the gencert script
from the Dex team to create a simple CA and a signed certificate and key pair. Or you can use
this similar script
that generates SHA256 certs with a longer life and larger key size.
The first option is to use the kubectl oidc authenticator, which sets the id_token as a bearer token
for all requests and refreshes the token once it expires. After you've logged into your provider, use
kubectl to add your id_token, refresh_token, client_id, and client_secret to configure the plugin.
Providers that don't return an id_token as part of their refresh token response aren't supported
by this plugin and should use "Option 2" below.
kubectl config set-credentials USER_NAME \
--auth-provider=oidc \
--auth-provider-arg=idp-issuer-url=( issuer url )\
--auth-provider-arg=client-id=( your client id )\
--auth-provider-arg=client-secret=( your client secret )\
--auth-provider-arg=refresh-token=( your refresh token )\
--auth-provider-arg=idp-certificate-authority=( path to your ca certificate )\
--auth-provider-arg=id-token=( your id_token )
As an example, running the below command after authenticating to your identity provider:
Once your id_token expires, kubectl will attempt to refresh your id_token using your refresh_token
and client_secret storing the new values for the refresh_token and id_token in your .kube/config.
Option 2 - Use the --token Option
The kubectl command lets you pass in a token using the --token option. Copy and paste the id_token into this option:
kubectl --token=eyJhbGciOiJSUzI1NiJ9.eyJpc3MiOiJodHRwczovL21sYi50cmVtb2xvLmxhbjo4MDQzL2F1dGgvaWRwL29pZGMiLCJhdWQiOiJrdWJlcm5ldGVzIiwiZXhwIjoxNDc0NTk2NjY5LCJqdGkiOiI2RDUzNXoxUEpFNjJOR3QxaWVyYm9RIiwiaWF0IjoxNDc0NTk2MzY5LCJuYmYiOjE0NzQ1OTYyNDksInN1YiI6Im13aW5kdSIsInVzZXJfcm9sZSI6WyJ1c2VycyIsIm5ldy1uYW1lc3BhY2Utdmlld2VyIl0sImVtYWlsIjoibXdpbmR1QG5vbW9yZWplZGkuY29tIn0.f2As579n9VNoaKzoF-dOQGmXkFKf1FMyNV0-va_B63jn-_n9LGSCca_6IVMP8pO-Zb4KvRqGyTP0r3HkHxYy5c81AnIh8ijarruczl-TK_yF5akjSTHFZD-0gRzlevBDiH8Q79NAr-ky0P4iIXS8lY9Vnjch5MF74Zx0c3alKJHJUnnpjIACByfF2SCaYzbWFMUNat-K1PaUk5-ujMBG7yYnr95xD-63n8CO8teGUAAEMx6zRjzfhnhbzX-ajwZLGwGUBT4WqjMs70-6a7_8gZmLZb2az1cZynkFRj2BaCkVT3A2RrjeEwZEtGXlMqKJ1_I2ulrOVsYx01_yD35-rw get nodes
Webhook Token Authentication
Webhook authentication is a hook for verifying bearer tokens.
--authentication-token-webhook-config-file a configuration file describing how to access the remote webhook service.
--authentication-token-webhook-cache-ttl how long to cache authentication decisions. Defaults to two minutes.
--authentication-token-webhook-version determines whether to use authentication.k8s.io/v1beta1 or authentication.k8s.io/v1TokenReview objects to send/receive information from the webhook. Defaults to v1beta1.
The configuration file uses the kubeconfig
file format. Within the file, clusters refers to the remote service and
users refers to the API server webhook. An example would be:
# Kubernetes API versionapiVersion:v1# kind of the API objectkind:Config# clusters refers to the remote service.clusters:- name:name-of-remote-authn-servicecluster:certificate-authority:/path/to/ca.pem # CA for verifying the remote service.server:https://authn.example.com/authenticate# URL of remote service to query. 'https' recommended for production.# users refers to the API server's webhook configuration.users:- name:name-of-api-serveruser:client-certificate:/path/to/cert.pem# cert for the webhook plugin to useclient-key:/path/to/key.pem # key matching the cert# kubeconfig files require a context. Provide one for the API server.current-context:webhookcontexts:- context:cluster:name-of-remote-authn-serviceuser:name-of-api-servername:webhook
When a client attempts to authenticate with the API server using a bearer token as discussed
above, the authentication webhook POSTs a JSON-serialized
TokenReview object containing the token to the remote service.
Note that webhook API objects are subject to the same versioning compatibility rules
as other Kubernetes API objects. Implementers should check the apiVersion field of the request to ensure correct deserialization,
and must respond with a TokenReview object of the same version as the request.
Note: The Kubernetes API server defaults to sending authentication.k8s.io/v1beta1 token reviews for backwards compatibility.
To opt into receiving authentication.k8s.io/v1 token reviews, the API server must be started with --authentication-token-webhook-version=v1.
{"apiVersion": "authentication.k8s.io/v1","kind": "TokenReview","spec": {# Opaque bearer token sent to the API server"token": "014fbff9a07c...",# Optional list of the audience identifiers for the server the token was presented to.# Audience-aware token authenticators (for example, OIDC token authenticators) # should verify the token was intended for at least one of the audiences in this list,# and return the intersection of this list and the valid audiences for the token in the response status.# This ensures the token is valid to authenticate to the server it was presented to.# If no audiences are provided, the token should be validated to authenticate to the Kubernetes API server."audiences": ["https://myserver.example.com","https://myserver.internal.example.com"]}}
{"apiVersion": "authentication.k8s.io/v1beta1","kind": "TokenReview","spec": {# Opaque bearer token sent to the API server"token": "014fbff9a07c...",# Optional list of the audience identifiers for the server the token was presented to.# Audience-aware token authenticators (for example, OIDC token authenticators) # should verify the token was intended for at least one of the audiences in this list,# and return the intersection of this list and the valid audiences for the token in the response status.# This ensures the token is valid to authenticate to the server it was presented to.# If no audiences are provided, the token should be validated to authenticate to the Kubernetes API server."audiences": ["https://myserver.example.com","https://myserver.internal.example.com"]}}
The remote service is expected to fill the status field of the request to indicate the success of the login.
The response body's spec field is ignored and may be omitted.
The remote service must return a response using the same TokenReview API version that it received.
A successful validation of the bearer token would return:
{"apiVersion": "authentication.k8s.io/v1","kind": "TokenReview","status": {"authenticated": true,"user": {# Required"username": "janedoe@example.com",# Optional"uid": "42",# Optional group memberships"groups": ["developers","qa"],# Optional additional information provided by the authenticator.# This should not contain confidential data, as it can be recorded in logs# or API objects, and is made available to admission webhooks."extra": {"extrafield1": ["extravalue1","extravalue2"]}},# Optional list audience-aware token authenticators can return,# containing the audiences from the `spec.audiences` list for which the provided token was valid.# If this is omitted, the token is considered to be valid to authenticate to the Kubernetes API server."audiences": ["https://myserver.example.com"]}}
{"apiVersion": "authentication.k8s.io/v1beta1","kind": "TokenReview","status": {"authenticated": true,"user": {# Required"username": "janedoe@example.com",# Optional"uid": "42",# Optional group memberships"groups": ["developers","qa"],# Optional additional information provided by the authenticator.# This should not contain confidential data, as it can be recorded in logs# or API objects, and is made available to admission webhooks."extra": {"extrafield1": ["extravalue1","extravalue2"]}},# Optional list audience-aware token authenticators can return,# containing the audiences from the `spec.audiences` list for which the provided token was valid.# If this is omitted, the token is considered to be valid to authenticate to the Kubernetes API server."audiences": ["https://myserver.example.com"]}}
{"apiVersion": "authentication.k8s.io/v1","kind": "TokenReview","status": {"authenticated": false,# Optionally include details about why authentication failed.# If no error is provided, the API will return a generic Unauthorized message.# The error field is ignored when authenticated=true."error": "Credentials are expired"}}
{"apiVersion": "authentication.k8s.io/v1beta1","kind": "TokenReview","status": {"authenticated": false,# Optionally include details about why authentication failed.# If no error is provided, the API will return a generic Unauthorized message.# The error field is ignored when authenticated=true."error": "Credentials are expired"}}
Authenticating Proxy
The API server can be configured to identify users from request header values, such as X-Remote-User.
It is designed for use in combination with an authenticating proxy, which sets the request header value.
--requestheader-username-headers Required, case-insensitive. Header names to check, in order,
for the user identity. The first header containing a value is used as the username.
--requestheader-group-headers 1.6+. Optional, case-insensitive. "X-Remote-Group" is suggested.
Header names to check, in order, for the user's groups. All values in all specified headers are used as group names.
--requestheader-extra-headers-prefix 1.6+. Optional, case-insensitive. "X-Remote-Extra-" is suggested.
Header prefixes to look for to determine extra information about the user (typically used by the configured authorization plugin).
Any headers beginning with any of the specified prefixes have the prefix removed.
The remainder of the header name is lowercased and percent-decoded
and becomes the extra key, and the header value is the extra value.
Note: Prior to 1.11.3 (and 1.10.7, 1.9.11), the extra key could only contain characters which
were legal in HTTP header labels.
In order to prevent header spoofing, the authenticating proxy is required to present a valid client
certificate to the API server for validation against the specified CA before the request headers are
checked. WARNING: do not reuse a CA that is used in a different context unless you understand
the risks and the mechanisms to protect the CA's usage.
--requestheader-client-ca-file Required. PEM-encoded certificate bundle. A valid client certificate
must be presented and validated against the certificate authorities in the specified file before the
request headers are checked for user names.
--requestheader-allowed-names Optional. List of Common Name values (CNs). If set, a valid client
certificate with a CN in the specified list must be presented before the request headers are checked
for user names. If empty, any CN is allowed.
Anonymous requests
When enabled, requests that are not rejected by other configured authentication methods are
treated as anonymous requests, and given a username of system:anonymous and a group of
system:unauthenticated.
For example, on a server with token authentication configured, and anonymous access enabled,
a request providing an invalid bearer token would receive a 401 Unauthorized error.
A request providing no bearer token would be treated as an anonymous request.
In 1.5.1-1.5.x, anonymous access is disabled by default, and can be enabled by
passing the --anonymous-auth=true option to the API server.
In 1.6+, anonymous access is enabled by default if an authorization mode other than AlwaysAllow
is used, and can be disabled by passing the --anonymous-auth=false option to the API server.
Starting in 1.6, the ABAC and RBAC authorizers require explicit authorization of the
system:anonymous user or the system:unauthenticated group, so legacy policy rules
that grant access to the * user or * group do not include anonymous users.
User impersonation
A user can act as another user through impersonation headers. These let requests
manually override the user info a request authenticates as. For example, an admin
could use this feature to debug an authorization policy by temporarily
impersonating another user and seeing if a request was denied.
Impersonation requests first authenticate as the requesting user, then switch
to the impersonated user info.
A user makes an API call with their credentials and impersonation headers.
API server authenticates the user.
API server ensures the authenticated users have impersonation privileges.
Request user info is replaced with impersonation values.
Request is evaluated, authorization acts on impersonated user info.
The following HTTP headers can be used to performing an impersonation request:
Impersonate-User: The username to act as.
Impersonate-Group: A group name to act as. Can be provided multiple times to set multiple groups.
Optional. Requires "Impersonate-User".
Impersonate-Extra-( extra name ): A dynamic header used to associate extra fields with the user.
Optional. Requires "Impersonate-User". In order to be preserved consistently, ( extra name )
must be lower-case, and any characters which aren't legal in HTTP header labels
MUST be utf8 and percent-encoded.
Impersonate-Uid: A unique identifier that represents the user being impersonated. Optional.
Requires "Impersonate-User". Kubernetes does not impose any format requirements on this string.
Note: Prior to 1.11.3 (and 1.10.7, 1.9.11), ( extra name ) could only contain characters which
were legal in HTTP header labels.
Note:Impersonate-Uid is only available in versions 1.22.0 and higher.
An example of the impersonation headers used when impersonating a user with groups:
Note:kubectl cannot impersonate extra fields or UIDs.
To impersonate a user, group, user identifier (UID) or extra fields, the impersonating user must
have the ability to perform the "impersonate" verb on the kind of attribute
being impersonated ("user", "group", "uid", etc.). For clusters that enable the RBAC
authorization plugin, the following ClusterRole encompasses the rules needed to
set user and group impersonation headers:
For impersonation, extra fields and impersonated UIDs are both under the "authentication.k8s.io" apiGroup.
Extra fields are evaluated as sub-resources of the resource "userextras". To
allow a user to use impersonation headers for the extra field "scopes" and
for UIDs, a user should be granted the following role:
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:scopes-and-uid-impersonatorrules:# Can set "Impersonate-Extra-scopes" header and the "Impersonate-Uid" header.- apiGroups:["authentication.k8s.io"]resources:["userextras/scopes","uids"]verbs:["impersonate"]
The values of impersonation headers can also be restricted by limiting the set
of resourceNames a resource can take.
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:limited-impersonatorrules:# Can impersonate the user "jane.doe@example.com"- apiGroups:[""]resources:["users"]verbs:["impersonate"]resourceNames:["jane.doe@example.com"]# Can impersonate the groups "developers" and "admins"- apiGroups:[""]resources:["groups"]verbs:["impersonate"]resourceNames:["developers","admins"]# Can impersonate the extras field "scopes" with the values "view" and "development"- apiGroups:["authentication.k8s.io"]resources:["userextras/scopes"]verbs:["impersonate"]resourceNames:["view","development"]# Can impersonate the uid "06f6ce97-e2c5-4ab8-7ba5-7654dd08d52b"- apiGroups:["authentication.k8s.io"]resources:["uids"]verbs:["impersonate"]resourceNames:["06f6ce97-e2c5-4ab8-7ba5-7654dd08d52b"]
Note: Impersonating a user or group allows you to perform any action as if you were that user or group;
for that reason, impersonation is not namespace scoped.
If you want to allow impersonation using Kubernetes RBAC,
this requires using a ClusterRole and a ClusterRoleBinding,
not a Role and RoleBinding.
client-go credential plugins
FEATURE STATE:Kubernetes v1.22 [stable]
k8s.io/client-go and tools using it such as kubectl and kubelet are able to execute an
external command to receive user credentials.
This feature is intended for client side integrations with authentication protocols not natively
supported by k8s.io/client-go (LDAP, Kerberos, OAuth2, SAML, etc.). The plugin implements the
protocol specific logic, then returns opaque credentials to use. Almost all credential plugin
use cases require a server side component with support for the webhook token authenticator
to interpret the credential format produced by the client plugin.
Example use case
In a hypothetical use case, an organization would run an external service that exchanges LDAP credentials
for user specific, signed tokens. The service would also be capable of responding to webhook token
authenticator requests to validate the tokens. Users would be required
to install a credential plugin on their workstation.
To authenticate against the API:
The user issues a kubectl command.
Credential plugin prompts the user for LDAP credentials, exchanges credentials with external service for a token.
Credential plugin returns token to client-go, which uses it as a bearer token against the API server.
apiVersion:v1kind:Configusers:- name:my-useruser:exec:# Command to execute. Required.command:"example-client-go-exec-plugin"# API version to use when decoding the ExecCredentials resource. Required.## The API version returned by the plugin MUST match the version listed here.## To integrate with tools that support multiple versions (such as client.authentication.k8s.io/v1beta1),# set an environment variable, pass an argument to the tool that indicates which version the exec plugin expects,# or read the version from the ExecCredential object in the KUBERNETES_EXEC_INFO environment variable.apiVersion:"client.authentication.k8s.io/v1"# Environment variables to set when executing the plugin. Optional.env:- name:"FOO"value:"bar"# Arguments to pass when executing the plugin. Optional.args:- "arg1"- "arg2"# Text shown to the user when the executable doesn't seem to be present. Optional.installHint:| example-client-go-exec-plugin is required to authenticate
to the current cluster. It can be installed:
On macOS: brew install example-client-go-exec-plugin
On Ubuntu: apt-get install example-client-go-exec-plugin
On Fedora: dnf install example-client-go-exec-plugin
...# Whether or not to provide cluster information, which could potentially contain# very large CA data, to this exec plugin as a part of the KUBERNETES_EXEC_INFO# environment variable.provideClusterInfo:true# The contract between the exec plugin and the standard input I/O stream. If the# contract cannot be satisfied, this plugin will not be run and an error will be# returned. Valid values are "Never" (this exec plugin never uses standard input),# "IfAvailable" (this exec plugin wants to use standard input if it is available),# or "Always" (this exec plugin requires standard input to function). Required.interactiveMode:Neverclusters:- name:my-clustercluster:server:"https://172.17.4.100:6443"certificate-authority:"/etc/kubernetes/ca.pem"extensions:- name:client.authentication.k8s.io/exec# reserved extension name for per cluster exec configextension:arbitrary:configthis:can be provided via the KUBERNETES_EXEC_INFO environment variable upon setting provideClusterInfoyou:["can","put","anything","here"]contexts:- name:my-clustercontext:cluster:my-clusteruser:my-usercurrent-context:my-cluster
apiVersion:v1kind:Configusers:- name:my-useruser:exec:# Command to execute. Required.command:"example-client-go-exec-plugin"# API version to use when decoding the ExecCredentials resource. Required.## The API version returned by the plugin MUST match the version listed here.## To integrate with tools that support multiple versions (such as client.authentication.k8s.io/v1),# set an environment variable, pass an argument to the tool that indicates which version the exec plugin expects,# or read the version from the ExecCredential object in the KUBERNETES_EXEC_INFO environment variable.apiVersion:"client.authentication.k8s.io/v1beta1"# Environment variables to set when executing the plugin. Optional.env:- name:"FOO"value:"bar"# Arguments to pass when executing the plugin. Optional.args:- "arg1"- "arg2"# Text shown to the user when the executable doesn't seem to be present. Optional.installHint:| example-client-go-exec-plugin is required to authenticate
to the current cluster. It can be installed:
On macOS: brew install example-client-go-exec-plugin
On Ubuntu: apt-get install example-client-go-exec-plugin
On Fedora: dnf install example-client-go-exec-plugin
...# Whether or not to provide cluster information, which could potentially contain# very large CA data, to this exec plugin as a part of the KUBERNETES_EXEC_INFO# environment variable.provideClusterInfo:true# The contract between the exec plugin and the standard input I/O stream. If the# contract cannot be satisfied, this plugin will not be run and an error will be# returned. Valid values are "Never" (this exec plugin never uses standard input),# "IfAvailable" (this exec plugin wants to use standard input if it is available),# or "Always" (this exec plugin requires standard input to function). Optional.# Defaults to "IfAvailable".interactiveMode:Neverclusters:- name:my-clustercluster:server:"https://172.17.4.100:6443"certificate-authority:"/etc/kubernetes/ca.pem"extensions:- name:client.authentication.k8s.io/exec# reserved extension name for per cluster exec configextension:arbitrary:configthis:can be provided via the KUBERNETES_EXEC_INFO environment variable upon setting provideClusterInfoyou:["can","put","anything","here"]contexts:- name:my-clustercontext:cluster:my-clusteruser:my-usercurrent-context:my-cluster
Relative command paths are interpreted as relative to the directory of the config file. If
KUBECONFIG is set to /home/jane/kubeconfig and the exec command is ./bin/example-client-go-exec-plugin,
the binary /home/jane/bin/example-client-go-exec-plugin is executed.
- name:my-useruser:exec:# Path relative to the directory of the kubeconfigcommand:"./bin/example-client-go-exec-plugin"apiVersion:"client.authentication.k8s.io/v1"interactiveMode:Never
Input and output formats
The executed command prints an ExecCredential object to stdout. k8s.io/client-go
authenticates against the Kubernetes API using the returned credentials in the status.
The executed command is passed an ExecCredential object as input via the KUBERNETES_EXEC_INFO
environment variable. This input contains helpful information like the expected API version
of the returned ExecCredential object and whether or not the plugin can use stdin to interact
with the user.
When run from an interactive session (i.e., a terminal), stdin can be exposed directly
to the plugin. Plugins should use the spec.interactive field of the input
ExecCredential object from the KUBERNETES_EXEC_INFO environment variable in order to
determine if stdin has been provided. A plugin's stdin requirements (i.e., whether
stdin is optional, strictly required, or never used in order for the plugin
to run successfully) is declared via the user.exec.interactiveMode field in the
kubeconfig (see table
below for valid values). The user.exec.interactiveMode field is optional in client.authentication.k8s.io/v1beta1
and required in client.authentication.k8s.io/v1.
interactiveMode values
interactiveMode Value
Meaning
Never
This exec plugin never needs to use standard input, and therefore the exec plugin will be run regardless of whether standard input is available for user input.
IfAvailable
This exec plugin would like to use standard input if it is available, but can still operate if standard input is not available. Therefore, the exec plugin will be run regardless of whether stdin is available for user input. If standard input is available for user input, then it will be provided to this exec plugin.
Always
This exec plugin requires standard input in order to run, and therefore the exec plugin will only be run if standard input is available for user input. If standard input is not available for user input, then the exec plugin will not be run and an error will be returned by the exec plugin runner.
To use bearer token credentials, the plugin returns a token in the status of the
ExecCredential
Alternatively, a PEM-encoded client certificate and key can be returned to use TLS client auth.
If the plugin returns a different certificate and key on a subsequent call, k8s.io/client-go
will close existing connections with the server to force a new TLS handshake.
If specified, clientKeyData and clientCertificateData must both must be present.
clientCertificateData may contain additional intermediate certificates to send to the server.
Optionally, the response can include the expiry of the credential formatted as a
RFC 3339 timestamp.
Presence or absence of an expiry has the following impact:
If an expiry is included, the bearer token and TLS credentials are cached until
the expiry time is reached, or if the server responds with a 401 HTTP status code,
or when the process exits.
If an expiry is omitted, the bearer token and TLS credentials are cached until
the server responds with a 401 HTTP status code or until the process exits.
To enable the exec plugin to obtain cluster-specific information, set provideClusterInfo on the user.exec
field in the kubeconfig.
The plugin will then be supplied this cluster-specific information in the KUBERNETES_EXEC_INFO environment variable.
Information from this environment variable can be used to perform cluster-specific
credential acquisition logic.
The following ExecCredential manifest describes a cluster information sample.
{
"apiVersion": "client.authentication.k8s.io/v1",
"kind": "ExecCredential",
"spec": {
"cluster": {
"server": "https://172.17.4.100:6443",
"certificate-authority-data": "LS0t...",
"config": {
"arbitrary": "config",
"this": "can be provided via the KUBERNETES_EXEC_INFO environment variable upon setting provideClusterInfo",
"you": ["can", "put", "anything", "here"]
}
},
"interactive": true }
}
{
"apiVersion": "client.authentication.k8s.io/v1beta1",
"kind": "ExecCredential",
"spec": {
"cluster": {
"server": "https://172.17.4.100:6443",
"certificate-authority-data": "LS0t...",
"config": {
"arbitrary": "config",
"this": "can be provided via the KUBERNETES_EXEC_INFO environment variable upon setting provideClusterInfo",
"you": ["can", "put", "anything", "here"]
}
},
"interactive": true }
}
API access to authentication information for a client
FEATURE STATE:Kubernetes v1.28 [stable]
If your cluster has the API enabled, you can use the SelfSubjectReview API to find out
how your Kubernetes cluster maps your authentication information to identify you as a client.
This works whether you are authenticating as a user (typically representing
a real person) or as a ServiceAccount.
SelfSubjectReview objects do not have any configurable fields. On receiving a request,
the Kubernetes API server fills the status with the user attributes and returns it to the user.
Request example (the body would be a SelfSubjectReview):
POST /apis/authentication.k8s.io/v1/selfsubjectreviews
For convenience, the kubectl auth whoami command is present. Executing this command will
produce the following output (yet different user attributes will be shown):
Simple output example
ATTRIBUTE VALUE
Username jane.doe
Groups [system:authenticated]
Complex example including extra attributes
ATTRIBUTE VALUE
Username jane.doe
UID b79dbf30-0c6a-11ed-861d-0242ac120002
Groups [students teachers system:authenticated]
Extra: skills [reading learning]
Extra: subjects [math sports]
By providing the output flag, it is also possible to print the JSON or YAML representation of the result:
Note: The Kubernetes API server fills the userInfo after all authentication mechanisms are applied,
including impersonation.
If you, or an authentication proxy, make a SelfSubjectReview using impersonation,
you see the user details and properties for the user that was impersonated.
By default, all authenticated users can create SelfSubjectReview objects when the APISelfSubjectReview
feature is enabled. It is allowed by the system:basic-user cluster role.
Note:
You can only make SelfSubjectReview requests if:
the APISelfSubjectReviewfeature gate
is enabled for your cluster (not needed for Kubernetes 1.28, but older
Kubernetes versions might not offer this feature gate, or might default it to be off)
(if you are running a version of Kubernetes older than v1.28) the API server for your
cluster has the authentication.k8s.io/v1alpha1 or authentication.k8s.io/v1beta1API group
enabled.
Bootstrap tokens are a simple bearer token that is meant to be used when
creating new clusters or joining new nodes to an existing cluster. It was built
to support kubeadm, but can be used in other contexts
for users that wish to start clusters without kubeadm. It is also built to
work, via RBAC policy, with the
Kubelet TLS Bootstrapping system.
Bootstrap Tokens Overview
Bootstrap Tokens are defined with a specific type
(bootstrap.kubernetes.io/token) of secrets that lives in the kube-system
namespace. These Secrets are then read by the Bootstrap Authenticator in the
API Server. Expired tokens are removed with the TokenCleaner controller in the
Controller Manager. The tokens are also used to create a signature for a
specific ConfigMap used in a "discovery" process through a BootstrapSigner
controller.
Token Format
Bootstrap Tokens take the form of abcdef.0123456789abcdef. More formally,
they must match the regular expression [a-z0-9]{6}\.[a-z0-9]{16}.
The first part of the token is the "Token ID" and is considered public
information. It is used when referring to a token without leaking the secret
part used for authentication. The second part is the "Token Secret" and should
only be shared with trusted parties.
Enabling Bootstrap Token Authentication
The Bootstrap Token authenticator can be enabled using the following flag on the
API server:
--enable-bootstrap-token-auth
When enabled, bootstrapping tokens can be used as bearer token credentials to
authenticate requests against the API server.
Authorization: Bearer 07401b.f395accd246ae52d
Tokens authenticate as the username system:bootstrap:<token id> and are members
of the group system:bootstrappers. Additional groups may be specified in the
token's Secret.
Expired tokens can be deleted automatically by enabling the tokencleaner
controller on the controller manager.
--controllers=*,tokencleaner
Bootstrap Token Secret Format
Each valid token is backed by a secret in the kube-system namespace. You can
find the full design doc
here.
Here is what the secret looks like.
apiVersion:v1kind:Secretmetadata:# Name MUST be of form "bootstrap-token-<token id>"name:bootstrap-token-07401bnamespace:kube-system# Type MUST be 'bootstrap.kubernetes.io/token'type:bootstrap.kubernetes.io/tokenstringData:# Human readable description. Optional.description:"The default bootstrap token generated by 'kubeadm init'."# Token ID and secret. Required.token-id:07401btoken-secret:f395accd246ae52d# Expiration. Optional.expiration:2017-03-10T03:22:11Z# Allowed usages.usage-bootstrap-authentication:"true"usage-bootstrap-signing:"true"# Extra groups to authenticate the token as. Must start with "system:bootstrappers:"auth-extra-groups:system:bootstrappers:worker,system:bootstrappers:ingress
The type of the secret must be bootstrap.kubernetes.io/token and the name must
be bootstrap-token-<token id>. It must also exist in the kube-system
namespace.
The usage-bootstrap-* members indicate what this secret is intended to be used
for. A value must be set to true to be enabled.
usage-bootstrap-authentication indicates that the token can be used to
authenticate to the API server as a bearer token.
usage-bootstrap-signing indicates that the token may be used to sign the
cluster-info ConfigMap as described below.
The expiration field controls the expiry of the token. Expired tokens are
rejected when used for authentication and ignored during ConfigMap signing.
The expiry value is encoded as an absolute UTC time using RFC3339. Enable the
tokencleaner controller to automatically delete expired tokens.
Token Management with kubeadm
You can use the kubeadm tool to manage tokens on a running cluster. See the
kubeadm token docs for details.
ConfigMap Signing
In addition to authentication, the tokens can be used to sign a ConfigMap. This
is used early in a cluster bootstrap process before the client trusts the API
server. The signed ConfigMap can be authenticated by the shared token.
Enable ConfigMap signing by enabling the bootstrapsigner controller on the
Controller Manager.
--controllers=*,bootstrapsigner
The ConfigMap that is signed is cluster-info in the kube-public namespace.
The typical flow is that a client reads this ConfigMap while unauthenticated and
ignoring TLS errors. It then validates the payload of the ConfigMap by looking
at a signature embedded in the ConfigMap.
The kubeconfig member of the ConfigMap is a config file with only the cluster
information filled out. The key thing being communicated here is the
certificate-authority-data. This may be expanded in the future.
The signature is a JWS signature using the "detached" mode. To validate the
signature, the user should encode the kubeconfig payload according to JWS
rules (base64 encoded while discarding any trailing =). That encoded payload
is then used to form a whole JWS by inserting it between the 2 dots. You can
verify the JWS using the HS256 scheme (HMAC-SHA256) with the full token (e.g.
07401b.f395accd246ae52d) as the shared secret. Users must verify that HS256
is used.
Warning: Any party with a bootstrapping token can create a valid signature for that
token. When using ConfigMap signing it's discouraged to share the same token with
many clients, since a compromised client can potentially man-in-the middle another
client relying on the signature to bootstrap TLS trust.
3.3 - Certificates and Certificate Signing Requests
Kubernetes certificate and trust bundle APIs enable automation of
X.509 credential provisioning by providing
a programmatic interface for clients of the Kubernetes API to request and obtain
X.509 certificates from a Certificate Authority (CA).
There is also experimental (alpha) support for distributing trust bundles.
Certificate signing requests
FEATURE STATE:Kubernetes v1.19 [stable]
A CertificateSigningRequest (CSR) resource is used to request that a certificate be signed
by a denoted signer, after which the request may be approved or denied before
finally being signed.
Request signing process
The CertificateSigningRequest resource type allows a client to ask for an X.509 certificate
be issued, based on a signing request.
The CertificateSigningRequest object includes a PEM-encoded PKCS#10 signing request in
the spec.request field. The CertificateSigningRequest denotes the signer (the
recipient that the request is being made to) using the spec.signerName field.
Note that spec.signerName is a required key after API version certificates.k8s.io/v1.
In Kubernetes v1.22 and later, clients may optionally set the spec.expirationSeconds
field to request a particular lifetime for the issued certificate. The minimum valid
value for this field is 600, i.e. ten minutes.
Once created, a CertificateSigningRequest must be approved before it can be signed.
Depending on the signer selected, a CertificateSigningRequest may be automatically approved
by a controller.
Otherwise, a CertificateSigningRequest must be manually approved either via the REST API (or client-go)
or by running kubectl certificate approve. Likewise, a CertificateSigningRequest may also be denied,
which tells the configured signer that it must not sign the request.
For certificates that have been approved, the next step is signing. The relevant signing controller
first validates that the signing conditions are met and then creates a certificate.
The signing controller then updates the CertificateSigningRequest, storing the new certificate into
the status.certificate field of the existing CertificateSigningRequest object. The
status.certificate field is either empty or contains a X.509 certificate, encoded in PEM format.
The CertificateSigningRequest status.certificate field is empty until the signer does this.
Once the status.certificate field has been populated, the request has been completed and clients can now
fetch the signed certificate PEM data from the CertificateSigningRequest resource.
The signers can instead deny certificate signing if the approval conditions are not met.
In order to reduce the number of old CertificateSigningRequest resources left in a cluster, a garbage collection
controller runs periodically. The garbage collection removes CertificateSigningRequests that have not changed
state for some duration:
Approved requests: automatically deleted after 1 hour
Denied requests: automatically deleted after 1 hour
Failed requests: automatically deleted after 1 hour
Pending requests: automatically deleted after 24 hours
All requests: automatically deleted after the issued certificate has expired
Certificate signing authorization
To allow creating a CertificateSigningRequest and retrieving any CertificateSigningRequest:
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:csr-approverrules:- apiGroups:- certificates.k8s.ioresources:- certificatesigningrequestsverbs:- get- list- watch- apiGroups:- certificates.k8s.ioresources:- certificatesigningrequests/approvalverbs:- update- apiGroups:- certificates.k8s.ioresources:- signersresourceNames:- example.com/my-signer-name# example.com/* can be used to authorize for all signers in the 'example.com' domainverbs:- approve
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:csr-signerrules:- apiGroups:- certificates.k8s.ioresources:- certificatesigningrequestsverbs:- get- list- watch- apiGroups:- certificates.k8s.ioresources:- certificatesigningrequests/statusverbs:- update- apiGroups:- certificates.k8s.ioresources:- signersresourceNames:- example.com/my-signer-name# example.com/* can be used to authorize for all signers in the 'example.com' domainverbs:- sign
Signers
Signers abstractly represent the entity or entities that might sign, or have
signed, a security certificate.
Any signer that is made available for outside a particular cluster should provide information
about how the signer works, so that consumers can understand what that means for CertifcateSigningRequests
and (if enabled) ClusterTrustBundles.
This includes:
Trust distribution: how trust anchors (CA certificates or certificate bundles) are distributed.
Permitted subjects: any restrictions on and behavior when a disallowed subject is requested.
Permitted x509 extensions: including IP subjectAltNames, DNS subjectAltNames, Email subjectAltNames, URI subjectAltNames etc, and behavior when a disallowed extension is requested.
Permitted key usages / extended key usages: any restrictions on and behavior when usages different than the signer-determined usages are specified in the CSR.
Expiration/certificate lifetime: whether it is fixed by the signer, configurable by the admin, determined by the CSR spec.expirationSeconds field, etc
and the behavior when the signer-determined expiration is different from the CSR spec.expirationSeconds field.
CA bit allowed/disallowed: and behavior if a CSR contains a request a for a CA certificate when the signer does not permit it.
Commonly, the status.certificate field of a CertificateSigningRequest contains a
single PEM-encoded X.509 certificate once the CSR is approved and the certificate is issued.
Some signers store multiple certificates into the status.certificate field. In
that case, the documentation for the signer should specify the meaning of
additional certificates; for example, this might be the certificate plus
intermediates to be presented during TLS handshakes.
If you want to make the trust anchor (root certificate) available, this should be done
separately from a CertificateSigningRequest and its status.certificate field. For example,
you could use a ClusterTrustBundle.
The PKCS#10 signing request format does not have a standard mechanism to specify a
certificate expiration or lifetime. The expiration or lifetime therefore has to be set
through the spec.expirationSeconds field of the CSR object. The built-in signers
use the ClusterSigningDuration configuration option, which defaults to 1 year,
(the --cluster-signing-duration command-line flag of the kube-controller-manager)
as the default when no spec.expirationSeconds is specified. When spec.expirationSeconds
is specified, the minimum of spec.expirationSeconds and ClusterSigningDuration is
used.
Note: The spec.expirationSeconds field was added in Kubernetes v1.22. Earlier versions of Kubernetes do not honor this field.
Kubernetes API servers prior to v1.22 will silently drop this field when the object is created.
Kubernetes signers
Kubernetes provides built-in signers that each have a well-known signerName:
kubernetes.io/kube-apiserver-client: signs certificates that will be honored as client certificates by the API server.
Never auto-approved by kube-controller-manager.
Trust distribution: signed certificates must be honored as client certificates by the API server. The CA bundle is not distributed by any other means.
Permitted subjects - no subject restrictions, but approvers and signers may choose not to approve or sign.
Certain subjects like cluster-admin level users or groups vary between distributions and installations,
but deserve additional scrutiny before approval and signing.
The CertificateSubjectRestriction admission plugin is enabled by default to restrict system:masters,
but it is often not the only cluster-admin subject in a cluster.
Permitted x509 extensions - honors subjectAltName and key usage extensions and discards other extensions.
Permitted key usages - must include ["client auth"]. Must not include key usages beyond ["digital signature", "key encipherment", "client auth"].
Expiration/certificate lifetime - for the kube-controller-manager implementation of this signer, set to the minimum
of the --cluster-signing-duration option or, if specified, the spec.expirationSeconds field of the CSR object.
CA bit allowed/disallowed - not allowed.
kubernetes.io/kube-apiserver-client-kubelet: signs client certificates that will be honored as client certificates by the
API server.
May be auto-approved by kube-controller-manager.
Trust distribution: signed certificates must be honored as client certificates by the API server. The CA bundle
is not distributed by any other means.
Permitted subjects - organizations are exactly ["system:nodes"], common name starts with "system:node:".
Permitted x509 extensions - honors key usage extensions, forbids subjectAltName extensions and drops other extensions.
Expiration/certificate lifetime - for the kube-controller-manager implementation of this signer, set to the minimum
of the --cluster-signing-duration option or, if specified, the spec.expirationSeconds field of the CSR object.
CA bit allowed/disallowed - not allowed.
kubernetes.io/kubelet-serving: signs serving certificates that are honored as a valid kubelet serving certificate
by the API server, but has no other guarantees.
Never auto-approved by kube-controller-manager.
Trust distribution: signed certificates must be honored by the API server as valid to terminate connections to a kubelet.
The CA bundle is not distributed by any other means.
Permitted subjects - organizations are exactly ["system:nodes"], common name starts with "system:node:".
Permitted x509 extensions - honors key usage and DNSName/IPAddress subjectAltName extensions, forbids EmailAddress and
URI subjectAltName extensions, drops other extensions. At least one DNS or IP subjectAltName must be present.
Expiration/certificate lifetime - for the kube-controller-manager implementation of this signer, set to the minimum
of the --cluster-signing-duration option or, if specified, the spec.expirationSeconds field of the CSR object.
CA bit allowed/disallowed - not allowed.
kubernetes.io/legacy-unknown: has no guarantees for trust at all. Some third-party distributions of Kubernetes
may honor client certificates signed by it. The stable CertificateSigningRequest API (version certificates.k8s.io/v1 and later)
does not allow to set the signerName as kubernetes.io/legacy-unknown.
Never auto-approved by kube-controller-manager.
Trust distribution: None. There is no standard trust or distribution for this signer in a Kubernetes cluster.
Permitted subjects - any
Permitted x509 extensions - honors subjectAltName and key usage extensions and discards other extensions.
Permitted key usages - any
Expiration/certificate lifetime - for the kube-controller-manager implementation of this signer, set to the minimum
of the --cluster-signing-duration option or, if specified, the spec.expirationSeconds field of the CSR object.
CA bit allowed/disallowed - not allowed.
The kube-controller-manager implements control plane signing for each of the built in
signers. Failures for all of these are only reported in kube-controller-manager logs.
Note: The spec.expirationSeconds field was added in Kubernetes v1.22. Earlier versions of Kubernetes do not honor this field.
Kubernetes API servers prior to v1.22 will silently drop this field when the object is created.
Distribution of trust happens out of band for these signers. Any trust outside of those described above are strictly
coincidental. For instance, some distributions may honor kubernetes.io/legacy-unknown as client certificates for the
kube-apiserver, but this is not a standard.
None of these usages are related to ServiceAccount token secrets .data[ca.crt] in any way. That CA bundle is only
guaranteed to verify a connection to the API server using the default service (kubernetes.default.svc).
Custom signers
You can also introduce your own custom signer, which should have a similar prefixed name but using your
own domain name. For example, if you represent an open source project that uses the domain open-fictional.example
then you might use issuer.open-fictional.example/service-mesh as a signer name.
A custom signer uses the Kubernetes API to issue a certificate. See API-based signers.
Signing
Control plane signer
The Kubernetes control plane implements each of the
Kubernetes signers,
as part of the kube-controller-manager.
Note: Prior to Kubernetes v1.18, the kube-controller-manager would sign any CSRs that
were marked as approved.
Note: The spec.expirationSeconds field was added in Kubernetes v1.22. Earlier versions of Kubernetes do not honor this field.
Kubernetes API servers prior to v1.22 will silently drop this field when the object is created.
API-based signers
Users of the REST API can sign CSRs by submitting an UPDATE request to the status
subresource of the CSR to be signed.
As part of this request, the status.certificate field should be set to contain the
signed certificate. This field contains one or more PEM-encoded certificates.
All PEM blocks must have the "CERTIFICATE" label, contain no headers,
and the encoded data must be a BER-encoded ASN.1 Certificate structure
as described in section 4 of RFC5280.
Non-PEM content may appear before or after the CERTIFICATE PEM blocks and is unvalidated,
to allow for explanatory text as described in section 5.2 of RFC7468.
When encoded in JSON or YAML, this field is base-64 encoded.
A CertificateSigningRequest containing the example certificate above would look like this:
Before a signer issues a certificate based on a CertificateSigningRequest,
the signer typically checks that the issuance for that CSR has been approved.
Control plane automated approval
The kube-controller-manager ships with a built-in approver for certificates with
a signerName of kubernetes.io/kube-apiserver-client-kubelet that delegates various
permissions on CSRs for node credentials to authorization.
The kube-controller-manager POSTs SubjectAccessReview resources to the API server
in order to check authorization for certificate approval.
Approval or rejection using kubectl
A Kubernetes administrator (with appropriate permissions) can manually approve
(or deny) CertificateSigningRequests by using the kubectl certificate approve and kubectl certificate deny commands.
Users of the REST API can approve CSRs by submitting an UPDATE request to the approval
subresource of the CSR to be approved. For example, you could write an
operator that watches for a particular
kind of CSR and then sends an UPDATE to approve them.
When you make an approval or rejection request, set either the Approved or Denied
status condition based on the state you determine:
For Approved CSRs:
apiVersion:certificates.k8s.io/v1kind:CertificateSigningRequest...status:conditions:- lastUpdateTime:"2020-02-08T11:37:35Z"lastTransitionTime:"2020-02-08T11:37:35Z"message:Approved by my custom approver controllerreason:ApprovedByMyPolicy# You can set this to any stringtype:Approved
For Denied CSRs:
apiVersion:certificates.k8s.io/v1kind:CertificateSigningRequest...status:conditions:- lastUpdateTime:"2020-02-08T11:37:35Z"lastTransitionTime:"2020-02-08T11:37:35Z"message:Denied by my custom approver controllerreason:DeniedByMyPolicy# You can set this to any stringtype:Denied
It's usual to set status.conditions.reason to a machine-friendly reason
code using TitleCase; this is a convention but you can set it to anything
you like. If you want to add a note for human consumption, use the
status.conditions.message field.
Cluster trust bundles
FEATURE STATE:Kubernetes v1.27 [alpha]
Note: In Kubernetes 1.28, you must enable the ClusterTrustBundlesfeature gateand the certificates.k8s.io/v1alpha1API group in order to use
this API.
A ClusterTrustBundles is a cluster-scoped object for distributing X.509 trust
anchors (root certificates) to workloads within the cluster. They're designed
to work well with the signer concept from CertificateSigningRequests.
All ClusterTrustBundle objects have strong validation on the contents of their
trustBundle field. That field must contain one or more X.509 certificates,
DER-serialized, each wrapped in a PEM CERTIFICATE block. The certificates
must parse as valid X.509 certificates.
Esoteric PEM features like inter-block data and intra-block headers are either
rejected during object validation, or can be ignored by consumers of the object.
Additionally, consumers are allowed to reorder the certificates in
the bundle with their own arbitrary but stable ordering.
ClusterTrustBundle objects should be considered world-readable within the
cluster. If your cluster uses RBAC
authorization, all ServiceAccounts have a default grant that allows them to
get, list, and watch all ClusterTrustBundle objects.
If you use your own authorization mechanism and you have enabled
ClusterTrustBundles in your cluster, you should set up an equivalent rule to
make these objects public within the cluster, so that they work as intended.
If you do not have permission to list cluster trust bundles by default in your
cluster, you can impersonate a service account you have access to in order to
see available ClusterTrustBundles:
kubectl get clustertrustbundles --as='system:serviceaccount:mynamespace:default'
Signer-linked ClusterTrustBundles
Signer-linked ClusterTrustBundles are associated with a signer name, like this:
apiVersion:certificates.k8s.io/v1alpha1kind:ClusterTrustBundlemetadata:name:example.com:mysigner:foospec:signerName:example.com/mysignertrustBundle:"<... PEM data ...>"
These ClusterTrustBundles are intended to be maintained by a signer-specific
controller in the cluster, so they have several security features:
To create or update a signer-linked ClusterTrustBundle, you must be permitted
to attest on the signer (custom authorization verb attest,
API group certificates.k8s.io; resource path signers). You can configure
authorization for the specific resource name
<signerNameDomain>/<signerNamePath> or match a pattern such as
<signerNameDomain>/*.
Signer-linked ClusterTrustBundles must be named with a prefix derived from
their spec.signerName field. Slashes (/) are replaced with colons (:),
and a final colon is appended. This is followed by an arbitary name. For
example, the signer example.com/mysigner can be linked to a
ClusterTrustBundle example.com:mysigner:<arbitrary-name>.
Signer-linked ClusterTrustBundles will typically be consumed in workloads
by a combination of a
field selector on the signer name, and a separate
label selector.
Signer-unlinked ClusterTrustBundles
Signer-unlinked ClusterTrustBundles have an empty spec.signerName field, like this:
apiVersion:certificates.k8s.io/v1alpha1kind:ClusterTrustBundlemetadata:name:foospec:# no signerName specified, so the field is blanktrustBundle:"<... PEM data ...>"
They are primarily intended for cluster configuration use cases. Each
signer-unlinked ClusterTrustBundle is an independent object, in contrast to the
customary grouping behavior of signer-linked ClusterTrustBundles.
Signer-unlinked ClusterTrustBundles have no attest verb requirement.
Instead, you control access to them directly using the usual mechanisms,
such as role-based access control.
To distinguish them from signer-linked ClusterTrustBundles, the names of
signer-unlinked ClusterTrustBundles must not contain a colon (:).
How to issue a certificate for a user
A few steps are required in order to get a normal user to be able to
authenticate and invoke an API. First, this user must have a certificate issued
by the Kubernetes cluster, and then present that certificate to the Kubernetes API.
Create private key
The following scripts show how to generate PKI private key and CSR. It is
important to set CN and O attribute of the CSR. CN is the name of the user and
O is the group that this user will belong to. You can refer to
RBAC for standard groups.
View the source code for the kube-controller-manager built in signer
View the source code for the kube-controller-manager built in approver
For details of X.509 itself, refer to RFC 5280 section 3.1
For information on the syntax of PKCS#10 certificate signing requests, refer to RFC 2986
3.4 - Admission Controllers Reference
This page provides an overview of Admission Controllers.
What are they?
An admission controller is a piece of code that intercepts requests to the
Kubernetes API server prior to persistence of the object, but after the request
is authenticated and authorized.
Admission controllers may be validating, mutating, or both. Mutating
controllers may modify objects related to the requests they admit; validating controllers may not.
Admission controllers limit requests to create, delete, modify objects. Admission
controllers can also block custom verbs, such as a request connect to a Pod via
an API server proxy. Admission controllers do not (and cannot) block requests
to read (get, watch or list) objects.
The admission controllers in Kubernetes 1.28 consist of the
list below, are compiled into the
kube-apiserver binary, and may only be configured by the cluster
administrator. In that list, there are two special controllers:
MutatingAdmissionWebhook and ValidatingAdmissionWebhook. These execute the
mutating and validating (respectively)
admission control webhooks
which are configured in the API.
Admission control phases
The admission control process proceeds in two phases. In the first phase,
mutating admission controllers are run. In the second phase, validating
admission controllers are run. Note again that some of the controllers are
both.
If any of the controllers in either phase reject the request, the entire
request is rejected immediately and an error is returned to the end-user.
Finally, in addition to sometimes mutating the object in question, admission
controllers may sometimes have side effects, that is, mutate related
resources as part of request processing. Incrementing quota usage is the
canonical example of why this is necessary. Any such side-effect needs a
corresponding reclamation or reconciliation process, as a given admission
controller does not know for sure that a given request will pass all of the
other admission controllers.
Why do I need them?
Several important features of Kubernetes require an admission controller to be enabled in order
to properly support the feature. As a result, a Kubernetes API server that is not properly
configured with the right set of admission controllers is an incomplete server and will not
support all the features you expect.
How do I turn on an admission controller?
The Kubernetes API server flag enable-admission-plugins takes a comma-delimited list of admission control plugins to invoke prior to modifying objects in the cluster.
For example, the following command line enables the NamespaceLifecycle and the LimitRanger
admission control plugins:
Note: Depending on the way your Kubernetes cluster is deployed and how the API server is
started, you may need to apply the settings in different ways. For example, you may
have to modify the systemd unit file if the API server is deployed as a systemd
service, you may modify the manifest file for the API server if Kubernetes is deployed
in a self-hosted way.
How do I turn off an admission controller?
The Kubernetes API server flag disable-admission-plugins takes a comma-delimited list of admission control plugins to be disabled, even if they are in the list of plugins enabled by default.
Note: The ValidatingAdmissionPolicy admission plugin is enabled
by default, but is only active if you enable the ValidatingAdmissionPolicyfeature gateand
the admissionregistration.k8s.io/v1alpha1 API.
What does each admission controller do?
AlwaysAdmit
FEATURE STATE:Kubernetes v1.13 [deprecated]
Type: Validating.
This admission controller allows all pods into the cluster. It is deprecated because
its behavior is the same as if there were no admission controller at all.
AlwaysDeny
FEATURE STATE:Kubernetes v1.13 [deprecated]
Type: Validating.
Rejects all requests. AlwaysDeny is deprecated as it has no real meaning.
AlwaysPullImages
Type: Mutating and Validating.
This admission controller modifies every new Pod to force the image pull policy to Always. This is useful in a
multitenant cluster so that users can be assured that their private images can only be used by those
who have the credentials to pull them. Without this admission controller, once an image has been pulled to a
node, any pod from any user can use it by knowing the image's name (assuming the Pod is
scheduled onto the right node), without any authorization check against the image. When this admission controller
is enabled, images are always pulled prior to starting containers, which means valid credentials are
required.
CertificateApproval
Type: Validating.
This admission controller observes requests to approve CertificateSigningRequest resources and performs additional
authorization checks to ensure the approving user has permission to approve certificate requests with the
spec.signerName requested on the CertificateSigningRequest resource.
See Certificate Signing Requests for more
information on the permissions required to perform different actions on CertificateSigningRequest resources.
CertificateSigning
Type: Validating.
This admission controller observes updates to the status.certificate field of CertificateSigningRequest resources
and performs an additional authorization checks to ensure the signing user has permission to sign certificate
requests with the spec.signerName requested on the CertificateSigningRequest resource.
See Certificate Signing Requests for more
information on the permissions required to perform different actions on CertificateSigningRequest resources.
CertificateSubjectRestriction
Type: Validating.
This admission controller observes creation of CertificateSigningRequest resources that have a spec.signerName
of kubernetes.io/kube-apiserver-client. It rejects any request that specifies a 'group' (or 'organization attribute')
of system:masters.
DefaultIngressClass
Type: Mutating.
This admission controller observes creation of Ingress objects that do not request any specific
ingress class and automatically adds a default ingress class to them. This way, users that do not
request any special ingress class do not need to care about them at all and they will get the
default one.
This admission controller does not do anything when no default ingress class is configured. When more than one ingress
class is marked as default, it rejects any creation of Ingress with an error and an administrator
must revisit their IngressClass objects and mark only one as default (with the annotation
"ingressclass.kubernetes.io/is-default-class"). This admission controller ignores any Ingress
updates; it acts only on creation.
See the Ingress documentation for more about ingress
classes and how to mark one as default.
DefaultStorageClass
Type: Mutating.
This admission controller observes creation of PersistentVolumeClaim objects that do not request any specific storage class
and automatically adds a default storage class to them.
This way, users that do not request any special storage class do not need to care about them at all and they
will get the default one.
This admission controller does not do anything when no default storage class is configured. When more than one storage
class is marked as default, it rejects any creation of PersistentVolumeClaim with an error and an administrator
must revisit their StorageClass objects and mark only one as default.
This admission controller ignores any PersistentVolumeClaim updates; it acts only on creation.
See persistent volume documentation about persistent volume claims and
storage classes and how to mark a storage class as default.
DefaultTolerationSeconds
Type: Mutating.
This admission controller sets the default forgiveness toleration for pods to tolerate
the taints notready:NoExecute and unreachable:NoExecute based on the k8s-apiserver input parameters
default-not-ready-toleration-seconds and default-unreachable-toleration-seconds if the pods don't already
have toleration for taints node.kubernetes.io/not-ready:NoExecute or
node.kubernetes.io/unreachable:NoExecute.
The default value for default-not-ready-toleration-seconds and default-unreachable-toleration-seconds is 5 minutes.
DenyServiceExternalIPs
Type: Validating.
This admission controller rejects all net-new usage of the Service field externalIPs. This
feature is very powerful (allows network traffic interception) and not well
controlled by policy. When enabled, users of the cluster may not create new
Services which use externalIPs and may not add new values to externalIPs on
existing Service objects. Existing uses of externalIPs are not affected,
and users may remove values from externalIPs on existing Service objects.
Most users do not need this feature at all, and cluster admins should consider disabling it.
Clusters that do need to use this feature should consider using some custom policy to manage usage
of it.
This admission controller is disabled by default.
EventRateLimit
FEATURE STATE:Kubernetes v1.13 [alpha]
Type: Validating.
This admission controller mitigates the problem where the API server gets flooded by
requests to store new Events. The cluster admin can specify event rate limits by:
Enabling the EventRateLimit admission controller;
Referencing an EventRateLimit configuration file from the file provided to the API
server's command line flag --admission-control-config-file:
This plug-in facilitates creation of dedicated nodes with extended resources.
If operators want to create dedicated nodes with extended resources (like GPUs, FPGAs etc.), they are expected to
taint the node with the extended resource
name as the key. This admission controller, if enabled, automatically
adds tolerations for such taints to pods requesting extended resources, so users don't have to manually
add these tolerations.
This admission controller is disabled by default.
ImagePolicyWebhook
Type: Validating.
The ImagePolicyWebhook admission controller allows a backend webhook to make admission decisions.
This admission controller is disabled by default.
Configuration file format
ImagePolicyWebhook uses a configuration file to set options for the behavior of the backend.
This file may be json or yaml and has the following format:
imagePolicy:kubeConfigFile:/path/to/kubeconfig/for/backend# time in s to cache approvalallowTTL:50# time in s to cache denialdenyTTL:50# time in ms to wait between retriesretryBackoff:500# determines behavior if the webhook backend failsdefaultAllow:true
Reference the ImagePolicyWebhook configuration file from the file provided to the API server's command line flag --admission-control-config-file:
The ImagePolicyWebhook config file must reference a
kubeconfig
formatted file which sets up the connection to the backend.
It is required that the backend communicate over TLS.
The kubeconfig file's cluster field must point to the remote service, and the user field
must contain the returned authorizer.
# clusters refers to the remote service.clusters:- name:name-of-remote-imagepolicy-servicecluster:certificate-authority:/path/to/ca.pem # CA for verifying the remote service.server:https://images.example.com/policy# URL of remote service to query. Must use 'https'.# users refers to the API server's webhook configuration.users:- name:name-of-api-serveruser:client-certificate:/path/to/cert.pem# cert for the webhook admission controller to useclient-key:/path/to/key.pem # key matching the cert
For additional HTTP configuration, refer to the
kubeconfig documentation.
Request payloads
When faced with an admission decision, the API Server POSTs a JSON serialized
imagepolicy.k8s.io/v1alpha1ImageReview object describing the action.
This object contains fields describing the containers being admitted, as well as
any pod annotations that match *.image-policy.k8s.io/*.
Note: The webhook API objects are subject to the same versioning compatibility rules
as other Kubernetes API objects. Implementers should be aware of looser compatibility
promises for alpha objects and check the apiVersion field of the request to
ensure correct deserialization.
Additionally, the API Server must enable the imagepolicy.k8s.io/v1alpha1 API extensions
group (--runtime-config=imagepolicy.k8s.io/v1alpha1=true).
The remote service is expected to fill the status field of the request and
respond to either allow or disallow access. The response body's spec field is ignored, and
may be omitted. A permissive response would return:
All annotations on a Pod that match *.image-policy.k8s.io/* are sent to the webhook.
Sending annotations allows users who are aware of the image policy backend to
send extra information to it, and for different backends implementations to
accept different information.
Examples of information you might put here are:
request to "break glass" to override a policy, in case of emergency.
a ticket number from a ticket system that documents the break-glass request
provide a hint to the policy server as to the imageID of the image being provided, to save it a lookup
In any case, the annotations are provided by the user and are not validated by Kubernetes in any way.
LimitPodHardAntiAffinityTopology
Type: Validating.
This admission controller denies any pod that defines AntiAffinity topology key other than
kubernetes.io/hostname in requiredDuringSchedulingRequiredDuringExecution.
This admission controller is disabled by default.
LimitRanger
Type: Mutating and Validating.
This admission controller will observe the incoming request and ensure that it does not violate
any of the constraints enumerated in the LimitRange object in a Namespace. If you are using
LimitRange objects in your Kubernetes deployment, you MUST use this admission controller to
enforce those constraints. LimitRanger can also be used to apply default resource requests to Pods
that don't specify any; currently, the default LimitRanger applies a 0.1 CPU requirement to all
Pods in the default namespace.
This admission controller calls any mutating webhooks which match the request. Matching
webhooks are called in serial; each one may modify the object if it desires.
This admission controller (as implied by the name) only runs in the mutating phase.
If a webhook called by this has side effects (for example, decrementing quota) it
must have a reconciliation system, as it is not guaranteed that subsequent
webhooks or validating admission controllers will permit the request to finish.
If you disable the MutatingAdmissionWebhook, you must also disable the
MutatingWebhookConfiguration object in the admissionregistration.k8s.io/v1
group/version via the --runtime-config flag, both are on by default.
Use caution when authoring and installing mutating webhooks
Users may be confused when the objects they try to create are different from
what they get back.
Built in control loops may break when the objects they try to create are
different when read back.
Setting originally unset fields is less likely to cause problems than
overwriting fields set in the original request. Avoid doing the latter.
Future changes to control loops for built-in resources or third-party resources
may break webhooks that work well today. Even when the webhook installation API
is finalized, not all possible webhook behaviors will be guaranteed to be supported
indefinitely.
NamespaceAutoProvision
Type: Mutating.
This admission controller examines all incoming requests on namespaced resources and checks
if the referenced namespace does exist.
It creates a namespace if it cannot be found.
This admission controller is useful in deployments that do not want to restrict creation of
a namespace prior to its usage.
NamespaceExists
Type: Validating.
This admission controller checks all requests on namespaced resources other than Namespace itself.
If the namespace referenced from a request doesn't exist, the request is rejected.
NamespaceLifecycle
Type: Validating.
This admission controller enforces that a Namespace that is undergoing termination cannot have
new objects created in it, and ensures that requests in a non-existent Namespace are rejected.
This admission controller also prevents deletion of three system reserved namespaces default,
kube-system, kube-public.
A Namespace deletion kicks off a sequence of operations that remove all objects (pods, services,
etc.) in that namespace. In order to enforce integrity of that process, we strongly recommend
running this admission controller.
NodeRestriction
Type: Validating.
This admission controller limits the Node and Pod objects a kubelet can modify. In order to be limited by this admission controller,
kubelets must use credentials in the system:nodes group, with a username in the form system:node:<nodeName>.
Such kubelets will only be allowed to modify their own Node API object, and only modify Pod API objects that are bound to their node.
kubelets are not allowed to update or remove taints from their Node API object.
The NodeRestriction admission plugin prevents kubelets from deleting their Node API object,
and enforces kubelet modification of labels under the kubernetes.io/ or k8s.io/ prefixes as follows:
Prevents kubelets from adding/removing/updating labels with a node-restriction.kubernetes.io/ prefix.
This label prefix is reserved for administrators to label their Node objects for workload isolation purposes,
and kubelets will not be allowed to modify labels with that prefix.
Allows kubelets to add/remove/update these labels and label prefixes:
Use of any other labels under the kubernetes.io or k8s.io prefixes by kubelets is reserved,
and may be disallowed or allowed by the NodeRestriction admission plugin in the future.
Future versions may add additional restrictions to ensure kubelets have the minimal set of
permissions required to operate correctly.
OwnerReferencesPermissionEnforcement
Type: Validating.
This admission controller protects the access to the metadata.ownerReferences of an object
so that only users with delete permission to the object can change it.
This admission controller also protects the access to metadata.ownerReferences[x].blockOwnerDeletion
of an object, so that only users with update permission to the finalizers
subresource of the referenced owner can change it.
PersistentVolumeClaimResize
FEATURE STATE:Kubernetes v1.24 [stable]
Type: Validating.
This admission controller implements additional validations for checking incoming
PersistentVolumeClaim resize requests.
Enabling the PersistentVolumeClaimResize admission controller is recommended.
This admission controller prevents resizing of all claims by default unless a claim's StorageClass
explicitly enables resizing by setting allowVolumeExpansion to true.
For example: all PersistentVolumeClaims created from the following StorageClass support volume expansion:
This admission controller automatically attaches region or zone labels to PersistentVolumes
as defined by the cloud provider (for example, Azure or GCP).
It helps ensure the Pods and the PersistentVolumes mounted are in the same
region and/or zone.
If the admission controller doesn't support automatic labelling your PersistentVolumes, you
may need to add the labels manually to prevent pods from mounting volumes from
a different zone. PersistentVolumeLabel is deprecated as labeling for persistent volumes has been taken over by
the cloud-controller-manager.
This admission controller is disabled by default.
PodNodeSelector
FEATURE STATE:Kubernetes v1.5 [alpha]
Type: Validating.
This admission controller defaults and limits what node selectors may be used within a namespace
by reading a namespace annotation and a global configuration.
This admission controller is disabled by default.
Configuration file format
PodNodeSelector uses a configuration file to set options for the behavior of the backend.
Note that the configuration file format will move to a versioned file in a future release.
This file may be json or yaml and has the following format:
This admission controller has the following behavior:
If the Namespace has an annotation with a key scheduler.alpha.kubernetes.io/node-selector,
use its value as the node selector.
If the namespace lacks such an annotation, use the clusterDefaultNodeSelector defined in the
PodNodeSelector plugin configuration file as the node selector.
Evaluate the pod's node selector against the namespace node selector for conflicts. Conflicts
result in rejection.
Evaluate the pod's node selector against the namespace-specific allowed selector defined the
plugin configuration file. Conflicts result in rejection.
Note: PodNodeSelector allows forcing pods to run on specifically labeled nodes. Also see the PodTolerationRestriction
admission plugin, which allows preventing pods from running on specifically tainted nodes.
PodSecurity
FEATURE STATE:Kubernetes v1.25 [stable]
Type: Validating.
The PodSecurity admission controller checks new Pods before they are
admitted, determines if it should be admitted based on the requested security context and the restrictions on permitted
Pod Security Standards
for the namespace that the Pod would be in.
PodSecurity replaced an older admission controller named PodSecurityPolicy.
PodTolerationRestriction
FEATURE STATE:Kubernetes v1.7 [alpha]
Type: Mutating and Validating.
The PodTolerationRestriction admission controller verifies any conflict between tolerations of a
pod and the tolerations of its namespace.
It rejects the pod request if there is a conflict.
It then merges the tolerations annotated on the namespace into the tolerations of the pod.
The resulting tolerations are checked against a list of allowed tolerations annotated to the namespace.
If the check succeeds, the pod request is admitted otherwise it is rejected.
If the namespace of the pod does not have any associated default tolerations or allowed
tolerations annotated, the cluster-level default tolerations or cluster-level list of allowed tolerations are used
instead if they are specified.
Tolerations to a namespace are assigned via the scheduler.alpha.kubernetes.io/defaultTolerations annotation key.
The list of allowed tolerations can be added via the scheduler.alpha.kubernetes.io/tolerationsWhitelist annotation key.
The priority admission controller uses the priorityClassName field and populates the integer
value of the priority.
If the priority class is not found, the Pod is rejected.
ResourceQuota
Type: Validating.
This admission controller will observe the incoming request and ensure that it does not violate
any of the constraints enumerated in the ResourceQuota object in a Namespace. If you are
using ResourceQuota objects in your Kubernetes deployment, you MUST use this admission
controller to enforce quota constraints.
If you define a RuntimeClass with Pod overhead
configured, this admission controller checks incoming Pods.
When enabled, this admission controller rejects any Pod create requests
that have the overhead already set.
For Pods that have a RuntimeClass configured and selected in their .spec,
this admission controller sets .spec.overhead in the Pod based on the value
defined in the corresponding RuntimeClass.
The Kubernetes project recommends that you do not use the
SecurityContextDeny admission controller.
The SecurityContextDeny admission controller plugin is deprecated and disabled
by default. It will be removed in a future version. If you choose to enable the
SecurityContextDeny admission controller plugin, you must enable the
SecurityContextDeny feature gate as well.
The SecurityContextDeny admission plugin is deprecated because it is outdated
and incomplete; it may be unusable or not do what you would expect. As
implemented, this plugin is unable to restrict all security-sensitive attributes
of the Pod API. For example, the privileged and ephemeralContainers fields
were never restricted by this plugin.
For more historical context on this plugin, see
The birth of PodSecurityPolicy
from the Kubernetes blog article about PodSecurityPolicy and its removal. The
article details the PodSecurityPolicy historical context and the birth of the
securityContext field for Pods.
ServiceAccount
Type: Mutating and Validating.
This admission controller implements automation for
serviceAccounts.
The Kubernetes project strongly recommends enabling this admission controller.
You should enable this admission controller if you intend to make any use of Kubernetes
ServiceAccount objects.
StorageObjectInUseProtection
Type: Mutating.
The StorageObjectInUseProtection plugin adds the kubernetes.io/pvc-protection or kubernetes.io/pv-protection
finalizers to newly created Persistent Volume Claims (PVCs) or Persistent Volumes (PV).
In case a user deletes a PVC or PV the PVC or PV is not removed until the finalizer is removed
from the PVC or PV by PVC or PV Protection Controller.
Refer to the
Storage Object in Use Protection
for more detailed information.
TaintNodesByCondition
Type: Mutating.
This admission controller taints newly created
Nodes as NotReady and NoSchedule. That tainting avoids a race condition that could cause Pods
to be scheduled on new Nodes before their taints were updated to accurately reflect their reported
conditions.
ValidatingAdmissionPolicy
Type: Validating.
This admission controller implements the CEL validation for incoming matched requests.
It is enabled when both feature gate validatingadmissionpolicy and admissionregistration.k8s.io/v1alpha1 group/version are enabled.
If any of the ValidatingAdmissionPolicy fails, the request fails.
ValidatingAdmissionWebhook
Type: Validating.
This admission controller calls any validating webhooks which match the request. Matching
webhooks are called in parallel; if any of them rejects the request, the request
fails. This admission controller only runs in the validation phase; the webhooks it calls may not
mutate the object, as opposed to the webhooks called by the MutatingAdmissionWebhook admission controller.
If a webhook called by this has side effects (for example, decrementing quota) it
must have a reconciliation system, as it is not guaranteed that subsequent
webhooks or other validating admission controllers will permit the request to finish.
If you disable the ValidatingAdmissionWebhook, you must also disable the
ValidatingWebhookConfiguration object in the admissionregistration.k8s.io/v1
group/version via the --runtime-config flag.
Is there a recommended set of admission controllers to use?
Yes. The recommended admission controllers are enabled by default
(shown here),
so you do not need to explicitly specify them.
You can enable additional admission controllers beyond the default set using the
--enable-admission-plugins flag (order doesn't matter).
3.5 - Dynamic Admission Control
In addition to compiled-in admission plugins,
admission plugins can be developed as extensions and run as webhooks configured at runtime.
This page describes how to build, configure, use, and monitor admission webhooks.
What are admission webhooks?
Admission webhooks are HTTP callbacks that receive admission requests and do
something with them. You can define two types of admission webhooks,
validating admission webhook
and
mutating admission webhook.
Mutating admission webhooks are invoked first, and can modify objects sent to the API server to enforce custom defaults.
After all object modifications are complete, and after the incoming object is validated by the API server,
validating admission webhooks are invoked and can reject requests to enforce custom policies.
Note: Admission webhooks that need to guarantee they see the final state of the object in order to enforce policy
should use a validating admission webhook, since objects can be modified after being seen by mutating webhooks.
Experimenting with admission webhooks
Admission webhooks are essentially part of the cluster control-plane. You should
write and deploy them with great caution. Please read the
user guides
for instructions if you intend to write/deploy production-grade admission webhooks.
In the following, we describe how to quickly experiment with admission webhooks.
Prerequisites
Ensure that MutatingAdmissionWebhook and ValidatingAdmissionWebhook
admission controllers are enabled.
Here
is a recommended set of admission controllers to enable in general.
Ensure that the admissionregistration.k8s.io/v1 API is enabled.
Write an admission webhook server
Please refer to the implementation of the admission webhook server
that is validated in a Kubernetes e2e test. The webhook handles the
AdmissionReview request sent by the API servers, and sends back its decision
as an AdmissionReview object in the same version it received.
See the webhook request section for details on the data sent to webhooks.
See the webhook response section for the data expected from webhooks.
The example admission webhook server leaves the ClientAuth field
empty,
which defaults to NoClientCert. This means that the webhook server does not
authenticate the identity of the clients, supposedly API servers. If you need
mutual TLS or other ways to authenticate the clients, see
how to authenticate API servers.
Deploy the admission webhook service
The webhook server in the e2e test is deployed in the Kubernetes cluster, via
the deployment API.
The test also creates a service
as the front-end of the webhook server. See
code.
You may also deploy your webhooks outside of the cluster. You will need to update
your webhook configurations accordingly.
The following is an example ValidatingWebhookConfiguration, a mutating webhook configuration is similar.
See the webhook configuration section for details about each config field.
Note: You must replace the <CA_BUNDLE> in the above example by a valid CA bundle
which is a PEM-encoded (field value is Base64 encoded) CA bundle for validating the webhook's server certificate.
The scope field specifies if only cluster-scoped resources ("Cluster") or namespace-scoped
resources ("Namespaced") will match this rule. "∗" means that there are no scope restrictions.
Note: When using clientConfig.service, the server cert must be valid for
<svc_name>.<svc_namespace>.svc.
Note: Default timeout for a webhook call is 10 seconds,
You can set the timeout and it is encouraged to use a short timeout for webhooks.
If the webhook call times out, the request is handled according to the webhook's
failure policy.
When an API server receives a request that matches one of the rules, the
API server sends an admissionReview request to webhook as specified in the
clientConfig.
After you create the webhook configuration, the system will take a few seconds
to honor the new configuration.
Authenticate API servers
If your admission webhooks require authentication, you can configure the
API servers to use basic auth, bearer token, or a cert to authenticate itself to
the webhooks. There are three steps to complete the configuration.
When starting the API server, specify the location of the admission control
configuration file via the --admission-control-config-file flag.
In the admission control configuration file, specify where the
MutatingAdmissionWebhook controller and ValidatingAdmissionWebhook controller
should read the credentials. The credentials are stored in kubeConfig files
(yes, the same schema that's used by kubectl), so the field name is
kubeConfigFile. Here is an example admission control configuration file:
# Deprecated in v1.17 in favor of apiserver.config.k8s.io/v1apiVersion:apiserver.k8s.io/v1alpha1kind:AdmissionConfigurationplugins:- name:ValidatingAdmissionWebhookconfiguration:# Deprecated in v1.17 in favor of apiserver.config.k8s.io/v1, kind=WebhookAdmissionConfigurationapiVersion:apiserver.config.k8s.io/v1alpha1kind:WebhookAdmissionkubeConfigFile:"<path-to-kubeconfig-file>"- name:MutatingAdmissionWebhookconfiguration:# Deprecated in v1.17 in favor of apiserver.config.k8s.io/v1, kind=WebhookAdmissionConfigurationapiVersion:apiserver.config.k8s.io/v1alpha1kind:WebhookAdmissionkubeConfigFile:"<path-to-kubeconfig-file>"
apiVersion:v1kind:Configusers:# name should be set to the DNS name of the service or the host (including port) of the URL the webhook is configured to speak to.# If a non-443 port is used for services, it must be included in the name when configuring 1.16+ API servers.## For a webhook configured to speak to a service on the default port (443), specify the DNS name of the service:# - name: webhook1.ns1.svc# user: ...## For a webhook configured to speak to a service on non-default port (e.g. 8443), specify the DNS name and port of the service in 1.16+:# - name: webhook1.ns1.svc:8443# user: ...# and optionally create a second stanza using only the DNS name of the service for compatibility with 1.15 API servers:# - name: webhook1.ns1.svc# user: ...## For webhooks configured to speak to a URL, match the host (and port) specified in the webhook's URL. Examples:# A webhook with `url: https://www.example.com`:# - name: www.example.com# user: ...## A webhook with `url: https://www.example.com:443`:# - name: www.example.com:443# user: ...## A webhook with `url: https://www.example.com:8443`:# - name: www.example.com:8443# user: ...#- name:'webhook1.ns1.svc'user:client-certificate-data:"<pem encoded certificate>"client-key-data:"<pem encoded key>"# The `name` supports using * to wildcard-match prefixing segments.- name:'*.webhook-company.org'user:password:"<password>"username:"<name>"# '*' is the default match.- name:'*'user:token:"<token>"
Of course you need to set up the webhook server to handle these authentication requests.
Webhook request and response
Request
Webhooks are sent as POST requests, with Content-Type: application/json,
with an AdmissionReview API object in the admission.k8s.io API group
serialized to JSON as the body.
Webhooks can specify what versions of AdmissionReview objects they accept
with the admissionReviewVersions field in their configuration:
admissionReviewVersions is a required field when creating webhook configurations.
Webhooks are required to support at least one AdmissionReview
version understood by the current and previous API server.
API servers send the first AdmissionReview version in the admissionReviewVersions list they support.
If none of the versions in the list are supported by the API server, the configuration will not be allowed to be created.
If an API server encounters a webhook configuration that was previously created and does not support any of the AdmissionReview
versions the API server knows how to send, attempts to call to the webhook will fail and be subject to the failure policy.
This example shows the data contained in an AdmissionReview object
for a request to update the scale subresource of an apps/v1Deployment:
apiVersion:admission.k8s.io/v1kind:AdmissionReviewrequest:# Random uid uniquely identifying this admission calluid:705ab4f5-6393-11e8-b7cc-42010a800002# Fully-qualified group/version/kind of the incoming objectkind:group:autoscalingversion:v1kind:Scale# Fully-qualified group/version/kind of the resource being modifiedresource:group:appsversion:v1resource:deployments# subresource, if the request is to a subresourcesubResource:scale# Fully-qualified group/version/kind of the incoming object in the original request to the API server.# This only differs from `kind` if the webhook specified `matchPolicy: Equivalent` and the# original request to the API server was converted to a version the webhook registered for.requestKind:group:autoscalingversion:v1kind:Scale# Fully-qualified group/version/kind of the resource being modified in the original request to the API server.# This only differs from `resource` if the webhook specified `matchPolicy: Equivalent` and the# original request to the API server was converted to a version the webhook registered for.requestResource:group:appsversion:v1resource:deployments# subresource, if the request is to a subresource# This only differs from `subResource` if the webhook specified `matchPolicy: Equivalent` and the# original request to the API server was converted to a version the webhook registered for.requestSubResource:scale# Name of the resource being modifiedname:my-deployment# Namespace of the resource being modified, if the resource is namespaced (or is a Namespace object)namespace:my-namespace# operation can be CREATE, UPDATE, DELETE, or CONNECToperation:UPDATEuserInfo:# Username of the authenticated user making the request to the API serverusername:admin# UID of the authenticated user making the request to the API serveruid:014fbff9a07c# Group memberships of the authenticated user making the request to the API servergroups:- system:authenticated- my-admin-group# Arbitrary extra info associated with the user making the request to the API server.# This is populated by the API server authentication layer and should be included# if any SubjectAccessReview checks are performed by the webhook.extra:some-key:- some-value1- some-value2# object is the new object being admitted.# It is null for DELETE operations.object:apiVersion:autoscaling/v1kind:Scale# oldObject is the existing object.# It is null for CREATE and CONNECT operations.oldObject:apiVersion:autoscaling/v1kind:Scale# options contains the options for the operation being admitted, like meta.k8s.io/v1 CreateOptions, UpdateOptions, or DeleteOptions.# It is null for CONNECT operations.options:apiVersion:meta.k8s.io/v1kind:UpdateOptions# dryRun indicates the API request is running in dry run mode and will not be persisted.# Webhooks with side effects should avoid actuating those side effects when dryRun is true.# See http://k8s.io/docs/reference/using-api/api-concepts/#make-a-dry-run-request for more details.dryRun:False
Response
Webhooks respond with a 200 HTTP status code, Content-Type: application/json,
and a body containing an AdmissionReview object (in the same version they were sent),
with the response stanza populated, serialized to JSON.
At a minimum, the response stanza must contain the following fields:
uid, copied from the request.uid sent to the webhook
allowed, either set to true or false
Example of a minimal response from a webhook to allow a request:
When rejecting a request, the webhook can customize the http code and message returned to the user
using the status field. The specified status object is returned to the user.
See the API documentation
for details about the status type.
Example of a response to forbid a request, customizing the HTTP status code and message presented to the user:
{
"apiVersion": "admission.k8s.io/v1",
"kind": "AdmissionReview",
"response": {
"uid": "<value from request.uid>",
"allowed": false,
"status": {
"code": 403,
"message": "You cannot do this because it is Tuesday and your name starts with A" }
}
}
When allowing a request, a mutating admission webhook may optionally modify the incoming object as well.
This is done using the patch and patchType fields in the response.
The only currently supported patchType is JSONPatch.
See JSON patch documentation for more details.
For patchType: JSONPatch, the patch field contains a base64-encoded array of JSON patch operations.
As an example, a single patch operation that would set spec.replicas would be
[{"op": "add", "path": "/spec/replicas", "value": 3}]
Base64-encoded, this would be W3sib3AiOiAiYWRkIiwgInBhdGgiOiAiL3NwZWMvcmVwbGljYXMiLCAidmFsdWUiOiAzfV0=
Admission webhooks can optionally return warning messages that are returned to the requesting client
in HTTP Warning headers with a warning code of 299. Warnings can be sent with allowed or rejected admission responses.
If you're implementing a webhook that returns a warning:
Don't include a "Warning:" prefix in the message
Use warning messages to describe problems the client making the API request should correct or be aware of
Limit warnings to 120 characters if possible
Caution: Individual warning messages over 256 characters may be truncated by the API server before being returned to clients.
If more than 4096 characters of warning messages are added (from all sources), additional warning messages are ignored.
{
"apiVersion": "admission.k8s.io/v1",
"kind": "AdmissionReview",
"response": {
"uid": "<value from request.uid>",
"allowed": true,
"warnings": [
"duplicate envvar entries specified with name MY_ENV",
"memory request less than 4MB specified for container mycontainer, which will not start successfully" ]
}
}
Webhook configuration
To register admission webhooks, create MutatingWebhookConfiguration or ValidatingWebhookConfiguration API objects.
The name of a MutatingWebhookConfiguration or a ValidatingWebhookConfiguration object must be a valid
DNS subdomain name.
Each configuration can contain one or more webhooks.
If multiple webhooks are specified in a single configuration, each must be given a unique name.
This is required in order to make resulting audit logs and metrics easier to match up to active
configurations.
Each webhook defines the following things.
Matching requests: rules
Each webhook must specify a list of rules used to determine if a request to the API server should be sent to the webhook.
Each rule specifies one or more operations, apiGroups, apiVersions, and resources, and a resource scope:
operations lists one or more operations to match. Can be "CREATE", "UPDATE", "DELETE", "CONNECT",
or "*" to match all.
apiGroups lists one or more API groups to match. "" is the core API group. "*" matches all API groups.
apiVersions lists one or more API versions to match. "*" matches all API versions.
resources lists one or more resources to match.
"*" matches all resources, but not subresources.
"*/*" matches all resources and subresources.
"pods/*" matches all subresources of pods.
"*/status" matches all status subresources.
scope specifies a scope to match. Valid values are "Cluster", "Namespaced", and "*".
Subresources match the scope of their parent resource. Default is "*".
"Cluster" means that only cluster-scoped resources will match this rule (Namespace API objects are cluster-scoped).
"Namespaced" means that only namespaced resources will match this rule.
"*" means that there are no scope restrictions.
If an incoming request matches one of the specified operations, groups, versions,
resources, and scope for any of a webhook's rules, the request is sent to the webhook.
Here are other examples of rules that could be used to specify which resources should be intercepted.
Match CREATE or UPDATE requests to apps/v1 and apps/v1beta1deployments and replicasets:
Webhooks may optionally limit which requests are intercepted based on the labels of the
objects they would be sent, by specifying an objectSelector. If specified, the objectSelector
is evaluated against both the object and oldObject that would be sent to the webhook,
and is considered to match if either object matches the selector.
A null object (oldObject in the case of create, or newObject in the case of delete),
or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object)
is not considered to match.
Use the object selector only if the webhook is opt-in, because end users may skip
the admission webhook by setting the labels.
This example shows a mutating webhook that would match a CREATE of any resource (but not subresources) with the label foo: bar:
See labels concept
for more examples of label selectors.
Matching requests: namespaceSelector
Webhooks may optionally limit which requests for namespaced resources are intercepted,
based on the labels of the containing namespace, by specifying a namespaceSelector.
The namespaceSelector decides whether to run the webhook on a request for a namespaced resource
(or a Namespace object), based on whether the namespace's labels match the selector.
If the object itself is a namespace, the matching is performed on object.metadata.labels.
If the object is a cluster scoped resource other than a Namespace, namespaceSelector has no effect.
This example shows a mutating webhook that matches a CREATE of any namespaced resource inside a namespace
that does not have a "runlevel" label of "0" or "1":
This example shows a validating webhook that matches a CREATE of any namespaced resource inside
a namespace that is associated with the "environment" of "prod" or "staging":
See labels concept
for more examples of label selectors.
Matching requests: matchPolicy
API servers can make objects available via multiple API groups or versions.
For example, if a webhook only specified a rule for some API groups/versions
(like apiGroups:["apps"], apiVersions:["v1","v1beta1"]),
and a request was made to modify the resource via another API group/version (like extensions/v1beta1),
the request would not be sent to the webhook.
The matchPolicy lets a webhook define how its rules are used to match incoming requests.
Allowed values are Exact or Equivalent.
Exact means a request should be intercepted only if it exactly matches a specified rule.
Equivalent means a request should be intercepted if modifies a resource listed in rules,
even via another API group or version.
In the example given above, the webhook that only registered for apps/v1 could use matchPolicy:
matchPolicy: Exact would mean the extensions/v1beta1 request would not be sent to the webhook
matchPolicy: Equivalent means the extensions/v1beta1 request would be sent to the webhook
(with the objects converted to a version the webhook had specified: apps/v1)
Specifying Equivalent is recommended, and ensures that webhooks continue to intercept the
resources they expect when upgrades enable new versions of the resource in the API server.
When a resource stops being served by the API server, it is no longer considered equivalent to
other versions of that resource that are still served.
For example, extensions/v1beta1 deployments were first deprecated and then removed (in Kubernetes v1.16).
Since that removal, a webhook with a apiGroups:["extensions"], apiVersions:["v1beta1"], resources:["deployments"] rule
does not intercept deployments created via apps/v1 APIs. For that reason, webhooks should prefer registering
for stable versions of resources.
This example shows a validating webhook that intercepts modifications to deployments (no matter the API group or version),
and is always sent an apps/v1Deployment object:
The matchPolicy for an admission webhooks defaults to Equivalent.
Matching requests: matchConditions
FEATURE STATE:Kubernetes v1.28 [beta]
You can define match conditions for webhooks if you need fine-grained request filtering. These
conditions are useful if you find that match rules, objectSelectors and namespaceSelectors still
doesn't provide the filtering you want over when to call out over HTTP. Match conditions are
CEL expressions. All match conditions must evaluate to true for the
webhook to be called.
Here is an example illustrating a few different uses for match conditions:
apiVersion:admissionregistration.k8s.io/v1kind:ValidatingWebhookConfigurationwebhooks:- name:my-webhook.example.commatchPolicy:Equivalentrules:- operations:['CREATE','UPDATE']apiGroups:['*']apiVersions:['*']resources:['*']failurePolicy:'Ignore'# Fail-open (optional)sideEffects:NoneclientConfig:service:namespace:my-namespacename:my-webhookcaBundle:'<omitted>'# You can have up to 64 matchConditions per webhookmatchConditions:- name:'exclude-leases'# Each match condition must have a unique nameexpression:'!(request.resource.group == "coordination.k8s.io" && request.resource.resource == "leases")'# Match non-lease resources.- name:'exclude-kubelet-requests'expression:'!("system:nodes" in request.userInfo.groups)'# Match requests made by non-node users.- name:'rbac'# Skip RBAC requests, which are handled by the second webhook.expression:'request.resource.group != "rbac.authorization.k8s.io"'# This example illustrates the use of the 'authorizer'. The authorization check is more expensive# than a simple expression, so in this example it is scoped to only RBAC requests by using a second# webhook. Both webhooks can be served by the same endpoint.- name:rbac.my-webhook.example.commatchPolicy:Equivalentrules:- operations:['CREATE','UPDATE']apiGroups:['rbac.authorization.k8s.io']apiVersions:['*']resources:['*']failurePolicy:'Fail'# Fail-closed (the default)sideEffects:NoneclientConfig:service:namespace:my-namespacename:my-webhookcaBundle:'<omitted>'# You can have up to 64 matchConditions per webhookmatchConditions:- name:'breakglass'# Skip requests made by users authorized to 'breakglass' on this webhook.# The 'breakglass' API verb does not need to exist outside this check.expression:'!authorizer.group("admissionregistration.k8s.io").resource("validatingwebhookconfigurations").name("my-webhook.example.com").check("breakglass").allowed()'
Note: You can define up to 64 elements in the matchConditions field per webhook.
Match conditions have access to the following CEL variables:
object - The object from the incoming request. The value is null for DELETE requests. The object
version may be converted based on the matchPolicy.
oldObject - The existing object. The value is null for CREATE requests.
request - The request portion of the AdmissionReview, excluding object and oldObject.
authorizer - A CEL Authorizer. May be used to perform authorization checks for the principal
(authenticated user) of the request. See
Authz in the Kubernetes CEL library
documentation for more details.
authorizer.requestResource - A shortcut for an authorization check configured with the request
resource (group, resource, (subresource), namespace, name).
Once the API server has determined a request should be sent to a webhook,
it needs to know how to contact the webhook. This is specified in the clientConfig
stanza of the webhook configuration.
Webhooks can either be called via a URL or a service reference,
and can optionally include a custom CA bundle to use to verify the TLS connection.
URL
url gives the location of the webhook, in standard URL form
(scheme://host:port/path).
The host should not refer to a service running in the cluster; use
a service reference by specifying the service field instead.
The host might be resolved via external DNS in some API servers
(e.g., kube-apiserver cannot resolve in-cluster DNS as that would
be a layering violation). host may also be an IP address.
Please note that using localhost or 127.0.0.1 as a host is
risky unless you take great care to run this webhook on all hosts
which run an API server which might need to make calls to this
webhook. Such installations are likely to be non-portable or not readily
run in a new cluster.
The scheme must be "https"; the URL must begin with "https://".
Attempting to use a user or basic auth (for example user:password@) is not allowed.
Fragments (#...) and query parameters (?...) are also not allowed.
Here is an example of a mutating webhook configured to call a URL
(and expects the TLS certificate to be verified using system trust roots, so does not specify a caBundle):
The service stanza inside clientConfig is a reference to the service for this webhook.
If the webhook is running within the cluster, then you should use service instead of url.
The service namespace and name are required. The port is optional and defaults to 443.
The path is optional and defaults to "/".
Here is an example of a mutating webhook configured to call a service on port "1234"
at the subpath "/my-path", and to verify the TLS connection against the ServerName
my-service-name.my-service-namespace.svc using a custom CA bundle:
Note: You must replace the <CA_BUNDLE> in the above example by a valid CA bundle
which is a PEM-encoded CA bundle for validating the webhook's server certificate.
Side effects
Webhooks typically operate only on the content of the AdmissionReview sent to them.
Some webhooks, however, make out-of-band changes as part of processing admission requests.
Webhooks that make out-of-band changes ("side effects") must also have a reconciliation mechanism
(like a controller) that periodically determines the actual state of the world, and adjusts
the out-of-band data modified by the admission webhook to reflect reality.
This is because a call to an admission webhook does not guarantee the admitted object will be persisted as is, or at all.
Later webhooks can modify the content of the object, a conflict could be encountered while writing to storage,
or the server could power off before persisting the object.
Additionally, webhooks with side effects must skip those side-effects when dryRun: true admission requests are handled.
A webhook must explicitly indicate that it will not have side-effects when run with dryRun,
or the dry-run request will not be sent to the webhook and the API request will fail instead.
Webhooks indicate whether they have side effects using the sideEffects field in the webhook configuration:
None: calling the webhook will have no side effects.
NoneOnDryRun: calling the webhook will possibly have side effects, but if a request with
dryRun: true is sent to the webhook, the webhook will suppress the side effects (the webhook
is dryRun-aware).
Here is an example of a validating webhook indicating it has no side effects on dryRun: true requests:
Because webhooks add to API request latency, they should evaluate as quickly as possible.
timeoutSeconds allows configuring how long the API server should wait for a webhook to respond
before treating the call as a failure.
If the timeout expires before the webhook responds, the webhook call will be ignored or
the API call will be rejected based on the failure policy.
The timeout value must be between 1 and 30 seconds.
Here is an example of a validating webhook with a custom timeout of 2 seconds:
The timeout for an admission webhook defaults to 10 seconds.
Reinvocation policy
A single ordering of mutating admissions plugins (including webhooks) does not work for all cases
(see https://issue.k8s.io/64333 as an example). A mutating webhook can add a new sub-structure
to the object (like adding a container to a pod), and other mutating plugins which have already
run may have opinions on those new structures (like setting an imagePullPolicy on all containers).
To allow mutating admission plugins to observe changes made by other plugins,
built-in mutating admission plugins are re-run if a mutating webhook modifies an object,
and mutating webhooks can specify a reinvocationPolicy to control whether they are reinvoked as well.
reinvocationPolicy may be set to Never or IfNeeded. It defaults to Never.
Never: the webhook must not be called more than once in a single admission evaluation.
IfNeeded: the webhook may be called again as part of the admission evaluation if the object
being admitted is modified by other admission plugins after the initial webhook call.
The important elements to note are:
The number of additional invocations is not guaranteed to be exactly one.
If additional invocations result in further modifications to the object, webhooks are not
guaranteed to be invoked again.
Webhooks that use this option may be reordered to minimize the number of additional invocations.
To validate an object after all mutations are guaranteed complete, use a validating admission
webhook instead (recommended for webhooks with side-effects).
Here is an example of a mutating webhook opting into being re-invoked if later admission plugins
modify the object:
Mutating webhooks must be idempotent, able to successfully process an object they have already admitted
and potentially modified. This is true for all mutating admission webhooks, since any change they can make
in an object could already exist in the user-provided object, but it is essential for webhooks that opt into reinvocation.
Failure policy
failurePolicy defines how unrecognized errors and timeout errors from the admission webhook
are handled. Allowed values are Ignore or Fail.
Ignore means that an error calling the webhook is ignored and the API request is allowed to continue.
Fail means that an error calling the webhook causes the admission to fail and the API request to be rejected.
Here is a mutating webhook configured to reject an API request if errors are encountered calling the admission webhook:
The default failurePolicy for an admission webhooks is Fail.
Monitoring admission webhooks
The API server provides ways to monitor admission webhook behaviors. These
monitoring mechanisms help cluster admins to answer questions like:
Which mutating webhook mutated the object in a API request?
What change did the mutating webhook applied to the object?
Which webhooks are frequently rejecting API requests? What's the reason for a rejection?
Mutating webhook auditing annotations
Sometimes it's useful to know which mutating webhook mutated the object in a API request, and what change did the
webhook apply.
The Kubernetes API server performs auditing on each
mutating webhook invocation. Each invocation generates an auditing annotation
capturing if a request object is mutated by the invocation, and optionally generates an annotation
capturing the applied patch from the webhook admission response. The annotations are set in the
audit event for given request on given stage of its execution, which is then pre-processed
according to a certain policy and written to a backend.
The audit level of a event determines which annotations get recorded:
At Metadata audit level or higher, an annotation with key
mutation.webhook.admission.k8s.io/round_{round idx}_index_{order idx} gets logged with JSON
payload indicating a webhook gets invoked for given request and whether it mutated the object or not.
For example, the following annotation gets recorded for a webhook being reinvoked. The webhook is
ordered the third in the mutating webhook chain, and didn't mutated the request object during the
invocation.
# the audit event recorded{"kind": "Event","apiVersion": "audit.k8s.io/v1","annotations": {"mutation.webhook.admission.k8s.io/round_1_index_2": "{\"configuration\":\"my-mutating-webhook-configuration.example.com\",\"webhook\":\"my-webhook.example.com\",\"mutated\": false}"# other annotations...}# other fields...}
# the annotation value deserialized{"configuration": "my-mutating-webhook-configuration.example.com","webhook": "my-webhook.example.com","mutated": false}
The following annotation gets recorded for a webhook being invoked in the first round. The webhook
is ordered the first in the mutating webhook chain, and mutated the request object during the
invocation.
# the audit event recorded{"kind": "Event","apiVersion": "audit.k8s.io/v1","annotations": {"mutation.webhook.admission.k8s.io/round_0_index_0": "{\"configuration\":\"my-mutating-webhook-configuration.example.com\",\"webhook\":\"my-webhook-always-mutate.example.com\",\"mutated\": true}"# other annotations...}# other fields...}
# the annotation value deserialized{"configuration": "my-mutating-webhook-configuration.example.com","webhook": "my-webhook-always-mutate.example.com","mutated": true}
At Request audit level or higher, an annotation with key
patch.webhook.admission.k8s.io/round_{round idx}_index_{order idx} gets logged with JSON payload indicating
a webhook gets invoked for given request and what patch gets applied to the request object.
For example, the following annotation gets recorded for a webhook being reinvoked. The webhook is ordered the fourth in the
mutating webhook chain, and responded with a JSON patch which got applied to the request object.
# the audit event recorded{"kind": "Event","apiVersion": "audit.k8s.io/v1","annotations": {"patch.webhook.admission.k8s.io/round_1_index_3": "{\"configuration\":\"my-other-mutating-webhook-configuration.example.com\",\"webhook\":\"my-webhook-always-mutate.example.com\",\"patch\":[{\"op\":\"add\",\"path\":\"/data/mutation-stage\",\"value\":\"yes\"}],\"patchType\":\"JSONPatch\"}"# other annotations...}# other fields...}
# the annotation value deserialized{"configuration": "my-other-mutating-webhook-configuration.example.com","webhook": "my-webhook-always-mutate.example.com","patchType": "JSONPatch","patch": [{"op": "add","path": "/data/mutation-stage","value": "yes"}]}
Admission webhook metrics
The API server exposes Prometheus metrics from the /metrics endpoint, which can be used for monitoring and
diagnosing API server status. The following metrics record status related to admission webhooks.
API server admission webhook rejection count
Sometimes it's useful to know which admission webhooks are frequently rejecting API requests, and the
reason for a rejection.
The API server exposes a Prometheus counter metric recording admission webhook rejections. The
metrics are labelled to identify the causes of webhook rejection(s):
name: the name of the webhook that rejected a request.
operation: the operation type of the request, can be one of CREATE,
UPDATE, DELETE and CONNECT.
type: the admission webhook type, can be one of admit and validating.
error_type: identifies if an error occurred during the webhook invocation
that caused the rejection. Its value can be one of:
calling_webhook_error: unrecognized errors or timeout errors from the admission webhook happened and the
webhook's Failure policy is set to Fail.
no_error: no error occurred. The webhook rejected the request with allowed: false in the admission
response. The metrics label rejection_code records the .status.code set in the admission response.
apiserver_internal_error: an API server internal error happened.
rejection_code: the HTTP status code set in the admission response when a
webhook rejected a request.
Example of the rejection count metrics:
# HELP apiserver_admission_webhook_rejection_count [ALPHA] Admission webhook rejection count, identified by name and broken out for each admission type (validating or admit) and operation. Additional labels specify an error type (calling_webhook_error or apiserver_internal_error if an error occurred; no_error otherwise) and optionally a non-zero rejection code if the webhook rejects the request with an HTTP status code (honored by the apiserver when the code is greater or equal to 400). Codes greater than 600 are truncated to 600, to keep the metrics cardinality bounded.
# TYPE apiserver_admission_webhook_rejection_count counter
apiserver_admission_webhook_rejection_count{error_type="calling_webhook_error",name="always-timeout-webhook.example.com",operation="CREATE",rejection_code="0",type="validating"} 1
apiserver_admission_webhook_rejection_count{error_type="calling_webhook_error",name="invalid-admission-response-webhook.example.com",operation="CREATE",rejection_code="0",type="validating"} 1
apiserver_admission_webhook_rejection_count{error_type="no_error",name="deny-unwanted-configmap-data.example.com",operation="CREATE",rejection_code="400",type="validating"} 13
Best practices and warnings
Idempotence
An idempotent mutating admission webhook is able to successfully process an object it has already admitted
and potentially modified. The admission can be applied multiple times without changing the result beyond
the initial application.
Example of idempotent mutating admission webhooks:
For a CREATE pod request, set the field .spec.securityContext.runAsNonRoot of the
pod to true, to enforce security best practices.
For a CREATE pod request, if the field .spec.containers[].resources.limits
of a container is not set, set default resource limits.
For a CREATE pod request, inject a sidecar container with name foo-sidecar if no container
with the name foo-sidecar already exists.
In the cases above, the webhook can be safely reinvoked, or admit an object that already has the fields set.
Example of non-idempotent mutating admission webhooks:
For a CREATE pod request, inject a sidecar container with name foo-sidecar
suffixed with the current timestamp (e.g. foo-sidecar-19700101-000000).
For a CREATE/UPDATE pod request, reject if the pod has label "env" set,
otherwise add an "env": "prod" label to the pod.
For a CREATE pod request, blindly append a sidecar container named
foo-sidecar without looking to see if there is already a foo-sidecar
container in the pod.
In the first case above, reinvoking the webhook can result in the same sidecar being injected multiple times to a pod, each time
with a different container name. Similarly the webhook can inject duplicated containers if the sidecar already exists in
a user-provided pod.
In the second case above, reinvoking the webhook will result in the webhook failing on its own output.
In the third case above, reinvoking the webhook will result in duplicated containers in the pod spec, which makes
the request invalid and rejected by the API server.
Intercepting all versions of an object
It is recommended that admission webhooks should always intercept all versions of an object by setting .webhooks[].matchPolicy
to Equivalent. It is also recommended that admission webhooks should prefer registering for stable versions of resources.
Failure to intercept all versions of an object can result in admission policies not being enforced for requests in certain
versions. See Matching requests: matchPolicy for examples.
Availability
It is recommended that admission webhooks should evaluate as quickly as possible (typically in
milliseconds), since they add to API request latency.
It is encouraged to use a small timeout for webhooks. See Timeouts for more detail.
It is recommended that admission webhooks should leverage some format of load-balancing, to
provide high availability and performance benefits. If a webhook is running within the cluster,
you can run multiple webhook backends behind a service to leverage the load-balancing that service
supports.
Guaranteeing the final state of the object is seen
Admission webhooks that need to guarantee they see the final state of the object in order to enforce policy
should use a validating admission webhook, since objects can be modified after being seen by mutating webhooks.
For example, a mutating admission webhook is configured to inject a sidecar container with name
"foo-sidecar" on every CREATE pod request. If the sidecar must be present, a validating
admisson webhook should also be configured to intercept CREATE pod requests, and validate that a
container with name "foo-sidecar" with the expected configuration exists in the to-be-created
object.
Avoiding deadlocks in self-hosted webhooks
A webhook running inside the cluster might cause deadlocks for its own deployment if it is configured
to intercept resources required to start its own pods.
For example, a mutating admission webhook is configured to admit CREATE pod requests only if a certain label is set in the
pod (e.g. "env": "prod"). The webhook server runs in a deployment which doesn't set the "env" label.
When a node that runs the webhook server pods
becomes unhealthy, the webhook deployment will try to reschedule the pods to another node. However the requests will
get rejected by the existing webhook server since the "env" label is unset, and the migration cannot happen.
It is recommended to exclude the namespace where your webhook is running with a
namespaceSelector.
Side effects
It is recommended that admission webhooks should avoid side effects if possible, which means the webhooks operate only on the
content of the AdmissionReview sent to them, and do not make out-of-band changes. The .webhooks[].sideEffects field should
be set to None if a webhook doesn't have any side effect.
If side effects are required during the admission evaluation, they must be suppressed when processing an
AdmissionReview object with dryRun set to true, and the .webhooks[].sideEffects field should be
set to NoneOnDryRun. See Side effects for more detail.
Avoiding operating on the kube-system namespace
The kube-system namespace contains objects created by the Kubernetes system,
e.g. service accounts for the control plane components, pods like kube-dns.
Accidentally mutating or rejecting requests in the kube-system namespace may
cause the control plane components to stop functioning or introduce unknown behavior.
If your admission webhooks don't intend to modify the behavior of the Kubernetes control
plane, exclude the kube-system namespace from being intercepted using a
namespaceSelector.
3.6 - Managing Service Accounts
A ServiceAccount provides an identity for processes that run in a Pod.
A process inside a Pod can use the identity of its associated service account to
authenticate to the cluster's API server.
This task guide explains some of the concepts behind ServiceAccounts. The
guide also explains how to obtain or revoke tokens that represent
ServiceAccounts.
Before you begin
You need to have a Kubernetes cluster, and the kubectl command-line tool must
be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a
cluster, you can create one by using
minikube
or you can use one of these Kubernetes playgrounds:
To be able to follow these steps exactly, ensure you have a namespace named
examplens.
If you don't, create one by running:
kubectl create namespace examplens
User accounts versus service accounts
Kubernetes distinguishes between the concept of a user account and a service account
for a number of reasons:
User accounts are for humans. Service accounts are for application processes,
which (for Kubernetes) run in containers that are part of pods.
User accounts are intended to be global: names must be unique across all
namespaces of a cluster. No matter what namespace you look at, a particular
username that represents a user represents the same user.
In Kubernetes, service accounts are namespaced: two different namespaces can
contain ServiceAccounts that have identical names.
Typically, a cluster's user accounts might be synchronised from a corporate
database, where new user account creation requires special privileges and is
tied to complex business processes. By contrast, service account creation is
intended to be more lightweight, allowing cluster users to create service accounts
for specific tasks on demand. Separating ServiceAccount creation from the steps to
onboard human users makes it easier for workloads to follow the principle of
least privilege.
Auditing considerations for humans and service accounts may differ; the separation
makes that easier to achieve.
A configuration bundle for a complex system may include definition of various service
accounts for components of that system. Because service accounts can be created
without many constraints and have namespaced names, such configuration is
usually portable.
Here's an example of how that looks for a launched Pod:
...- name:kube-api-access-<random-suffix>projected:sources:- serviceAccountToken:path:token# must match the path the app expects- configMap:items:- key:ca.crtpath:ca.crtname:kube-root-ca.crt- downwardAPI:items:- fieldRef:apiVersion:v1fieldPath:metadata.namespacepath:namespace
That manifest snippet defines a projected volume that consists of three sources. In this case,
each source also represents a single path within that volume. The three sources are:
A serviceAccountToken source, that contains a token that the kubelet acquires from kube-apiserver.
The kubelet fetches time-bound tokens using the TokenRequest API. A token served for a TokenRequest expires
either when the pod is deleted or after a defined lifespan (by default, that is 1 hour).
The kubelet also refreshes that token before the token expires.
The token is bound to the specific Pod and has the kube-apiserver as its audience.
This mechanism superseded an earlier mechanism that added a volume based on a Secret,
where the Secret represented the ServiceAccount for the Pod, but did not expire.
A configMap source. The ConfigMap contains a bundle of certificate authority data. Pods can use these
certificates to make sure that they are connecting to your cluster's kube-apiserver (and not to middlebox
or an accidentally misconfigured peer).
A downwardAPI source that looks up the name of the namespace containing the Pod, and makes
that name information available to application code running inside the Pod.
Any container within the Pod that mounts this particular volume can access the above information.
Note: There is no specific mechanism to invalidate a token issued via TokenRequest. If you no longer
trust a bound service account token for a Pod, you can delete that Pod. Deleting a Pod expires
its bound service account tokens.
Manual Secret management for ServiceAccounts
Versions of Kubernetes before v1.22 automatically created credentials for accessing
the Kubernetes API. This older mechanism was based on creating token Secrets that
could then be mounted into running Pods.
In more recent versions, including Kubernetes v1.28, API credentials
are obtained directly using the
TokenRequest API,
and are mounted into Pods using a projected volume.
The tokens obtained using this method have bounded lifetimes, and are automatically
invalidated when the Pod they are mounted into is deleted.
You can still manually create a Secret to hold a service account token; for example, if you need a token that never expires.
Once you manually create a Secret and link it to a ServiceAccount, the Kubernetes control plane automatically populates the token into that Secret.
Note: Although the manual mechanism for creating a long-lived ServiceAccount token exists,
using TokenRequest
to obtain short-lived API access tokens is recommended instead.
Control plane details
ServiceAccount controller
A ServiceAccount controller manages the ServiceAccounts inside namespaces, and
ensures a ServiceAccount named "default" exists in every active namespace.
Token controller
The service account token controller runs as part of kube-controller-manager.
This controller acts asynchronously. It:
watches for ServiceAccount deletion and deletes all corresponding ServiceAccount
token Secrets.
watches for ServiceAccount token Secret addition, and ensures the referenced
ServiceAccount exists, and adds a token to the Secret if needed.
watches for Secret deletion and removes a reference from the corresponding
ServiceAccount if needed.
You must pass a service account private key file to the token controller in
the kube-controller-manager using the --service-account-private-key-file
flag. The private key is used to sign generated service account tokens.
Similarly, you must pass the corresponding public key to the kube-apiserver
using the --service-account-key-file flag. The public key will be used to
verify the tokens during authentication.
ServiceAccount admission controller
The modification of pods is implemented via a plugin
called an Admission Controller.
It is part of the API server.
This admission controller acts synchronously to modify pods as they are created.
When this plugin is active (and it is by default on most distributions), then
it does the following when a Pod is created:
If the pod does not have a .spec.serviceAccountName set, the admission controller sets the name of the
ServiceAccount for this incoming Pod to default.
The admission controller ensures that the ServiceAccount referenced by the incoming Pod exists. If there
is no ServiceAccount with a matching name, the admission controller rejects the incoming Pod. That check
applies even for the default ServiceAccount.
Provided that neither the ServiceAccount's automountServiceAccountToken field nor the
Pod's automountServiceAccountToken field is set to false:
the admission controller mutates the incoming Pod, adding an extra
volume that contains
a token for API access.
the admission controller adds a volumeMount to each container in the Pod,
skipping any containers that already have a volume mount defined for the path
/var/run/secrets/kubernetes.io/serviceaccount.
For Linux containers, that volume is mounted at /var/run/secrets/kubernetes.io/serviceaccount;
on Windows nodes, the mount is at the equivalent path.
If the spec of the incoming Pod doesn't already contain any imagePullSecrets, then the
admission controller adds imagePullSecrets, copying them from the ServiceAccount.
TokenRequest API
FEATURE STATE:Kubernetes v1.22 [stable]
You use the TokenRequest
subresource of a ServiceAccount to obtain a time-bound token for that ServiceAccount.
You don't need to call this to obtain an API token for use within a container, since
the kubelet sets this up for you using a projected volume.
The Kubernetes control plane (specifically, the ServiceAccount admission controller)
adds a projected volume to Pods, and the kubelet ensures that this volume contains a token
that lets containers authenticate as the right ServiceAccount.
(This mechanism superseded an earlier mechanism that added a volume based on a Secret,
where the Secret represented the ServiceAccount for the Pod but did not expire.)
Here's an example of how that looks for a launched Pod:
That manifest snippet defines a projected volume that combines information from three sources:
A serviceAccountToken source, that contains a token that the kubelet acquires from kube-apiserver.
The kubelet fetches time-bound tokens using the TokenRequest API. A token served for a TokenRequest expires
either when the pod is deleted or after a defined lifespan (by default, that is 1 hour).
The token is bound to the specific Pod and has the kube-apiserver as its audience.
A configMap source. The ConfigMap contains a bundle of certificate authority data. Pods can use these
certificates to make sure that they are connecting to your cluster's kube-apiserver (and not to middlebox
or an accidentally misconfigured peer).
A downwardAPI source. This downwardAPI volume makes the name of the namespace containing the Pod available
to application code running inside the Pod.
Any container within the Pod that mounts this volume can access the above information.
Create additional API tokens
Caution: Only create long-lived API tokens if the token request mechanism
is not suitable. The token request mechanism provides time-limited tokens; because these
expire, they represent a lower risk to information security.
To create a non-expiring, persisted API token for a ServiceAccount, create a
Secret of type kubernetes.io/service-account-token with an annotation
referencing the ServiceAccount. The control plane then generates a long-lived token and
updates that Secret with that generated token data.
Learn more about Kubernetes authorization, including details about creating
policies using the supported authorization modules.
In Kubernetes, you must be authenticated (logged in) before your request can be
authorized (granted permission to access). For information about authentication,
see Controlling Access to the Kubernetes API.
Kubernetes expects attributes that are common to REST API requests. This means
that Kubernetes authorization works with existing organization-wide or
cloud-provider-wide access control systems which may handle other APIs besides
the Kubernetes API.
Determine Whether a Request is Allowed or Denied
Kubernetes authorizes API requests using the API server. It evaluates all of the
request attributes against all policies and allows or denies the request. All
parts of an API request must be allowed by some policy in order to proceed. This
means that permissions are denied by default.
(Although Kubernetes uses the API server, access controls and policies that
depend on specific fields of specific kinds of objects are handled by Admission
Controllers.)
When multiple authorization modules are configured, each is checked in sequence.
If any authorizer approves or denies a request, that decision is immediately
returned and no other authorizer is consulted. If all modules have no opinion on
the request, then the request is denied. A deny returns an HTTP status code 403.
Review Your Request Attributes
Kubernetes reviews only the following API request attributes:
user - The user string provided during authentication.
group - The list of group names to which the authenticated user belongs.
extra - A map of arbitrary string keys to string values, provided by the authentication layer.
API - Indicates whether the request is for an API resource.
Request path - Path to miscellaneous non-resource endpoints like /api or /healthz.
API request verb - API verbs like get, list, create, update, patch, watch, delete, and deletecollection are used for resource requests. To determine the request verb for a resource API endpoint, see Determine the request verb.
HTTP request verb - Lowercased HTTP methods like get, post, put, and delete are used for non-resource requests.
Resource - The ID or name of the resource that is being accessed (for resource requests only) -- For resource requests using get, update, patch, and delete verbs, you must provide the resource name.
Subresource - The subresource that is being accessed (for resource requests only).
Namespace - The namespace of the object that is being accessed (for namespaced resource requests only).
API group - The API Group being accessed (for resource requests only). An empty string designates the coreAPI group.
Determine the Request Verb
Non-resource requests
Requests to endpoints other than /api/v1/... or /apis/<group>/<version>/...
are considered "non-resource requests", and use the lower-cased HTTP method of the request as the verb.
For example, a GET request to endpoints like /api or /healthz would use get as the verb.
Resource requests
To determine the request verb for a resource API endpoint, review the HTTP verb
used and whether or not the request acts on an individual resource or a
collection of resources:
HTTP verb
request verb
POST
create
GET, HEAD
get (for individual resources), list (for collections, including full object content), watch (for watching an individual resource or collection of resources)
Caution: The get, list and watch verbs can all return the full details of a resource. In terms of the returned data they are equivalent. For example, list on secrets will still reveal the data attributes of any returned resources.
Kubernetes sometimes checks authorization for additional permissions using specialized verbs. For example:
impersonate verb on users, groups, and serviceaccounts in the core API group, and the userextras in the authentication.k8s.io API group.
Authorization Modes
The Kubernetes API server may authorize a request using one of several authorization modes:
Node - A special-purpose authorization mode that grants permissions to kubelets based on the pods they are scheduled to run. To learn more about using the Node authorization mode, see Node Authorization.
ABAC - Attribute-based access control (ABAC) defines an access control paradigm whereby access rights are granted to users through the use of policies which combine attributes together. The policies can use any type of attributes (user attributes, resource attributes, object, environment attributes, etc). To learn more about using the ABAC mode, see ABAC Mode.
RBAC - Role-based access control (RBAC) is a method of regulating access to computer or network resources based on the roles of individual users within an enterprise. In this context, access is the ability of an individual user to perform a specific task, such as view, create, or modify a file. To learn more about using the RBAC mode, see RBAC Mode
When specified RBAC (Role-Based Access Control) uses the rbac.authorization.k8s.io API group to drive authorization decisions, allowing admins to dynamically configure permission policies through the Kubernetes API.
To enable RBAC, start the apiserver with --authorization-mode=RBAC.
Webhook - A WebHook is an HTTP callback: an HTTP POST that occurs when something happens; a simple event-notification via HTTP POST. A web application implementing WebHooks will POST a message to a URL when certain things happen. To learn more about using the Webhook mode, see Webhook Mode.
Checking API Access
kubectl provides the auth can-i subcommand for quickly querying the API authorization layer.
The command uses the SelfSubjectAccessReview API to determine if the current user can perform
a given action, and works regardless of the authorization mode used.
kubectl auth can-i create deployments --namespace dev
SelfSubjectAccessReview is part of the authorization.k8s.io API group, which
exposes the API server authorization to external services. Other resources in
this group include:
SubjectAccessReview - Access review for any user, not only the current one. Useful for delegating authorization decisions to the API server. For example, the kubelet and extension API servers use this to determine user access to their own APIs.
LocalSubjectAccessReview - Like SubjectAccessReview but restricted to a specific namespace.
SelfSubjectRulesReview - A review which returns the set of actions a user can perform within a namespace. Useful for users to quickly summarize their own access, or for UIs to hide/show actions.
These APIs can be queried by creating normal Kubernetes resources, where the response "status"
field of the returned object is the result of the query.
You must include a flag in your policy to indicate which authorization module
your policies include:
The following flags can be used:
--authorization-mode=ABAC Attribute-Based Access Control (ABAC) mode allows you to configure policies using local files.
--authorization-mode=RBAC Role-based access control (RBAC) mode allows you to create and store policies using the Kubernetes API.
--authorization-mode=Webhook WebHook is an HTTP callback mode that allows you to manage authorization using a remote REST endpoint.
--authorization-mode=Node Node authorization is a special-purpose authorization mode that specifically authorizes API requests made by kubelets.
--authorization-mode=AlwaysDeny This flag blocks all requests. Use this flag only for testing.
--authorization-mode=AlwaysAllow This flag allows all requests. Use this flag only if you do not require authorization for your API requests.
You can choose more than one authorization module. Modules are checked in order
so an earlier module has higher priority to allow or deny a request.
Privilege escalation via workload creation or edits
Users who can create/edit pods in a namespace, either directly or through a controller
such as an operator, could escalate their privileges in that namespace.
Caution: System administrators, use care when granting access to create or edit workloads.
Details of how these can be misused are documented in escalation paths
Escalation paths
Mounting arbitrary secrets in that namespace
Can be used to access secrets meant for other workloads
Can be used to obtain a more privileged service account's service account token
Using arbitrary Service Accounts in that namespace
Can perform Kubernetes API actions as another workload (impersonation)
Can perform any privileged actions that Service Account has
Mounting configmaps meant for other workloads in that namespace
Can be used to obtain information meant for other workloads, such as DB host names.
Mounting volumes meant for other workloads in that namespace
Can be used to obtain information meant for other workloads, and change it.
Caution: System administrators should be cautious when deploying CRDs that
change the above areas. These may open privilege escalations paths.
This should be considered when deciding on your RBAC controls.
Role-based access control (RBAC) is a method of regulating access to computer or
network resources based on the roles of individual users within your organization.
RBAC authorization uses the rbac.authorization.k8s.ioAPI group to drive authorization
decisions, allowing you to dynamically configure policies through the Kubernetes API.
To enable RBAC, start the API server
with the --authorization-mode flag set to a comma-separated list that includes RBAC;
for example:
The RBAC API declares four kinds of Kubernetes object: Role, ClusterRole,
RoleBinding and ClusterRoleBinding. You can describe or amend the RBAC
objects
using tools such as kubectl, just like any other Kubernetes object.
Caution: These objects, by design, impose access restrictions. If you are making changes
to a cluster as you learn, see
privilege escalation prevention and bootstrapping
to understand how those restrictions can prevent you making some changes.
Role and ClusterRole
An RBAC Role or ClusterRole contains rules that represent a set of permissions.
Permissions are purely additive (there are no "deny" rules).
A Role always sets permissions within a particular namespace;
when you create a Role, you have to specify the namespace it belongs in.
ClusterRole, by contrast, is a non-namespaced resource. The resources have different names (Role
and ClusterRole) because a Kubernetes object always has to be either namespaced or not namespaced;
it can't be both.
ClusterRoles have several uses. You can use a ClusterRole to:
define permissions on namespaced resources and be granted access within individual namespace(s)
define permissions on namespaced resources and be granted access across all namespaces
define permissions on cluster-scoped resources
If you want to define a role within a namespace, use a Role; if you want to define
a role cluster-wide, use a ClusterRole.
Role example
Here's an example Role in the "default" namespace that can be used to grant read access to
pods:
apiVersion:rbac.authorization.k8s.io/v1kind:Rolemetadata:namespace:defaultname:pod-readerrules:- apiGroups:[""]# "" indicates the core API groupresources:["pods"]verbs:["get","watch","list"]
ClusterRole example
A ClusterRole can be used to grant the same permissions as a Role.
Because ClusterRoles are cluster-scoped, you can also use them to grant access to:
namespaced resources (like Pods), across all namespaces
For example: you can use a ClusterRole to allow a particular user to run
kubectl get pods --all-namespaces
Here is an example of a ClusterRole that can be used to grant read access to
secrets in any particular namespace,
or across all namespaces (depending on how it is bound):
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:# "namespace" omitted since ClusterRoles are not namespacedname:secret-readerrules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing Secret# objects is "secrets"resources:["secrets"]verbs:["get","watch","list"]
The name of a Role or a ClusterRole object must be a valid
path segment name.
RoleBinding and ClusterRoleBinding
A role binding grants the permissions defined in a role to a user or set of users.
It holds a list of subjects (users, groups, or service accounts), and a reference to the
role being granted.
A RoleBinding grants permissions within a specific namespace whereas a ClusterRoleBinding
grants that access cluster-wide.
A RoleBinding may reference any Role in the same namespace. Alternatively, a RoleBinding
can reference a ClusterRole and bind that ClusterRole to the namespace of the RoleBinding.
If you want to bind a ClusterRole to all the namespaces in your cluster, you use a
ClusterRoleBinding.
The name of a RoleBinding or ClusterRoleBinding object must be a valid
path segment name.
RoleBinding examples
Here is an example of a RoleBinding that grants the "pod-reader" Role to the user "jane"
within the "default" namespace.
This allows "jane" to read pods in the "default" namespace.
apiVersion:rbac.authorization.k8s.io/v1# This role binding allows "jane" to read pods in the "default" namespace.# You need to already have a Role named "pod-reader" in that namespace.kind:RoleBindingmetadata:name:read-podsnamespace:defaultsubjects:# You can specify more than one "subject"- kind:Username:jane# "name" is case sensitiveapiGroup:rbac.authorization.k8s.ioroleRef:# "roleRef" specifies the binding to a Role / ClusterRolekind:Role#this must be Role or ClusterRolename:pod-reader# this must match the name of the Role or ClusterRole you wish to bind toapiGroup:rbac.authorization.k8s.io
A RoleBinding can also reference a ClusterRole to grant the permissions defined in that
ClusterRole to resources inside the RoleBinding's namespace. This kind of reference
lets you define a set of common roles across your cluster, then reuse them within
multiple namespaces.
For instance, even though the following RoleBinding refers to a ClusterRole,
"dave" (the subject, case sensitive) will only be able to read Secrets in the "development"
namespace, because the RoleBinding's namespace (in its metadata) is "development".
apiVersion:rbac.authorization.k8s.io/v1# This role binding allows "dave" to read secrets in the "development" namespace.# You need to already have a ClusterRole named "secret-reader".kind:RoleBindingmetadata:name:read-secrets## The namespace of the RoleBinding determines where the permissions are granted.# This only grants permissions within the "development" namespace.namespace:developmentsubjects:- kind:Username:dave# Name is case sensitiveapiGroup:rbac.authorization.k8s.ioroleRef:kind:ClusterRolename:secret-readerapiGroup:rbac.authorization.k8s.io
ClusterRoleBinding example
To grant permissions across a whole cluster, you can use a ClusterRoleBinding.
The following ClusterRoleBinding allows any user in the group "manager" to read
secrets in any namespace.
apiVersion:rbac.authorization.k8s.io/v1# This cluster role binding allows anyone in the "manager" group to read secrets in any namespace.kind:ClusterRoleBindingmetadata:name:read-secrets-globalsubjects:- kind:Groupname:manager# Name is case sensitiveapiGroup:rbac.authorization.k8s.ioroleRef:kind:ClusterRolename:secret-readerapiGroup:rbac.authorization.k8s.io
After you create a binding, you cannot change the Role or ClusterRole that it refers to.
If you try to change a binding's roleRef, you get a validation error. If you do want
to change the roleRef for a binding, you need to remove the binding object and create
a replacement.
There are two reasons for this restriction:
Making roleRef immutable allows granting someone update permission on an existing binding
object, so that they can manage the list of subjects, without being able to change
the role that is granted to those subjects.
A binding to a different role is a fundamentally different binding.
Requiring a binding to be deleted/recreated in order to change the roleRef
ensures the full list of subjects in the binding is intended to be granted
the new role (as opposed to enabling or accidentally modifying only the roleRef
without verifying all of the existing subjects should be given the new role's
permissions).
The kubectl auth reconcile command-line utility creates or updates a manifest file containing RBAC objects,
and handles deleting and recreating binding objects if required to change the role they refer to.
See command usage and examples for more information.
Referring to resources
In the Kubernetes API, most resources are represented and accessed using a string representation of
their object name, such as pods for a Pod. RBAC refers to resources using exactly the same
name that appears in the URL for the relevant API endpoint.
Some Kubernetes APIs involve a
subresource, such as the logs for a Pod. A request for a Pod's logs looks like:
GET /api/v1/namespaces/{namespace}/pods/{name}/log
In this case, pods is the namespaced resource for Pod resources, and log is a
subresource of pods. To represent this in an RBAC role, use a slash (/) to
delimit the resource and subresource. To allow a subject to read pods and
also access the log subresource for each of those Pods, you write:
You can also refer to resources by name for certain requests through the resourceNames list.
When specified, requests can be restricted to individual instances of a resource.
Here is an example that restricts its subject to only get or update a
ConfigMap named my-configmap:
apiVersion:rbac.authorization.k8s.io/v1kind:Rolemetadata:namespace:defaultname:configmap-updaterrules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing ConfigMap# objects is "configmaps"resources:["configmaps"]resourceNames:["my-configmap"]verbs:["update","get"]
Note: You cannot restrict create or deletecollection requests by their resource name.
For create, this limitation is because the name of the new object may not be known at authorization time.
If you restrict list or watch by resourceName, clients must include a metadata.name field selector in their list or watch request that matches the specified resourceName in order to be authorized.
For example, kubectl get configmaps --field-selector=metadata.name=my-configmap
Rather than referring to individual resources, apiGroups, and verbs,
you can use the wildcard * symbol to refer to all such objects.
For nonResourceURLs, you can use the wildcard * as a suffix glob match.
For resourceNames, an empty set means that everything is allowed.
Here is an example that allows access to perform any current and future action on
all current and future resources in the example.com API group.
This is similar to the built-in cluster-admin role.
apiVersion:rbac.authorization.k8s.io/v1kind:Rolemetadata:namespace:defaultname:example.com-superuser# DO NOT USE THIS ROLE, IT IS JUST AN EXAMPLErules:- apiGroups:["example.com"]resources:["*"]verbs:["*"]
Caution: Using wildcards in resource and verb entries could result in overly permissive access being granted
to sensitive resources.
For instance, if a new resource type is added, or a new subresource is added,
or a new custom verb is checked, the wildcard entry automatically grants access, which may be undesirable.
The principle of least privilege
should be employed, using specific resources and verbs to ensure only the permissions required for the
workload to function correctly are applied.
Aggregated ClusterRoles
You can aggregate several ClusterRoles into one combined ClusterRole.
A controller, running as part of the cluster control plane, watches for ClusterRole
objects with an aggregationRule set. The aggregationRule defines a label
selector that the controller
uses to match other ClusterRole objects that should be combined into the rules
field of this one.
Caution: The control plane overwrites any values that you manually specify in the rules field of an
aggregate ClusterRole. If you want to change or add rules, do so in the ClusterRole objects
that are selected by the aggregationRule.
Here is an example aggregated ClusterRole:
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:monitoringaggregationRule:clusterRoleSelectors:- matchLabels:rbac.example.com/aggregate-to-monitoring:"true"rules:[]# The control plane automatically fills in the rules
If you create a new ClusterRole that matches the label selector of an existing aggregated ClusterRole,
that change triggers adding the new rules into the aggregated ClusterRole.
Here is an example that adds rules to the "monitoring" ClusterRole, by creating another
ClusterRole labeled rbac.example.com/aggregate-to-monitoring: true.
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:monitoring-endpointslabels:rbac.example.com/aggregate-to-monitoring:"true"# When you create the "monitoring-endpoints" ClusterRole,# the rules below will be added to the "monitoring" ClusterRole.rules:- apiGroups:[""]resources:["services","endpointslices","pods"]verbs:["get","list","watch"]
The default user-facing roles use ClusterRole aggregation. This lets you,
as a cluster administrator, include rules for custom resources, such as those served by
CustomResourceDefinitions
or aggregated API servers, to extend the default roles.
For example: the following ClusterRoles let the "admin" and "edit" default roles manage the custom resource
named CronTab, whereas the "view" role can perform only read actions on CronTab resources.
You can assume that CronTab objects are named "crontabs" in URLs as seen by the API server.
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:aggregate-cron-tabs-editlabels:# Add these permissions to the "admin" and "edit" default roles.rbac.authorization.k8s.io/aggregate-to-admin:"true"rbac.authorization.k8s.io/aggregate-to-edit:"true"rules:- apiGroups:["stable.example.com"]resources:["crontabs"]verbs:["get","list","watch","create","update","patch","delete"]---kind:ClusterRoleapiVersion:rbac.authorization.k8s.io/v1metadata:name:aggregate-cron-tabs-viewlabels:# Add these permissions to the "view" default role.rbac.authorization.k8s.io/aggregate-to-view:"true"rules:- apiGroups:["stable.example.com"]resources:["crontabs"]verbs:["get","list","watch"]
Role examples
The following examples are excerpts from Role or ClusterRole objects, showing only
the rules section.
Allow reading "pods" resources in the core
API Group:
rules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing Pod# objects is "pods"resources:["pods"]verbs:["get","list","watch"]
Allow reading/writing Deployments (at the HTTP level: objects with "deployments"
in the resource part of their URL) in the "apps" API groups:
rules:- apiGroups:["apps"]## at the HTTP level, the name of the resource for accessing Deployment# objects is "deployments"resources:["deployments"]verbs:["get","list","watch","create","update","patch","delete"]
Allow reading Pods in the core API group, as well as reading or writing Job
resources in the "batch" API group:
rules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing Pod# objects is "pods"resources:["pods"]verbs:["get","list","watch"]- apiGroups:["batch"]## at the HTTP level, the name of the resource for accessing Job# objects is "jobs"resources:["jobs"]verbs:["get","list","watch","create","update","patch","delete"]
Allow reading a ConfigMap named "my-config" (must be bound with a
RoleBinding to limit to a single ConfigMap in a single namespace):
rules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing ConfigMap# objects is "configmaps"resources:["configmaps"]resourceNames:["my-config"]verbs:["get"]
Allow reading the resource "nodes" in the core group (because a
Node is cluster-scoped, this must be in a ClusterRole bound with a
ClusterRoleBinding to be effective):
rules:- apiGroups:[""]## at the HTTP level, the name of the resource for accessing Node# objects is "nodes"resources:["nodes"]verbs:["get","list","watch"]
Allow GET and POST requests to the non-resource endpoint /healthz and
all subpaths (must be in a ClusterRole bound with a ClusterRoleBinding
to be effective):
rules:- nonResourceURLs:["/healthz","/healthz/*"]# '*' in a nonResourceURL is a suffix glob matchverbs:["get","post"]
Referring to subjects
A RoleBinding or ClusterRoleBinding binds a role to subjects.
Subjects can be groups, users or
ServiceAccounts.
Kubernetes represents usernames as strings.
These can be: plain names, such as "alice"; email-style names, like "bob@example.com";
or numeric user IDs represented as a string. It is up to you as a cluster administrator
to configure the authentication modules
so that authentication produces usernames in the format you want.
Caution: The prefix system: is reserved for Kubernetes system use, so you should ensure
that you don't have users or groups with names that start with system: by
accident.
Other than this special prefix, the RBAC authorization system does not require any format
for usernames.
In Kubernetes, Authenticator modules provide group information.
Groups, like users, are represented as strings, and that string has no format requirements,
other than that the prefix system: is reserved.
ServiceAccounts have names prefixed
with system:serviceaccount:, and belong to groups that have names prefixed with system:serviceaccounts:.
Note:
system:serviceaccount: (singular) is the prefix for service account usernames.
system:serviceaccounts: (plural) is the prefix for service account groups.
RoleBinding examples
The following examples are RoleBinding excerpts that only
show the subjects section.
API servers create a set of default ClusterRole and ClusterRoleBinding objects.
Many of these are system: prefixed, which indicates that the resource is directly
managed by the cluster control plane.
All of the default ClusterRoles and ClusterRoleBindings are labeled with kubernetes.io/bootstrapping=rbac-defaults.
Caution: Take care when modifying ClusterRoles and ClusterRoleBindings with names
that have a system: prefix.
Modifications to these resources can result in non-functional clusters.
Auto-reconciliation
At each start-up, the API server updates default cluster roles with any missing permissions,
and updates default cluster role bindings with any missing subjects.
This allows the cluster to repair accidental modifications, and helps to keep roles and role bindings
up-to-date as permissions and subjects change in new Kubernetes releases.
To opt out of this reconciliation, set the rbac.authorization.kubernetes.io/autoupdate
annotation on a default cluster role or rolebinding to false.
Be aware that missing default permissions and subjects can result in non-functional clusters.
Auto-reconciliation is enabled by default if the RBAC authorizer is active.
API discovery roles
Default role bindings authorize unauthenticated and authenticated users to read API information
that is deemed safe to be publicly accessible (including CustomResourceDefinitions).
To disable anonymous unauthenticated access, add --anonymous-auth=false to
the API server configuration.
To view the configuration of these roles via kubectl run:
kubectl get clusterroles system:discovery -o yaml
Note: If you edit that ClusterRole, your changes will be overwritten on API server restart
via auto-reconciliation. To avoid that overwriting,
either do not manually edit the role, or disable auto-reconciliation.
Kubernetes RBAC API discovery roles
Default ClusterRole
Default ClusterRoleBinding
Description
system:basic-user
system:authenticated group
Allows a user read-only access to basic information about themselves. Prior to v1.14, this role was also bound to system:unauthenticated by default.
system:discovery
system:authenticated group
Allows read-only access to API discovery endpoints needed to discover and negotiate an API level. Prior to v1.14, this role was also bound to system:unauthenticated by default.
system:public-info-viewer
system:authenticated and system:unauthenticated groups
Allows read-only access to non-sensitive information about the cluster. Introduced in Kubernetes v1.14.
User-facing roles
Some of the default ClusterRoles are not system: prefixed. These are intended to be user-facing roles.
They include super-user roles (cluster-admin), roles intended to be granted cluster-wide
using ClusterRoleBindings, and roles intended to be granted within particular
namespaces using RoleBindings (admin, edit, view).
User-facing ClusterRoles use ClusterRole aggregation to allow admins to include
rules for custom resources on these ClusterRoles. To add rules to the admin, edit, or view roles, create
a ClusterRole with one or more of the following labels:
Allows super-user access to perform any action on any resource.
When used in a ClusterRoleBinding, it gives full control over every resource in the cluster and in all namespaces.
When used in a RoleBinding, it gives full control over every resource in the role binding's namespace, including the namespace itself.
admin
None
Allows admin access, intended to be granted within a namespace using a RoleBinding.
If used in a RoleBinding, allows read/write access to most resources in a namespace,
including the ability to create roles and role bindings within the namespace.
This role does not allow write access to resource quota or to the namespace itself.
This role also does not allow write access to EndpointSlices (or Endpoints) in clusters created
using Kubernetes v1.22+. More information is available in the
"Write Access for EndpointSlices and Endpoints" section.
edit
None
Allows read/write access to most objects in a namespace.
This role does not allow viewing or modifying roles or role bindings.
However, this role allows accessing Secrets and running Pods as any ServiceAccount in
the namespace, so it can be used to gain the API access levels of any ServiceAccount in
the namespace. This role also does not allow write access to EndpointSlices (or Endpoints) in
clusters created using Kubernetes v1.22+. More information is available in the
"Write Access for EndpointSlices and Endpoints" section.
view
None
Allows read-only access to see most objects in a namespace.
It does not allow viewing roles or role bindings.
This role does not allow viewing Secrets, since reading
the contents of Secrets enables access to ServiceAccount credentials
in the namespace, which would allow API access as any ServiceAccount
in the namespace (a form of privilege escalation).
Core component roles
Default ClusterRole
Default ClusterRoleBinding
Description
system:kube-scheduler
system:kube-scheduler user
Allows access to the resources required by the scheduler component.
system:volume-scheduler
system:kube-scheduler user
Allows access to the volume resources required by the kube-scheduler component.
system:kube-controller-manager
system:kube-controller-manager user
Allows access to the resources required by the controller manager component.
The permissions required by individual controllers are detailed in the controller roles.
system:node
None
Allows access to resources required by the kubelet, including read access to all secrets, and write access to all pod status objects.
You should use the Node authorizer and NodeRestriction admission plugin instead of the system:node role, and allow granting API access to kubelets based on the Pods scheduled to run on them.
The system:node role only exists for compatibility with Kubernetes clusters upgraded from versions prior to v1.8.
system:node-proxier
system:kube-proxy user
Allows access to the resources required by the kube-proxy component.
Other component roles
Default ClusterRole
Default ClusterRoleBinding
Description
system:auth-delegator
None
Allows delegated authentication and authorization checks.
This is commonly used by add-on API servers for unified authentication and authorization.
Allows read access to control-plane monitoring endpoints (i.e. kube-apiserver liveness and readiness endpoints (/healthz, /livez, /readyz), the individual health-check endpoints (/healthz/*, /livez/*, /readyz/*), and /metrics). Note that individual health check endpoints and the metric endpoint may expose sensitive information.
Roles for built-in controllers
The Kubernetes controller manager runs
controllers that are built in to the Kubernetes
control plane.
When invoked with --use-service-account-credentials, kube-controller-manager starts each controller
using a separate service account.
Corresponding roles exist for each built-in controller, prefixed with system:controller:.
If the controller manager is not started with --use-service-account-credentials, it runs all control loops
using its own credential, which must be granted all the relevant roles.
These roles include:
The RBAC API prevents users from escalating privileges by editing roles or role bindings.
Because this is enforced at the API level, it applies even when the RBAC authorizer is not in use.
Restrictions on role creation or update
You can only create/update a role if at least one of the following things is true:
You already have all the permissions contained in the role, at the same scope as the object being modified
(cluster-wide for a ClusterRole, within the same namespace or cluster-wide for a Role).
You are granted explicit permission to perform the escalate verb on the roles or
clusterroles resource in the rbac.authorization.k8s.io API group.
For example, if user-1 does not have the ability to list Secrets cluster-wide, they cannot create a ClusterRole
containing that permission. To allow a user to create/update roles:
Grant them a role that allows them to create/update Role or ClusterRole objects, as desired.
Grant them permission to include specific permissions in the roles they create/update:
implicitly, by giving them those permissions (if they attempt to create or modify a Role or
ClusterRole with permissions they themselves have not been granted, the API request will be forbidden)
or explicitly allow specifying any permission in a Role or ClusterRole by giving them
permission to perform the escalate verb on roles or clusterroles resources in the
rbac.authorization.k8s.io API group
Restrictions on role binding creation or update
You can only create/update a role binding if you already have all the permissions contained in the referenced role
(at the same scope as the role binding) or if you have been authorized to perform the bind verb on the referenced role.
For example, if user-1 does not have the ability to list Secrets cluster-wide, they cannot create a ClusterRoleBinding
to a role that grants that permission. To allow a user to create/update role bindings:
Grant them a role that allows them to create/update RoleBinding or ClusterRoleBinding objects, as desired.
Grant them permissions needed to bind a particular role:
implicitly, by giving them the permissions contained in the role.
explicitly, by giving them permission to perform the bind verb on the particular Role (or ClusterRole).
For example, this ClusterRole and RoleBinding would allow user-1 to grant other users the admin, edit, and view roles in the namespace user-1-namespace:
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:name:role-grantorrules:- apiGroups:["rbac.authorization.k8s.io"]resources:["rolebindings"]verbs:["create"]- apiGroups:["rbac.authorization.k8s.io"]resources:["clusterroles"]verbs:["bind"]# omit resourceNames to allow binding any ClusterRoleresourceNames:["admin","edit","view"]---apiVersion:rbac.authorization.k8s.io/v1kind:RoleBindingmetadata:name:role-grantor-bindingnamespace:user-1-namespaceroleRef:apiGroup:rbac.authorization.k8s.iokind:ClusterRolename:role-grantorsubjects:- apiGroup:rbac.authorization.k8s.iokind:Username:user-1
When bootstrapping the first roles and role bindings, it is necessary for the initial user to grant permissions they do not yet have.
To bootstrap initial roles and role bindings:
Use a credential with the "system:masters" group, which is bound to the "cluster-admin" super-user role by the default bindings.
Command-line utilities
kubectl create role
Creates a Role object defining permissions within a single namespace. Examples:
Create a Role named "pod-reader" that allows users to perform get, watch and list on pods:
kubectl create role pod-reader --verb=get --verb=list --verb=watch --resource=pods
Create a Role named "pod-reader" with resourceNames specified:
kubectl create role pod-reader --verb=get --resource=pods --resource-name=readablepod --resource-name=anotherpod
Create a Role named "foo" with apiGroups specified:
kubectl create role foo --verb=get,list,watch --resource=replicasets.apps
Create a Role named "foo" with subresource permissions:
kubectl create role foo --verb=get,list,watch --resource=pods,pods/status
Create a Role named "my-component-lease-holder" with permissions to get/update a resource with a specific name:
kubectl create role my-component-lease-holder --verb=get,list,watch,update --resource=lease --resource-name=my-component
kubectl create clusterrole
Creates a ClusterRole. Examples:
Create a ClusterRole named "pod-reader" that allows user to perform get, watch and list on pods:
Default RBAC policies grant scoped permissions to control-plane components, nodes,
and controllers, but grant no permissions to service accounts outside the kube-system namespace
(beyond discovery permissions given to all authenticated users).
This allows you to grant particular roles to particular ServiceAccounts as needed.
Fine-grained role bindings provide greater security, but require more effort to administrate.
Broader grants can give unnecessary (and potentially escalating) API access to
ServiceAccounts, but are easier to administrate.
In order from most secure to least secure, the approaches are:
Grant a role to an application-specific service account (best practice)
This requires the application to specify a serviceAccountName in its pod spec,
and for the service account to be created (via the API, application manifest, kubectl create serviceaccount, etc.).
For example, grant read-only permission within "my-namespace" to the "my-sa" service account:
Many add-ons run as the
"default" service account in the kube-system namespace.
To allow those add-ons to run with super-user access, grant cluster-admin
permissions to the "default" service account in the kube-system namespace.
Caution: Enabling this means the kube-system namespace contains Secrets
that grant super-user access to your cluster's API.
Grant a role to all service accounts in a namespace
If you want all applications in a namespace to have a role, no matter what service account they use,
you can grant a role to the service account group for that namespace.
For example, grant read-only permission within "my-namespace" to all service accounts in that namespace:
Grant super-user access to all service accounts cluster-wide (strongly discouraged)
If you don't care about partitioning permissions at all, you can grant super-user access to all service accounts.
Warning: This allows any application full access to your cluster, and also grants
any user with read access to Secrets (or the ability to create any pod)
full access to your cluster.
Kubernetes clusters created before Kubernetes v1.22 include write access to
EndpointSlices (and Endpoints) in the aggregated "edit" and "admin" roles.
As a mitigation for CVE-2021-25740,
this access is not part of the aggregated roles in clusters that you create using
Kubernetes v1.22 or later.
Existing clusters that have been upgraded to Kubernetes v1.22 will not be
subject to this change. The CVE
announcement includes
guidance for restricting this access in existing clusters.
If you want new clusters to retain this level of access in the aggregated roles,
you can create the following ClusterRole:
apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRolemetadata:annotations:kubernetes.io/description:|- Add endpoints write permissions to the edit and admin roles. This was
removed by default in 1.22 because of CVE-2021-25740. See
https://issue.k8s.io/103675. This can allow writers to direct LoadBalancer
or Ingress implementations to expose backend IPs that would not otherwise
be accessible, and can circumvent network policies or security controls
intended to prevent/isolate access to those backends.
EndpointSlices were never included in the edit or admin roles, so there
is nothing to restore for the EndpointSlice API.labels:rbac.authorization.k8s.io/aggregate-to-edit:"true"name:custom:aggregate-to-edit:endpoints# you can change this if you wishrules:- apiGroups:[""]resources:["endpoints"]verbs:["create","delete","deletecollection","patch","update"]
Upgrading from ABAC
Clusters that originally ran older Kubernetes versions often used
permissive ABAC policies, including granting full API access to all
service accounts.
Default RBAC policies grant scoped permissions to control-plane components, nodes,
and controllers, but grant no permissions to service accounts outside the kube-system namespace
(beyond discovery permissions given to all authenticated users).
While far more secure, this can be disruptive to existing workloads expecting to automatically receive API permissions.
Here are two approaches for managing this transition:
Parallel authorizers
Run both the RBAC and ABAC authorizers, and specify a policy file that contains
the legacy ABAC policy:
To explain that first command line option in detail: if earlier authorizers, such as Node,
deny a request, then the RBAC authorizer attempts to authorize the API request. If RBAC
also denies that API request, the ABAC authorizer is then run. This means that any request
allowed by either the RBAC or ABAC policies is allowed.
When the kube-apiserver is run with a log level of 5 or higher for the RBAC component
(--vmodule=rbac*=5 or --v=5), you can see RBAC denials in the API server log
(prefixed with RBAC).
You can use that information to determine which roles need to be granted to which users, groups, or service accounts.
Once you have granted roles to service accounts and workloads
are running with no RBAC denial messages in the server logs, you can remove the ABAC authorizer.
Permissive RBAC permissions
You can replicate a permissive ABAC policy using RBAC role bindings.
Warning:
The following policy allows ALL service accounts to act as cluster administrators.
Any application running in a container receives service account credentials automatically,
and could perform any action against the API, including viewing secrets and modifying permissions.
This is not a recommended policy.
After you have transitioned to use RBAC, you should adjust the access controls
for your cluster to ensure that these meet your information security needs.
3.9 - Using ABAC Authorization
Attribute-based access control (ABAC) defines an access control paradigm whereby access rights are granted
to users through the use of policies which combine attributes together.
Policy File Format
To enable ABAC mode, specify --authorization-policy-file=SOME_FILENAME and --authorization-mode=ABAC
on startup.
The file format is one JSON object per line. There
should be no enclosing list or map, only one map per line.
Each line is a "policy object", where each such object is a map with the following
properties:
Versioning properties:
apiVersion, type string; valid values are "abac.authorization.kubernetes.io/v1beta1". Allows versioning
and conversion of the policy format.
kind, type string: valid values are "Policy". Allows versioning and conversion of the policy format.
spec property set to a map with the following properties:
Subject-matching properties:
user, type string; the user-string from --token-auth-file. If you specify user, it must match the
username of the authenticated user.
group, type string; if you specify group, it must match one of the groups of the authenticated user.
system:authenticated matches all authenticated requests. system:unauthenticated matches all
unauthenticated requests.
Resource-matching properties:
apiGroup, type string; an API group.
Ex: apps, networking.k8s.io
Wildcard: * matches all API groups.
namespace, type string; a namespace.
Ex: kube-system
Wildcard: * matches all resource requests.
resource, type string; a resource type
Ex: pods, deployments
Wildcard: * matches all resource requests.
Non-resource-matching properties:
nonResourcePath, type string; non-resource request paths.
Ex: /version or /apis
Wildcard:
* matches all non-resource requests.
/foo/* matches all subpaths of /foo/.
readonly, type boolean, when true, means that the Resource-matching policy only applies to get, list,
and watch operations, Non-resource-matching policy only applies to get operation.
Note:
An unset property is the same as a property set to the zero value for its type
(e.g. empty string, 0, false). However, unset should be preferred for
readability.
In the future, policies may be expressed in a JSON format, and managed via a
REST interface.
Authorization Algorithm
A request has attributes which correspond to the properties of a policy object.
When a request is received, the attributes are determined. Unknown attributes
are set to the zero value of its type (e.g. empty string, 0, false).
A property set to "*" will match any value of the corresponding attribute.
The tuple of attributes is checked for a match against every policy in the
policy file. If at least one line matches the request attributes, then the
request is authorized (but may fail later validation).
To permit any authenticated user to do something, write a policy with the
group property set to "system:authenticated".
To permit any unauthenticated user to do something, write a policy with the
group property set to "system:unauthenticated".
To permit a user to do anything, write a policy with the apiGroup, namespace,
resource, and nonResourcePath properties set to "*".
Kubectl
Kubectl uses the /api and /apis endpoints of apiserver to discover
served resource types, and validates objects sent to the API by create/update
operations using schema information located at /openapi/v2.
When using ABAC authorization, those special resources have to be explicitly
exposed via the nonResourcePath property in a policy (see examples below):
/api, /api/*, /apis, and /apis/* for API version negotiation.
/version for retrieving the server version via kubectl version.
/swaggerapi/* for create/update operations.
To inspect the HTTP calls involved in a specific kubectl operation you can turn
up the verbosity:
Creating a new namespace leads to the creation of a new service account in the following format:
system:serviceaccount:<namespace>:default
For example, if you wanted to grant the default service account (in the kube-system namespace) full
privilege to the API using ABAC, you would add this line to your policy file:
the ability to create TokenReviews and SubjectAccessReviews for delegated
authentication/authorization checks
In future releases, the node authorizer may add or remove permissions to ensure
kubelets have the minimal set of permissions required to operate correctly.
In order to be authorized by the Node authorizer, kubelets must use a credential
that identifies them as being in the system:nodes group, with a username of
system:node:<nodeName>.
This group and user name format match the identity created for each kubelet as part of
kubelet TLS bootstrapping.
The value of <nodeName>must match precisely the name of the node as
registered by the kubelet. By default, this is the host name as provided by
hostname, or overridden via the
kubelet option--hostname-override. However, when using the --cloud-provider kubelet
option, the specific hostname may be determined by the cloud provider, ignoring
the local hostname and the --hostname-override option.
For specifics about how the kubelet determines the hostname, see the
kubelet options reference.
To enable the Node authorizer, start the apiserver with --authorization-mode=Node.
To limit the API objects kubelets are able to write, enable the
NodeRestriction
admission plugin by starting the apiserver with
--enable-admission-plugins=...,NodeRestriction,...
Migration considerations
Kubelets outside the system:nodes group
Kubelets outside the system:nodes group would not be authorized by the Node
authorization mode, and would need to continue to be authorized via whatever
mechanism currently authorizes them.
The node admission plugin would not restrict requests from these kubelets.
Kubelets with undifferentiated usernames
In some deployments, kubelets have credentials that place them in the system:nodes group,
but do not identify the particular node they are associated with,
because they do not have a username in the system:node:... format.
These kubelets would not be authorized by the Node authorization mode,
and would need to continue to be authorized via whatever mechanism currently authorizes them.
The NodeRestriction admission plugin would ignore requests from these kubelets,
since the default node identifier implementation would not consider that a node identity.
3.11 - Mapping PodSecurityPolicies to Pod Security Standards
The tables below enumerate the configuration parameters on
PodSecurityPolicy objects, whether the field mutates
and/or validates pods, and how the configuration values map to the
Pod Security Standards.
For each applicable parameter, the allowed values for the
Baseline and
Restricted profiles are listed.
Anything outside the allowed values for those profiles would fall under the
Privileged profile. "No opinion"
means all values are allowed under all Pod Security Standards.
Baseline: "runtime/default,"(Trailing comma to allow unset)
Restricted: "runtime/default"(No trailing comma)
localhost/* values are also permitted for both Baseline & Restricted.
3.12 - Webhook Mode
A WebHook is an HTTP callback: an HTTP POST that occurs when something happens; a simple event-notification via HTTP POST. A web application implementing WebHooks will POST a message to a URL when certain things happen.
When specified, mode Webhook causes Kubernetes to query an outside REST
service when determining user privileges.
Configuration File Format
Mode Webhook requires a file for HTTP configuration, specify by the
--authorization-webhook-config-file=SOME_FILENAME flag.
The configuration file uses the kubeconfig
file format. Within the file "users" refers to the API Server webhook and
"clusters" refers to the remote service.
A configuration example which uses HTTPS client auth:
# Kubernetes API versionapiVersion:v1# kind of the API objectkind:Config# clusters refers to the remote service.clusters:- name:name-of-remote-authz-servicecluster:# CA for verifying the remote service.certificate-authority:/path/to/ca.pem# URL of remote service to query. Must use 'https'. May not include parameters.server:https://authz.example.com/authorize# users refers to the API Server's webhook configuration.users:- name:name-of-api-serveruser:client-certificate:/path/to/cert.pem# cert for the webhook plugin to useclient-key:/path/to/key.pem # key matching the cert# kubeconfig files require a context. Provide one for the API Server.current-context:webhookcontexts:- context:cluster:name-of-remote-authz-serviceuser:name-of-api-servername:webhook
Request Payloads
When faced with an authorization decision, the API Server POSTs a JSON-
serialized authorization.k8s.io/v1beta1SubjectAccessReview object describing the
action. This object contains fields describing the user attempting to make the
request, and either details about the resource being accessed or requests
attributes.
Note that webhook API objects are subject to the same versioning compatibility rules
as other Kubernetes API objects. Implementers should be aware of looser
compatibility promises for beta objects and check the "apiVersion" field of the
request to ensure correct deserialization. Additionally, the API Server must
enable the authorization.k8s.io/v1beta1 API extensions group (--runtime-config=authorization.k8s.io/v1beta1=true).
The remote service is expected to fill the status field of
the request and respond to either allow or disallow access. The response body's
spec field is ignored and may be omitted. A permissive response would return:
The first method is preferred in most cases, and indicates the authorization
webhook does not allow, or has "no opinion" about the request, but if other
authorizers are configured, they are given a chance to allow the request.
If there are no other authorizers, or none of them allow the request, the
request is forbidden. The webhook would return:
{
"apiVersion": "authorization.k8s.io/v1beta1",
"kind": "SubjectAccessReview",
"status": {
"allowed": false,
"reason": "user does not have read access to the namespace" }
}
The second method denies immediately, short-circuiting evaluation by other
configured authorizers. This should only be used by webhooks that have
detailed knowledge of the full authorizer configuration of the cluster.
The webhook would return:
{
"apiVersion": "authorization.k8s.io/v1beta1",
"kind": "SubjectAccessReview",
"status": {
"allowed": false,
"denied": true,
"reason": "user does not have read access to the namespace" }
}
Non-resource paths include: /api, /apis, /metrics,
/logs, /debug, /healthz, /livez, /openapi/v2, /readyz, and
/version. Clients require access to /api, /api/*, /apis, /apis/*,
and /version to discover what resources and versions are present on the server.
Access to other non-resource paths can be disallowed without restricting access
to the REST api.
For further documentation refer to the authorization.v1beta1 API objects and
webhook.go.
3.13 - Kubelet authentication/authorization
Overview
A kubelet's HTTPS endpoint exposes APIs which give access to data of varying sensitivity,
and allow you to perform operations with varying levels of power on the node and within containers.
This document describes how to authenticate and authorize access to the kubelet's HTTPS endpoint.
Kubelet authentication
By default, requests to the kubelet's HTTPS endpoint that are not rejected by other configured
authentication methods are treated as anonymous requests, and given a username of system:anonymous
and a group of system:unauthenticated.
To disable anonymous access and send 401 Unauthorized responses to unauthenticated requests:
start the kubelet with the --anonymous-auth=false flag
To enable X509 client certificate authentication to the kubelet's HTTPS endpoint:
start the kubelet with the --client-ca-file flag, providing a CA bundle to verify client certificates with
start the apiserver with --kubelet-client-certificate and --kubelet-client-key flags
To enable API bearer tokens (including service account tokens) to be used to authenticate to the kubelet's HTTPS endpoint:
ensure the authentication.k8s.io/v1beta1 API group is enabled in the API server
start the kubelet with the --authentication-token-webhook and --kubeconfig flags
the kubelet calls the TokenReview API on the configured API server to determine user information from bearer tokens
Kubelet authorization
Any request that is successfully authenticated (including an anonymous request) is then authorized. The default authorization mode is AlwaysAllow, which allows all requests.
There are many possible reasons to subdivide access to the kubelet API:
anonymous auth is enabled, but anonymous users' ability to call the kubelet API should be limited
bearer token auth is enabled, but arbitrary API users' (like service accounts) ability to call the kubelet API should be limited
client certificate auth is enabled, but only some of the client certificates signed by the configured CA should be allowed to use the kubelet API
To subdivide access to the kubelet API, delegate authorization to the API server:
ensure the authorization.k8s.io/v1beta1 API group is enabled in the API server
start the kubelet with the --authorization-mode=Webhook and the --kubeconfig flags
the kubelet calls the SubjectAccessReview API on the configured API server to determine whether each request is authorized
The kubelet authorizes API requests using the same request attributes approach as the apiserver.
The verb is determined from the incoming request's HTTP verb:
HTTP verb
request verb
POST
create
GET, HEAD
get
PUT
update
PATCH
patch
DELETE
delete
The resource and subresource is determined from the incoming request's path:
Kubelet API
resource
subresource
/stats/*
nodes
stats
/metrics/*
nodes
metrics
/logs/*
nodes
log
/spec/*
nodes
spec
all others
nodes
proxy
The namespace and API group attributes are always an empty string, and
the resource name is always the name of the kubelet's Node API object.
When running in this mode, ensure the user identified by the --kubelet-client-certificate and --kubelet-client-key
flags passed to the apiserver is authorized for the following attributes:
verb=*, resource=nodes, subresource=proxy
verb=*, resource=nodes, subresource=stats
verb=*, resource=nodes, subresource=log
verb=*, resource=nodes, subresource=spec
verb=*, resource=nodes, subresource=metrics
3.14 - TLS bootstrapping
In a Kubernetes cluster, the components on the worker nodes - kubelet and kube-proxy - need
to communicate with Kubernetes control plane components, specifically kube-apiserver.
In order to ensure that communication is kept private, not interfered with, and ensure that
each component of the cluster is talking to another trusted component, we strongly
recommend using client TLS certificates on nodes.
The normal process of bootstrapping these components, especially worker nodes that need certificates
so they can communicate safely with kube-apiserver, can be a challenging process as it is often outside
of the scope of Kubernetes and requires significant additional work.
This in turn, can make it challenging to initialize or scale a cluster.
In order to simplify the process, beginning in version 1.4, Kubernetes introduced a certificate request
and signing API. The proposal can be found here.
This document describes the process of node initialization, how to set up TLS client certificate bootstrapping for
kubelets, and how it works.
Initialization process
When a worker node starts up, the kubelet does the following:
Look for its kubeconfig file
Retrieve the URL of the API server and credentials, normally a TLS key and signed certificate from the kubeconfig file
Attempt to communicate with the API server using the credentials.
Assuming that the kube-apiserver successfully validates the kubelet's credentials,
it will treat the kubelet as a valid node, and begin to assign pods to it.
Note that the above process depends upon:
Existence of a key and certificate on the local host in the kubeconfig
The certificate having been signed by a Certificate Authority (CA) trusted by the kube-apiserver
All of the following are responsibilities of whoever sets up and manages the cluster:
Creating the CA key and certificate
Distributing the CA certificate to the control plane nodes, where kube-apiserver is running
Creating a key and certificate for each kubelet; strongly recommended to have a unique one, with a unique CN, for each kubelet
Signing the kubelet certificate using the CA key
Distributing the kubelet key and signed certificate to the specific node on which the kubelet is running
The TLS Bootstrapping described in this document is intended to simplify, and partially or even
completely automate, steps 3 onwards, as these are the most common when initializing or scaling
a cluster.
Bootstrap initialization
In the bootstrap initialization process, the following occurs:
kubelet begins
kubelet sees that it does not have a kubeconfig file
kubelet searches for and finds a bootstrap-kubeconfig file
kubelet reads its bootstrap file, retrieving the URL of the API server and a limited usage "token"
kubelet connects to the API server, authenticates using the token
kubelet now has limited credentials to create and retrieve a certificate signing request (CSR)
kubelet creates a CSR for itself with the signerName set to kubernetes.io/kube-apiserver-client-kubelet
CSR is approved in one of two ways:
If configured, kube-controller-manager automatically approves the CSR
If configured, an outside process, possibly a person, approves the CSR using the Kubernetes API or via kubectl
Certificate is created for the kubelet
Certificate is issued to the kubelet
kubelet retrieves the certificate
kubelet creates a proper kubeconfig with the key and signed certificate
kubelet begins normal operation
Optional: if configured, kubelet automatically requests renewal of the certificate when it is close to expiry
The renewed certificate is approved and issued, either automatically or manually, depending on configuration.
The rest of this document describes the necessary steps to configure TLS Bootstrapping, and its limitations.
Configuration
To configure for TLS bootstrapping and optional automatic approval, you must configure options on the following components:
kube-apiserver
kube-controller-manager
kubelet
in-cluster resources: ClusterRoleBinding and potentially ClusterRole
In addition, you need your Kubernetes Certificate Authority (CA).
Certificate Authority
As without bootstrapping, you will need a Certificate Authority (CA) key and certificate.
As without bootstrapping, these will be used to sign the kubelet certificate. As before,
it is your responsibility to distribute them to control plane nodes.
For the purposes of this document, we will assume these have been distributed to control
plane nodes at /var/lib/kubernetes/ca.pem (certificate) and /var/lib/kubernetes/ca-key.pem (key).
We will refer to these as "Kubernetes CA certificate and key".
All Kubernetes components that use these certificates - kubelet, kube-apiserver,
kube-controller-manager - assume the key and certificate to be PEM-encoded.
kube-apiserver configuration
The kube-apiserver has several requirements to enable TLS bootstrapping:
Recognizing CA that signs the client certificate
Authenticating the bootstrapping kubelet to the system:bootstrappers group
Authorize the bootstrapping kubelet to create a certificate signing request (CSR)
Recognizing client certificates
This is normal for all client certificate authentication.
If not already set, add the --client-ca-file=FILENAME flag to the kube-apiserver command to enable
client certificate authentication, referencing a certificate authority bundle
containing the signing certificate, for example
--client-ca-file=/var/lib/kubernetes/ca.pem.
Initial bootstrap authentication
In order for the bootstrapping kubelet to connect to kube-apiserver and request a certificate,
it must first authenticate to the server. You can use any
authenticator that can authenticate the kubelet.
While any authentication strategy can be used for the kubelet's initial
bootstrap credentials, the following two authenticators are recommended for ease
of provisioning.
Using bootstrap tokens is a simpler and more easily managed method to authenticate kubelets,
and does not require any additional flags when starting kube-apiserver.
Whichever method you choose, the requirement is that the kubelet be able to authenticate as a user with the rights to:
create and retrieve CSRs
be automatically approved to request node client certificates, if automatic approval is enabled.
A kubelet authenticating using bootstrap tokens is authenticated as a user in the group
system:bootstrappers, which is the standard method to use.
As this feature matures, you
should ensure tokens are bound to a Role Based Access Control (RBAC) policy
which limits requests (using the bootstrap token) strictly to client
requests related to certificate provisioning. With RBAC in place, scoping the
tokens to a group allows for great flexibility. For example, you could disable a
particular bootstrap group's access when you are done provisioning the nodes.
Bootstrap tokens
Bootstrap tokens are described in detail here.
These are tokens that are stored as secrets in the Kubernetes cluster, and then issued to the individual kubelet.
You can use a single token for an entire cluster, or issue one per worker node.
The process is two-fold:
Create a Kubernetes secret with the token ID, secret and scope(s).
Issue the token to the kubelet
From the kubelet's perspective, one token is like another and has no special meaning.
From the kube-apiserver's perspective, however, the bootstrap token is special.
Due to its type, namespace and name, kube-apiserver recognizes it as a special token,
and grants anyone authenticating with that token special bootstrap rights, notably treating
them as a member of the system:bootstrappers group. This fulfills a basic requirement
for TLS bootstrapping.
The details for creating the secret are available here.
If you want to use bootstrap tokens, you must enable it on kube-apiserver with the flag:
--enable-bootstrap-token-auth=true
Token authentication file
kube-apiserver has the ability to accept tokens as authentication.
These tokens are arbitrary but should represent at least 128 bits of entropy derived
from a secure random number generator (such as /dev/urandom on most modern Linux
systems). There are multiple ways you can generate a token. For example:
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
This will generate tokens that look like 02b50b05283e98dd0fd71db496ef01e8.
The token file should look like the following example, where the first three
values can be anything and the quoted group name should be as depicted:
Add the --token-auth-file=FILENAME flag to the kube-apiserver command (in your
systemd unit file perhaps) to enable the token file. See docs
here for
further details.
Authorize kubelet to create CSR
Now that the bootstrapping node is authenticated as part of the
system:bootstrappers group, it needs to be authorized to create a
certificate signing request (CSR) as well as retrieve it when done.
Fortunately, Kubernetes ships with a ClusterRole with precisely these (and
only these) permissions, system:node-bootstrapper.
To do this, you only need to create a ClusterRoleBinding that binds the system:bootstrappers
group to the cluster role system:node-bootstrapper.
# enable bootstrapping nodes to create CSRapiVersion:rbac.authorization.k8s.io/v1kind:ClusterRoleBindingmetadata:name:create-csrs-for-bootstrappingsubjects:- kind:Groupname:system:bootstrappersapiGroup:rbac.authorization.k8s.ioroleRef:kind:ClusterRolename:system:node-bootstrapperapiGroup:rbac.authorization.k8s.io
kube-controller-manager configuration
While the apiserver receives the requests for certificates from the kubelet and authenticates those requests,
the controller-manager is responsible for issuing actual signed certificates.
The controller-manager performs this function via a certificate-issuing control loop.
This takes the form of a
cfssl local signer using
assets on disk. Currently, all certificates issued have one year validity and a
default set of key usages.
In order for the controller-manager to sign certificates, it needs the following:
access to the "Kubernetes CA key and certificate" that you created and distributed
enabling CSR signing
Access to key and certificate
As described earlier, you need to create a Kubernetes CA key and certificate, and distribute it to the control plane nodes.
These will be used by the controller-manager to sign the kubelet certificates.
Since these signed certificates will, in turn, be used by the kubelet to authenticate as a regular kubelet
to kube-apiserver, it is important that the CA provided to the controller-manager at this stage also be
trusted by kube-apiserver for authentication. This is provided to kube-apiserver with the flag --client-ca-file=FILENAME
(for example, --client-ca-file=/var/lib/kubernetes/ca.pem), as described in the kube-apiserver configuration section.
To provide the Kubernetes CA key and certificate to kube-controller-manager, use the following flags:
The validity duration of signed certificates can be configured with flag:
--cluster-signing-duration
Approval
In order to approve CSRs, you need to tell the controller-manager that it is acceptable to approve them. This is done by granting
RBAC permissions to the correct group.
There are two distinct sets of permissions:
nodeclient: If a node is creating a new certificate for a node, then it does not have a certificate yet.
It is authenticating using one of the tokens listed above, and thus is part of the group system:bootstrappers.
selfnodeclient: If a node is renewing its certificate, then it already has a certificate (by definition),
which it uses continuously to authenticate as part of the group system:nodes.
To enable the kubelet to request and receive a new certificate, create a ClusterRoleBinding that binds
the group in which the bootstrapping node is a member system:bootstrappers to the ClusterRole that
grants it permission, system:certificates.k8s.io:certificatesigningrequests:nodeclient:
# Approve all CSRs for the group "system:bootstrappers"apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRoleBindingmetadata:name:auto-approve-csrs-for-groupsubjects:- kind:Groupname:system:bootstrappersapiGroup:rbac.authorization.k8s.ioroleRef:kind:ClusterRolename:system:certificates.k8s.io:certificatesigningrequests:nodeclientapiGroup:rbac.authorization.k8s.io
To enable the kubelet to renew its own client certificate, create a ClusterRoleBinding that binds
the group in which the fully functioning node is a member system:nodes to the ClusterRole that
grants it permission, system:certificates.k8s.io:certificatesigningrequests:selfnodeclient:
# Approve renewal CSRs for the group "system:nodes"apiVersion:rbac.authorization.k8s.io/v1kind:ClusterRoleBindingmetadata:name:auto-approve-renewals-for-nodessubjects:- kind:Groupname:system:nodesapiGroup:rbac.authorization.k8s.ioroleRef:kind:ClusterRolename:system:certificates.k8s.io:certificatesigningrequests:selfnodeclientapiGroup:rbac.authorization.k8s.io
The csrapproving controller that ships as part of
kube-controller-manager and is enabled
by default. The controller uses the
SubjectAccessReview API to
determine if a given user is authorized to request a CSR, then approves based on
the authorization outcome. To prevent conflicts with other approvers, the
built-in approver doesn't explicitly deny CSRs. It only ignores unauthorized
requests. The controller also prunes expired certificates as part of garbage
collection.
kubelet configuration
Finally, with the control plane nodes properly set up and all of the necessary
authentication and authorization in place, we can configure the kubelet.
The kubelet requires the following configuration to bootstrap:
A path to store the key and certificate it generates (optional, can use default)
A path to a kubeconfig file that does not yet exist; it will place the bootstrapped config file here
A path to a bootstrap kubeconfig file to provide the URL for the server and bootstrap credentials, e.g. a bootstrap token
Optional: instructions to rotate certificates
The bootstrap kubeconfig should be in a path available to the kubelet, for example /var/lib/kubelet/bootstrap-kubeconfig.
Its format is identical to a normal kubeconfig file. A sample file might look as follows:
certificate-authority: path to a CA file, used to validate the server certificate presented by kube-apiserver
server: URL to kube-apiserver
token: the token to use
The format of the token does not matter, as long as it matches what kube-apiserver expects. In the above example, we used a bootstrap token.
As stated earlier, any valid authentication method can be used, not only tokens.
Because the bootstrap kubeconfigis a standard kubeconfig, you can use kubectl to generate it. To create the above example file:
When starting the kubelet, if the file specified via --kubeconfig does not
exist, the bootstrap kubeconfig specified via --bootstrap-kubeconfig is used
to request a client certificate from the API server. On approval of the
certificate request and receipt back by the kubelet, a kubeconfig file
referencing the generated key and obtained certificate is written to the path
specified by --kubeconfig. The certificate and key file will be placed in the
directory specified by --cert-dir.
Client and serving certificates
All of the above relate to kubelet client certificates, specifically, the certificates a kubelet
uses to authenticate to kube-apiserver.
A kubelet also can use serving certificates. The kubelet itself exposes an https endpoint for certain features.
To secure these, the kubelet can do one of:
use provided key and certificate, via the --tls-private-key-file and --tls-cert-file flags
create self-signed key and certificate, if a key and certificate are not provided
request serving certificates from the cluster server, via the CSR API
The client certificate provided by TLS bootstrapping is signed, by default, for client auth only, and thus cannot
be used as serving certificates, or server auth.
However, you can enable its server certificate, at least partially, via certificate rotation.
Certificate rotation
Kubernetes v1.8 and higher kubelet implements features for enabling
rotation of its client and/or serving certificates. Note, rotation of serving
certificate is a beta feature and requires the RotateKubeletServerCertificate
feature flag on the kubelet (enabled by default).
You can configure the kubelet to rotate its client certificates by creating new CSRs
as its existing credentials expire. To enable this feature, use the rotateCertificates
field of kubelet configuration file
or pass the following command line argument to the kubelet (deprecated):
--rotate-certificates
Enabling RotateKubeletServerCertificate causes the kubelet both to request a serving
certificate after bootstrapping its client credentials and to rotate that
certificate. To enable this behavior, use the field serverTLSBootstrap of
the kubelet configuration file
or pass the following command line argument to the kubelet (deprecated):
--rotate-server-certificates
Note:
The CSR approving controllers implemented in core Kubernetes do not
approve node serving certificates for
security reasons. To use
RotateKubeletServerCertificate operators need to run a custom approving
controller, or manually approve the serving certificate requests.
A deployment-specific approval process for kubelet serving certificates should typically only approve CSRs which:
are requested by nodes (ensure the spec.username field is of the form
system:node:<nodeName> and spec.groups contains system:nodes)
request usages for a serving certificate (ensure spec.usages contains server auth,
optionally contains digital signature and key encipherment, and contains no other usages)
only have IP and DNS subjectAltNames that belong to the requesting node,
and have no URI and Email subjectAltNames (parse the x509 Certificate Signing Request
in spec.request to verify subjectAltNames)
Other authenticating components
All of TLS bootstrapping described in this document relates to the kubelet. However,
other components may need to communicate directly with kube-apiserver. Notable is kube-proxy, which
is part of the Kubernetes node components and runs on every node, but may also include other components such as monitoring or networking.
Like the kubelet, these other components also require a method of authenticating to kube-apiserver.
You have several options for generating these credentials:
The old way: Create and distribute certificates the same way you did for kubelet before TLS bootstrapping
DaemonSet: Since the kubelet itself is loaded on each node, and is sufficient to start base services,
you can run kube-proxy and other node-specific services not as a standalone process, but rather as a
daemonset in the kube-system namespace. Since it will be in-cluster, you can give it a proper service
account with appropriate permissions to perform its activities. This may be the simplest way to configure
such services.
kubectl approval
CSRs can be approved outside of the approval flows built into the controller
manager.
The signing controller does not immediately sign all certificate requests.
Instead, it waits until they have been flagged with an "Approved" status by an
appropriately-privileged user. This flow is intended to allow for automated
approval handled by an external approval controller or the approval controller
implemented in the core controller-manager. However cluster administrators can
also manually approve certificate requests using kubectl. An administrator can
list CSRs with kubectl get csr and describe one in detail with
kubectl describe csr <name>. An administrator can approve or deny a CSR with
kubectl certificate approve <name> and kubectl certificate deny <name>.
3.15 - Validating Admission Policy
FEATURE STATE:Kubernetes v1.28 [beta]
This page provides an overview of Validating Admission Policy.
What is Validating Admission Policy?
Validating admission policies offer a declarative, in-process alternative to validating admission webhooks.
Validating admission policies use the Common Expression Language (CEL) to declare the validation
rules of a policy.
Validation admission policies are highly configurable, enabling policy authors to define policies
that can be parameterized and scoped to resources as needed by cluster administrators.
What Resources Make a Policy
A policy is generally made up of three resources:
The ValidatingAdmissionPolicy describes the abstract logic of a policy
(think: "this policy makes sure a particular label is set to a particular value").
A ValidatingAdmissionPolicyBinding links the above resources together and provides scoping.
If you only want to require an owner label to be set for Pods, the binding is where you would
specify this restriction.
A parameter resource provides information to a ValidatingAdmissionPolicy to make it a concrete
statement (think "the owner label must be set to something that ends in .company.com").
A native type such as ConfigMap or a CRD defines the schema of a parameter resource.
ValidatingAdmissionPolicy objects specify what Kind they are expecting for their parameter resource.
At least a ValidatingAdmissionPolicy and a corresponding ValidatingAdmissionPolicyBinding
must be defined for a policy to have an effect.
If a ValidatingAdmissionPolicy does not need to be configured via parameters, simply leave
spec.paramKind in ValidatingAdmissionPolicy not specified.
Before you begin
Ensure the ValidatingAdmissionPolicyfeature gate is enabled.
Ensure that the admissionregistration.k8s.io/v1beta1 API is enabled.
Getting Started with Validating Admission Policy
Validating Admission Policy is part of the cluster control-plane. You should write and deploy them
with great caution. The following describes how to quickly experiment with Validating Admission Policy.
Creating a ValidatingAdmissionPolicy
The following is an example of a ValidatingAdmissionPolicy.
spec.validations contains CEL expressions which use the Common Expression Language (CEL)
to validate the request. If an expression evaluates to false, the validation check is enforced
according to the spec.failurePolicy field.
Note: You can quickly test CEL expressions in CEL Playground.
To configure a validating admission policy for use in a cluster, a binding is required.
The following is an example of a ValidatingAdmissionPolicyBinding.:
The above provides a simple example of using ValidatingAdmissionPolicy without a parameter configured.
Validation actions
Each ValidatingAdmissionPolicyBinding must specify one or more
validationActions to declare how validations of a policy are enforced.
The supported validationActions are:
Deny: Validation failure results in a denied request.
Warn: Validation failure is reported to the request client
as a warning.
Audit: Validation failure is included in the audit event for the API request.
For example, to both warn clients about a validation failure and to audit the
validation failures, use:
validationActions:[Warn, Audit]
Deny and Warn may not be used together since this combination
needlessly duplicates the validation failure both in the
API response body and the HTTP warning headers.
A validation that evaluates to false is always enforced according to these
actions. Failures defined by the failurePolicy are enforced
according to these actions only if the failurePolicy is set to Fail (or not specified),
otherwise the failures are ignored.
Parameter resources allow a policy configuration to be separate from its definition.
A policy can define paramKind, which outlines GVK of the parameter resource,
and then a policy binding ties a policy by name (via policyName) to a particular parameter resource via paramRef.
If parameter configuration is needed, the following is an example of a ValidatingAdmissionPolicy
with parameter configuration.
The spec.paramKind field of the ValidatingAdmissionPolicy specifies the kind of resources used
to parameterize this policy. For this example, it is configured by ReplicaLimit custom resources.
Note in this example how the CEL expression references the parameters via the CEL params variable,
e.g. params.maxReplicas. spec.matchConstraints specifies what resources this policy is
designed to validate. Note that the native types such like ConfigMap could also be used as
parameter reference.
The spec.validations fields contain CEL expressions. If an expression evaluates to false, the
validation check is enforced according to the spec.failurePolicy field.
The validating admission policy author is responsible for providing the ReplicaLimit parameter CRD.
To configure an validating admission policy for use in a cluster, a binding and parameter resource
are created. The following is an example of a ValidatingAdmissionPolicyBinding
that uses a cluster-wide param - the same param will be used to validate
every resource request that matches the binding:
This policy parameter resource limits deployments to a max of 3 replicas.
An admission policy may have multiple bindings. To bind all other environments
to have a maxReplicas limit of 100, create another ValidatingAdmissionPolicyBinding:
apiVersion:admissionregistration.k8s.io/v1beta1kind:ValidatingAdmissionPolicyBindingmetadata:name:"replicalimit-binding-nontest"spec:policyName:"replicalimit-policy.example.com"validationActions:[Deny]paramRef:name:"replica-limit-prod.example.com"namespace:"default"matchResources:namespaceSelector:matchExpressions:- key:environmentoperator:NotInvalues:- test
Notice this binding applies a different parameter to resources which
are not in the test environment.
For each admission request, the API server evaluates CEL expressions of each
(policy, binding, param) combination that match the request. For a request
to be admitted it must pass all evaluations.
If multiple bindings match the request, the policy will be evaluated for each,
and they must all pass evaluation for the policy to be considered passed.
If multiple parameters match a single binding, the policy rules will be evaluated
for each param, and they too must all pass for the binding to be considered passed.
Bindings can have overlapping match criteria. The policy is evaluated for each
matching binding-parameter combination. A policy may even be evaluated multiple
times if multiple bindings match it, or a single binding that matches multiple
parameters.
The params object representing a parameter resource will not be set if a parameter resource has
not been bound, so for policies requiring a parameter resource, it can be useful to add a check to
ensure one has been bound. A parameter resource will not be bound and params will be null
if paramKind of the policy, or paramRef of the binding are not specified.
For the use cases require parameter configuration, we recommend to add a param check in
spec.validations[0].expression:
- expression: "params != null"
message: "params missing but required to bind to this policy"
Optional parameters
It can be convenient to be able to have optional parameters as part of a parameter resource, and
only validate them if present. CEL provides has(), which checks if the key passed to it exists.
CEL also implements Boolean short-circuiting. If the first half of a logical OR evaluates to true,
it won’t evaluate the other half (since the result of the entire OR will be true regardless).
Combining the two, we can provide a way to validate optional parameters:
Here, we first check that the optional parameter is present with !has(params.optionalNumber).
If optionalNumber hasn’t been defined, then the expression short-circuits since
!has(params.optionalNumber) will evaluate to true.
If optionalNumber has been defined, then the latter half of the CEL expression will be
evaluated, and optionalNumber will be checked to ensure that it contains a value between 5 and
10 inclusive.
Per-namespace Parameters
As the author of a ValidatingAdmissionPolicy and its ValidatingAdmissionPolicyBinding,
you can choose to specify cluster-wide, or per-namespace parameters.
If you specify a namespace for the binding's paramRef, the control plane only
searches for parameters in that namespace.
However, if namespace is not specified in the ValidatingAdmissionPolicyBinding, the
API server can search for relevant parameters in the namespace that a request is against.
For example, if you make a request to modify a ConfigMap in the default namespace and
there is a relevant ValidatingAdmissionPolicyBinding with no namespace set, then the
API server looks for a parameter object in default.
This design enables policy configuration that depends on the namespace
of the resource being manipulated, for more fine-tuned control.
Parameter selector
In addition to specify a parameter in a binding by name, you may
choose instead to specify label selector, such that all resources of the
policy's paramKind, and the param's namespace (if applicable) that match the
label selector are selected for evaluation. See selector for more information on how label selectors match resources.
If multiple parameters are found to meet the condition, the policy's rules are
evaluated for each parameter found and the results will be ANDed together.
If namespace is provided, only objects of the paramKind in the provided
namespace are eligible for selection. Otherwise, when namespace is empty and
paramKind is namespace-scoped, the namespace used in the request being
admitted will be used.
Authorization checks
We introduced the authorization check for parameter resources.
User is expected to have read access to the resources referenced by paramKind in
ValidatingAdmissionPolicy and paramRef in ValidatingAdmissionPolicyBinding.
Note that if a resource in paramKind fails resolving via the restmapper, read access to all
resources of groups is required.
Failure Policy
failurePolicy defines how mis-configurations and CEL expressions evaluating to error from the
admission policy are handled. Allowed values are Ignore or Fail.
Ignore means that an error calling the ValidatingAdmissionPolicy is ignored and the API
request is allowed to continue.
Fail means that an error calling the ValidatingAdmissionPolicy causes the admission to fail
and the API request to be rejected.
Note that the failurePolicy is defined inside ValidatingAdmissionPolicy:
apiVersion:admissionregistration.k8s.io/v1beta1kind:ValidatingAdmissionPolicyspec:...failurePolicy:Ignore# The default is "Fail"validations:- expression:"object.spec.xyz == params.x"
Validation Expression
spec.validations[i].expression represents the expression which will be evaluated by CEL.
To learn more, see the CEL language specification
CEL expressions have access to the contents of the Admission request/response, organized into CEL
variables as well as some other useful variables:
'object' - The object from the incoming request. The value is null for DELETE requests.
'oldObject' - The existing object. The value is null for CREATE requests.
'params' - Parameter resource referred to by the policy binding being evaluated. The value is
null if ParamKind is not specified.
namespaceObject - The namespace, as a Kubernetes resource, that the incoming object belongs to.
The value is null if the incoming object is cluster-scoped.
authorizer - A CEL Authorizer. May be used to perform authorization checks for the principal
(authenticated user) of the request. See
Authz in the Kubernetes CEL library
documentation for more details.
authorizer.requestResource - A shortcut for an authorization check configured with the request
resource (group, resource, (subresource), namespace, name).
The apiVersion, kind, metadata.name and metadata.generateName are always accessible from
the root of the object. No other metadata properties are accessible.
Equality on arrays with list type of 'set' or 'map' ignores element order, i.e. [1, 2] == [2, 1].
Concatenation on arrays with x-kubernetes-list-type use the semantics of the list type:
'set': X + Y performs a union where the array positions of all elements in X are preserved and
non-intersecting elements in Y are appended, retaining their partial order.
'map': X + Y performs a merge where the array positions of all keys in X are preserved but the values
are overwritten by values in Y when the key sets of X and Y intersect. Elements in Y with
non-intersecting keys are appended, retaining their partial order.
spec.validation[i].reason represents a machine-readable description of why this validation failed.
If this is the first validation in the list to fail, this reason, as well as the corresponding
HTTP response code, are used in the HTTP response to the client.
The currently supported reasons are: Unauthorized, Forbidden, Invalid, RequestEntityTooLarge.
If not set, StatusReasonInvalid is used in the response to the client.
Matching requests: matchConditions
You can define match conditions for a ValidatingAdmissionPolicy if you need fine-grained request filtering. These
conditions are useful if you find that match rules, objectSelectors and namespaceSelectors still
doesn't provide the filtering you want. Match conditions are
CEL expressions. All match conditions must evaluate to true for the
resource to be evaluated.
Here is an example illustrating a few different uses for match conditions:
apiVersion:admissionregistration.k8s.io/v1alpha1kind:ValidatingAdmissionPolicymetadata:name:"demo-policy.example.com"spec:failurePolicy:FailmatchConstraints:resourceRules:- apiGroups:["*"]apiVersions:["*"]operations:["CREATE","UPDATE"]resources:["*"]matchConditions:- name:'exclude-leases'# Each match condition must have a unique nameexpression:'!(request.resource.group == "coordination.k8s.io" && request.resource.resource == "leases")'# Match non-lease resources.- name:'exclude-kubelet-requests'expression:'!("system:nodes" in request.userInfo.groups)'# Match requests made by non-node users.- name:'rbac'# Skip RBAC requests.expression:'request.resource.group != "rbac.authorization.k8s.io"'validations:- expression:"!object.metadata.name.contains('demo') || object.metadata.namespace == 'demo'"
Match conditions have access to the same CEL variables as validation expressions.
In the event of an error evaluating a match condition the policy is not evaluated. Whether to reject
the request is determined as follows:
If any match condition evaluated to false (regardless of other errors), the API server skips the policy.
Otherwise:
for failurePolicy: Fail, reject the request (without evaluating the policy).
apiVersion:admissionregistration.k8s.io/v1alpha1kind:ValidatingAdmissionPolicymetadata:name:"demo-policy.example.com"spec:failurePolicy:FailmatchConstraints:resourceRules:- apiGroups:["apps"]apiVersions:["v1"]operations:["CREATE","UPDATE"]resources:["deployments"]validations:- key:"high-replica-count"expression:"object.spec.replicas > 50"messageExpression:"'Deployment spec.replicas set to ' + string(object.spec.replicas)"
When an API request is validated with this admission policy, the resulting audit event will look like:
# the audit event recorded
{
"kind": "Event",
"apiVersion": "audit.k8s.io/v1",
"annotations": {
"demo-policy.example.com/high-replica-count": "Deployment spec.replicas set to 128"
# other annotations
...
}
# other fields
...
}
In this example the annotation will only be included if the spec.replicas of the Deployment is more than
50, otherwise the CEL expression evalutes to null and the annotation will not be included.
Note that audit annotation keys are prefixed by the name of the ValidatingAdmissionWebhook and a /. If
another admission controller, such as an admission webhook, uses the exact same audit annotation key, the
value of the first admission controller to include the audit annotation will be included in the audit
event and all other values will be ignored.
Message expression
To return a more friendly message when the policy rejects a request, we can use a CEL expression
to composite a message with spec.validations[i].messageExpression. Similar to the validation expression,
a message expression has access to object, oldObject, request, params, and namespaceObject.
Unlike validations, message expression must evaluate to a string.
For example, to better inform the user of the reason of denial when the policy refers to a parameter,
we can have the following validation:
apiVersion:admissionregistration.k8s.io/v1alpha1kind:ValidatingAdmissionPolicymetadata:name:"deploy-replica-policy.example.com"spec:paramKind:apiVersion:rules.example.com/v1kind:ReplicaLimitmatchConstraints:resourceRules:- apiGroups:["apps"]apiVersions:["v1"]operations:["CREATE","UPDATE"]resources:["deployments"]validations:- expression:"object.spec.replicas <= params.maxReplicas"messageExpression:"'object.spec.replicas must be no greater than ' + string(params.maxReplicas)"reason:Invalid
After creating a params object that limits the replicas to 3 and setting up the binding,
when we try to create a deployment with 5 replicas, we will receive the following message.
$ kubectl create deploy --image=nginx nginx --replicas=5
error: failed to create deployment: deployments.apps "nginx" is forbidden: ValidatingAdmissionPolicy 'deploy-replica-policy.example.com' with binding 'demo-binding-test.example.com' denied request: object.spec.replicas must be no greater than 3
This is more informative than a static message of "too many replicas".
The message expression takes precedence over the static message defined in spec.validations[i].message if both are defined.
However, if the message expression fails to evaluate, the static message will be used instead.
Additionally, if the message expression evaluates to a multi-line string,
the evaluation result will be discarded and the static message will be used if present.
Note that static message is validated against multi-line strings.
Type checking
When a policy definition is created or updated, the validation process parses the expressions it contains
and reports any syntax errors, rejecting the definition if any errors are found.
Afterward, the referred variables are checked for type errors, including missing fields and type confusion,
against the matched types of spec.matchConstraints.
The result of type checking can be retrieved from status.typeChecking.
The presence of status.typeChecking indicates the completion of type checking,
and an empty status.typeChecking means that no errors were detected.
For example, given the following policy definition:
apiVersion:admissionregistration.k8s.io/v1beta1kind:ValidatingAdmissionPolicymetadata:name:"deploy-replica-policy.example.com"spec:matchConstraints:resourceRules:- apiGroups:["apps"]apiVersions:["v1"]operations:["CREATE","UPDATE"]resources:["deployments"]validations:- expression:"object.replicas > 1"# should be "object.spec.replicas > 1"message:"must be replicated"reason:Invalid
If multiple resources are matched in spec.matchConstraints, all of matched resources will be checked against.
For example, the following policy definition
apiVersion:admissionregistration.k8s.io/v1beta1kind:ValidatingAdmissionPolicymetadata:name:"replica-policy.example.com"spec:matchConstraints:resourceRules:- apiGroups:["apps"]apiVersions:["v1"]operations:["CREATE","UPDATE"]resources:["deployments","replicasets"]validations:- expression:"object.replicas > 1"# should be "object.spec.replicas > 1"message:"must be replicated"reason:Invalid
will have multiple types and type checking result of each type in the warning message.
No wildcard matching. If spec.matchConstraints.resourceRules contains "*" in any of apiGroups, apiVersions or resources,
the types that "*" matches will not be checked.
The number of matched types is limited to 10. This is to prevent a policy that manually specifying too many types.
to consume excessive computing resources. In the order of ascending group, version, and then resource, 11th combination and beyond are ignored.
Type Checking does not affect the policy behavior in any way. Even if the type checking detects errors, the policy will continue
to evaluate. If errors do occur during evaluate, the failure policy will decide its outcome.
Type Checking does not apply to CRDs, including matched CRD types and reference of paramKind. The support for CRDs will come in future release.
Variable composition
If an expression grows too complicated, or part of the expression is reusable and computationally expensive to evaluate,
you can extract some part of the expressions into variables. A variable is a named expression that can be referred later
in variables in other expressions.
A variable is lazily evaluated when it is first referred. Any error that occurs during the evaluation will be
reported during the evaluation of the referring expression. Both the result and potential error are memorized and
count only once towards the runtime cost.
The order of variables are important because a variable can refer to other variables that are defined before it.
This ordering prevents circular references.
The following is a more complex example of enforcing that image repo names match the environment defined in its namespace.
# This policy enforces that all containers of a deployment has the image repo match the environment label of its namespace.# Except for "exempt" deployments, or any containers that do not belong to the "example.com" organization (e.g. common sidecars).# For example, if the namespace has a label of {"environment": "staging"}, all container images must be either staging.example.com/*# or do not contain "example.com" at all, unless the deployment has {"exempt": "true"} label.apiVersion:admissionregistration.k8s.io/v1beta1kind:ValidatingAdmissionPolicymetadata:name:"image-matches-namespace-environment.policy.example.com"spec:failurePolicy:FailmatchConstraints:resourceRules:- apiGroups:["apps"]apiVersions:["v1"]operations:["CREATE","UPDATE"]resources:["deployments"]variables:- name:environmentexpression:"'environment' in namespaceObject.metadata.labels ? namespaceObject.metadata.labels['environment'] : 'prod'"- name:exemptexpression:"'exempt' in object.metadata.labels && object.metadata.labels['exempt'] == 'true'"- name:containersexpression:"object.spec.template.spec.containers"- name:containersToCheckexpression:"variables.containers.filter(c, c.image.contains('example.com/'))"validations:- expression:"variables.exempt || variables.containersToCheck.all(c, c.image.startsWith(variables.environment + '.'))"messageExpression:"'only ' + variables.environment + ' images are allowed in namespace ' + namespaceObject.metadata.name"
With the policy bound to the namespace default, which is labeled environment: prod,
the following attempt to create a deployment would be rejected.
error: failed to create deployment: deployments.apps "invalid" is forbidden: ValidatingAdmissionPolicy 'image-matches-namespace-environment.policy.example.com' with binding 'demo-binding-test.example.com' denied request: only prod images are allowed in namespace default
4 - Well-Known Labels, Annotations and Taints
Kubernetes reserves all labels and annotations in the kubernetes.io and k8s.io namespaces.
This document serves both as a reference to the values and as a coordination point for assigning values.
Labels, annotations and taints used on API objects
If this annotation is set to true on a FlowSchema or PriorityLevelConfiguration, the spec for that object
is managed by the kube-apiserver. If the API server does not recognize an APF object, and you annotate it
for automatic update, the API server deletes the entire object. Otherwise, the API server does not manage the
object spec.
For more details, read Maintenance of the Mandatory and Suggested Configuration Objects.
Use of this annotation is Alpha.
For Kubernetes version 1.28, you can use this annotation on Secrets,
ConfigMaps, or custom resources if the
CustomResourceDefinition
defining them has the applyset.kubernetes.io/is-parent-type label.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
This annotation is applied to the parent object used to track an ApplySet to extend the scope of
the ApplySet beyond the parent object's own namespace (if any).
The value is a comma-separated list of the names of namespaces other than the parent's namespace
in which objects are found.
Use of this annotation is Alpha.
For Kubernetes version 1.28, you can use this annotation on Secrets, ConfigMaps,
or custom resources if the CustomResourceDefinition
defining them has the applyset.kubernetes.io/is-parent-type label.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
This annotation is applied to the parent object used to track an ApplySet to optimize listing of
ApplySet member objects. It is optional in the ApplySet specification, as tools can perform discovery
or use a different optimization. However, as of Kubernetes version 1.28,
it is required by kubectl. When present, the value of this annotation must be a comma separated list
of the group-kinds, in the fully-qualified name format, i.e. <resource>.<group>.
Use of this label is Alpha.
For Kubernetes version 1.28, you can use this label on Secrets, ConfigMaps,
or custom resources if the CustomResourceDefinition
defining them has the applyset.kubernetes.io/is-parent-type label.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
This label is what makes an object an ApplySet parent object.
Its value is the unique ID of the ApplySet, which is derived from the identity of the parent
object itself. This ID must be the base64 encoding (using the URL safe encoding of RFC4648) of
the hash of the group-kind-name-namespace of the object it is on, in the form:
<base64(sha256(<name>.<namespace>.<kind>.<group>))>.
There is no relation between the value of this label and object UID.
Use of this label is Alpha.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
You can set this label on a CustomResourceDefinition (CRD) to identify the custom resource type it
defines (not the CRD itself) as an allowed parent for an ApplySet.
The only permitted value for this label is "true"; if you want to mark a CRD as
not being a valid parent for ApplySets, omit this label.
Use of this label is Alpha.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
This label is what makes an object a member of an ApplySet.
The value of the label must match the value of the applyset.kubernetes.io/id
label on the parent object.
Use of this annotation is Alpha.
For Kubernetes version 1.28, you can use this annotation on Secrets,
ConfigMaps, or custom resources if the CustomResourceDefinitiondefining them has the
applyset.kubernetes.io/is-parent-type label.
Part of the specification used to implement
ApplySet-based pruning in kubectl.
This annotation is applied to the parent object used to track an ApplySet to indicate which
tooling manages that ApplySet. Tooling should refuse to mutate ApplySets belonging to other tools.
The value must be in the format <toolname>/<semver>.
apps.kubernetes.io/pod-index (beta)
Type: Label
Example: apps.kubernetes.io/pod-index: "0"
Used on: Pod
When a StatefulSet controller creates a Pod for the StatefulSet, it sets this label on that Pod.
The value of the label is the ordinal index of the pod being created.
See Pod Index Label
in the StatefulSet topic for more details.
Note the PodIndexLabel
feature gate must be enabled for this label to be added to pods.
When this annotation is set to "true", the cluster autoscaler is allowed to evict a Pod
even if other rules would normally prevent that.
The cluster autoscaler never evicts Pods that have this annotation explicitly set to
"false"; you could set that on an important Pod that you want to keep running.
If this annotation is not set then the cluster autoscaler follows its Pod-level behavior.
This annotation is used in manifests to mark an object as local configuration that
should not be submitted to the Kubernetes API.
A value of "true" for this annotation declares that the object is only consumed by
client-side tooling and should not be submitted to the API server.
A value of "false" can be used to declare that the object should be submitted to
the API server even when it would otherwise be assumed to be local.
This annotation is part of the Kubernetes Resource Model (KRM) Functions Specification,
which is used by Kustomize and similar third-party tools.
For example, Kustomize removes objects with this annotation from its final build output.
This annotation allows you to specify the AppArmor security profile for a container within a
Kubernetes pod.
To learn more, see the AppArmor tutorial.
The tutorial illustrates using AppArmor to restrict a container's abilities and access.
The profile specified dictates the set of rules and restrictions that the containerized process must
adhere to. This helps enforce security policies and isolation for your containers.
internal.config.kubernetes.io/* (reserved prefix)
Type: Annotation
Used on: All objects
This prefix is reserved for internal use by tools that act as orchestrators in accordance
with the Kubernetes Resource Model (KRM) Functions Specification.
Annotations with this prefix are internal to the orchestration process and are not persisted to
the manifests on the filesystem. In other words, the orchestrator tool should set these
annotations when reading files from the local filesystem and remove them when writing the output
of functions back to the filesystem.
A KRM function must not modify annotations with this prefix, unless otherwise specified for a
given annotation. This enables orchestrator tools to add additional internal annotations, without
requiring changes to existing functions.
This annotation records the slash-delimited, OS-agnostic, relative path to the manifest file the
object was loaded from. The path is relative to a fixed location on the filesystem, determined by
the orchestrator tool.
This annotation is part of the Kubernetes Resource Model (KRM) Functions Specification, which is
used by Kustomize and similar third-party tools.
A KRM Function should not modify this annotation on input objects unless it is modifying the
referenced files. A KRM Function may include this annotation on objects it generates.
internal.config.kubernetes.io/index
Type: Annotation
Example: internal.config.kubernetes.io/index: "2"
Used on: All objects
This annotation records the zero-indexed position of the YAML document that contains the object
within the manifest file the object was loaded from. Note that YAML documents are separated by
three dashes (---) and can each contain one object. When this annotation is not specified, a
value of 0 is implied.
This annotation is part of the Kubernetes Resource Model (KRM) Functions Specification,
which is used by Kustomize and similar third-party tools.
A KRM Function should not modify this annotation on input objects unless it is modifying the
referenced files. A KRM Function may include this annotation on objects it generates.
kubernetes.io/arch
Type: Label
Example: kubernetes.io/arch: "amd64"
Used on: Node
The Kubelet populates this with runtime.GOARCH as defined by Go.
This can be handy if you are mixing ARM and x86 nodes.
kubernetes.io/os
Type: Label
Example: kubernetes.io/os: "linux"
Used on: Node, Pod
For nodes, the kubelet populates this with runtime.GOOS as defined by Go. This can be handy if you are
mixing operating systems in your cluster (for example: mixing Linux and Windows nodes).
You can also set this label on a Pod. Kubernetes allows you to set any value for this label;
if you use this label, you should nevertheless set it to the Go runtime.GOOS string for the operating
system that this Pod actually works with.
When the kubernetes.io/os label value for a Pod does not match the label value on a Node,
the kubelet on the node will not admit the Pod. However, this is not taken into account by
the kube-scheduler. Alternatively, the kubelet refuses to run a Pod where you have specified a Pod OS, if
this isn't the same as the operating system for the node where that kubelet is running. Just
look for Pods OS for more details.
The Kubernetes API server (part of the control plane)
sets this label on all namespaces. The label value is set
to the name of the namespace. You can't change this label's value.
This is useful if you want to target a specific namespace with a label
selector.
kubernetes.io/limit-ranger
Type: Annotation
Example: kubernetes.io/limit-ranger: "LimitRanger plugin set: cpu, memory request for container nginx; cpu, memory limit for container nginx"
Used on: Pod
Kubernetes by default doesn't provide any resource limit, that means unless you explicitly define
limits, your container can consume unlimited CPU and memory.
You can define a default request or default limit for pods. You do this by creating a LimitRange
in the relevant namespace. Pods deployed after you define a LimitRange will have these limits
applied to them.
The annotation kubernetes.io/limit-ranger records that resource defaults were specified for the Pod,
and they were applied successfully.
For more details, read about LimitRanges.
To specify how an add-on should be managed, you can use the addonmanager.kubernetes.io/mode label.
This label can have one of three values: Reconcile, EnsureExists, or Ignore.
Reconcile: Addon resources will be periodically reconciled with the expected state.
If there are any differences, the add-on manager will recreate, reconfigure or delete
the resources as needed. This is the default mode if no label is specified.
EnsureExists: Addon resources will be checked for existence only but will not be modified
after creation. The add-on manager will create or re-create the resources when there is
no instance of the resource with that name.
Ignore: Addon resources will be ignored. This mode is useful for add-ons that are not
compatible with the add-on manager or that are managed by another controller.
The kube-apiserver sets this label on any APIService object that the API server
has created automatically. The label marks how the control plane should manage that
APIService. You should not add, modify, or remove this label by yourself.
Note: Automanaged APIService objects are deleted by kube-apiserver when it has no built-in
or custom resource API corresponding to the API group/version of the APIService.
There are two possible values:
onstart: The APIService should be reconciled when an API server starts up, but not otherwise.
true: The API server should reconcile this APIService continuously.
This annotation on a Service denotes if the Endpoints controller should go ahead and create
Endpoints for unready Pods. Endpoints of these Services retain their DNS records and continue
receiving traffic for the Service from the moment the kubelet starts all containers in the pod
and marks it Running, til the kubelet stops all containers and deletes the pod from
the API server.
The Kubelet populates this label with the hostname of the node. Note that the hostname
can be changed from the "actual" hostname by passing the --hostname-override flag to
the kubelet.
This label is also used as part of the topology hierarchy.
See topology.kubernetes.io/zone for more information.
The value for this annotation must be true to take effect.
This annotation indicates that Pods running as this ServiceAccount may only reference
Secret API objects specified in the ServiceAccount's secrets field.
Kubernetes automatically enables the ServiceNodeExclusion feature gate on
the clusters it creates. With this feature gate enabled on a cluster,
you can add labels to particular worker nodes to exclude them from the list of backend servers.
The following command can be used to exclude a worker node from the list of backend servers in a
backend set:
This annotation is used to set Pod Deletion Cost
which allows users to influence ReplicaSet downscaling order.
The annotation value parses into an int32 type.
This annotation controls whether a DaemonSet pod should be evicted by a ClusterAutoscaler.
This annotation needs to be specified on DaemonSet pods in a DaemonSet manifest.
When this annotation is set to "true", the ClusterAutoscaler is allowed to evict
a DaemonSet Pod, even if other rules would normally prevent that.
To disallow the ClusterAutoscaler from evicting DaemonSet pods,
you can set this annotation to "false" for important DaemonSet pods.
If this annotation is not set, then the ClusterAutoscaler follows its overall behavior
(i.e evict the DaemonSets based on its configuration).
Note: This annotation only impacts DaemonSet Pods.
kubernetes.io/ingress-bandwidth
Type: Annotation
Example: kubernetes.io/ingress-bandwidth: 10M
Used on: Pod
You can apply quality-of-service traffic shaping to a pod and effectively limit its available
bandwidth. Ingress traffic to a Pod is handled by shaping queued packets to effectively
handle data. To limit the bandwidth on a Pod, write an object definition JSON file and specify
the data traffic speed using kubernetes.io/ingress-bandwidth annotation. The unit used for
specifying ingress rate is bits per second, as a
Quantity.
For example, 10M means 10 megabits per second.
Note: Ingress traffic shaping annotation is an experimental feature.
If you want to enable traffic shaping support, you must add the bandwidth plugin to your CNI
configuration file (default /etc/cni/net.d) and ensure that the binary is included in your CNI
bin dir (default /opt/cni/bin).
kubernetes.io/egress-bandwidth
Type: Annotation
Example: kubernetes.io/egress-bandwidth: 10M
Used on: Pod
Egress traffic from a Pod is handled by policing, which simply drops packets in excess of the
configured rate. The limits you place on a Pod do not affect the bandwidth of other Pods.
To limit the bandwidth on a Pod, write an object definition JSON file and specify the data traffic
speed using kubernetes.io/egress-bandwidth annotation. The unit used for specifying egress rate
is bits per second, as a Quantity.
For example, 10M means 10 megabits per second.
Note: Egress traffic shaping annotation is an experimental feature.
If you want to enable traffic shaping support, you must add the bandwidth plugin to your CNI
configuration file (default /etc/cni/net.d) and ensure that the binary is included in your CNI
bin dir (default /opt/cni/bin).
The Kubelet populates this with the instance type as defined by the cloud provider.
This will be set only if you are using a cloud provider. This setting is handy
if you want to target certain workloads to certain instance types, but typically you want
to rely on the Kubernetes scheduler to perform resource-based scheduling.
You should aim to schedule based on properties rather than on instance types
(for example: require a GPU, instead of requiring a g2.2xlarge).
When this annotation is set on a PersistentVolumeClaim (PVC), that indicates that the lifecycle
of the PVC has passed through initial binding setup. When present, that information changes
how the control plane interprets the state of PVC objects.
The value of this annotation does not matter to Kubernetes.
If this annotation is set on a PersistentVolume or PersistentVolumeClaim, it indicates that a
storage binding (PersistentVolume → PersistentVolumeClaim, or PersistentVolumeClaim → PersistentVolume)
was installed by the controller.
If the annotation isn't set, and there is a storage binding in place, the absence of that
annotation means that the binding was done manually.
The value of this annotation does not matter.
This annotation is added to a PersistentVolume(PV) that has been dynamically provisioned by Kubernetes.
Its value is the name of volume plugin that created the volume. It serves both users (to show where a PV
comes from) and Kubernetes (to recognize dynamically provisioned PVs in its decisions).
It is added to a PersistentVolume(PV) and PersistentVolumeClaim(PVC) that is supposed to be
dynamically provisioned/deleted by its corresponding CSI driver through the CSIMigration feature gate.
When this annotation is set, the Kubernetes components will "stand-down" and the
external-provisioner will act on the objects.
When a StatefulSet controller creates a Pod for the StatefulSet, the control plane
sets this label on that Pod. The value of the label is the name of the Pod being created.
See Pod Name Label
in the StatefulSet topic for more details.
On Node: The kubelet or the external cloud-controller-manager populates this
with the information from the cloud provider. This will be set only if you are using
a cloud provider. However, you can consider setting this on nodes if it makes sense
in your topology.
On PersistentVolume: topology-aware volume provisioners will automatically set
node affinity constraints on a PersistentVolume.
A zone represents a logical failure domain. It is common for Kubernetes clusters to
span multiple zones for increased availability. While the exact definition of a zone
is left to infrastructure implementations, common properties of a zone include
very low network latency within a zone, no-cost network traffic within a zone, and
failure independence from other zones.
For example, nodes within a zone might share a network switch, but nodes in different
zones should not.
A region represents a larger domain, made up of one or more zones.
It is uncommon for Kubernetes clusters to span multiple regions,
While the exact definition of a zone or region is left to infrastructure implementations,
common properties of a region include higher network latency between them than within them,
non-zero cost for network traffic between them, and failure independence from other zones or regions.
For example, nodes within a region might share power infrastructure (e.g. a UPS or generator),
but nodes in different regions typically would not.
Kubernetes makes a few assumptions about the structure of zones and regions:
regions and zones are hierarchical: zones are strict subsets of regions and
no zone can be in 2 regions
zone names are unique across regions; for example region "africa-east-1" might be comprised
of zones "africa-east-1a" and "africa-east-1b"
It should be safe to assume that topology labels do not change.
Even though labels are strictly mutable, consumers of them can assume that a given node
is not going to be moved between zones without being destroyed and recreated.
Kubernetes can use this information in various ways.
For example, the scheduler automatically tries to spread the Pods in a ReplicaSet across nodes
in a single-zone cluster (to reduce the impact of node failures, see
kubernetes.io/hostname).
With multiple-zone clusters, this spreading behavior also applies to zones (to reduce the impact of zone failures).
This is achieved via SelectorSpreadPriority.
SelectorSpreadPriority is a best effort placement. If the zones in your cluster are
heterogeneous (for example: different numbers of nodes, different types of nodes, or different pod
resource requirements), this placement might prevent equal spreading of your Pods across zones.
If desired, you can use homogenous zones (same number and types of nodes) to reduce the probability
of unequal spreading.
The scheduler (through the VolumeZonePredicate predicate) also will ensure that Pods,
that claim a given volume, are only placed into the same zone as that volume.
Volumes cannot be attached across zones.
If PersistentVolumeLabel does not support automatic labeling of your PersistentVolumes,
you should consider adding the labels manually (or adding support for PersistentVolumeLabel).
With PersistentVolumeLabel, the scheduler prevents Pods from mounting volumes in a different zone.
If your infrastructure doesn't have this constraint, you don't need to add the zone labels to the volumes at all.
This annotation can be used for PersistentVolume(PV) or PersistentVolumeClaim(PVC)
to specify the name of StorageClass.
When both the storageClassName attribute and the volume.beta.kubernetes.io/storage-class
annotation are specified, the annotation volume.beta.kubernetes.io/storage-class
takes precedence over the storageClassName attribute.
This annotation has been deprecated. Instead, set the
storageClassName field
for the PersistentVolumeClaim or PersistentVolume.
Example : volume.beta.kubernetes.io/mount-options: "ro,soft"
Used on: PersistentVolume
A Kubernetes administrator can specify additional
mount options
for when a PersistentVolume is mounted on a node.
volume.kubernetes.io/storage-provisioner
Type: Annotation
Used on: PersistentVolumeClaim
This annotation is added to a PVC that is supposed to be dynamically provisioned.
Its value is the name of a volume plugin that is supposed to provision a volume
for this PVC.
volume.kubernetes.io/selected-node
Type: Annotation
Used on: PersistentVolumeClaim
This annotation is added to a PVC that is triggered by a scheduler to be
dynamically provisioned. Its value is the name of the selected node.
If a node has the annotation volumes.kubernetes.io/controller-managed-attach-detach,
its storage attach and detach operations are being managed by the volume attach/detachcontroller.
This annotation was used for enabling topology aware hints on Services. Topology aware
hints have since been renamed: the concept is now called
topology aware routing.
Setting the annotation to Auto, on a Service, configured the Kubernetes control plane to
add topology hints on EndpointSlices associated with that Service. You can also explicitly
set the annotation to Disabled.
If you are running a version of Kubernetes older than 1.28,
check the documentation for that Kubernetes version to see how topology aware routing
works in that release.
There are no other valid values for this annotation. If you don't want topology aware hints
for a Service, don't add this annotation.
service.kubernetes.io/topology-mode
Type: Annotation
Example: service.kubernetes.io/topology-mode: Auto
Used on: Service
This annotation provides a way to define how Services handle network topology;
for example, you can configure a Service so that Kubernetes prefers keeping traffic between
a client and server within a single topology zone.
In some cases this can help reduce costs or improve network performance.
This label records the name of the
Service that the EndpointSlice is backing. All EndpointSlices should have this label set to
the name of their associated Service.
This annotation records the unique ID of the
ServiceAccount that the token (stored in the Secret of type kubernetes.io/service-account-token)
represents.
The control plane only adds this label to Secrets that have the type
kubernetes.io/service-account-token.
The value of this label records the date (ISO 8601 format, UTC time zone) when the control plane
last saw a request where the client authenticated using the service account token.
If a legacy token was last used before the cluster gained the feature (added in Kubernetes v1.26),
then the label isn't set.
The label is used to indicate the controller or entity that manages the EndpointSlice. This label
aims to enable different EndpointSlice objects to be managed by different controllers or entities
within the same cluster.
The label can be set to "true" on an Endpoints resource to indicate that the
EndpointSliceMirroring controller should not mirror this resource with EndpointSlices.
When a single StorageClass resource has this annotation set to "true", new PersistentVolumeClaim
resource without a class specified will be assigned this default class.
The kubelet can set this annotation on a Node to denote its configured IPv4 and/or IPv6 address.
When kubelet is started with the --cloud-provider flag set to any value (includes both external
and legacy in-tree cloud providers), it sets this annotation on the Node to denote an IP address
set from the command line flag (--node-ip). This IP is verified with the cloud provider as valid
by the cloud-controller-manager.
This annotation is used to record the original (expected) creation timestamp for a Job,
when that Job is part of a CronJob.
The control plane sets the value to that timestamp in RFC3339 format. If the Job belongs to a CronJob
with a timezone specified, then the timestamp is in that timezone. Otherwise, the timestamp is in controller-manager's local time.
The value of the annotation is the container name that is default for this Pod.
For example, kubectl logs or kubectl exec without -c or --container flag
will use this default container.
The value of the annotation is the container name that is the default logging container for this
Pod. For example, kubectl logs without -c or --container flag will use this default
container.
Note: This annotation is deprecated. You should use the
kubectl.kubernetes.io/default-container
annotation instead. Kubernetes versions 1.25 and newer ignore this annotation.
The control plane adds this annotation to
an Endpoints object if the associated
Service has more than 1000 backing endpoints.
The annotation indicates that the Endpoints object is over capacity and the number of endpoints
has been truncated to 1000.
If the number of backend endpoints falls below 1000, the control plane removes this annotation.
The control plane previously set annotation on
an Endpoints object. This annotation provided
the following detail:
Who is the current leader.
The time when the current leadership was acquired.
The duration of the lease (of the leadership) in seconds.
The time the current lease (the current leadership) should be renewed.
The number of leadership transitions that happened in the past.
Kubernetes now uses Leases to
manage leader assignment for the Kubernetes control plane.
batch.kubernetes.io/job-tracking (deprecated)
Type: Annotation
Example: batch.kubernetes.io/job-tracking: ""
Used on: Jobs
The presence of this annotation on a Job used to indicate that the control plane is
tracking the Job status using finalizers.
Adding or removing this annotation no longer has an effect (Kubernetes v1.27 and later)
All Jobs are tracked with finalizers.
job-name (deprecated)
Type: Label
Example: job-name: "pi"
Used on: Jobs and Pods controlled by Jobs
Note: Starting from Kubernetes 1.27, this label is deprecated.
Kubernetes 1.27 and newer ignore this label and use the prefixed job-name label.
controller-uid (deprecated)
Type: Label
Example: controller-uid: "$UID"
Used on: Jobs and Pods controlled by Jobs
Note: Starting from Kubernetes 1.27, this label is deprecated.
Kubernetes 1.27 and newer ignore this label and use the prefixed controller-uid label.
batch.kubernetes.io/job-name
Type: Label
Example: batch.kubernetes.io/job-name: "pi"
Used on: Jobs and Pods controlled by Jobs
This label is used as a user-friendly way to get Pods corresponding to a Job.
The job-name comes from the name of the Job and allows for an easy way to
get Pods corresponding to the Job.
This label is used as a programmatic way to get all Pods corresponding to a Job.
The controller-uid is a unique identifer that gets set in the selector field so the Job
controller can get all the corresponding Pods.
This annotation requires the PodTolerationRestriction
admission controller to be enabled. This annotation key allows assigning tolerations to a
namespace and any new pods created in this namespace would get these tolerations added.
This annotation is only useful when the (Alpha)
PodTolerationRestriction
admission controller is enabled. The annotation value is a JSON document that defines a list of
allowed tolerations for the namespace it annotates. When you create a Pod or modify its
tolerations, the API server checks the tolerations to see if they are mentioned in the allow list.
The pod is admitted only if the check succeeds.
The kubelet detects memory pressure based on memory.available and allocatableMemory.available
observed on a Node. The observed values are then compared to the corresponding thresholds that can
be set on the kubelet to determine if the Node condition and taint should be added/removed.
The kubelet detects disk pressure based on imagefs.available, imagefs.inodesFree,
nodefs.available and nodefs.inodesFree(Linux only) observed on a Node.
The observed values are then compared to the corresponding thresholds that can be set on the
kubelet to determine if the Node condition and taint should be added/removed.
This is initially set by the kubelet when the cloud provider used indicates a requirement for
additional network configuration. Only when the route on the cloud is configured properly will the
taint be removed by the cloud provider.
The kubelet checks D-value of the size of /proc/sys/kernel/pid_max and the PIDs consumed by
Kubernetes on a node to get the number of available PIDs that referred to as the pid.available
metric. The metric is then compared to the corresponding threshold that can be set on the kubelet
to determine if the node condition and taint should be added/removed.
A user can manually add the taint to a Node marking it out-of-service.
If the NodeOutOfServiceVolumeDetachfeature gate
is enabled on kube-controller-manager, and a Node is marked out-of-service with this taint,
the Pods on the node will be forcefully deleted if there are no matching tolerations on it and
volume detach operations for the Pods terminating on the node will happen immediately.
This allows the Pods on the out-of-service node to recover quickly on a different node.
Sets this taint on a Node to mark it as unusable, when kubelet is started with the "external"
cloud provider, until a controller from the cloud-controller-manager initializes this Node, and
then removes the taint.
If a Node is in a cloud provider specified shutdown state, the Node gets tainted accordingly
with node.cloudprovider.kubernetes.io/shutdown and the taint effect of NoSchedule.
These labels are used by the Node Feature Discovery (NFD) component to advertise
features on a node. All built-in labels use the feature.node.kubernetes.io label
namespace and have the format feature.node.kubernetes.io/<feature-name>: "true".
NFD has many extension points for creating vendor and application-specific labels.
For details, see the customization guide.
For node(s) where the Node Feature Discovery (NFD)
master
is scheduled, this annotation records the version of the NFD master.
It is used for informative use only.
This annotation records a comma-separated list of node feature labels managed by
Node Feature Discovery (NFD).
NFD uses this for an internal mechanism. You should not edit this annotation yourself.
This annotation records a comma-separated list of
extended resources
managed by Node Feature Discovery (NFD).
NFD uses this for an internal mechanism. You should not edit this annotation yourself.
nfd.node.kubernetes.io/node-name
Type: Label
Example: nfd.node.kubernetes.io/node-name: node-1
Used on: Nodes
It specifies which node the NodeFeature object is targeting.
Creators of NodeFeature objects must set this label and
consumers of the objects are supposed to use the label for
filtering features designated for a certain node.
Note: These Node Feature Discovery (NFD) labels or annotations only apply to
the nodes where NFD is running. To learn more about NFD and
its components go to its official documentation.
The cloud controller manager integration with AWS elastic load balancing configures
the load balancer for a Service based on this annotation. The value determines
how often the load balancer writes log entries. For example, if you set the value
to 5, the log writes occur 5 seconds apart.
The cloud controller manager integration with AWS elastic load balancing configures
the load balancer for a Service based on this annotation. Access logging is enabled
if you set the annotation to "true".
Example: service.beta.kubernetes.io/aws-load-balancer-access-log-enabled: example
Used on: Service
The cloud controller manager integration with AWS elastic load balancing configures
the load balancer for a Service based on this annotation. The load balancer
writes logs to an S3 bucket with the name you specify.
The cloud controller manager integration with AWS elastic load balancing configures
the load balancer for a Service based on this annotation. The load balancer
writes log objects with the prefix that you specify.
The cloud controller manager integration with AWS elastic load balancing configures
tags (an AWS concept) for a load balancer based on the comma-separated key/value
pairs in the value of this annotation.
The cloud controller manager integration with AWS elastic load balancing configures
the load balancer based on this annotation. The load balancer's connection draining
setting depends on the value you set.
If you configure connection draining
for a Service of type: LoadBalancer, and you use the AWS cloud, the integration configures
the draining period based on this annotation. The value you set determines the draining
timeout in seconds.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The load balancer has a configured idle
timeout period (in seconds) that applies to its connections. If no data has been
sent or received by the time that the idle timeout period elapses, the load balancer
closes the connection.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. If you set this annotation to "true",
each load balancer node distributes requests evenly across the registered targets
in all enabled availability zones.
If you disable cross-zone load balancing, each load balancer node distributes requests
evenly across the registered targets in its availability zone only.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The value is a comma-separated list
of elastic IP address allocation IDs.
This annotation is only relevant for Services of type: LoadBalancer, where
the load balancer is an AWS Network Load Balancer.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value is a comma-separated
list of extra AWS VPC security groups to configure for the load balancer.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value specifies the number of
successive successful health checks required for a backend to be considered healthy
for traffic.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value specifies the interval,
in seconds, between health check probes made by the load balancer.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value determines the
path part of the URL that is used for HTTP health checks.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value determines which
port the load balancer connects to when performing health checks.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value determines how the
load balancer checks the health of backend targets.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value specifies the number
of seconds before a probe that hasn't yet succeeded is automatically treated as
having failed.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. The annotation value specifies the number of
successive unsuccessful health checks required for a backend to be considered unhealthy
for traffic.
The cloud controller manager integration with AWS elastic load balancing configures
a load balancer based on this annotation. When you set this annotation to "true",
the integration configures an internal load balancer.
If you set this annotation on a Service, and you also annotate that Service with
service.beta.kubernetes.io/aws-load-balancer-type: "external", and you use the
AWS load balancer controller
in your cluster, then the AWS load balancer controller sets the name of that load
balancer to the value you set for this annotation.
See annotations
in the AWS load balancer controller documentation.
The official Kubernetes integration with AWS elastic load balancing configures
a load balancer based on this annotation. The only permitted value is "*",
which indicates that the load balancer should wrap TCP connections to the backend
Pod with the PROXY protocol.
The AWS load balancer controller uses this annotation to specify a comma seperated list
of security groups you want to attach to an AWS load balancer. Both name and ID of security
are supported where name matches a Name tag, not the groupName attribute.
When this annotation is added to a Service, the load-balancer controller attaches the security groups
referenced by the annotation to the load balancer. If you omit this annotation, the AWS load balancer
controller automatically creates a new security group and attaches it to the load balancer.
Note: Kubernetes v1.27 and later do not directly set or read this annotation. However, the AWS
load balancer controller (part of the Kubernetes project) does still use the
service.beta.kubernetes.io/aws-load-balancer-security-groups annotation.
The official integration with AWS elastic load balancing configures TLS for a Service of
type: LoadBalancer based on this annotation. The value of the annotation is the
AWS Resource Name (ARN) of the X.509 certificate that the load balancer listener should
use.
(The TLS protocol is based on an older technology that abbreviates to SSL.)
The official integration with AWS elastic load balancing configures TLS for a Service of
type: LoadBalancer based on this annotation. The value of the annotation is the name
of an AWS policy for negotiating TLS with a client peer.
The official integration with AWS elastic load balancing configures TLS for a Service of
type: LoadBalancer based on this annotation. The value of the annotation is either "*",
which means that all the load balancer's ports should use TLS, or it is a comma separated
list of port numbers.
Kubernetes' official integration with AWS uses this annotation to configure a
load balancer and determine in which AWS availability zones to deploy the managed
load balancing service. The value is either a comma separated list of subnet names, or a
comma separated list of subnet IDs.
Kubernetes' official integration with AWS uses this annotation to determine which
nodes in your cluster should be considered as valid targets for the load balancer.
Kubernetes' official integrations with AWS use this annotation to determine
whether the AWS cloud provider integration should manage a Service of
type: LoadBalancer.
There are two permitted values:
nlb
the cloud controller manager configures a Network Load Balancer
external
the cloud controller manager does not configure any load balancer
If you deploy a Service of type: LoadBalancer on AWS, and you don't set any
service.beta.kubernetes.io/aws-load-balancer-type annotation,
the AWS integration deploys a classic Elastic Load Balancer. This behavior,
with no annotation present, is the default unless you specify otherwise.
When you set this annotation to external on a Service of type: LoadBalancer,
and your cluster has a working deployment of the AWS Load Balancer controller,
then the AWS Load Balancer controller attempts to deploy a load balancer based
on the Service specification.
Caution: Do not modify or add the service.beta.kubernetes.io/aws-load-balancer-type annotation
on an existing Service object. See the AWS documentation on this topic for more
details.
Value must be one of privileged, baseline, or restricted which correspond to
Pod Security Standard levels.
Specifically, the enforce label prohibits the creation of any Pod in the labeled
Namespace which does not meet the requirements outlined in the indicated level.
Value must be latest or a valid Kubernetes version in the format v<major>.<minor>.
This determines the version of the
Pod Security Standard
policies to apply when validating a Pod.
Value must be one of privileged, baseline, or restricted which correspond to
Pod Security Standard levels.
Specifically, the audit label does not prevent the creation of a Pod in the labeled
Namespace which does not meet the requirements outlined in the indicated level,
but adds an this annotation to the Pod.
Value must be latest or a valid Kubernetes version in the format v<major>.<minor>.
This determines the version of the
Pod Security Standard
policies to apply when validating a Pod.
Value must be one of privileged, baseline, or restricted which correspond to
Pod Security Standard levels.
Specifically, the warn label does not prevent the creation of a Pod in the labeled
Namespace which does not meet the requirements outlined in the indicated level,
but returns a warning to the user after doing so.
Note that warnings are also displayed when creating or updating objects that contain
Pod templates, such as Deployments, Jobs, StatefulSets, etc.
Value must be latest or a valid Kubernetes version in the format v<major>.<minor>.
This determines the version of the Pod Security Standard
policies to apply when validating a submitted Pod.
Note that warnings are also displayed when creating or updating objects that contain
Pod templates, such as Deployments, Jobs, StatefulSets, etc.
Used on: ClusterRole, ClusterRoleBinding, Role, RoleBinding
When this annotation is set to "true" on default RBAC objects created by the API server,
they are automatically updated at server start to add missing permissions and subjects
(extra permissions and subjects are left in place).
To prevent autoupdating a particular role or rolebinding, set this annotation to "false".
If you create your own RBAC objects and set this annotation to "false", kubectl auth reconcile
(which allows reconciling arbitrary RBAC objects in a manifest)
respects this annotation and does not automatically add missing permissions and subjects.
kubernetes.io/psp (deprecated)
Type: Annotation
Example: kubernetes.io/psp: restricted
Used on: Pod
This annotation was only relevant if you were using
PodSecurityPolicy objects.
Kubernetes v1.28 does not support the PodSecurityPolicy API.
When the PodSecurityPolicy admission controller admitted a Pod, the admission controller
modified the Pod to have this annotation.
The value of the annotation was the name of the PodSecurityPolicy that was used for validation.
Kubernetes before v1.25 allowed you to configure seccomp behavior using this annotation.
See Restrict a Container's Syscalls with seccomp to
learn the supported way to specify seccomp restrictions for a Pod.
Kubernetes before v1.25 allowed you to configure seccomp behavior using this annotation.
See Restrict a Container's Syscalls with seccomp to
learn the supported way to specify seccomp restrictions for a Pod.
Value can either be true or false. This determines whether a user can modify
the mode of the source volume when a PersistentVolumeClaim is being created from
a VolumeSnapshot.
Annotation that kubeadm uses to preserve the CRI socket information given to kubeadm at
init/join time for later use. kubeadm annotates the Node object with this information.
The annotation remains "alpha", since ideally this should be a field in KubeletConfiguration
instead.
Annotation that kubeadm places on locally managed etcd Pods to keep track of
a list of URLs where etcd clients should connect to.
This is used mainly for etcd cluster health check purposes.
Annotation that kubeadm places on locally managed kube-apiserver Pods to keep track
of the exposed advertise address/port endpoint for that API server instance.
Annotation that kubeadm places on ConfigMaps that it manages for configuring components.
It contains a hash (SHA-256) used to determine if the user has applied settings different
from the kubeadm defaults for a particular component.
node-role.kubernetes.io/control-plane
Type: Label
Used on: Node
A marker label to indicate that the node is used to run control plane components.
The kubeadm tool applies this label to the control plane nodes that it manages.
Other cluster management tools typically also set this taint.
You can label control plane nodes with this label to make it easier to schedule Pods
only onto these nodes, or to avoid running Pods on the control plane.
If this label is set, the EndpointSlice controller
ignores that node while calculating Topology Aware Hints.
Taint that kubeadm applies on control plane nodes to restrict placing Pods and
allow only specific pods to schedule on them.
If this Taint is applied, control plane nodes allow only critical workloads to
be scheduled onto them. You can manually remove this taint with the following
command on a specific node.
Taint that kubeadm previously applied on control plane nodes to allow only critical
workloads to schedule on them. Replaced by the
node-role.kubernetes.io/control-plane
taint. kubeadm no longer sets or uses this deprecated taint.
4.1 - Audit Annotations
This page serves as a reference for the audit annotations of the kubernetes.io
namespace. These annotations apply to Event object from API group
audit.k8s.io.
Note: The following annotations are not used within the Kubernetes API. When you
enable auditing in your cluster,
audit event data is written using Event from API group audit.k8s.io.
The annotations apply to audit events. Audit events are different from objects in the
Event API (API group
events.k8s.io).
Value must be one of user, namespace, or runtimeClass which correspond to
Pod Security Exemption
dimensions. This annotation indicates on which dimension was based the exemption
from the PodSecurity enforcement.
Value must be privileged:<version>, baseline:<version>,
restricted:<version> which correspond to Pod Security
Standard levels accompanied by
a version which must be latest or a valid Kubernetes version in the format
v<MAJOR>.<MINOR>. This annotations informs about the enforcement level that
allowed or denied the pod during PodSecurity admission.
Example: pod-security.kubernetes.io/audit-violations: would violate PodSecurity "restricted:latest": allowPrivilegeEscalation != false (container "example" must set securityContext.allowPrivilegeEscalation=false), ...
Value details an audit policy violation, it contains the
Pod Security Standard level
that was transgressed as well as the specific policies on the fields that were
violated from the PodSecurity enforcement.
Example: missing-san.invalid-cert.kubernetes.io/example-svc.example-namespace.svc: "relies on a legacy Common Name field instead of the SAN extension for subject validation"
Used by Kubernetes version v1.24 and later
This annotation indicates a webhook or aggregated API server
is using an invalid certificate that is missing subjectAltNames.
Support for these certificates was disabled by default in Kubernetes 1.19,
and removed in Kubernetes 1.23.
Requests to endpoints using these certificates will fail.
Services using these certificates should replace them as soon as possible
to avoid disruption when running in Kubernetes 1.23+ environments.
Example: insecure-sha1.invalid-cert.kubernetes.io/example-svc.example-namespace.svc: "uses an insecure SHA-1 signature"
Used by Kubernetes version v1.24 and later
This annotation indicates a webhook or aggregated API server
is using an insecure certificate signed with a SHA-1 hash.
Support for these insecure certificates is disabled by default in Kubernetes 1.24,
and will be removed in a future release.
Services using these certificates should replace them as soon as possible,
to ensure connections are secured properly and to avoid disruption in future releases.
This annotation indicates that a admission policy validation evaluted to false
for an API request, or that the validation resulted in an error while the policy
was configured with failurePolicy: Fail.
The value of the annotation is a JSON object. The message in the JSON
provides the message about the validation failure.
The policy, binding and expressionIndex in the JSON identifies the
name of the ValidatingAdmissionPolicy, the name of the
ValidatingAdmissionPolicyBinding and the index in the policy validations of
the CEL expressions that failed, respectively.
The validationActions shows what actions were taken for this validation failure.
See Validating Admission Policy
for more details about validationActions.
5 - Kubernetes API
Kubernetes' API is the application that serves Kubernetes functionality through a RESTful interface and stores the state of the cluster.
Kubernetes resources and "records of intent" are all stored as API objects, and modified via RESTful calls to the API. The API allows configuration to be managed in a declarative way. Users can interact with the Kubernetes API directly, or via tools like kubectl. The core Kubernetes API is flexible and can also be extended to support custom resources.
5.1 - Workload Resources
5.1.1 - Pod
Pod is a collection of containers that can run on a host.
apiVersion: v1
import "k8s.io/api/core/v1"
Pod
Pod is a collection of containers that can run on a host. This resource is created by clients and scheduled onto hosts.
List of containers belonging to the pod. Containers cannot currently be added or removed. There must be at least one container in a Pod. Cannot be updated.
List of initialization containers belonging to the pod. Init containers are executed in order prior to containers being started. If any init container fails, the pod is considered to have failed and is handled according to its restartPolicy. The name for an init container or normal container must be unique among all containers. Init containers may not have Lifecycle actions, Readiness probes, Liveness probes, or Startup probes. The resourceRequirements of an init container are taken into account during scheduling by finding the highest request/limit for each resource type, and then using the max of of that value or the sum of the normal containers. Limits are applied to init containers in a similar fashion. Init containers cannot currently be added or removed. Cannot be updated. More info: https://kubernetes.io/docs/concepts/workloads/pods/init-containers/
List of ephemeral containers run in this pod. Ephemeral containers may be run in an existing pod to perform user-initiated actions such as debugging. This list cannot be specified when creating a pod, and it cannot be modified by updating the pod spec. In order to add an ephemeral container to an existing pod, use the pod's ephemeralcontainers subresource.
EnableServiceLinks indicates whether information about services should be injected into pod's environment variables, matching the syntax of Docker links. Optional: Defaults to true.
os (PodOS)
Specifies the OS of the containers in the pod. Some pod and container fields are restricted if this is set.
If the OS field is set to linux, the following fields must be unset: -securityContext.windowsOptions
If the OS field is set to windows, following fields must be unset: - spec.hostPID - spec.hostIPC - spec.hostUsers - spec.securityContext.seLinuxOptions - spec.securityContext.seccompProfile - spec.securityContext.fsGroup - spec.securityContext.fsGroupChangePolicy - spec.securityContext.sysctls - spec.shareProcessNamespace - spec.securityContext.runAsUser - spec.securityContext.runAsGroup - spec.securityContext.supplementalGroups - spec.containers[].securityContext.seLinuxOptions - spec.containers[].securityContext.seccompProfile - spec.containers[].securityContext.capabilities - spec.containers[].securityContext.readOnlyRootFilesystem - spec.containers[].securityContext.privileged - spec.containers[].securityContext.allowPrivilegeEscalation - spec.containers[].securityContext.procMount - spec.containers[].securityContext.runAsUser - spec.containers[*].securityContext.runAsGroup
NodeName is a request to schedule this pod onto a specific node. If it is non-empty, the scheduler simply schedules this pod onto that node, assuming that it fits resource requirements.
Describes pod anti-affinity scheduling rules (e.g. avoid putting this pod in the same node, zone, etc. as some other pod(s)).
tolerations ([]Toleration)
If specified, the pod's tolerations.
The pod this Toleration is attached to tolerates any taint that matches the triple <key,value,effect> using the matching operator .
tolerations.key (string)
Key is the taint key that the toleration applies to. Empty means match all taint keys. If the key is empty, operator must be Exists; this combination means to match all values and all keys.
tolerations.operator (string)
Operator represents a key's relationship to the value. Valid operators are Exists and Equal. Defaults to Equal. Exists is equivalent to wildcard for value, so that a pod can tolerate all taints of a particular category.
tolerations.value (string)
Value is the taint value the toleration matches to. If the operator is Exists, the value should be empty, otherwise just a regular string.
tolerations.effect (string)
Effect indicates the taint effect to match. Empty means match all taint effects. When specified, allowed values are NoSchedule, PreferNoSchedule and NoExecute.
tolerations.tolerationSeconds (int64)
TolerationSeconds represents the period of time the toleration (which must be of effect NoExecute, otherwise this field is ignored) tolerates the taint. By default, it is not set, which means tolerate the taint forever (do not evict). Zero and negative values will be treated as 0 (evict immediately) by the system.
schedulerName (string)
If specified, the pod will be dispatched by specified scheduler. If not specified, the pod will be dispatched by default scheduler.
runtimeClassName (string)
RuntimeClassName refers to a RuntimeClass object in the node.k8s.io group, which should be used to run this pod. If no RuntimeClass resource matches the named class, the pod will not be run. If unset or empty, the "legacy" RuntimeClass will be used, which is an implicit class with an empty definition that uses the default runtime handler. More info: https://git.k8s.io/enhancements/keps/sig-node/585-runtime-class
priorityClassName (string)
If specified, indicates the pod's priority. "system-node-critical" and "system-cluster-critical" are two special keywords which indicate the highest priorities with the former being the highest priority. Any other name must be defined by creating a PriorityClass object with that name. If not specified, the pod priority will be default or zero if there is no default.
priority (int32)
The priority value. Various system components use this field to find the priority of the pod. When Priority Admission Controller is enabled, it prevents users from setting this field. The admission controller populates this field from PriorityClassName. The higher the value, the higher the priority.
preemptionPolicy (string)
PreemptionPolicy is the Policy for preempting pods with lower priority. One of Never, PreemptLowerPriority. Defaults to PreemptLowerPriority if unset.
Map: unique values on keys topologyKey, whenUnsatisfiable will be kept during a merge
TopologySpreadConstraints describes how a group of pods ought to spread across topology domains. Scheduler will schedule pods in a way which abides by the constraints. All topologySpreadConstraints are ANDed.
TopologySpreadConstraint specifies how to spread matching pods among the given topology.
MaxSkew describes the degree to which pods may be unevenly distributed. When whenUnsatisfiable=DoNotSchedule, it is the maximum permitted difference between the number of matching pods in the target topology and the global minimum. The global minimum is the minimum number of matching pods in an eligible domain or zero if the number of eligible domains is less than MinDomains. For example, in a 3-zone cluster, MaxSkew is set to 1, and pods with the same labelSelector spread as 2/2/1: In this case, the global minimum is 1. | zone1 | zone2 | zone3 | | P P | P P | P | - if MaxSkew is 1, incoming pod can only be scheduled to zone3 to become 2/2/2; scheduling it onto zone1(zone2) would make the ActualSkew(3-1) on zone1(zone2) violate MaxSkew(1). - if MaxSkew is 2, incoming pod can be scheduled onto any zone. When whenUnsatisfiable=ScheduleAnyway, it is used to give higher precedence to topologies that satisfy it. It's a required field. Default value is 1 and 0 is not allowed.
TopologyKey is the key of node labels. Nodes that have a label with this key and identical values are considered to be in the same topology. We consider each <key, value> as a "bucket", and try to put balanced number of pods into each bucket. We define a domain as a particular instance of a topology. Also, we define an eligible domain as a domain whose nodes meet the requirements of nodeAffinityPolicy and nodeTaintsPolicy. e.g. If TopologyKey is "kubernetes.io/hostname", each Node is a domain of that topology. And, if TopologyKey is "topology.kubernetes.io/zone", each zone is a domain of that topology. It's a required field.
WhenUnsatisfiable indicates how to deal with a pod if it doesn't satisfy the spread constraint. - DoNotSchedule (default) tells the scheduler not to schedule it. - ScheduleAnyway tells the scheduler to schedule the pod in any location,
but giving higher precedence to topologies that would help reduce the
skew.
A constraint is considered "Unsatisfiable" for an incoming pod if and only if every possible node assignment for that pod would violate "MaxSkew" on some topology. For example, in a 3-zone cluster, MaxSkew is set to 1, and pods with the same labelSelector spread as 3/1/1: | zone1 | zone2 | zone3 | | P P P | P | P | If WhenUnsatisfiable is set to DoNotSchedule, incoming pod can only be scheduled to zone2(zone3) to become 3/2/1(3/1/2) as ActualSkew(2-1) on zone2(zone3) satisfies MaxSkew(1). In other words, the cluster can still be imbalanced, but scheduler won't make it more imbalanced. It's a required field.
LabelSelector is used to find matching pods. Pods that match this label selector are counted to determine the number of pods in their corresponding topology domain.
MatchLabelKeys is a set of pod label keys to select the pods over which spreading will be calculated. The keys are used to lookup values from the incoming pod labels, those key-value labels are ANDed with labelSelector to select the group of existing pods over which spreading will be calculated for the incoming pod. The same key is forbidden to exist in both MatchLabelKeys and LabelSelector. MatchLabelKeys cannot be set when LabelSelector isn't set. Keys that don't exist in the incoming pod labels will be ignored. A null or empty list means only match against labelSelector.
This is a beta field and requires the MatchLabelKeysInPodTopologySpread feature gate to be enabled (enabled by default).
topologySpreadConstraints.minDomains (int32)
MinDomains indicates a minimum number of eligible domains. When the number of eligible domains with matching topology keys is less than minDomains, Pod Topology Spread treats "global minimum" as 0, and then the calculation of Skew is performed. And when the number of eligible domains with matching topology keys equals or greater than minDomains, this value has no effect on scheduling. As a result, when the number of eligible domains is less than minDomains, scheduler won't schedule more than maxSkew Pods to those domains. If value is nil, the constraint behaves as if MinDomains is equal to 1. Valid values are integers greater than 0. When value is not nil, WhenUnsatisfiable must be DoNotSchedule.
For example, in a 3-zone cluster, MaxSkew is set to 2, MinDomains is set to 5 and pods with the same labelSelector spread as 2/2/2: | zone1 | zone2 | zone3 | | P P | P P | P P | The number of domains is less than 5(MinDomains), so "global minimum" is treated as 0. In this situation, new pod with the same labelSelector cannot be scheduled, because computed skew will be 3(3 - 0) if new Pod is scheduled to any of the three zones, it will violate MaxSkew.
This is a beta field and requires the MinDomainsInPodTopologySpread feature gate to be enabled (enabled by default).
NodeAffinityPolicy indicates how we will treat Pod's nodeAffinity/nodeSelector when calculating pod topology spread skew. Options are: - Honor: only nodes matching nodeAffinity/nodeSelector are included in the calculations. - Ignore: nodeAffinity/nodeSelector are ignored. All nodes are included in the calculations.
If this value is nil, the behavior is equivalent to the Honor policy. This is a beta-level feature default enabled by the NodeInclusionPolicyInPodTopologySpread feature flag.
NodeTaintsPolicy indicates how we will treat node taints when calculating pod topology spread skew. Options are: - Honor: nodes without taints, along with tainted nodes for which the incoming pod has a toleration, are included. - Ignore: node taints are ignored. All nodes are included.
If this value is nil, the behavior is equivalent to the Ignore policy. This is a beta-level feature default enabled by the NodeInclusionPolicyInPodTopologySpread feature flag.
Overhead represents the resource overhead associated with running a pod for a given RuntimeClass. This field will be autopopulated at admission time by the RuntimeClass admission controller. If the RuntimeClass admission controller is enabled, overhead must not be set in Pod create requests. The RuntimeClass admission controller will reject Pod create requests which have the overhead already set. If RuntimeClass is configured and selected in the PodSpec, Overhead will be set to the value defined in the corresponding RuntimeClass, otherwise it will remain unset and treated as zero. More info: https://git.k8s.io/enhancements/keps/sig-node/688-pod-overhead/README.md
Optional duration in seconds the pod needs to terminate gracefully. May be decreased in delete request. Value must be non-negative integer. The value zero indicates stop immediately via the kill signal (no opportunity to shut down). If this value is nil, the default grace period will be used instead. The grace period is the duration in seconds after the processes running in the pod are sent a termination signal and the time when the processes are forcibly halted with a kill signal. Set this value longer than the expected cleanup time for your process. Defaults to 30 seconds.
activeDeadlineSeconds (int64)
Optional duration in seconds the pod may be active on the node relative to StartTime before the system will actively try to mark it failed and kill associated containers. Value must be a positive integer.
PodReadinessGate contains the reference to a pod condition
readinessGates.conditionType (string), required
ConditionType refers to a condition in the pod's condition list with matching type.
Hostname and Name resolution
hostname (string)
Specifies the hostname of the Pod If not specified, the pod's hostname will be set to a system-defined value.
setHostnameAsFQDN (boolean)
If true the pod's hostname will be configured as the pod's FQDN, rather than the leaf name (the default). In Linux containers, this means setting the FQDN in the hostname field of the kernel (the nodename field of struct utsname). In Windows containers, this means setting the registry value of hostname for the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters to FQDN. If a pod does not have FQDN, this has no effect. Default to false.
subdomain (string)
If specified, the fully qualified Pod hostname will be "<hostname>.<subdomain>.<pod namespace>.svc.<cluster domain>". If not specified, the pod will not have a domainname at all.
hostAliases ([]HostAlias)
Patch strategy: merge on key ip
HostAliases is an optional list of hosts and IPs that will be injected into the pod's hosts file if specified. This is only valid for non-hostNetwork pods.
HostAlias holds the mapping between IP and hostnames that will be injected as an entry in the pod's hosts file.
hostAliases.hostnames ([]string)
Hostnames for the above IP address.
hostAliases.ip (string)
IP address of the host file entry.
dnsConfig (PodDNSConfig)
Specifies the DNS parameters of a pod. Parameters specified here will be merged to the generated DNS configuration based on DNSPolicy.
PodDNSConfig defines the DNS parameters of a pod in addition to those generated from DNSPolicy.
dnsConfig.nameservers ([]string)
A list of DNS name server IP addresses. This will be appended to the base nameservers generated from DNSPolicy. Duplicated nameservers will be removed.
dnsConfig.options ([]PodDNSConfigOption)
A list of DNS resolver options. This will be merged with the base options generated from DNSPolicy. Duplicated entries will be removed. Resolution options given in Options will override those that appear in the base DNSPolicy.
PodDNSConfigOption defines DNS resolver options of a pod.
dnsConfig.options.name (string)
Required.
dnsConfig.options.value (string)
dnsConfig.searches ([]string)
A list of DNS search domains for host-name lookup. This will be appended to the base search paths generated from DNSPolicy. Duplicated search paths will be removed.
dnsPolicy (string)
Set DNS policy for the pod. Defaults to "ClusterFirst". Valid values are 'ClusterFirstWithHostNet', 'ClusterFirst', 'Default' or 'None'. DNS parameters given in DNSConfig will be merged with the policy selected with DNSPolicy. To have DNS options set along with hostNetwork, you have to specify DNS policy explicitly to 'ClusterFirstWithHostNet'.
Hosts namespaces
hostNetwork (boolean)
Host networking requested for this pod. Use the host's network namespace. If this option is set, the ports that will be used must be specified. Default to false.
hostPID (boolean)
Use the host's pid namespace. Optional: Default to false.
hostIPC (boolean)
Use the host's ipc namespace. Optional: Default to false.
shareProcessNamespace (boolean)
Share a single process namespace between all of the containers in a pod. When this is set containers will be able to view and signal processes from other containers in the same pod, and the first process in each container will not be assigned PID 1. HostPID and ShareProcessNamespace cannot both be set. Optional: Default to false.
AutomountServiceAccountToken indicates whether a service account token should be automatically mounted.
Security context
securityContext (PodSecurityContext)
SecurityContext holds pod-level security attributes and common container settings. Optional: Defaults to empty. See type description for default values of each field.
PodSecurityContext holds pod-level security attributes and common container settings. Some fields are also present in container.securityContext. Field values of container.securityContext take precedence over field values of PodSecurityContext.
securityContext.runAsUser (int64)
The UID to run the entrypoint of the container process. Defaults to user specified in image metadata if unspecified. May also be set in SecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence for that container. Note that this field cannot be set when spec.os.name is windows.
securityContext.runAsNonRoot (boolean)
Indicates that the container must run as a non-root user. If true, the Kubelet will validate the image at runtime to ensure that it does not run as UID 0 (root) and fail to start the container if it does. If unset or false, no such validation will be performed. May also be set in SecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
securityContext.runAsGroup (int64)
The GID to run the entrypoint of the container process. Uses runtime default if unset. May also be set in SecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence for that container. Note that this field cannot be set when spec.os.name is windows.
securityContext.supplementalGroups ([]int64)
A list of groups applied to the first process run in each container, in addition to the container's primary GID, the fsGroup (if specified), and group memberships defined in the container image for the uid of the container process. If unspecified, no additional groups are added to any container. Note that group memberships defined in the container image for the uid of the container process are still effective, even if they are not included in this list. Note that this field cannot be set when spec.os.name is windows.
securityContext.fsGroup (int64)
A special supplemental group that applies to all containers in a pod. Some volume types allow the Kubelet to change the ownership of that volume to be owned by the pod:
The owning GID will be the FSGroup 2. The setgid bit is set (new files created in the volume will be owned by FSGroup) 3. The permission bits are OR'd with rw-rw----
If unset, the Kubelet will not modify the ownership and permissions of any volume. Note that this field cannot be set when spec.os.name is windows.
securityContext.fsGroupChangePolicy (string)
fsGroupChangePolicy defines behavior of changing ownership and permission of the volume before being exposed inside Pod. This field will only apply to volume types which support fsGroup based ownership(and permissions). It will have no effect on ephemeral volume types such as: secret, configmaps and emptydir. Valid values are "OnRootMismatch" and "Always". If not specified, "Always" is used. Note that this field cannot be set when spec.os.name is windows.
securityContext.seccompProfile (SeccompProfile)
The seccomp options to use by the containers in this pod. Note that this field cannot be set when spec.os.name is windows.
SeccompProfile defines a pod/container's seccomp profile settings. Only one profile source may be set.
type indicates which kind of seccomp profile will be applied. Valid options are:
Localhost - a profile defined in a file on the node should be used. RuntimeDefault - the container runtime default profile should be used. Unconfined - no profile should be applied.
localhostProfile indicates a profile defined in a file on the node should be used. The profile must be preconfigured on the node to work. Must be a descending path, relative to the kubelet's configured seccomp profile location. Must be set if type is "Localhost". Must NOT be set for any other type.
securityContext.seLinuxOptions (SELinuxOptions)
The SELinux context to be applied to all containers. If unspecified, the container runtime will allocate a random SELinux context for each container. May also be set in SecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence for that container. Note that this field cannot be set when spec.os.name is windows.
SELinuxOptions are the labels to be applied to the container
securityContext.seLinuxOptions.level (string)
Level is SELinux level label that applies to the container.
securityContext.seLinuxOptions.role (string)
Role is a SELinux role label that applies to the container.
securityContext.seLinuxOptions.type (string)
Type is a SELinux type label that applies to the container.
securityContext.seLinuxOptions.user (string)
User is a SELinux user label that applies to the container.
securityContext.sysctls ([]Sysctl)
Sysctls hold a list of namespaced sysctls used for the pod. Pods with unsupported sysctls (by the container runtime) might fail to launch. Note that this field cannot be set when spec.os.name is windows.
The Windows specific settings applied to all containers. If unspecified, the options within a container's SecurityContext will be used. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is linux.
WindowsSecurityContextOptions contain Windows-specific options and credentials.
GMSACredentialSpec is where the GMSA admission webhook (https://github.com/kubernetes-sigs/windows-gmsa) inlines the contents of the GMSA credential spec named by the GMSACredentialSpecName field.
HostProcess determines if a container should be run as a 'Host Process' container. All of a Pod's containers must have the same effective HostProcess value (it is not allowed to have a mix of HostProcess containers and non-HostProcess containers). In addition, if HostProcess is true then HostNetwork must also be set to true.
The UserName in Windows to run the entrypoint of the container process. Defaults to the user specified in image metadata if unspecified. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
Alpha level
hostUsers (boolean)
Use the host's user namespace. Optional: Default to true. If set to true or not present, the pod will be run in the host user namespace, useful for when the pod needs a feature only available to the host user namespace, such as loading a kernel module with CAP_SYS_MODULE. When set to false, a new userns is created for the pod. Setting false is useful for mitigating container breakout vulnerabilities even allowing users to run their containers as root without actually having root privileges on the host. This field is alpha-level and is only honored by servers that enable the UserNamespacesSupport feature.
resourceClaims ([]PodResourceClaim)
Patch strategies: retainKeys, merge on key name
Map: unique values on key name will be kept during a merge
ResourceClaims defines which ResourceClaims must be allocated and reserved before the Pod is allowed to start. The resources will be made available to those containers which consume them by name.
This is an alpha field and requires enabling the DynamicResourceAllocation feature gate.
This field is immutable.
PodResourceClaim references exactly one ResourceClaim through a ClaimSource. It adds a name to it that uniquely identifies the ResourceClaim inside the Pod. Containers that need access to the ResourceClaim reference it with this name.
resourceClaims.name (string), required
Name uniquely identifies this resource claim inside the pod. This must be a DNS_LABEL.
resourceClaims.source (ClaimSource)
Source describes where to find the ResourceClaim.
*ClaimSource describes a reference to a ResourceClaim.
Exactly one of these fields should be set. Consumers of this type must treat an empty object as if it has an unknown value.*
resourceClaims.source.resourceClaimName (string)
ResourceClaimName is the name of a ResourceClaim object in the same namespace as this pod.
ResourceClaimTemplateName is the name of a ResourceClaimTemplate object in the same namespace as this pod.
The template will be used to create a new ResourceClaim, which will be bound to this pod. When this pod is deleted, the ResourceClaim will also be deleted. The pod name and resource name, along with a generated component, will be used to form a unique name for the ResourceClaim, which will be recorded in pod.status.resourceClaimStatuses.
This field is immutable and no changes will be made to the corresponding ResourceClaim by the control plane after creating the ResourceClaim.
schedulingGates ([]PodSchedulingGate)
Patch strategy: merge on key name
Map: unique values on key name will be kept during a merge
SchedulingGates is an opaque list of values that if specified will block scheduling the pod. If schedulingGates is not empty, the pod will stay in the SchedulingGated state and the scheduler will not attempt to schedule the pod.
SchedulingGates can only be set at pod creation time, and be removed only afterwards.
This is a beta feature enabled by the PodSchedulingReadiness feature gate.
PodSchedulingGate is associated to a Pod to guard its scheduling.
schedulingGates.name (string), required
Name of the scheduling gate. Each scheduling gate must have a unique name field.
Deprecated
serviceAccount (string)
DeprecatedServiceAccount is a depreciated alias for ServiceAccountName. Deprecated: Use serviceAccountName instead.
Container
A single application container that you want to run within a pod.
name (string), required
Name of the container specified as a DNS_LABEL. Each container in a pod must have a unique name (DNS_LABEL). Cannot be updated.
Image
image (string)
Container image name. More info: https://kubernetes.io/docs/concepts/containers/images This field is optional to allow higher level config management to default or override container images in workload controllers like Deployments and StatefulSets.
Entrypoint array. Not executed within a shell. The container image's ENTRYPOINT is used if this is not provided. Variable references $(VAR_NAME) are expanded using the container's environment. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Cannot be updated. More info: https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
args ([]string)
Arguments to the entrypoint. The container image's CMD is used if this is not provided. Variable references $(VAR_NAME) are expanded using the container's environment. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Cannot be updated. More info: https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
workingDir (string)
Container's working directory. If not specified, the container runtime's default will be used, which might be configured in the container image. Cannot be updated.
Ports
ports ([]ContainerPort)
Patch strategy: merge on key containerPort
Map: unique values on keys containerPort, protocol will be kept during a merge
List of ports to expose from the container. Not specifying a port here DOES NOT prevent that port from being exposed. Any port which is listening on the default "0.0.0.0" address inside a container will be accessible from the network. Modifying this array with strategic merge patch may corrupt the data. For more information See https://github.com/kubernetes/kubernetes/issues/108255. Cannot be updated.
ContainerPort represents a network port in a single container.
ports.containerPort (int32), required
Number of port to expose on the pod's IP address. This must be a valid port number, 0 < x < 65536.
ports.hostIP (string)
What host IP to bind the external port to.
ports.hostPort (int32)
Number of port to expose on the host. If specified, this must be a valid port number, 0 < x < 65536. If HostNetwork is specified, this must match ContainerPort. Most containers do not need this.
ports.name (string)
If specified, this must be an IANA_SVC_NAME and unique within the pod. Each named port in a pod must have a unique name. Name for the port that can be referred to by services.
ports.protocol (string)
Protocol for port. Must be UDP, TCP, or SCTP. Defaults to "TCP".
Environment variables
env ([]EnvVar)
Patch strategy: merge on key name
List of environment variables to set in the container. Cannot be updated.
EnvVar represents an environment variable present in a Container.
env.name (string), required
Name of the environment variable. Must be a C_IDENTIFIER.
env.value (string)
Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".
env.valueFrom (EnvVarSource)
Source for the environment variable's value. Cannot be used if value is not empty.
EnvVarSource represents a source for the value of an EnvVar.
Selects a field of the pod: supports metadata.name, metadata.namespace, metadata.labels['\<KEY>'], metadata.annotations['\<KEY>'], spec.nodeName, spec.serviceAccountName, status.hostIP, status.podIP, status.podIPs.
Selects a resource of the container: only resources limits and requests (limits.cpu, limits.memory, limits.ephemeral-storage, requests.cpu, requests.memory and requests.ephemeral-storage) are currently supported.
env.valueFrom.secretKeyRef (SecretKeySelector)
Selects a key of a secret in the pod's namespace
SecretKeySelector selects a key of a Secret.
env.valueFrom.secretKeyRef.key (string), required
The key of the secret to select from. Must be a valid secret key.
Specify whether the Secret or its key must be defined
envFrom ([]EnvFromSource)
List of sources to populate environment variables in the container. The keys defined within a source must be a C_IDENTIFIER. All invalid keys will be reported as an event when the container is starting. When a key exists in multiple sources, the value associated with the last source will take precedence. Values defined by an Env with a duplicate key will take precedence. Cannot be updated.
EnvFromSource represents the source of a set of ConfigMaps
envFrom.configMapRef (ConfigMapEnvSource)
The ConfigMap to select from
*ConfigMapEnvSource selects a ConfigMap to populate the environment variables with.
The contents of the target ConfigMap's Data field will represent the key-value pairs as environment variables.*
Pod volumes to mount into the container's filesystem. Cannot be updated.
VolumeMount describes a mounting of a Volume within a container.
volumeMounts.mountPath (string), required
Path within the container at which the volume should be mounted. Must not contain ':'.
volumeMounts.name (string), required
This must match the Name of a Volume.
volumeMounts.mountPropagation (string)
mountPropagation determines how mounts are propagated from the host to container and the other way around. When not set, MountPropagationNone is used. This field is beta in 1.10.
volumeMounts.readOnly (boolean)
Mounted read-only if true, read-write otherwise (false or unspecified). Defaults to false.
volumeMounts.subPath (string)
Path within the volume from which the container's volume should be mounted. Defaults to "" (volume's root).
volumeMounts.subPathExpr (string)
Expanded path within the volume from which the container's volume should be mounted. Behaves similarly to SubPath but environment variable references $(VAR_NAME) are expanded using the container's environment. Defaults to "" (volume's root). SubPathExpr and SubPath are mutually exclusive.
volumeDevices ([]VolumeDevice)
Patch strategy: merge on key devicePath
volumeDevices is the list of block devices to be used by the container.
volumeDevice describes a mapping of a raw block device within a container.
volumeDevices.devicePath (string), required
devicePath is the path inside of the container that the device will be mapped to.
volumeDevices.name (string), required
name must match the name of a persistentVolumeClaim in the pod
ResourceRequirements describes the compute resource requirements.
resources.claims ([]ResourceClaim)
Map: unique values on key name will be kept during a merge
Claims lists the names of resources, defined in spec.resourceClaims, that are used by this container.
This is an alpha field and requires enabling the DynamicResourceAllocation feature gate.
This field is immutable. It can only be set for containers.
ResourceClaim references one entry in PodSpec.ResourceClaims.
resources.claims.name (string), required
Name must match the name of one entry in pod.spec.resourceClaims of the Pod where this field is used. It makes that resource available inside a container.
Requests describes the minimum amount of compute resources required. If Requests is omitted for a container, it defaults to Limits if that is explicitly specified, otherwise to an implementation-defined value. Requests cannot exceed Limits. More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
resizePolicy ([]ContainerResizePolicy)
Atomic: will be replaced during a merge
Resources resize policy for the container.
ContainerResizePolicy represents resource resize policy for the container.
resizePolicy.resourceName (string), required
Name of the resource to which this resource resize policy applies. Supported values: cpu, memory.
resizePolicy.restartPolicy (string), required
Restart policy to apply when specified resource is resized. If not specified, it defaults to NotRequired.
Lifecycle
lifecycle (Lifecycle)
Actions that the management system should take in response to container lifecycle events. Cannot be updated.
Lifecycle describes actions that the management system should take in response to container lifecycle events. For the PostStart and PreStop lifecycle handlers, management of the container blocks until the action is complete, unless the container process fails, in which case the handler is aborted.
PreStop is called immediately before a container is terminated due to an API request or management event such as liveness/startup probe failure, preemption, resource contention, etc. The handler is not called if the container crashes or exits. The Pod's termination grace period countdown begins before the PreStop hook is executed. Regardless of the outcome of the handler, the container will eventually terminate within the Pod's termination grace period (unless delayed by finalizers). Other management of the container blocks until the hook completes or until the termination grace period is reached. More info: https://kubernetes.io/docs/concepts/containers/container-lifecycle-hooks/#container-hooks
terminationMessagePath (string)
Optional: Path at which the file to which the container's termination message will be written is mounted into the container's filesystem. Message written is intended to be brief final status, such as an assertion failure message. Will be truncated by the node if greater than 4096 bytes. The total message length across all containers will be limited to 12kb. Defaults to /dev/termination-log. Cannot be updated.
terminationMessagePolicy (string)
Indicate how the termination message should be populated. File will use the contents of terminationMessagePath to populate the container status message on both success and failure. FallbackToLogsOnError will use the last chunk of container log output if the termination message file is empty and the container exited with an error. The log output is limited to 2048 bytes or 80 lines, whichever is smaller. Defaults to File. Cannot be updated.
StartupProbe indicates that the Pod has successfully initialized. If specified, no other probes are executed until this completes successfully. If this probe fails, the Pod will be restarted, just as if the livenessProbe failed. This can be used to provide different probe parameters at the beginning of a Pod's lifecycle, when it might take a long time to load data or warm a cache, than during steady-state operation. This cannot be updated. More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#container-probes
restartPolicy (string)
RestartPolicy defines the restart behavior of individual containers in a pod. This field may only be set for init containers, and the only allowed value is "Always". For non-init containers or when this field is not specified, the restart behavior is defined by the Pod's restart policy and the container type. Setting the RestartPolicy as "Always" for the init container will have the following effect: this init container will be continually restarted on exit until all regular containers have terminated. Once all regular containers have completed, all init containers with restartPolicy "Always" will be shut down. This lifecycle differs from normal init containers and is often referred to as a "sidecar" container. Although this init container still starts in the init container sequence, it does not wait for the container to complete before proceeding to the next init container. Instead, the next init container starts immediately after this init container is started, or after any startupProbe has successfully completed.
SecurityContext holds security configuration that will be applied to a container. Some fields are present in both SecurityContext and PodSecurityContext. When both are set, the values in SecurityContext take precedence.
securityContext.runAsUser (int64)
The UID to run the entrypoint of the container process. Defaults to user specified in image metadata if unspecified. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
securityContext.runAsNonRoot (boolean)
Indicates that the container must run as a non-root user. If true, the Kubelet will validate the image at runtime to ensure that it does not run as UID 0 (root) and fail to start the container if it does. If unset or false, no such validation will be performed. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
securityContext.runAsGroup (int64)
The GID to run the entrypoint of the container process. Uses runtime default if unset. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
securityContext.readOnlyRootFilesystem (boolean)
Whether this container has a read-only root filesystem. Default is false. Note that this field cannot be set when spec.os.name is windows.
securityContext.procMount (string)
procMount denotes the type of proc mount to use for the containers. The default is DefaultProcMount which uses the container runtime defaults for readonly paths and masked paths. This requires the ProcMountType feature flag to be enabled. Note that this field cannot be set when spec.os.name is windows.
securityContext.privileged (boolean)
Run container in privileged mode. Processes in privileged containers are essentially equivalent to root on the host. Defaults to false. Note that this field cannot be set when spec.os.name is windows.
AllowPrivilegeEscalation controls whether a process can gain more privileges than its parent process. This bool directly controls if the no_new_privs flag will be set on the container process. AllowPrivilegeEscalation is true always when the container is: 1) run as Privileged 2) has CAP_SYS_ADMIN Note that this field cannot be set when spec.os.name is windows.
securityContext.capabilities (Capabilities)
The capabilities to add/drop when running containers. Defaults to the default set of capabilities granted by the container runtime. Note that this field cannot be set when spec.os.name is windows.
Adds and removes POSIX capabilities from running containers.
securityContext.capabilities.add ([]string)
Added capabilities
securityContext.capabilities.drop ([]string)
Removed capabilities
securityContext.seccompProfile (SeccompProfile)
The seccomp options to use by this container. If seccomp options are provided at both the pod & container level, the container options override the pod options. Note that this field cannot be set when spec.os.name is windows.
SeccompProfile defines a pod/container's seccomp profile settings. Only one profile source may be set.
type indicates which kind of seccomp profile will be applied. Valid options are:
Localhost - a profile defined in a file on the node should be used. RuntimeDefault - the container runtime default profile should be used. Unconfined - no profile should be applied.
localhostProfile indicates a profile defined in a file on the node should be used. The profile must be preconfigured on the node to work. Must be a descending path, relative to the kubelet's configured seccomp profile location. Must be set if type is "Localhost". Must NOT be set for any other type.
securityContext.seLinuxOptions (SELinuxOptions)
The SELinux context to be applied to the container. If unspecified, the container runtime will allocate a random SELinux context for each container. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
SELinuxOptions are the labels to be applied to the container
securityContext.seLinuxOptions.level (string)
Level is SELinux level label that applies to the container.
securityContext.seLinuxOptions.role (string)
Role is a SELinux role label that applies to the container.
securityContext.seLinuxOptions.type (string)
Type is a SELinux type label that applies to the container.
securityContext.seLinuxOptions.user (string)
User is a SELinux user label that applies to the container.
The Windows specific settings applied to all containers. If unspecified, the options from the PodSecurityContext will be used. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is linux.
WindowsSecurityContextOptions contain Windows-specific options and credentials.
GMSACredentialSpec is where the GMSA admission webhook (https://github.com/kubernetes-sigs/windows-gmsa) inlines the contents of the GMSA credential spec named by the GMSACredentialSpecName field.
HostProcess determines if a container should be run as a 'Host Process' container. All of a Pod's containers must have the same effective HostProcess value (it is not allowed to have a mix of HostProcess containers and non-HostProcess containers). In addition, if HostProcess is true then HostNetwork must also be set to true.
The UserName in Windows to run the entrypoint of the container process. Defaults to the user specified in image metadata if unspecified. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
Debugging
stdin (boolean)
Whether this container should allocate a buffer for stdin in the container runtime. If this is not set, reads from stdin in the container will always result in EOF. Default is false.
stdinOnce (boolean)
Whether the container runtime should close the stdin channel after it has been opened by a single attach. When stdin is true the stdin stream will remain open across multiple attach sessions. If stdinOnce is set to true, stdin is opened on container start, is empty until the first client attaches to stdin, and then remains open and accepts data until the client disconnects, at which time stdin is closed and remains closed until the container is restarted. If this flag is false, a container processes that reads from stdin will never receive an EOF. Default is false
tty (boolean)
Whether this container should allocate a TTY for itself, also requires 'stdin' to be true. Default is false.
EphemeralContainer
An EphemeralContainer is a temporary container that you may add to an existing Pod for user-initiated activities such as debugging. Ephemeral containers have no resource or scheduling guarantees, and they will not be restarted when they exit or when a Pod is removed or restarted. The kubelet may evict a Pod if an ephemeral container causes the Pod to exceed its resource allocation.
To add an ephemeral container, use the ephemeralcontainers subresource of an existing Pod. Ephemeral containers may not be removed or restarted.
name (string), required
Name of the ephemeral container specified as a DNS_LABEL. This name must be unique among all containers, init containers and ephemeral containers.
targetContainerName (string)
If set, the name of the container from PodSpec that this ephemeral container targets. The ephemeral container will be run in the namespaces (IPC, PID, etc) of this container. If not set then the ephemeral container uses the namespaces configured in the Pod spec.
The container runtime must implement support for this feature. If the runtime does not support namespace targeting then the result of setting this field is undefined.
Entrypoint array. Not executed within a shell. The image's ENTRYPOINT is used if this is not provided. Variable references $(VAR_NAME) are expanded using the container's environment. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Cannot be updated. More info: https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
args ([]string)
Arguments to the entrypoint. The image's CMD is used if this is not provided. Variable references $(VAR_NAME) are expanded using the container's environment. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Cannot be updated. More info: https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/#running-a-command-in-a-shell
workingDir (string)
Container's working directory. If not specified, the container runtime's default will be used, which might be configured in the container image. Cannot be updated.
Environment variables
env ([]EnvVar)
Patch strategy: merge on key name
List of environment variables to set in the container. Cannot be updated.
EnvVar represents an environment variable present in a Container.
env.name (string), required
Name of the environment variable. Must be a C_IDENTIFIER.
env.value (string)
Variable references $(VAR_NAME) are expanded using the previously defined environment variables in the container and any service environment variables. If a variable cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless of whether the variable exists or not. Defaults to "".
env.valueFrom (EnvVarSource)
Source for the environment variable's value. Cannot be used if value is not empty.
EnvVarSource represents a source for the value of an EnvVar.
Selects a field of the pod: supports metadata.name, metadata.namespace, metadata.labels['\<KEY>'], metadata.annotations['\<KEY>'], spec.nodeName, spec.serviceAccountName, status.hostIP, status.podIP, status.podIPs.
Selects a resource of the container: only resources limits and requests (limits.cpu, limits.memory, limits.ephemeral-storage, requests.cpu, requests.memory and requests.ephemeral-storage) are currently supported.
env.valueFrom.secretKeyRef (SecretKeySelector)
Selects a key of a secret in the pod's namespace
SecretKeySelector selects a key of a Secret.
env.valueFrom.secretKeyRef.key (string), required
The key of the secret to select from. Must be a valid secret key.
Specify whether the Secret or its key must be defined
envFrom ([]EnvFromSource)
List of sources to populate environment variables in the container. The keys defined within a source must be a C_IDENTIFIER. All invalid keys will be reported as an event when the container is starting. When a key exists in multiple sources, the value associated with the last source will take precedence. Values defined by an Env with a duplicate key will take precedence. Cannot be updated.
EnvFromSource represents the source of a set of ConfigMaps
envFrom.configMapRef (ConfigMapEnvSource)
The ConfigMap to select from
*ConfigMapEnvSource selects a ConfigMap to populate the environment variables with.
The contents of the target ConfigMap's Data field will represent the key-value pairs as environment variables.*
Pod volumes to mount into the container's filesystem. Subpath mounts are not allowed for ephemeral containers. Cannot be updated.
VolumeMount describes a mounting of a Volume within a container.
volumeMounts.mountPath (string), required
Path within the container at which the volume should be mounted. Must not contain ':'.
volumeMounts.name (string), required
This must match the Name of a Volume.
volumeMounts.mountPropagation (string)
mountPropagation determines how mounts are propagated from the host to container and the other way around. When not set, MountPropagationNone is used. This field is beta in 1.10.
volumeMounts.readOnly (boolean)
Mounted read-only if true, read-write otherwise (false or unspecified). Defaults to false.
volumeMounts.subPath (string)
Path within the volume from which the container's volume should be mounted. Defaults to "" (volume's root).
volumeMounts.subPathExpr (string)
Expanded path within the volume from which the container's volume should be mounted. Behaves similarly to SubPath but environment variable references $(VAR_NAME) are expanded using the container's environment. Defaults to "" (volume's root). SubPathExpr and SubPath are mutually exclusive.
volumeDevices ([]VolumeDevice)
Patch strategy: merge on key devicePath
volumeDevices is the list of block devices to be used by the container.
volumeDevice describes a mapping of a raw block device within a container.
volumeDevices.devicePath (string), required
devicePath is the path inside of the container that the device will be mapped to.
volumeDevices.name (string), required
name must match the name of a persistentVolumeClaim in the pod
Resources
resizePolicy ([]ContainerResizePolicy)
Atomic: will be replaced during a merge
Resources resize policy for the container.
ContainerResizePolicy represents resource resize policy for the container.
resizePolicy.resourceName (string), required
Name of the resource to which this resource resize policy applies. Supported values: cpu, memory.
resizePolicy.restartPolicy (string), required
Restart policy to apply when specified resource is resized. If not specified, it defaults to NotRequired.
Lifecycle
terminationMessagePath (string)
Optional: Path at which the file to which the container's termination message will be written is mounted into the container's filesystem. Message written is intended to be brief final status, such as an assertion failure message. Will be truncated by the node if greater than 4096 bytes. The total message length across all containers will be limited to 12kb. Defaults to /dev/termination-log. Cannot be updated.
terminationMessagePolicy (string)
Indicate how the termination message should be populated. File will use the contents of terminationMessagePath to populate the container status message on both success and failure. FallbackToLogsOnError will use the last chunk of container log output if the termination message file is empty and the container exited with an error. The log output is limited to 2048 bytes or 80 lines, whichever is smaller. Defaults to File. Cannot be updated.
restartPolicy (string)
Restart policy for the container to manage the restart behavior of each container within a pod. This may only be set for init containers. You cannot set this field on ephemeral containers.
Debugging
stdin (boolean)
Whether this container should allocate a buffer for stdin in the container runtime. If this is not set, reads from stdin in the container will always result in EOF. Default is false.
stdinOnce (boolean)
Whether the container runtime should close the stdin channel after it has been opened by a single attach. When stdin is true the stdin stream will remain open across multiple attach sessions. If stdinOnce is set to true, stdin is opened on container start, is empty until the first client attaches to stdin, and then remains open and accepts data until the client disconnects, at which time stdin is closed and remains closed until the container is restarted. If this flag is false, a container processes that reads from stdin will never receive an EOF. Default is false
tty (boolean)
Whether this container should allocate a TTY for itself, also requires 'stdin' to be true. Default is false.
Security context
securityContext (SecurityContext)
Optional: SecurityContext defines the security options the ephemeral container should be run with. If set, the fields of SecurityContext override the equivalent fields of PodSecurityContext.
SecurityContext holds security configuration that will be applied to a container. Some fields are present in both SecurityContext and PodSecurityContext. When both are set, the values in SecurityContext take precedence.
securityContext.runAsUser (int64)
The UID to run the entrypoint of the container process. Defaults to user specified in image metadata if unspecified. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
securityContext.runAsNonRoot (boolean)
Indicates that the container must run as a non-root user. If true, the Kubelet will validate the image at runtime to ensure that it does not run as UID 0 (root) and fail to start the container if it does. If unset or false, no such validation will be performed. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
securityContext.runAsGroup (int64)
The GID to run the entrypoint of the container process. Uses runtime default if unset. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
securityContext.readOnlyRootFilesystem (boolean)
Whether this container has a read-only root filesystem. Default is false. Note that this field cannot be set when spec.os.name is windows.
securityContext.procMount (string)
procMount denotes the type of proc mount to use for the containers. The default is DefaultProcMount which uses the container runtime defaults for readonly paths and masked paths. This requires the ProcMountType feature flag to be enabled. Note that this field cannot be set when spec.os.name is windows.
securityContext.privileged (boolean)
Run container in privileged mode. Processes in privileged containers are essentially equivalent to root on the host. Defaults to false. Note that this field cannot be set when spec.os.name is windows.
AllowPrivilegeEscalation controls whether a process can gain more privileges than its parent process. This bool directly controls if the no_new_privs flag will be set on the container process. AllowPrivilegeEscalation is true always when the container is: 1) run as Privileged 2) has CAP_SYS_ADMIN Note that this field cannot be set when spec.os.name is windows.
securityContext.capabilities (Capabilities)
The capabilities to add/drop when running containers. Defaults to the default set of capabilities granted by the container runtime. Note that this field cannot be set when spec.os.name is windows.
Adds and removes POSIX capabilities from running containers.
securityContext.capabilities.add ([]string)
Added capabilities
securityContext.capabilities.drop ([]string)
Removed capabilities
securityContext.seccompProfile (SeccompProfile)
The seccomp options to use by this container. If seccomp options are provided at both the pod & container level, the container options override the pod options. Note that this field cannot be set when spec.os.name is windows.
SeccompProfile defines a pod/container's seccomp profile settings. Only one profile source may be set.
type indicates which kind of seccomp profile will be applied. Valid options are:
Localhost - a profile defined in a file on the node should be used. RuntimeDefault - the container runtime default profile should be used. Unconfined - no profile should be applied.
localhostProfile indicates a profile defined in a file on the node should be used. The profile must be preconfigured on the node to work. Must be a descending path, relative to the kubelet's configured seccomp profile location. Must be set if type is "Localhost". Must NOT be set for any other type.
securityContext.seLinuxOptions (SELinuxOptions)
The SELinux context to be applied to the container. If unspecified, the container runtime will allocate a random SELinux context for each container. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is windows.
SELinuxOptions are the labels to be applied to the container
securityContext.seLinuxOptions.level (string)
Level is SELinux level label that applies to the container.
securityContext.seLinuxOptions.role (string)
Role is a SELinux role label that applies to the container.
securityContext.seLinuxOptions.type (string)
Type is a SELinux type label that applies to the container.
securityContext.seLinuxOptions.user (string)
User is a SELinux user label that applies to the container.
The Windows specific settings applied to all containers. If unspecified, the options from the PodSecurityContext will be used. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence. Note that this field cannot be set when spec.os.name is linux.
WindowsSecurityContextOptions contain Windows-specific options and credentials.
GMSACredentialSpec is where the GMSA admission webhook (https://github.com/kubernetes-sigs/windows-gmsa) inlines the contents of the GMSA credential spec named by the GMSACredentialSpecName field.
HostProcess determines if a container should be run as a 'Host Process' container. All of a Pod's containers must have the same effective HostProcess value (it is not allowed to have a mix of HostProcess containers and non-HostProcess containers). In addition, if HostProcess is true then HostNetwork must also be set to true.
The UserName in Windows to run the entrypoint of the container process. Defaults to the user specified in image metadata if unspecified. May also be set in PodSecurityContext. If set in both SecurityContext and PodSecurityContext, the value specified in SecurityContext takes precedence.
Not allowed
ports ([]ContainerPort)
Patch strategy: merge on key containerPort
Map: unique values on keys containerPort, protocol will be kept during a merge
Ports are not allowed for ephemeral containers.
ContainerPort represents a network port in a single container.
ports.containerPort (int32), required
Number of port to expose on the pod's IP address. This must be a valid port number, 0 < x < 65536.
ports.hostIP (string)
What host IP to bind the external port to.
ports.hostPort (int32)
Number of port to expose on the host. If specified, this must be a valid port number, 0 < x < 65536. If HostNetwork is specified, this must match ContainerPort. Most containers do not need this.
ports.name (string)
If specified, this must be an IANA_SVC_NAME and unique within the pod. Each named port in a pod must have a unique name. Name for the port that can be referred to by services.
ports.protocol (string)
Protocol for port. Must be UDP, TCP, or SCTP. Defaults to "TCP".
resources (ResourceRequirements)
Resources are not allowed for ephemeral containers. Ephemeral containers use spare resources already allocated to the pod.
ResourceRequirements describes the compute resource requirements.
resources.claims ([]ResourceClaim)
Map: unique values on key name will be kept during a merge
Claims lists the names of resources, defined in spec.resourceClaims, that are used by this container.
This is an alpha field and requires enabling the DynamicResourceAllocation feature gate.
This field is immutable. It can only be set for containers.
ResourceClaim references one entry in PodSpec.ResourceClaims.
resources.claims.name (string), required
Name must match the name of one entry in pod.spec.resourceClaims of the Pod where this field is used. It makes that resource available inside a container.
Requests describes the minimum amount of compute resources required. If Requests is omitted for a container, it defaults to Limits if that is explicitly specified, otherwise to an implementation-defined value. Requests cannot exceed Limits. More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
lifecycle (Lifecycle)
Lifecycle is not allowed for ephemeral containers.
Lifecycle describes actions that the management system should take in response to container lifecycle events. For the PostStart and PreStop lifecycle handlers, management of the container blocks until the action is complete, unless the container process fails, in which case the handler is aborted.
PreStop is called immediately before a container is terminated due to an API request or management event such as liveness/startup probe failure, preemption, resource contention, etc. The handler is not called if the container crashes or exits. The Pod's termination grace period countdown begins before the PreStop hook is executed. Regardless of the outcome of the handler, the container will eventually terminate within the Pod's termination grace period (unless delayed by finalizers). Other management of the container blocks until the hook completes or until the termination grace period is reached. More info: https://kubernetes.io/docs/concepts/containers/container-lifecycle-hooks/#container-hooks
LifecycleHandler defines a specific action that should be taken in a lifecycle hook. One and only one of the fields, except TCPSocket must be specified.
exec (ExecAction)
Exec specifies the action to take.
ExecAction describes a "run in container" action.
exec.command ([]string)
Command is the command line to execute inside the container, the working directory for the command is root ('/') in the container's filesystem. The command is simply exec'd, it is not run inside a shell, so traditional shell instructions ('|', etc) won't work. To use a shell, you need to explicitly call out to that shell. Exit status of 0 is treated as live/healthy and non-zero is unhealthy.
httpGet (HTTPGetAction)
HTTPGet specifies the http request to perform.
HTTPGetAction describes an action based on HTTP Get requests.
httpGet.port (IntOrString), required
Name or number of the port to access on the container. Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
httpGet.host (string)
Host name to connect to, defaults to the pod IP. You probably want to set "Host" in httpHeaders instead.
httpGet.httpHeaders ([]HTTPHeader)
Custom headers to set in the request. HTTP allows repeated headers.
HTTPHeader describes a custom header to be used in HTTP probes
httpGet.httpHeaders.name (string), required
The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.
httpGet.httpHeaders.value (string), required
The header field value
httpGet.path (string)
Path to access on the HTTP server.
httpGet.scheme (string)
Scheme to use for connecting to the host. Defaults to HTTP.
tcpSocket (TCPSocketAction)
Deprecated. TCPSocket is NOT supported as a LifecycleHandler and kept for the backward compatibility. There are no validation of this field and lifecycle hooks will fail in runtime when tcp handler is specified.
TCPSocketAction describes an action based on opening a socket
tcpSocket.port (IntOrString), required
Number or name of the port to access on the container. Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
tcpSocket.host (string)
Optional: Host name to connect to, defaults to the pod IP.
NodeAffinity
Node affinity is a group of node affinity scheduling rules.
The scheduler will prefer to schedule pods to nodes that satisfy the affinity expressions specified by this field, but it may choose a node that violates one or more of the expressions. The node that is most preferred is the one with the greatest sum of weights, i.e. for each node that meets all of the scheduling requirements (resource request, requiredDuringScheduling affinity expressions, etc.), compute a sum by iterating through the elements of this field and adding "weight" to the sum if the node matches the corresponding matchExpressions; the node(s) with the highest sum are the most preferred.
An empty preferred scheduling term matches all objects with implicit weight 0 (i.e. it's a no-op). A null preferred scheduling term matches no objects (i.e. is also a no-op).
A node selector term, associated with the corresponding weight.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
If the affinity requirements specified by this field are not met at scheduling time, the pod will not be scheduled onto the node. If the affinity requirements specified by this field cease to be met at some point during pod execution (e.g. due to an update), the system may or may not try to eventually evict the pod from its node.
A node selector represents the union of the results of one or more label queries over a set of nodes; that is, it represents the OR of the selectors represented by the node selector terms.
Required. A list of node selector terms. The terms are ORed.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
The scheduler will prefer to schedule pods to nodes that satisfy the affinity expressions specified by this field, but it may choose a node that violates one or more of the expressions. The node that is most preferred is the one with the greatest sum of weights, i.e. for each node that meets all of the scheduling requirements (resource request, requiredDuringScheduling affinity expressions, etc.), compute a sum by iterating through the elements of this field and adding "weight" to the sum if the node has pods which matches the corresponding podAffinityTerm; the node(s) with the highest sum are the most preferred.
The weights of all of the matched WeightedPodAffinityTerm fields are added per-node to find the most preferred node(s)
Required. A pod affinity term, associated with the corresponding weight.
Defines a set of pods (namely those matching the labelSelector relative to the given namespace(s)) that this pod should be co-located (affinity) or not co-located (anti-affinity) with, where co-located is defined as running on a node whose value of the label with key matches that of any node on which a pod of the set of pods is running
This pod should be co-located (affinity) or not co-located (anti-affinity) with the pods matching the labelSelector in the specified namespaces, where co-located is defined as running on a node whose value of the label with key topologyKey matches that of any node on which any of the selected pods is running. Empty topologyKey is not allowed.
A label query over the set of namespaces that the term applies to. The term is applied to the union of the namespaces selected by this field and the ones listed in the namespaces field. null selector and null or empty namespaces list means "this pod's namespace". An empty selector ({}) matches all namespaces.
namespaces specifies a static list of namespace names that the term applies to. The term is applied to the union of the namespaces listed in this field and the ones selected by namespaceSelector. null or empty namespaces list and null namespaceSelector means "this pod's namespace".
If the affinity requirements specified by this field are not met at scheduling time, the pod will not be scheduled onto the node. If the affinity requirements specified by this field cease to be met at some point during pod execution (e.g. due to a pod label update), the system may or may not try to eventually evict the pod from its node. When there are multiple elements, the lists of nodes corresponding to each podAffinityTerm are intersected, i.e. all terms must be satisfied.
Defines a set of pods (namely those matching the labelSelector relative to the given namespace(s)) that this pod should be co-located (affinity) or not co-located (anti-affinity) with, where co-located is defined as running on a node whose value of the label with key matches that of any node on which a pod of the set of pods is running
This pod should be co-located (affinity) or not co-located (anti-affinity) with the pods matching the labelSelector in the specified namespaces, where co-located is defined as running on a node whose value of the label with key topologyKey matches that of any node on which any of the selected pods is running. Empty topologyKey is not allowed.
A label query over the set of namespaces that the term applies to. The term is applied to the union of the namespaces selected by this field and the ones listed in the namespaces field. null selector and null or empty namespaces list means "this pod's namespace". An empty selector ({}) matches all namespaces.
namespaces specifies a static list of namespace names that the term applies to. The term is applied to the union of the namespaces listed in this field and the ones selected by namespaceSelector. null or empty namespaces list and null namespaceSelector means "this pod's namespace".
PodAntiAffinity
Pod anti affinity is a group of inter pod anti affinity scheduling rules.
The scheduler will prefer to schedule pods to nodes that satisfy the anti-affinity expressions specified by this field, but it may choose a node that violates one or more of the expressions. The node that is most preferred is the one with the greatest sum of weights, i.e. for each node that meets all of the scheduling requirements (resource request, requiredDuringScheduling anti-affinity expressions, etc.), compute a sum by iterating through the elements of this field and adding "weight" to the sum if the node has pods which matches the corresponding podAffinityTerm; the node(s) with the highest sum are the most preferred.
The weights of all of the matched WeightedPodAffinityTerm fields are added per-node to find the most preferred node(s)
Required. A pod affinity term, associated with the corresponding weight.
Defines a set of pods (namely those matching the labelSelector relative to the given namespace(s)) that this pod should be co-located (affinity) or not co-located (anti-affinity) with, where co-located is defined as running on a node whose value of the label with key matches that of any node on which a pod of the set of pods is running
This pod should be co-located (affinity) or not co-located (anti-affinity) with the pods matching the labelSelector in the specified namespaces, where co-located is defined as running on a node whose value of the label with key topologyKey matches that of any node on which any of the selected pods is running. Empty topologyKey is not allowed.
A label query over the set of namespaces that the term applies to. The term is applied to the union of the namespaces selected by this field and the ones listed in the namespaces field. null selector and null or empty namespaces list means "this pod's namespace". An empty selector ({}) matches all namespaces.
namespaces specifies a static list of namespace names that the term applies to. The term is applied to the union of the namespaces listed in this field and the ones selected by namespaceSelector. null or empty namespaces list and null namespaceSelector means "this pod's namespace".
If the anti-affinity requirements specified by this field are not met at scheduling time, the pod will not be scheduled onto the node. If the anti-affinity requirements specified by this field cease to be met at some point during pod execution (e.g. due to a pod label update), the system may or may not try to eventually evict the pod from its node. When there are multiple elements, the lists of nodes corresponding to each podAffinityTerm are intersected, i.e. all terms must be satisfied.
Defines a set of pods (namely those matching the labelSelector relative to the given namespace(s)) that this pod should be co-located (affinity) or not co-located (anti-affinity) with, where co-located is defined as running on a node whose value of the label with key matches that of any node on which a pod of the set of pods is running
This pod should be co-located (affinity) or not co-located (anti-affinity) with the pods matching the labelSelector in the specified namespaces, where co-located is defined as running on a node whose value of the label with key topologyKey matches that of any node on which any of the selected pods is running. Empty topologyKey is not allowed.
A label query over the set of namespaces that the term applies to. The term is applied to the union of the namespaces selected by this field and the ones listed in the namespaces field. null selector and null or empty namespaces list means "this pod's namespace". An empty selector ({}) matches all namespaces.
namespaces specifies a static list of namespace names that the term applies to. The term is applied to the union of the namespaces listed in this field and the ones selected by namespaceSelector. null or empty namespaces list and null namespaceSelector means "this pod's namespace".
Probe
Probe describes a health check to be performed against a container to determine whether it is alive or ready to receive traffic.
exec (ExecAction)
Exec specifies the action to take.
ExecAction describes a "run in container" action.
exec.command ([]string)
Command is the command line to execute inside the container, the working directory for the command is root ('/') in the container's filesystem. The command is simply exec'd, it is not run inside a shell, so traditional shell instructions ('|', etc) won't work. To use a shell, you need to explicitly call out to that shell. Exit status of 0 is treated as live/healthy and non-zero is unhealthy.
httpGet (HTTPGetAction)
HTTPGet specifies the http request to perform.
HTTPGetAction describes an action based on HTTP Get requests.
httpGet.port (IntOrString), required
Name or number of the port to access on the container. Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
httpGet.host (string)
Host name to connect to, defaults to the pod IP. You probably want to set "Host" in httpHeaders instead.
httpGet.httpHeaders ([]HTTPHeader)
Custom headers to set in the request. HTTP allows repeated headers.
HTTPHeader describes a custom header to be used in HTTP probes
httpGet.httpHeaders.name (string), required
The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.
httpGet.httpHeaders.value (string), required
The header field value
httpGet.path (string)
Path to access on the HTTP server.
httpGet.scheme (string)
Scheme to use for connecting to the host. Defaults to HTTP.
tcpSocket (TCPSocketAction)
TCPSocket specifies an action involving a TCP port.
TCPSocketAction describes an action based on opening a socket
tcpSocket.port (IntOrString), required
Number or name of the port to access on the container. Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
tcpSocket.host (string)
Optional: Host name to connect to, defaults to the pod IP.
Optional duration in seconds the pod needs to terminate gracefully upon probe failure. The grace period is the duration in seconds after the processes running in the pod are sent a termination signal and the time when the processes are forcibly halted with a kill signal. Set this value longer than the expected cleanup time for your process. If this value is nil, the pod's terminationGracePeriodSeconds will be used. Otherwise, this value overrides the value provided by the pod spec. Value must be non-negative integer. The value zero indicates stop immediately via the kill signal (no opportunity to shut down). This is a beta field and requires enabling ProbeTerminationGracePeriod feature gate. Minimum value is 1. spec.terminationGracePeriodSeconds is used if unset.
periodSeconds (int32)
How often (in seconds) to perform the probe. Default to 10 seconds. Minimum value is 1.
Minimum consecutive failures for the probe to be considered failed after having succeeded. Defaults to 3. Minimum value is 1.
successThreshold (int32)
Minimum consecutive successes for the probe to be considered successful after having failed. Defaults to 1. Must be 1 for liveness and startup. Minimum value is 1.
grpc (GRPCAction)
GRPC specifies an action involving a GRPC port.
**
grpc.port (int32), required
Port number of the gRPC service. Number must be in the range 1 to 65535.
If this is not specified, the default behavior is defined by gRPC.
PodStatus
PodStatus represents information about the status of a pod. Status may trail the actual state of a system, especially if the node that hosts the pod cannot contact the control plane.
nominatedNodeName (string)
nominatedNodeName is set only when this pod preempts other pods on the node, but it cannot be scheduled right away as preemption victims receive their graceful termination periods. This field does not guarantee that the pod will be scheduled on this node. Scheduler may decide to place the pod elsewhere if other nodes become available sooner. Scheduler may also decide to give the resources on this node to a higher priority pod that is created after preemption. As a result, this field may be different than PodSpec.nodeName when the pod is scheduled.
hostIP (string)
hostIP holds the IP address of the host to which the pod is assigned. Empty if the pod has not started yet. A pod can be assigned to a node that has a problem in kubelet which in turns mean that HostIP will not be updated even if there is a node is assigned to pod
hostIPs ([]HostIP)
Patch strategy: merge on key ip
Atomic: will be replaced during a merge
hostIPs holds the IP addresses allocated to the host. If this field is specified, the first entry must match the hostIP field. This list is empty if the pod has not started yet. A pod can be assigned to a node that has a problem in kubelet which in turns means that HostIPs will not be updated even if there is a node is assigned to this pod.
HostIP represents a single IP address allocated to the host.
hostIPs.ip (string)
IP is the IP address assigned to the host
startTime (Time)
RFC 3339 date and time at which the object was acknowledged by the Kubelet. This is before the Kubelet pulled the container image(s) for the pod.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
phase (string)
The phase of a Pod is a simple, high-level summary of where the Pod is in its lifecycle. The conditions array, the reason and message fields, and the individual container status arrays contain more detail about the pod's status. There are five possible phase values:
Pending: The pod has been accepted by the Kubernetes system, but one or more of the container images has not been created. This includes time before being scheduled as well as time spent downloading images over the network, which could take a while. Running: The pod has been bound to a node, and all of the containers have been created. At least one container is still running, or is in the process of starting or restarting. Succeeded: All containers in the pod have terminated in success, and will not be restarted. Failed: All containers in the pod have terminated, and at least one container has terminated in failure. The container either exited with non-zero status or was terminated by the system. Unknown: For some reason the state of the pod could not be obtained, typically due to an error in communicating with the host of the pod.
A human readable message indicating details about why the pod is in this condition.
reason (string)
A brief CamelCase message indicating details about why the pod is in this state. e.g. 'Evicted'
podIP (string)
podIP address allocated to the pod. Routable at least within the cluster. Empty if not yet allocated.
podIPs ([]PodIP)
Patch strategy: merge on key ip
podIPs holds the IP addresses allocated to the pod. If this field is specified, the 0th entry must match the podIP field. Pods may be allocated at most 1 value for each of IPv4 and IPv6. This list is empty if no IPs have been allocated yet.
PodIP represents a single IP address allocated to the pod.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastTransitionTime (Time)
Last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
Human-readable message indicating details about last transition.
conditions.reason (string)
Unique, one-word, CamelCase reason for the condition's last transition.
ContainerStatus contains details for the current status of this container.
ephemeralContainerStatuses ([]ContainerStatus)
Status for any ephemeral containers that have run in this pod.
ContainerStatus contains details for the current status of this container.
resourceClaimStatuses ([]PodResourceClaimStatus)
Patch strategies: retainKeys, merge on key name
Map: unique values on key name will be kept during a merge
Status of resource claims.
PodResourceClaimStatus is stored in the PodStatus for each PodResourceClaim which references a ResourceClaimTemplate. It stores the generated name for the corresponding ResourceClaim.
resourceClaimStatuses.name (string), required
Name uniquely identifies this resource claim inside the pod. This must match the name of an entry in pod.spec.resourceClaims, which implies that the string must be a DNS_LABEL.
resourceClaimStatuses.resourceClaimName (string)
ResourceClaimName is the name of the ResourceClaim that was generated for the Pod in the namespace of the Pod. It this is unset, then generating a ResourceClaim was not necessary. The pod.spec.resourceClaims entry can be ignored in this case.
resize (string)
Status of resources resize desired for pod's containers. It is empty if no resources resize is pending. Any changes to container resources will automatically set this to "Proposed"
The container for which to stream logs. Defaults to only container if there is one container in the pod.
follow (in query): boolean
Follow the log stream of the pod. Defaults to false.
insecureSkipTLSVerifyBackend (in query): boolean
insecureSkipTLSVerifyBackend indicates that the apiserver should not confirm the validity of the serving certificate of the backend it is connecting to. This will make the HTTPS connection between the apiserver and the backend insecure. This means the apiserver cannot verify the log data it is receiving came from the real kubelet. If the kubelet is configured to verify the apiserver's TLS credentials, it does not mean the connection to the real kubelet is vulnerable to a man in the middle attack (e.g. an attacker could not intercept the actual log data coming from the real kubelet).
limitBytes (in query): integer
If set, the number of bytes to read from the server before terminating the log output. This may not display a complete final line of logging, and may return slightly more or slightly less than the specified limit.
Return previous terminated container logs. Defaults to false.
sinceSeconds (in query): integer
A relative time in seconds before the current time from which to show logs. If this value precedes the time a pod was started, only logs since the pod start will be returned. If this value is in the future, no logs will be returned. Only one of sinceSeconds or sinceTime may be specified.
tailLines (in query): integer
If set, the number of lines from the end of the logs to show. If not specified, logs are shown from the creation of the container or sinceSeconds or sinceTime
timestamps (in query): boolean
If true, add an RFC3339 or RFC3339Nano timestamp at the beginning of every line of log output. Defaults to false.
Response
200 (string): OK
401: Unauthorized
get read status of the specified Pod
HTTP Request
GET /api/v1/namespaces/{namespace}/pods/{name}/status
ReplicationControllerSpec is the specification of a replication controller.
selector (map[string]string)
Selector is a label query over pods that should match the Replicas count. If Selector is empty, it is defaulted to the labels present on the Pod template. Label keys and values that must match in order to be controlled by this replication controller, if empty defaulted to labels on Pod template. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
Minimum number of seconds for which a newly created pod should be ready without any of its container crashing, for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready)
ReplicationControllerStatus
ReplicationControllerStatus represents the current status of a replication controller.
The number of available replicas (ready for at least minReadySeconds) for this replication controller.
readyReplicas (int32)
The number of ready replicas for this replication controller.
fullyLabeledReplicas (int32)
The number of pods that have labels matching the labels of the pod template of the replication controller.
conditions ([]ReplicationControllerCondition)
Patch strategy: merge on key type
Represents the latest available observations of a replication controller's current state.
ReplicationControllerCondition describes the state of a replication controller at a certain point.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of replication controller condition.
conditions.lastTransitionTime (Time)
The last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
A human readable message indicating details about the transition.
conditions.reason (string)
The reason for the condition's last transition.
observedGeneration (int64)
ObservedGeneration reflects the generation of the most recently observed replication controller.
ReplicationControllerList
ReplicationControllerList is a collection of replication controllers.
Minimum number of seconds for which a newly created pod should be ready without any of its container crashing, for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready)
ReplicaSetStatus
ReplicaSetStatus represents the current status of a ReplicaSet.
The number of available replicas (ready for at least minReadySeconds) for this replica set.
readyReplicas (int32)
readyReplicas is the number of pods targeted by this ReplicaSet with a Ready Condition.
fullyLabeledReplicas (int32)
The number of pods that have labels matching the labels of the pod template of the replicaset.
conditions ([]ReplicaSetCondition)
Patch strategy: merge on key type
Represents the latest available observations of a replica set's current state.
ReplicaSetCondition describes the state of a replica set at a certain point.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of replica set condition.
conditions.lastTransitionTime (Time)
The last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
A human readable message indicating details about the transition.
conditions.reason (string)
The reason for the condition's last transition.
observedGeneration (int64)
ObservedGeneration reflects the generation of the most recently observed ReplicaSet.
Label selector for pods. Existing ReplicaSets whose pods are selected by this will be the ones affected by this deployment. It must match the pod template's labels.
Template describes the pods that will be created. The only allowed template.spec.restartPolicy value is "Always".
replicas (int32)
Number of desired pods. This is a pointer to distinguish between explicit zero and not specified. Defaults to 1.
minReadySeconds (int32)
Minimum number of seconds for which a newly created pod should be ready without any of its container crashing, for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready)
strategy (DeploymentStrategy)
Patch strategy: retainKeys
The deployment strategy to use to replace existing pods with new ones.
DeploymentStrategy describes how to replace existing pods with new ones.
strategy.type (string)
Type of deployment. Can be "Recreate" or "RollingUpdate". Default is RollingUpdate.
strategy.rollingUpdate (RollingUpdateDeployment)
Rolling update config params. Present only if DeploymentStrategyType = RollingUpdate.
Spec to control the desired behavior of rolling update.
strategy.rollingUpdate.maxSurge (IntOrString)
The maximum number of pods that can be scheduled above the desired number of pods. Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%). This can not be 0 if MaxUnavailable is 0. Absolute number is calculated from percentage by rounding up. Defaults to 25%. Example: when this is set to 30%, the new ReplicaSet can be scaled up immediately when the rolling update starts, such that the total number of old and new pods do not exceed 130% of desired pods. Once old pods have been killed, new ReplicaSet can be scaled up further, ensuring that total number of pods running at any time during the update is at most 130% of desired pods.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
The maximum number of pods that can be unavailable during the update. Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%). Absolute number is calculated from percentage by rounding down. This can not be 0 if MaxSurge is 0. Defaults to 25%. Example: when this is set to 30%, the old ReplicaSet can be scaled down to 70% of desired pods immediately when the rolling update starts. Once new pods are ready, old ReplicaSet can be scaled down further, followed by scaling up the new ReplicaSet, ensuring that the total number of pods available at all times during the update is at least 70% of desired pods.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
revisionHistoryLimit (int32)
The number of old ReplicaSets to retain to allow rollback. This is a pointer to distinguish between explicit zero and not specified. Defaults to 10.
progressDeadlineSeconds (int32)
The maximum time in seconds for a deployment to make progress before it is considered to be failed. The deployment controller will continue to process failed deployments and a condition with a ProgressDeadlineExceeded reason will be surfaced in the deployment status. Note that progress will not be estimated during the time a deployment is paused. Defaults to 600s.
paused (boolean)
Indicates that the deployment is paused.
DeploymentStatus
DeploymentStatus is the most recently observed status of the Deployment.
replicas (int32)
Total number of non-terminated pods targeted by this deployment (their labels match the selector).
availableReplicas (int32)
Total number of available pods (ready for at least minReadySeconds) targeted by this deployment.
readyReplicas (int32)
readyReplicas is the number of pods targeted by this Deployment with a Ready Condition.
unavailableReplicas (int32)
Total number of unavailable pods targeted by this deployment. This is the total number of pods that are still required for the deployment to have 100% available capacity. They may either be pods that are running but not yet available or pods that still have not been created.
updatedReplicas (int32)
Total number of non-terminated pods targeted by this deployment that have the desired template spec.
collisionCount (int32)
Count of hash collisions for the Deployment. The Deployment controller uses this field as a collision avoidance mechanism when it needs to create the name for the newest ReplicaSet.
conditions ([]DeploymentCondition)
Patch strategy: merge on key type
Represents the latest available observations of a deployment's current state.
DeploymentCondition describes the state of a deployment at a certain point.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of deployment condition.
conditions.lastTransitionTime (Time)
Last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastUpdateTime (Time)
The last time this condition was updated.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
A human readable message indicating details about the transition.
conditions.reason (string)
The reason for the condition's last transition.
observedGeneration (int64)
The generation observed by the deployment controller.
Status is the current status of Pods in this StatefulSet. This data may be out of date by some window of time.
StatefulSetSpec
A StatefulSetSpec is the specification of a StatefulSet.
serviceName (string), required
serviceName is the name of the service that governs this StatefulSet. This service must exist before the StatefulSet, and is responsible for the network identity of the set. Pods get DNS/hostnames that follow the pattern: pod-specific-string.serviceName.default.svc.cluster.local where "pod-specific-string" is managed by the StatefulSet controller.
template is the object that describes the pod that will be created if insufficient replicas are detected. Each pod stamped out by the StatefulSet will fulfill this Template, but have a unique identity from the rest of the StatefulSet. Each pod will be named with the format <statefulsetname>-<podindex>. For example, a pod in a StatefulSet named "web" with index number "3" would be named "web-3". The only allowed template.spec.restartPolicy value is "Always".
replicas (int32)
replicas is the desired number of replicas of the given Template. These are replicas in the sense that they are instantiations of the same Template, but individual replicas also have a consistent identity. If unspecified, defaults to 1.
updateStrategy (StatefulSetUpdateStrategy)
updateStrategy indicates the StatefulSetUpdateStrategy that will be employed to update Pods in the StatefulSet when a revision is made to Template.
StatefulSetUpdateStrategy indicates the strategy that the StatefulSet controller will use to perform updates. It includes any additional parameters necessary to perform the update for the indicated strategy.
updateStrategy.type (string)
Type indicates the type of the StatefulSetUpdateStrategy. Default is RollingUpdate.
The maximum number of pods that can be unavailable during the update. Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%). Absolute number is calculated from percentage by rounding up. This can not be 0. Defaults to 1. This field is alpha-level and is only honored by servers that enable the MaxUnavailableStatefulSet feature. The field applies to all pods in the range 0 to Replicas-1. That means if there is any unavailable pod in the range 0 to Replicas-1, it will be counted towards MaxUnavailable.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
updateStrategy.rollingUpdate.partition (int32)
Partition indicates the ordinal at which the StatefulSet should be partitioned for updates. During a rolling update, all pods from ordinal Replicas-1 to Partition are updated. All pods from ordinal Partition-1 to 0 remain untouched. This is helpful in being able to do a canary based deployment. The default value is 0.
podManagementPolicy (string)
podManagementPolicy controls how pods are created during initial scale up, when replacing pods on nodes, or when scaling down. The default policy is OrderedReady, where pods are created in increasing order (pod-0, then pod-1, etc) and the controller will wait until each pod is ready before continuing. When scaling down, the pods are removed in the opposite order. The alternative policy is Parallel which will create pods in parallel to match the desired scale without waiting, and on scale down will delete all pods at once.
revisionHistoryLimit (int32)
revisionHistoryLimit is the maximum number of revisions that will be maintained in the StatefulSet's revision history. The revision history consists of all revisions not represented by a currently applied StatefulSetSpec version. The default value is 10.
volumeClaimTemplates is a list of claims that pods are allowed to reference. The StatefulSet controller is responsible for mapping network identities to claims in a way that maintains the identity of a pod. Every claim in this list must have at least one matching (by name) volumeMount in one container in the template. A claim in this list takes precedence over any volumes in the template, with the same name.
minReadySeconds (int32)
Minimum number of seconds for which a newly created pod should be ready without any of its container crashing for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready)
persistentVolumeClaimRetentionPolicy describes the lifecycle of persistent volume claims created from volumeClaimTemplates. By default, all persistent volume claims are created as needed and retained until manually deleted. This policy allows the lifecycle to be altered, for example by deleting persistent volume claims when their stateful set is deleted, or when their pod is scaled down. This requires the StatefulSetAutoDeletePVC feature gate to be enabled, which is alpha. +optional
StatefulSetPersistentVolumeClaimRetentionPolicy describes the policy used for PVCs created from the StatefulSet VolumeClaimTemplates.
WhenDeleted specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is deleted. The default policy of Retain causes PVCs to not be affected by StatefulSet deletion. The Delete policy causes those PVCs to be deleted.
WhenScaled specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is scaled down. The default policy of Retain causes PVCs to not be affected by a scaledown. The Delete policy causes the associated PVCs for any excess pods above the replica count to be deleted.
ordinals (StatefulSetOrdinals)
ordinals controls the numbering of replica indices in a StatefulSet. The default ordinals behavior assigns a "0" index to the first replica and increments the index by one for each additional replica requested. Using the ordinals field requires the StatefulSetStartOrdinal feature gate to be enabled, which is beta.
StatefulSetOrdinals describes the policy used for replica ordinal assignment in this StatefulSet.
ordinals.start (int32)
start is the number representing the first replica's index. It may be used to number replicas from an alternate index (eg: 1-indexed) over the default 0-indexed names, or to orchestrate progressive movement of replicas from one StatefulSet to another. If set, replica indices will be in the range:
[.spec.ordinals.start, .spec.ordinals.start + .spec.replicas).
If unset, defaults to 0. Replica indices will be in the range:
[0, .spec.replicas).
StatefulSetStatus
StatefulSetStatus represents the current state of a StatefulSet.
replicas (int32), required
replicas is the number of Pods created by the StatefulSet controller.
readyReplicas (int32)
readyReplicas is the number of pods created for this StatefulSet with a Ready Condition.
currentReplicas (int32)
currentReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version indicated by currentRevision.
updatedReplicas (int32)
updatedReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version indicated by updateRevision.
availableReplicas (int32)
Total number of available pods (ready for at least minReadySeconds) targeted by this statefulset.
collisionCount (int32)
collisionCount is the count of hash collisions for the StatefulSet. The StatefulSet controller uses this field as a collision avoidance mechanism when it needs to create the name for the newest ControllerRevision.
conditions ([]StatefulSetCondition)
Patch strategy: merge on key type
Represents the latest available observations of a statefulset's current state.
StatefulSetCondition describes the state of a statefulset at a certain point.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of statefulset condition.
conditions.lastTransitionTime (Time)
Last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
A human readable message indicating details about the transition.
conditions.reason (string)
The reason for the condition's last transition.
currentRevision (string)
currentRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence [0,currentReplicas).
updateRevision (string)
updateRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence [replicas-updatedReplicas,replicas)
observedGeneration (int64)
observedGeneration is the most recent generation observed for this StatefulSet. It corresponds to the StatefulSet's generation, which is updated on mutation by the API Server.
ControllerRevision implements an immutable snapshot of state data.
apiVersion: apps/v1
import "k8s.io/api/apps/v1"
ControllerRevision
ControllerRevision implements an immutable snapshot of state data. Clients are responsible for serializing and deserializing the objects that contain their internal state. Once a ControllerRevision has been successfully created, it can not be updated. The API Server will fail validation of all requests that attempt to mutate the Data field. ControllerRevisions may, however, be deleted. Note that, due to its use by both the DaemonSet and StatefulSet controllers for update and rollback, this object is beta. However, it may be subject to name and representation changes in future releases, and clients should not depend on its stability. It is primarily for internal use by controllers.
Revision indicates the revision of the state represented by Data.
data (RawExtension)
Data is the serialized representation of the state.
*RawExtension is used to hold extensions in external versions.
To use this, make a field which has RawExtension as its type in your external, versioned struct, and Object in your internal struct. You also need to register your various plugin types.
// Internal package:
type MyAPIObject struct {
runtime.TypeMeta json:",inline"
MyPlugin runtime.Object json:"myPlugin"
}
type PluginA struct {
AOption string json:"aOption"
}
// External package:
type MyAPIObject struct {
runtime.TypeMeta json:",inline"
MyPlugin runtime.RawExtension json:"myPlugin"
}
type PluginA struct {
AOption string json:"aOption"
}
// On the wire, the JSON will look something like this:
So what happens? Decode first uses json or yaml to unmarshal the serialized data into your external MyAPIObject. That causes the raw JSON to be stored, but not unpacked. The next step is to copy (using pkg/conversion) into the internal struct. The runtime package's DefaultScheme has conversion functions installed which will unpack the JSON stored in RawExtension, turning it into the correct object type, and storing it in the Object. (TODO: In the case where the object is of an unknown type, a runtime.Unknown object will be created and stored.)*
ControllerRevisionList
ControllerRevisionList is a resource containing a list of ControllerRevision objects.
An object that describes the pod that will be created. The DaemonSet will create exactly one copy of this pod on every node that matches the template's node selector (or on every node if no node selector is specified). The only allowed template.spec.restartPolicy value is "Always". More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicationcontroller#pod-template
minReadySeconds (int32)
The minimum number of seconds for which a newly created DaemonSet pod should be ready without any of its container crashing, for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready).
updateStrategy (DaemonSetUpdateStrategy)
An update strategy to replace existing DaemonSet pods with new pods.
DaemonSetUpdateStrategy is a struct used to control the update strategy for a DaemonSet.
updateStrategy.type (string)
Type of daemon set update. Can be "RollingUpdate" or "OnDelete". Default is RollingUpdate.
The maximum number of nodes with an existing available DaemonSet pod that can have an updated DaemonSet pod during during an update. Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%). This can not be 0 if MaxUnavailable is 0. Absolute number is calculated from percentage by rounding up to a minimum of 1. Default value is 0. Example: when this is set to 30%, at most 30% of the total number of nodes that should be running the daemon pod (i.e. status.desiredNumberScheduled) can have their a new pod created before the old pod is marked as deleted. The update starts by launching new pods on 30% of nodes. Once an updated pod is available (Ready for at least minReadySeconds) the old DaemonSet pod on that node is marked deleted. If the old pod becomes unavailable for any reason (Ready transitions to false, is evicted, or is drained) an updated pod is immediatedly created on that node without considering surge limits. Allowing surge implies the possibility that the resources consumed by the daemonset on any given node can double if the readiness check fails, and so resource intensive daemonsets should take into account that they may cause evictions during disruption.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
The maximum number of DaemonSet pods that can be unavailable during the update. Value can be an absolute number (ex: 5) or a percentage of total number of DaemonSet pods at the start of the update (ex: 10%). Absolute number is calculated from percentage by rounding up. This cannot be 0 if MaxSurge is 0 Default value is 1. Example: when this is set to 30%, at most 30% of the total number of nodes that should be running the daemon pod (i.e. status.desiredNumberScheduled) can have their pods stopped for an update at any given time. The update starts by stopping at most 30% of those DaemonSet pods and then brings up new DaemonSet pods in their place. Once the new pods are available, it then proceeds onto other DaemonSet pods, thus ensuring that at least 70% of original number of DaemonSet pods are available at all times during the update.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
revisionHistoryLimit (int32)
The number of old history to retain to allow rollback. This is a pointer to distinguish between explicit zero and not specified. Defaults to 10.
DaemonSetStatus
DaemonSetStatus represents the current status of a daemon set.
numberReady (int32), required
numberReady is the number of nodes that should be running the daemon pod and have one or more of the daemon pod running with a Ready Condition.
numberAvailable (int32)
The number of nodes that should be running the daemon pod and have one or more of the daemon pod running and available (ready for at least spec.minReadySeconds)
numberUnavailable (int32)
The number of nodes that should be running the daemon pod and have none of the daemon pod running and available (ready for at least spec.minReadySeconds)
The total number of nodes that are running updated daemon pod
collisionCount (int32)
Count of hash collisions for the DaemonSet. The DaemonSet controller uses this field as a collision avoidance mechanism when it needs to create the name for the newest ControllerRevision.
conditions ([]DaemonSetCondition)
Patch strategy: merge on key type
Represents the latest available observations of a DaemonSet's current state.
DaemonSetCondition describes the state of a DaemonSet at a certain point.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of DaemonSet condition.
conditions.lastTransitionTime (Time)
Last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
A human readable message indicating details about the transition.
conditions.reason (string)
The reason for the condition's last transition.
observedGeneration (int64)
The most recent generation observed by the daemon set controller.
Specifies the maximum desired number of pods the job should run at any given time. The actual number of pods running in steady state will be less than this number when ((.spec.completions - .status.successful) < .spec.parallelism), i.e. when the work left to do is less than max parallelism. More info: https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/
Lifecycle
completions (int32)
Specifies the desired number of successfully finished pods the job should be run with. Setting to null means that the success of any pod signals the success of all pods, and allows parallelism to have any positive value. Setting to 1 means that parallelism is limited to 1 and the success of that pod signals the success of the job. More info: https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/
completionMode (string)
completionMode specifies how Pod completions are tracked. It can be NonIndexed (default) or Indexed.
NonIndexed means that the Job is considered complete when there have been .spec.completions successfully completed Pods. Each Pod completion is homologous to each other.
Indexed means that the Pods of a Job get an associated completion index from 0 to (.spec.completions - 1), available in the annotation batch.kubernetes.io/job-completion-index. The Job is considered complete when there is one successfully completed Pod for each index. When value is Indexed, .spec.completions must be specified and .spec.parallelism must be less than or equal to 10^5. In addition, The Pod name takes the form $(job-name)-$(index)-$(random-string), the Pod hostname takes the form $(job-name)-$(index).
More completion modes can be added in the future. If the Job controller observes a mode that it doesn't recognize, which is possible during upgrades due to version skew, the controller skips updates for the Job.
backoffLimit (int32)
Specifies the number of retries before marking this job failed. Defaults to 6
activeDeadlineSeconds (int64)
Specifies the duration in seconds relative to the startTime that the job may be continuously active before the system tries to terminate it; value must be positive integer. If a Job is suspended (at creation or through an update), this timer will effectively be stopped and reset when the Job is resumed again.
ttlSecondsAfterFinished (int32)
ttlSecondsAfterFinished limits the lifetime of a Job that has finished execution (either Complete or Failed). If this field is set, ttlSecondsAfterFinished after the Job finishes, it is eligible to be automatically deleted. When the Job is being deleted, its lifecycle guarantees (e.g. finalizers) will be honored. If this field is unset, the Job won't be automatically deleted. If this field is set to zero, the Job becomes eligible to be deleted immediately after it finishes.
suspend (boolean)
suspend specifies whether the Job controller should create Pods or not. If a Job is created with suspend set to true, no Pods are created by the Job controller. If a Job is suspended after creation (i.e. the flag goes from false to true), the Job controller will delete all active Pods associated with this Job. Users must design their workload to gracefully handle this. Suspending a Job will reset the StartTime field of the Job, effectively resetting the ActiveDeadlineSeconds timer too. Defaults to false.
manualSelector controls generation of pod labels and pod selectors. Leave manualSelector unset unless you are certain what you are doing. When false or unset, the system pick labels unique to this job and appends those labels to the pod template. When true, the user is responsible for picking unique labels and specifying the selector. Failure to pick a unique label may cause this and other jobs to not function correctly. However, You may see manualSelector=true in jobs that were created with the old extensions/v1beta1 API. More info: https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/#specifying-your-own-pod-selector
Beta level
podFailurePolicy (PodFailurePolicy)
Specifies the policy of handling failed pods. In particular, it allows to specify the set of actions and conditions which need to be satisfied to take the associated action. If empty, the default behaviour applies - the counter of failed pods, represented by the jobs's .status.failed field, is incremented and it is checked against the backoffLimit. This field cannot be used in combination with restartPolicy=OnFailure.
This field is beta-level. It can be used when the JobPodFailurePolicy feature gate is enabled (enabled by default).
PodFailurePolicy describes how failed pods influence the backoffLimit.
A list of pod failure policy rules. The rules are evaluated in order. Once a rule matches a Pod failure, the remaining of the rules are ignored. When no rule matches the Pod failure, the default handling applies - the counter of pod failures is incremented and it is checked against the backoffLimit. At most 20 elements are allowed.
PodFailurePolicyRule describes how a pod failure is handled when the requirements are met. One of onExitCodes and onPodConditions, but not both, can be used in each rule.
podFailurePolicy.rules.action (string), required
Specifies the action taken on a pod failure when the requirements are satisfied. Possible values are:
FailJob: indicates that the pod's job is marked as Failed and all
running pods are terminated.
FailIndex: indicates that the pod's index is marked as Failed and will
not be restarted.
This value is alpha-level. It can be used when the
JobBackoffLimitPerIndex feature gate is enabled (disabled by default).
Ignore: indicates that the counter towards the .backoffLimit is not
incremented and a replacement pod is created.
Count: indicates that the pod is handled in the default way - the
counter towards the .backoffLimit is incremented.
Additional values are considered to be added in the future. Clients should react to an unknown action by skipping the rule.
Represents the requirement on the pod conditions. The requirement is represented as a list of pod condition patterns. The requirement is satisfied if at least one pattern matches an actual pod condition. At most 20 elements are allowed.
PodFailurePolicyOnPodConditionsPattern describes a pattern for matching an actual pod condition type.
Specifies the required Pod condition status. To match a pod condition it is required that the specified status equals the pod condition status. Defaults to True.
Represents the requirement on the container exit codes.
PodFailurePolicyOnExitCodesRequirement describes the requirement for handling a failed pod based on its container exit codes. In particular, it lookups the .state.terminated.exitCode for each app container and init container status, represented by the .status.containerStatuses and .status.initContainerStatuses fields in the Pod status, respectively. Containers completed with success (exit code 0) are excluded from the requirement check.
Represents the relationship between the container exit code(s) and the specified values. Containers completed with success (exit code 0) are excluded from the requirement check. Possible values are:
In: the requirement is satisfied if at least one container exit code
(might be multiple if there are multiple containers not restricted
by the 'containerName' field) is in the set of specified values.
NotIn: the requirement is satisfied if at least one container exit code
(might be multiple if there are multiple containers not restricted
by the 'containerName' field) is not in the set of specified values.
Additional values are considered to be added in the future. Clients should react to an unknown operator by assuming the requirement is not satisfied.
Specifies the set of values. Each returned container exit code (might be multiple in case of multiple containers) is checked against this set of values with respect to the operator. The list of values must be ordered and must not contain duplicates. Value '0' cannot be used for the In operator. At least one element is required. At most 255 elements are allowed.
Restricts the check for exit codes to the container with the specified name. When null, the rule applies to all containers. When specified, it should match one the container or initContainer names in the pod template.
Alpha level
backoffLimitPerIndex (int32)
Specifies the limit for the number of retries within an index before marking this index as failed. When enabled the number of failures per index is kept in the pod's batch.kubernetes.io/job-index-failure-count annotation. It can only be set when Job's completionMode=Indexed, and the Pod's restart policy is Never. The field is immutable. This field is alpha-level. It can be used when the JobBackoffLimitPerIndex feature gate is enabled (disabled by default).
maxFailedIndexes (int32)
Specifies the maximal number of failed indexes before marking the Job as failed, when backoffLimitPerIndex is set. Once the number of failed indexes exceeds this number the entire Job is marked as Failed and its execution is terminated. When left as null the job continues execution of all of its indexes and is marked with the Complete Job condition. It can only be specified when backoffLimitPerIndex is set. It can be null or up to completions. It is required and must be less than or equal to 10^4 when is completions greater than 10^5. This field is alpha-level. It can be used when the JobBackoffLimitPerIndex feature gate is enabled (disabled by default).
podReplacementPolicy (string)
podReplacementPolicy specifies when to create replacement Pods. Possible values are: - TerminatingOrFailed means that we recreate pods
when they are terminating (has a metadata.deletionTimestamp) or failed.
Failed means to wait until a previously created Pod is fully terminated (has phase
Failed or Succeeded) before creating a replacement Pod.
When using podFailurePolicy, Failed is the the only allowed value. TerminatingOrFailed and Failed are allowed values when podFailurePolicy is not in use. This is an alpha field. Enable JobPodReplacementPolicy to be able to use this field.
JobStatus
JobStatus represents the current state of a Job.
startTime (Time)
Represents time when the job controller started processing a job. When a Job is created in the suspended state, this field is not set until the first time it is resumed. This field is reset every time a Job is resumed from suspension. It is represented in RFC3339 form and is in UTC.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
completionTime (Time)
Represents time when the job was completed. It is not guaranteed to be set in happens-before order across separate operations. It is represented in RFC3339 form and is in UTC. The completion time is only set when the job finishes successfully.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
active (int32)
The number of pending and running pods.
failed (int32)
The number of pods which reached phase Failed.
succeeded (int32)
The number of pods which reached phase Succeeded.
completedIndexes (string)
completedIndexes holds the completed indexes when .spec.completionMode = "Indexed" in a text format. The indexes are represented as decimal integers separated by commas. The numbers are listed in increasing order. Three or more consecutive numbers are compressed and represented by the first and last element of the series, separated by a hyphen. For example, if the completed indexes are 1, 3, 4, 5 and 7, they are represented as "1,3-5,7".
conditions ([]JobCondition)
Patch strategy: merge on key type
Atomic: will be replaced during a merge
The latest available observations of an object's current state. When a Job fails, one of the conditions will have type "Failed" and status true. When a Job is suspended, one of the conditions will have type "Suspended" and status true; when the Job is resumed, the status of this condition will become false. When a Job is completed, one of the conditions will have type "Complete" and status true. More info: https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/
JobCondition describes current state of a job.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of job condition, Complete or Failed.
conditions.lastProbeTime (Time)
Last time the condition was checked.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastTransitionTime (Time)
Last time the condition transit from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
Human readable message indicating details about last transition.
conditions.reason (string)
(brief) reason for the condition's last transition.
uncountedTerminatedPods (UncountedTerminatedPods)
uncountedTerminatedPods holds the UIDs of Pods that have terminated but the job controller hasn't yet accounted for in the status counters.
The job controller creates pods with a finalizer. When a pod terminates (succeeded or failed), the controller does three steps to account for it in the job status:
Add the pod UID to the arrays in this field. 2. Remove the pod finalizer. 3. Remove the pod UID from the arrays while increasing the corresponding
counter.
Old jobs might not be tracked using this field, in which case the field remains null.
UncountedTerminatedPods holds UIDs of Pods that have terminated but haven't been accounted in Job status counters.
uncountedTerminatedPods.failed ([]string)
Set: unique values will be kept during a merge
failed holds UIDs of failed Pods.
uncountedTerminatedPods.succeeded ([]string)
Set: unique values will be kept during a merge
succeeded holds UIDs of succeeded Pods.
Beta level
ready (int32)
The number of pods which have a Ready condition.
This field is beta-level. The job controller populates the field when the feature gate JobReadyPods is enabled (enabled by default).
Alpha level
failedIndexes (string)
FailedIndexes holds the failed indexes when backoffLimitPerIndex=true. The indexes are represented in the text format analogous as for the completedIndexes field, ie. they are kept as decimal integers separated by commas. The numbers are listed in increasing order. Three or more consecutive numbers are compressed and represented by the first and last element of the series, separated by a hyphen. For example, if the failed indexes are 1, 3, 4, 5 and 7, they are represented as "1,3-5,7". This field is alpha-level. It can be used when the JobBackoffLimitPerIndex feature gate is enabled (disabled by default).
terminating (int32)
The number of pods which are terminating (in phase Pending or Running and have a deletionTimestamp).
This field is alpha-level. The job controller populates the field when the feature gate JobPodReplacementPolicy is enabled (disabled by default).
The time zone name for the given schedule, see https://en.wikipedia.org/wiki/List_of_tz_database_time_zones. If not specified, this will default to the time zone of the kube-controller-manager process. The set of valid time zone names and the time zone offset is loaded from the system-wide time zone database by the API server during CronJob validation and the controller manager during execution. If no system-wide time zone database can be found a bundled version of the database is used instead. If the time zone name becomes invalid during the lifetime of a CronJob or due to a change in host configuration, the controller will stop creating new new Jobs and will create a system event with the reason UnknownTimeZone. More information can be found in https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/#time-zones
concurrencyPolicy (string)
Specifies how to treat concurrent executions of a Job. Valid values are:
"Allow" (default): allows CronJobs to run concurrently; - "Forbid": forbids concurrent runs, skipping next run if previous run hasn't finished yet; - "Replace": cancels currently running job and replaces it with a new one
startingDeadlineSeconds (int64)
Optional deadline in seconds for starting the job if it misses scheduled time for any reason. Missed jobs executions will be counted as failed ones.
suspend (boolean)
This flag tells the controller to suspend subsequent executions, it does not apply to already started executions. Defaults to false.
successfulJobsHistoryLimit (int32)
The number of successful finished jobs to retain. Value must be non-negative integer. Defaults to 3.
failedJobsHistoryLimit (int32)
The number of failed finished jobs to retain. Value must be non-negative integer. Defaults to 1.
CronJobStatus
CronJobStatus represents the current state of a cron job.
Information when was the last time the job was successfully scheduled.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
lastSuccessfulTime (Time)
Information when was the last time the job successfully completed.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
reference to scaled resource; horizontal pod autoscaler will learn the current resource consumption and will set the desired number of pods by using its Scale subresource.
CrossVersionObjectReference contains enough information to let you identify the referred resource.
minReplicas is the lower limit for the number of replicas to which the autoscaler can scale down. It defaults to 1 pod. minReplicas is allowed to be 0 if the alpha feature gate HPAScaleToZero is enabled and at least one Object or External metric is configured. Scaling is active as long as at least one metric value is available.
targetCPUUtilizationPercentage (int32)
targetCPUUtilizationPercentage is the target average CPU utilization (represented as a percentage of requested CPU) over all the pods; if not specified the default autoscaling policy will be used.
HorizontalPodAutoscalerStatus
current status of a horizontal pod autoscaler
currentReplicas (int32), required
currentReplicas is the current number of replicas of pods managed by this autoscaler.
desiredReplicas (int32), required
desiredReplicas is the desired number of replicas of pods managed by this autoscaler.
currentCPUUtilizationPercentage (int32)
currentCPUUtilizationPercentage is the current average CPU utilization over all pods, represented as a percentage of requested CPU, e.g. 70 means that an average pod is using now 70% of its requested CPU.
lastScaleTime (Time)
lastScaleTime is the last time the HorizontalPodAutoscaler scaled the number of pods; used by the autoscaler to control how often the number of pods is changed.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
observedGeneration (int64)
observedGeneration is the most recent generation observed by this autoscaler.
HorizontalPodAutoscaler is the configuration for a horizontal pod autoscaler, which automatically manages the replica count of any resource implementing the scale subresource based on the metrics specified.
apiVersion: autoscaling/v2
import "k8s.io/api/autoscaling/v2"
HorizontalPodAutoscaler
HorizontalPodAutoscaler is the configuration for a horizontal pod autoscaler, which automatically manages the replica count of any resource implementing the scale subresource based on the metrics specified.
scaleTargetRef points to the target resource to scale, and is used to the pods for which metrics should be collected, as well as to actually change the replica count.
CrossVersionObjectReference contains enough information to let you identify the referred resource.
minReplicas is the lower limit for the number of replicas to which the autoscaler can scale down. It defaults to 1 pod. minReplicas is allowed to be 0 if the alpha feature gate HPAScaleToZero is enabled and at least one Object or External metric is configured. Scaling is active as long as at least one metric value is available.
behavior (HorizontalPodAutoscalerBehavior)
behavior configures the scaling behavior of the target in both Up and Down directions (scaleUp and scaleDown fields respectively). If not set, the default HPAScalingRules for scale up and scale down are used.
HorizontalPodAutoscalerBehavior configures the scaling behavior of the target in both Up and Down directions (scaleUp and scaleDown fields respectively).
behavior.scaleDown (HPAScalingRules)
scaleDown is scaling policy for scaling Down. If not set, the default value is to allow to scale down to minReplicas pods, with a 300 second stabilization window (i.e., the highest recommendation for the last 300sec is used).
HPAScalingRules configures the scaling behavior for one direction. These Rules are applied after calculating DesiredReplicas from metrics for the HPA. They can limit the scaling velocity by specifying scaling policies. They can prevent flapping by specifying the stabilization window, so that the number of replicas is not set instantly, instead, the safest value from the stabilization window is chosen.
behavior.scaleDown.policies ([]HPAScalingPolicy)
Atomic: will be replaced during a merge
policies is a list of potential scaling polices which can be used during scaling. At least one policy must be specified, otherwise the HPAScalingRules will be discarded as invalid
HPAScalingPolicy is a single policy which must hold true for a specified past interval.
periodSeconds specifies the window of time for which the policy should hold true. PeriodSeconds must be greater than zero and less than or equal to 1800 (30 min).
behavior.scaleDown.selectPolicy (string)
selectPolicy is used to specify which policy should be used. If not set, the default value Max is used.
stabilizationWindowSeconds is the number of seconds for which past recommendations should be considered while scaling up or scaling down. StabilizationWindowSeconds must be greater than or equal to zero and less than or equal to 3600 (one hour). If not set, use the default values: - For scale up: 0 (i.e. no stabilization is done). - For scale down: 300 (i.e. the stabilization window is 300 seconds long).
behavior.scaleUp (HPAScalingRules)
scaleUp is scaling policy for scaling Up. If not set, the default value is the higher of:
increase no more than 4 pods per 60 seconds
double the number of pods per 60 seconds
No stabilization is used.
HPAScalingRules configures the scaling behavior for one direction. These Rules are applied after calculating DesiredReplicas from metrics for the HPA. They can limit the scaling velocity by specifying scaling policies. They can prevent flapping by specifying the stabilization window, so that the number of replicas is not set instantly, instead, the safest value from the stabilization window is chosen.
behavior.scaleUp.policies ([]HPAScalingPolicy)
Atomic: will be replaced during a merge
policies is a list of potential scaling polices which can be used during scaling. At least one policy must be specified, otherwise the HPAScalingRules will be discarded as invalid
HPAScalingPolicy is a single policy which must hold true for a specified past interval.
behavior.scaleUp.policies.type (string), required
type is used to specify the scaling policy.
behavior.scaleUp.policies.value (int32), required
value contains the amount of change which is permitted by the policy. It must be greater than zero
periodSeconds specifies the window of time for which the policy should hold true. PeriodSeconds must be greater than zero and less than or equal to 1800 (30 min).
behavior.scaleUp.selectPolicy (string)
selectPolicy is used to specify which policy should be used. If not set, the default value Max is used.
stabilizationWindowSeconds is the number of seconds for which past recommendations should be considered while scaling up or scaling down. StabilizationWindowSeconds must be greater than or equal to zero and less than or equal to 3600 (one hour). If not set, use the default values: - For scale up: 0 (i.e. no stabilization is done). - For scale down: 300 (i.e. the stabilization window is 300 seconds long).
metrics ([]MetricSpec)
Atomic: will be replaced during a merge
metrics contains the specifications for which to use to calculate the desired replica count (the maximum replica count across all metrics will be used). The desired replica count is calculated multiplying the ratio between the target value and the current value by the current number of pods. Ergo, metrics used must decrease as the pod count is increased, and vice-versa. See the individual metric source types for more information about how each type of metric must respond. If not set, the default metric will be set to 80% average CPU utilization.
MetricSpec specifies how to scale based on a single metric (only type and one other matching field should be set at once).
metrics.type (string), required
type is the type of metric source. It should be one of "ContainerResource", "External", "Object", "Pods" or "Resource", each mapping to a matching field in the object. Note: "ContainerResource" type is available on when the feature-gate HPAContainerMetrics is enabled
containerResource refers to a resource metric (such as those specified in requests and limits) known to Kubernetes describing a single container in each pod of the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source. This is an alpha feature and can be enabled by the HPAContainerMetrics feature flag.
ContainerResourceMetricSource indicates how to scale on a resource metric known to Kubernetes, as specified in requests and limits, describing each pod in the current scale target (e.g. CPU or memory). The values will be averaged together before being compared to the target. Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source. Only one "target" type should be set.
averageUtilization is the target value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods. Currently only valid for Resource metric source type
value is the target value of the metric (as a quantity).
metrics.external (ExternalMetricSource)
external refers to a global metric that is not associated with any Kubernetes object. It allows autoscaling based on information coming from components running outside of cluster (for example length of queue in cloud messaging service, or QPS from loadbalancer running outside of cluster).
ExternalMetricSource indicates how to scale on a metric not associated with any Kubernetes object (for example length of queue in cloud messaging service, or QPS from loadbalancer running outside of cluster).
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
metrics.external.target (MetricTarget), required
target specifies the target value for the given metric
MetricTarget defines the target value, average value, or average utilization of a specific metric
metrics.external.target.type (string), required
type represents whether the metric type is Utilization, Value, or AverageValue
averageUtilization is the target value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods. Currently only valid for Resource metric source type
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
metrics.object.target (MetricTarget), required
target specifies the target value for the given metric
MetricTarget defines the target value, average value, or average utilization of a specific metric
metrics.object.target.type (string), required
type represents whether the metric type is Utilization, Value, or AverageValue
metrics.object.target.averageUtilization (int32)
averageUtilization is the target value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods. Currently only valid for Resource metric source type
value is the target value of the metric (as a quantity).
metrics.pods (PodsMetricSource)
pods refers to a metric describing each pod in the current scale target (for example, transactions-processed-per-second). The values will be averaged together before being compared to the target value.
PodsMetricSource indicates how to scale on a metric describing each pod in the current scale target (for example, transactions-processed-per-second). The values will be averaged together before being compared to the target value.
metrics.pods.metric (MetricIdentifier), required
metric identifies the target metric by name and selector
MetricIdentifier defines the name and optionally selector for a metric
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
metrics.pods.target (MetricTarget), required
target specifies the target value for the given metric
MetricTarget defines the target value, average value, or average utilization of a specific metric
metrics.pods.target.type (string), required
type represents whether the metric type is Utilization, Value, or AverageValue
metrics.pods.target.averageUtilization (int32)
averageUtilization is the target value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods. Currently only valid for Resource metric source type
value is the target value of the metric (as a quantity).
metrics.resource (ResourceMetricSource)
resource refers to a resource metric (such as those specified in requests and limits) known to Kubernetes describing each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source.
ResourceMetricSource indicates how to scale on a resource metric known to Kubernetes, as specified in requests and limits, describing each pod in the current scale target (e.g. CPU or memory). The values will be averaged together before being compared to the target. Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source. Only one "target" type should be set.
metrics.resource.name (string), required
name is the name of the resource in question.
metrics.resource.target (MetricTarget), required
target specifies the target value for the given metric
MetricTarget defines the target value, average value, or average utilization of a specific metric
metrics.resource.target.type (string), required
type represents whether the metric type is Utilization, Value, or AverageValue
averageUtilization is the target value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods. Currently only valid for Resource metric source type
value is the target value of the metric (as a quantity).
HorizontalPodAutoscalerStatus
HorizontalPodAutoscalerStatus describes the current status of a horizontal pod autoscaler.
desiredReplicas (int32), required
desiredReplicas is the desired number of replicas of pods managed by this autoscaler, as last calculated by the autoscaler.
conditions ([]HorizontalPodAutoscalerCondition)
Patch strategy: merge on key type
Map: unique values on key type will be kept during a merge
conditions is the set of conditions required for this autoscaler to scale its target, and indicates whether or not those conditions are met.
HorizontalPodAutoscalerCondition describes the state of a HorizontalPodAutoscaler at a certain point.
conditions.status (string), required
status is the status of the condition (True, False, Unknown)
conditions.type (string), required
type describes the current condition
conditions.lastTransitionTime (Time)
lastTransitionTime is the last time the condition transitioned from one status to another
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message is a human-readable explanation containing details about the transition
conditions.reason (string)
reason is the reason for the condition's last transition.
currentMetrics ([]MetricStatus)
Atomic: will be replaced during a merge
currentMetrics is the last read state of the metrics used by this autoscaler.
MetricStatus describes the last-read state of a single metric.
currentMetrics.type (string), required
type is the type of metric source. It will be one of "ContainerResource", "External", "Object", "Pods" or "Resource", each corresponds to a matching field in the object. Note: "ContainerResource" type is available on when the feature-gate HPAContainerMetrics is enabled
container resource refers to a resource metric (such as those specified in requests and limits) known to Kubernetes describing a single container in each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source.
ContainerResourceMetricStatus indicates the current value of a resource metric known to Kubernetes, as specified in requests and limits, describing a single container in each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source.
currentAverageUtilization is the current value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
external refers to a global metric that is not associated with any Kubernetes object. It allows autoscaling based on information coming from components running outside of cluster (for example length of queue in cloud messaging service, or QPS from loadbalancer running outside of cluster).
ExternalMetricStatus indicates the current value of a global metric not associated with any Kubernetes object.
currentAverageUtilization is the current value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
currentMetrics.object (ObjectMetricStatus)
object refers to a metric describing a single kubernetes object (for example, hits-per-second on an Ingress object).
ObjectMetricStatus indicates the current value of a metric describing a kubernetes object (for example, hits-per-second on an Ingress object).
currentAverageUtilization is the current value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
currentMetrics.pods (PodsMetricStatus)
pods refers to a metric describing each pod in the current scale target (for example, transactions-processed-per-second). The values will be averaged together before being compared to the target value.
PodsMetricStatus indicates the current value of a metric describing each pod in the current scale target (for example, transactions-processed-per-second).
currentAverageUtilization is the current value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
selector is the string-encoded form of a standard kubernetes label selector for the given metric When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping. When unset, just the metricName will be used to gather metrics.
currentMetrics.resource (ResourceMetricStatus)
resource refers to a resource metric (such as those specified in requests and limits) known to Kubernetes describing each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source.
ResourceMetricStatus indicates the current value of a resource metric known to Kubernetes, as specified in requests and limits, describing each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes, and have special scaling options on top of those available to normal per-pod metrics using the "pods" source.
currentAverageUtilization is the current value of the average of the resource metric across all relevant pods, represented as a percentage of the requested value of the resource for the pods.
value is the current value of the metric (as a quantity).
currentMetrics.resource.name (string), required
name is the name of the resource in question.
currentReplicas (int32)
currentReplicas is current number of replicas of pods managed by this autoscaler, as last seen by the autoscaler.
lastScaleTime (Time)
lastScaleTime is the last time the HorizontalPodAutoscaler scaled the number of pods, used by the autoscaler to control how often the number of pods is changed.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
observedGeneration (int64)
observedGeneration is the most recent generation observed by this autoscaler.
HorizontalPodAutoscalerList
HorizontalPodAutoscalerList is a list of horizontal pod autoscaler objects.
value represents the integer value of this priority class. This is the actual priority that pods receive when they have the name of this class in their pod spec.
description (string)
description is an arbitrary string that usually provides guidelines on when this priority class should be used.
globalDefault (boolean)
globalDefault specifies whether this PriorityClass should be considered as the default priority for pods that do not have any priority class. Only one PriorityClass can be marked as globalDefault. However, if more than one PriorityClasses exists with their globalDefault field set to true, the smallest value of such global default PriorityClasses will be used as the default priority.
preemptionPolicy (string)
preemptionPolicy is the Policy for preempting pods with lower priority. One of Never, PreemptLowerPriority. Defaults to PreemptLowerPriority if unset.
PriorityClassList
PriorityClassList is a collection of priority classes.
Status describes where resources for the Pod can be allocated.
PodSchedulingContextSpec
PodSchedulingContextSpec describes where resources for the Pod are needed.
potentialNodes ([]string)
Set: unique values will be kept during a merge
PotentialNodes lists nodes where the Pod might be able to run.
The size of this field is limited to 128. This is large enough for many clusters. Larger clusters may need more attempts to find a node that suits all pending resources. This may get increased in the future, but not reduced.
selectedNode (string)
SelectedNode is the node for which allocation of ResourceClaims that are referenced by the Pod and that use "WaitForFirstConsumer" allocation is to be attempted.
PodSchedulingContextStatus
PodSchedulingContextStatus describes where resources for the Pod can be allocated.
resourceClaims ([]ResourceClaimSchedulingStatus)
Map: unique values on key name will be kept during a merge
ResourceClaims describes resource availability for each pod.spec.resourceClaim entry where the corresponding ResourceClaim uses "WaitForFirstConsumer" allocation mode.
ResourceClaimSchedulingStatus contains information about one particular ResourceClaim with "WaitForFirstConsumer" allocation mode.
resourceClaims.name (string)
Name matches the pod.spec.resourceClaims[*].Name field.
resourceClaims.unsuitableNodes ([]string)
Set: unique values will be kept during a merge
UnsuitableNodes lists nodes that the ResourceClaim cannot be allocated for.
The size of this field is limited to 128, the same as for PodSchedulingSpec.PotentialNodes. This may get increased in the future, but not reduced.
PodSchedulingContextList
PodSchedulingContextList is a collection of Pod scheduling objects.
ResourceClaim describes which resources are needed by a resource consumer.
apiVersion: resource.k8s.io/v1alpha2
import "k8s.io/api/resource/v1alpha2"
ResourceClaim
ResourceClaim describes which resources are needed by a resource consumer. Its status tracks whether the resource has been allocated and what the resulting attributes are.
This is an alpha type and requires enabling the DynamicResourceAllocation feature gate.
Status describes whether the resource is available and with which attributes.
ResourceClaimSpec
ResourceClaimSpec defines how a resource is to be allocated.
resourceClassName (string), required
ResourceClassName references the driver and additional parameters via the name of a ResourceClass that was created as part of the driver deployment.
allocationMode (string)
Allocation can start immediately or when a Pod wants to use the resource. "WaitForFirstConsumer" is the default.
parametersRef (ResourceClaimParametersReference)
ParametersRef references a separate object with arbitrary parameters that will be used by the driver when allocating a resource for the claim.
The object must be in the same namespace as the ResourceClaim.
ResourceClaimParametersReference contains enough information to let you locate the parameters for a ResourceClaim. The object must be in the same namespace as the ResourceClaim.
parametersRef.kind (string), required
Kind is the type of resource being referenced. This is the same value as in the parameter object's metadata, for example "ConfigMap".
parametersRef.name (string), required
Name is the name of resource being referenced.
parametersRef.apiGroup (string)
APIGroup is the group for the resource being referenced. It is empty for the core API. This matches the group in the APIVersion that is used when creating the resources.
ResourceClaimStatus
ResourceClaimStatus tracks whether the resource has been allocated and what the resulting attributes are.
allocation (AllocationResult)
Allocation is set by the resource driver once a resource or set of resources has been allocated successfully. If this is not specified, the resources have not been allocated yet.
AllocationResult contains attributes of an allocated resource.
allocation.availableOnNodes (NodeSelector)
This field will get set by the resource driver after it has allocated the resource to inform the scheduler where it can schedule Pods using the ResourceClaim.
Setting this field is optional. If null, the resource is available everywhere.
A node selector represents the union of the results of one or more label queries over a set of nodes; that is, it represents the OR of the selectors represented by the node selector terms.
Required. A list of node selector terms. The terms are ORed.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
A list of node selector requirements by node's fields.
allocation.resourceHandles ([]ResourceHandle)
Atomic: will be replaced during a merge
ResourceHandles contain the state associated with an allocation that should be maintained throughout the lifetime of a claim. Each ResourceHandle contains data that should be passed to a specific kubelet plugin once it lands on a node. This data is returned by the driver after a successful allocation and is opaque to Kubernetes. Driver documentation may explain to users how to interpret this data if needed.
Setting this field is optional. It has a maximum size of 32 entries. If null (or empty), it is assumed this allocation will be processed by a single kubelet plugin with no ResourceHandle data attached. The name of the kubelet plugin invoked will match the DriverName set in the ResourceClaimStatus this AllocationResult is embedded in.
ResourceHandle holds opaque resource data for processing by a specific kubelet plugin.
allocation.resourceHandles.data (string)
Data contains the opaque data associated with this ResourceHandle. It is set by the controller component of the resource driver whose name matches the DriverName set in the ResourceClaimStatus this ResourceHandle is embedded in. It is set at allocation time and is intended for processing by the kubelet plugin whose name matches the DriverName set in this ResourceHandle.
The maximum size of this field is 16KiB. This may get increased in the future, but not reduced.
allocation.resourceHandles.driverName (string)
DriverName specifies the name of the resource driver whose kubelet plugin should be invoked to process this ResourceHandle's data once it lands on a node. This may differ from the DriverName set in ResourceClaimStatus this ResourceHandle is embedded in.
allocation.shareable (boolean)
Shareable determines whether the resource supports more than one consumer at a time.
deallocationRequested (boolean)
DeallocationRequested indicates that a ResourceClaim is to be deallocated.
The driver then must deallocate this claim and reset the field together with clearing the Allocation field.
While DeallocationRequested is set, no new consumers may be added to ReservedFor.
driverName (string)
DriverName is a copy of the driver name from the ResourceClass at the time when allocation started.
reservedFor ([]ResourceClaimConsumerReference)
Map: unique values on key uid will be kept during a merge
ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started.
There can be at most 32 such reservations. This may get increased in the future, but not reduced.
ResourceClaimConsumerReference contains enough information to let you locate the consumer of a ResourceClaim. The user must be a resource in the same namespace as the ResourceClaim.
reservedFor.name (string), required
Name is the name of resource being referenced.
reservedFor.resource (string), required
Resource is the type of resource being referenced, for example "pods".
reservedFor.uid (string), required
UID identifies exactly one incarnation of the resource.
reservedFor.apiGroup (string)
APIGroup is the group for the resource being referenced. It is empty for the core API. This matches the group in the APIVersion that is used when creating the resources.
Spec for the ResourceClaim. The entire content is copied unchanged into the ResourceClaim that gets created from this template. The same fields as in a ResourceClaim are also valid here.
ObjectMeta may contain labels and annotations that will be copied into the PVC when creating it. No other fields are allowed and will be rejected during validation.
ResourceClaimTemplateList
ResourceClaimTemplateList is a collection of claim templates.
DriverName defines the name of the dynamic resource driver that is used for allocation of a ResourceClaim that uses this class.
Resource drivers have a unique name in forward domain order (acme.example.com).
parametersRef (ResourceClassParametersReference)
ParametersRef references an arbitrary separate object that may hold parameters that will be used by the driver when allocating a resource that uses this class. A dynamic resource driver can distinguish between parameters stored here and and those stored in ResourceClaimSpec.
ResourceClassParametersReference contains enough information to let you locate the parameters for a ResourceClass.
parametersRef.kind (string), required
Kind is the type of resource being referenced. This is the same value as in the parameter object's metadata.
parametersRef.name (string), required
Name is the name of resource being referenced.
parametersRef.apiGroup (string)
APIGroup is the group for the resource being referenced. It is empty for the core API. This matches the group in the APIVersion that is used when creating the resources.
parametersRef.namespace (string)
Namespace that contains the referenced resource. Must be empty for cluster-scoped resources and non-empty for namespaced resources.
suitableNodes (NodeSelector)
Only nodes matching the selector will be considered by the scheduler when trying to find a Node that fits a Pod when that Pod uses a ResourceClaim that has not been allocated yet.
Setting this field is optional. If null, all nodes are candidates.
A node selector represents the union of the results of one or more label queries over a set of nodes; that is, it represents the OR of the selectors represented by the node selector terms.
Required. A list of node selector terms. The terms are ORed.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
Service is a named abstraction of software service (for example, mysql) consisting of local port (for example 3306) that the proxy listens on, and the selector that determines which pods will answer requests sent through the proxy.
apiVersion: v1
import "k8s.io/api/core/v1"
Service
Service is a named abstraction of software service (for example, mysql) consisting of local port (for example 3306) that the proxy listens on, and the selector that determines which pods will answer requests sent through the proxy.
ServiceSpec describes the attributes that a user creates on a service.
selector (map[string]string)
Route service traffic to pods with label keys and values matching this selector. If empty or not present, the service is assumed to have an external process managing its endpoints, which Kubernetes will not modify. Only applies to types ClusterIP, NodePort, and LoadBalancer. Ignored if type is ExternalName. More info: https://kubernetes.io/docs/concepts/services-networking/service/
ports ([]ServicePort)
Patch strategy: merge on key port
Map: unique values on keys port, protocol will be kept during a merge
ServicePort contains information on service's port.
ports.port (int32), required
The port that will be exposed by this service.
ports.targetPort (IntOrString)
Number or name of the port to access on the pods targeted by the service. Number must be in the range 1 to 65535. Name must be an IANA_SVC_NAME. If this is a string, it will be looked up as a named port in the target Pod's container ports. If this is not specified, the value of the 'port' field is used (an identity map). This field is ignored for services with clusterIP=None, and should be omitted or set equal to the 'port' field. More info: https://kubernetes.io/docs/concepts/services-networking/service/#defining-a-service
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
ports.protocol (string)
The IP protocol for this port. Supports "TCP", "UDP", and "SCTP". Default is TCP.
ports.name (string)
The name of this port within the service. This must be a DNS_LABEL. All ports within a ServiceSpec must have unique names. When considering the endpoints for a Service, this must match the 'name' field in the EndpointPort. Optional if only one ServicePort is defined on this service.
ports.nodePort (int32)
The port on each node on which this service is exposed when type is NodePort or LoadBalancer. Usually assigned by the system. If a value is specified, in-range, and not in use it will be used, otherwise the operation will fail. If not specified, a port will be allocated if this Service requires one. If this field is specified when creating a Service which does not need it, creation will fail. This field will be wiped when updating a Service to no longer need it (e.g. changing type from NodePort to ClusterIP). More info: https://kubernetes.io/docs/concepts/services-networking/service/#type-nodeport
ports.appProtocol (string)
The application protocol for this port. This is used as a hint for implementations to offer richer behavior for protocols that they understand. This field follows standard Kubernetes label syntax. Valid values are either:
Other protocols should use implementation-defined prefixed names such as mycompany.com/my-custom-protocol.
type (string)
type determines how the Service is exposed. Defaults to ClusterIP. Valid options are ExternalName, ClusterIP, NodePort, and LoadBalancer. "ClusterIP" allocates a cluster-internal IP address for load-balancing to endpoints. Endpoints are determined by the selector or if that is not specified, by manual construction of an Endpoints object or EndpointSlice objects. If clusterIP is "None", no virtual IP is allocated and the endpoints are published as a set of endpoints rather than a virtual IP. "NodePort" builds on ClusterIP and allocates a port on every node which routes to the same endpoints as the clusterIP. "LoadBalancer" builds on NodePort and creates an external load-balancer (if supported in the current cloud) which routes to the same endpoints as the clusterIP. "ExternalName" aliases this service to the specified externalName. Several other fields do not apply to ExternalName services. More info: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
ipFamilies ([]string)
Atomic: will be replaced during a merge
IPFamilies is a list of IP families (e.g. IPv4, IPv6) assigned to this service. This field is usually assigned automatically based on cluster configuration and the ipFamilyPolicy field. If this field is specified manually, the requested family is available in the cluster, and ipFamilyPolicy allows it, it will be used; otherwise creation of the service will fail. This field is conditionally mutable: it allows for adding or removing a secondary IP family, but it does not allow changing the primary IP family of the Service. Valid values are "IPv4" and "IPv6". This field only applies to Services of types ClusterIP, NodePort, and LoadBalancer, and does apply to "headless" services. This field will be wiped when updating a Service to type ExternalName.
This field may hold a maximum of two entries (dual-stack families, in either order). These families must correspond to the values of the clusterIPs field, if specified. Both clusterIPs and ipFamilies are governed by the ipFamilyPolicy field.
ipFamilyPolicy (string)
IPFamilyPolicy represents the dual-stack-ness requested or required by this Service. If there is no value provided, then this field will be set to SingleStack. Services can be "SingleStack" (a single IP family), "PreferDualStack" (two IP families on dual-stack configured clusters or a single IP family on single-stack clusters), or "RequireDualStack" (two IP families on dual-stack configured clusters, otherwise fail). The ipFamilies and clusterIPs fields depend on the value of this field. This field will be wiped when updating a service to type ExternalName.
clusterIP (string)
clusterIP is the IP address of the service and is usually assigned randomly. If an address is specified manually, is in-range (as per system configuration), and is not in use, it will be allocated to the service; otherwise creation of the service will fail. This field may not be changed through updates unless the type field is also being changed to ExternalName (which requires this field to be blank) or the type field is being changed from ExternalName (in which case this field may optionally be specified, as describe above). Valid values are "None", empty string (""), or a valid IP address. Setting this to "None" makes a "headless service" (no virtual IP), which is useful when direct endpoint connections are preferred and proxying is not required. Only applies to types ClusterIP, NodePort, and LoadBalancer. If this field is specified when creating a Service of type ExternalName, creation will fail. This field will be wiped when updating a Service to type ExternalName. More info: https://kubernetes.io/docs/concepts/services-networking/service/#virtual-ips-and-service-proxies
clusterIPs ([]string)
Atomic: will be replaced during a merge
ClusterIPs is a list of IP addresses assigned to this service, and are usually assigned randomly. If an address is specified manually, is in-range (as per system configuration), and is not in use, it will be allocated to the service; otherwise creation of the service will fail. This field may not be changed through updates unless the type field is also being changed to ExternalName (which requires this field to be empty) or the type field is being changed from ExternalName (in which case this field may optionally be specified, as describe above). Valid values are "None", empty string (""), or a valid IP address. Setting this to "None" makes a "headless service" (no virtual IP), which is useful when direct endpoint connections are preferred and proxying is not required. Only applies to types ClusterIP, NodePort, and LoadBalancer. If this field is specified when creating a Service of type ExternalName, creation will fail. This field will be wiped when updating a Service to type ExternalName. If this field is not specified, it will be initialized from the clusterIP field. If this field is specified, clients must ensure that clusterIPs[0] and clusterIP have the same value.
externalIPs is a list of IP addresses for which nodes in the cluster will also accept traffic for this service. These IPs are not managed by Kubernetes. The user is responsible for ensuring that traffic arrives at a node with this IP. A common example is external load-balancers that are not part of the Kubernetes system.
Only applies to Service Type: LoadBalancer. This feature depends on whether the underlying cloud-provider supports specifying the loadBalancerIP when a load balancer is created. This field will be ignored if the cloud-provider does not support the feature. Deprecated: This field was under-specified and its meaning varies across implementations. Using it is non-portable and it may not support dual-stack. Users are encouraged to use implementation-specific annotations when available.
loadBalancerClass is the class of the load balancer implementation this Service belongs to. If specified, the value of this field must be a label-style identifier, with an optional prefix, e.g. "internal-vip" or "example.com/internal-vip". Unprefixed names are reserved for end-users. This field can only be set when the Service type is 'LoadBalancer'. If not set, the default load balancer implementation is used, today this is typically done through the cloud provider integration, but should apply for any default implementation. If set, it is assumed that a load balancer implementation is watching for Services with a matching class. Any default load balancer implementation (e.g. cloud providers) should ignore Services that set this field. This field can only be set when creating or updating a Service to type 'LoadBalancer'. Once set, it can not be changed. This field will be wiped when a service is updated to a non 'LoadBalancer' type.
externalName (string)
externalName is the external reference that discovery mechanisms will return as an alias for this service (e.g. a DNS CNAME record). No proxying will be involved. Must be a lowercase RFC-1123 hostname (https://tools.ietf.org/html/rfc1123) and requires type to be "ExternalName".
externalTrafficPolicy (string)
externalTrafficPolicy describes how nodes distribute service traffic they receive on one of the Service's "externally-facing" addresses (NodePorts, ExternalIPs, and LoadBalancer IPs). If set to "Local", the proxy will configure the service in a way that assumes that external load balancers will take care of balancing the service traffic between nodes, and so each node will deliver traffic only to the node-local endpoints of the service, without masquerading the client source IP. (Traffic mistakenly sent to a node with no endpoints will be dropped.) The default value, "Cluster", uses the standard behavior of routing to all endpoints evenly (possibly modified by topology and other features). Note that traffic sent to an External IP or LoadBalancer IP from within the cluster will always get "Cluster" semantics, but clients sending to a NodePort from within the cluster may need to take traffic policy into account when picking a node.
internalTrafficPolicy (string)
InternalTrafficPolicy describes how nodes distribute service traffic they receive on the ClusterIP. If set to "Local", the proxy will assume that pods only want to talk to endpoints of the service on the same node as the pod, dropping the traffic if there are no local endpoints. The default value, "Cluster", uses the standard behavior of routing to all endpoints evenly (possibly modified by topology and other features).
healthCheckNodePort (int32)
healthCheckNodePort specifies the healthcheck nodePort for the service. This only applies when type is set to LoadBalancer and externalTrafficPolicy is set to Local. If a value is specified, is in-range, and is not in use, it will be used. If not specified, a value will be automatically allocated. External systems (e.g. load-balancers) can use this port to determine if a given node holds endpoints for this service or not. If this field is specified when creating a Service which does not need it, creation will fail. This field will be wiped when updating a Service to no longer need it (e.g. changing type). This field cannot be updated once set.
publishNotReadyAddresses (boolean)
publishNotReadyAddresses indicates that any agent which deals with endpoints for this Service should disregard any indications of ready/not-ready. The primary use case for setting this field is for a StatefulSet's Headless Service to propagate SRV DNS records for its Pods for the purpose of peer discovery. The Kubernetes controllers that generate Endpoints and EndpointSlice resources for Services interpret this to mean that all endpoints are considered "ready" even if the Pods themselves are not. Agents which consume only Kubernetes generated endpoints through the Endpoints or EndpointSlice resources can safely assume this behavior.
sessionAffinityConfig (SessionAffinityConfig)
sessionAffinityConfig contains the configurations of session affinity.
SessionAffinityConfig represents the configurations of session affinity.
sessionAffinityConfig.clientIP (ClientIPConfig)
clientIP contains the configurations of Client IP based session affinity.
ClientIPConfig represents the configurations of Client IP based session affinity.
timeoutSeconds specifies the seconds of ClientIP type session sticky time. The value must be >0 && <=86400(for 1 day) if ServiceAffinity == "ClientIP". Default value is 10800(for 3 hours).
allocateLoadBalancerNodePorts (boolean)
allocateLoadBalancerNodePorts defines if NodePorts will be automatically allocated for services with type LoadBalancer. Default is "true". It may be set to "false" if the cluster load-balancer does not rely on NodePorts. If the caller requests specific NodePorts (by specifying a value), those requests will be respected, regardless of this field. This field may only be set for services with type LoadBalancer and will be cleared if the type is changed to any other type.
ServiceStatus
ServiceStatus represents the current status of a service.
conditions ([]Condition)
Patch strategy: merge on key type
Map: unique values on key type will be kept during a merge
Current service state
Condition contains details for one aspect of the current state of this API Resource.
conditions.lastTransitionTime (Time), required
lastTransitionTime is the last time the condition transitioned from one status to another. This should be when the underlying condition changed. If that is not known, then using the time when the API field changed is acceptable.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string), required
message is a human readable message indicating details about the transition. This may be an empty string.
conditions.reason (string), required
reason contains a programmatic identifier indicating the reason for the condition's last transition. Producers of specific condition types may define expected values and meanings for this field, and whether the values are considered a guaranteed API. The value should be a CamelCase string. This field may not be empty.
conditions.status (string), required
status of the condition, one of True, False, Unknown.
conditions.type (string), required
type of condition in CamelCase or in foo.example.com/CamelCase.
conditions.observedGeneration (int64)
observedGeneration represents the .metadata.generation that the condition was set based upon. For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date with respect to the current state of the instance.
loadBalancer (LoadBalancerStatus)
LoadBalancer contains the current status of the load-balancer, if one is present.
LoadBalancerStatus represents the status of a load-balancer.
loadBalancer.ingress ([]LoadBalancerIngress)
Ingress is a list containing ingress points for the load-balancer. Traffic intended for the service should be sent to these ingress points.
LoadBalancerIngress represents the status of a load-balancer ingress point: traffic intended for the service should be sent to an ingress point.
loadBalancer.ingress.hostname (string)
Hostname is set for load-balancer ingress points that are DNS based (typically AWS load-balancers)
loadBalancer.ingress.ip (string)
IP is set for load-balancer ingress points that are IP based (typically GCE or OpenStack load-balancers)
loadBalancer.ingress.ipMode (string)
IPMode specifies how the load-balancer IP behaves, and may only be specified when the ip field is specified. Setting this to "VIP" indicates that traffic is delivered to the node with the destination set to the load-balancer's IP and port. Setting this to "Proxy" indicates that traffic is delivered to the node or pod with the destination set to the node's IP and node port or the pod's IP and port. Service implementations may use this information to adjust traffic routing.
loadBalancer.ingress.ports ([]PortStatus)
Atomic: will be replaced during a merge
Ports is a list of records of service ports If used, every port defined in the service should have an entry in it
**
loadBalancer.ingress.ports.port (int32), required
Port is the port number of the service port of which status is recorded here
Protocol is the protocol of the service port of which status is recorded here The supported values are: "TCP", "UDP", "SCTP"
loadBalancer.ingress.ports.error (string)
Error is to record the problem with the service port The format of the error shall comply with the following rules: - built-in error values shall be specified in this file and those shall use
CamelCase names
cloud provider specific error values must have names that comply with the
format foo.example.com/CamelCase.
The set of all endpoints is the union of all subsets. Addresses are placed into subsets according to the IPs they share. A single address with multiple ports, some of which are ready and some of which are not (because they come from different containers) will result in the address being displayed in different subsets for the different ports. No address will appear in both Addresses and NotReadyAddresses in the same subset. Sets of addresses and ports that comprise a service.
*EndpointSubset is a group of addresses with a common set of ports. The expanded set of endpoints is the Cartesian product of Addresses x Ports. For example, given:
IP addresses which offer the related ports that are marked as ready. These endpoints should be considered safe for load balancers and clients to utilize.
EndpointAddress is a tuple that describes single IP address.
subsets.addresses.ip (string), required
The IP of this endpoint. May not be loopback (127.0.0.0/8 or ::1), link-local (169.254.0.0/16 or fe80::/10), or link-local multicast (224.0.0.0/24 or ff02::/16).
subsets.addresses.hostname (string)
The Hostname of this endpoint
subsets.addresses.nodeName (string)
Optional: Node hosting this endpoint. This can be used to determine endpoints local to a node.
IP addresses which offer the related ports but are not currently marked as ready because they have not yet finished starting, have recently failed a readiness check, or have recently failed a liveness check.
EndpointAddress is a tuple that describes single IP address.
subsets.notReadyAddresses.ip (string), required
The IP of this endpoint. May not be loopback (127.0.0.0/8 or ::1), link-local (169.254.0.0/16 or fe80::/10), or link-local multicast (224.0.0.0/24 or ff02::/16).
subsets.notReadyAddresses.hostname (string)
The Hostname of this endpoint
subsets.notReadyAddresses.nodeName (string)
Optional: Node hosting this endpoint. This can be used to determine endpoints local to a node.
Port numbers available on the related IP addresses.
EndpointPort is a tuple that describes a single port.
subsets.ports.port (int32), required
The port number of the endpoint.
subsets.ports.protocol (string)
The IP protocol for this port. Must be UDP, TCP, or SCTP. Default is TCP.
subsets.ports.name (string)
The name of this port. This must match the 'name' field in the corresponding ServicePort. Must be a DNS_LABEL. Optional only if one port is defined.
subsets.ports.appProtocol (string)
The application protocol for this port. This is used as a hint for implementations to offer richer behavior for protocols that they understand. This field follows standard Kubernetes label syntax. Valid values are either:
EndpointSlice represents a subset of the endpoints that implement a service.
apiVersion: discovery.k8s.io/v1
import "k8s.io/api/discovery/v1"
EndpointSlice
EndpointSlice represents a subset of the endpoints that implement a service. For a given service there may be multiple EndpointSlice objects, selected by labels, which must be joined to produce the full set of endpoints.
addressType specifies the type of address carried by this EndpointSlice. All addresses in this slice must be the same type. This field is immutable after creation. The following address types are currently supported: * IPv4: Represents an IPv4 Address. * IPv6: Represents an IPv6 Address. * FQDN: Represents a Fully Qualified Domain Name.
endpoints ([]Endpoint), required
Atomic: will be replaced during a merge
endpoints is a list of unique endpoints in this slice. Each slice may include a maximum of 1000 endpoints.
Endpoint represents a single logical "backend" implementing a service.
endpoints.addresses ([]string), required
Set: unique values will be kept during a merge
addresses of this endpoint. The contents of this field are interpreted according to the corresponding EndpointSlice addressType field. Consumers must handle different types of addresses in the context of their own capabilities. This must contain at least one address but no more than 100. These are all assumed to be fungible and clients may choose to only use the first element. Refer to: https://issue.k8s.io/106267
endpoints.conditions (EndpointConditions)
conditions contains information about the current status of the endpoint.
EndpointConditions represents the current condition of an endpoint.
endpoints.conditions.ready (boolean)
ready indicates that this endpoint is prepared to receive traffic, according to whatever system is managing the endpoint. A nil value indicates an unknown state. In most cases consumers should interpret this unknown state as ready. For compatibility reasons, ready should never be "true" for terminating endpoints, except when the normal readiness behavior is being explicitly overridden, for example when the associated Service has set the publishNotReadyAddresses flag.
endpoints.conditions.serving (boolean)
serving is identical to ready except that it is set regardless of the terminating state of endpoints. This condition should be set to true for a ready endpoint that is terminating. If nil, consumers should defer to the ready condition.
endpoints.conditions.terminating (boolean)
terminating indicates that this endpoint is terminating. A nil value indicates an unknown state. Consumers should interpret this unknown state to mean that the endpoint is not terminating.
endpoints.deprecatedTopology (map[string]string)
deprecatedTopology contains topology information part of the v1beta1 API. This field is deprecated, and will be removed when the v1beta1 API is removed (no sooner than kubernetes v1.24). While this field can hold values, it is not writable through the v1 API, and any attempts to write to it will be silently ignored. Topology information can be found in the zone and nodeName fields instead.
endpoints.hints (EndpointHints)
hints contains information associated with how an endpoint should be consumed.
EndpointHints provides hints describing how an endpoint should be consumed.
endpoints.hints.forZones ([]ForZone)
Atomic: will be replaced during a merge
forZones indicates the zone(s) this endpoint should be consumed by to enable topology aware routing.
ForZone provides information about which zones should consume this endpoint.
endpoints.hints.forZones.name (string), required
name represents the name of the zone.
endpoints.hostname (string)
hostname of this endpoint. This field may be used by consumers of endpoints to distinguish endpoints from each other (e.g. in DNS names). Multiple endpoints which use the same hostname should be considered fungible (e.g. multiple A values in DNS). Must be lowercase and pass DNS Label (RFC 1123) validation.
endpoints.nodeName (string)
nodeName represents the name of the Node hosting this endpoint. This can be used to determine endpoints local to a Node.
targetRef is a reference to a Kubernetes object that represents this endpoint.
endpoints.zone (string)
zone is the name of the Zone this endpoint exists in.
ports ([]EndpointPort)
Atomic: will be replaced during a merge
ports specifies the list of network ports exposed by each endpoint in this slice. Each port must have a unique name. When ports is empty, it indicates that there are no defined ports. When a port is defined with a nil port value, it indicates "all ports". Each slice may include a maximum of 100 ports.
EndpointPort represents a Port used by an EndpointSlice
ports.port (int32)
port represents the port number of the endpoint. If this is not specified, ports are not restricted and must be interpreted in the context of the specific consumer.
ports.protocol (string)
protocol represents the IP protocol for this port. Must be UDP, TCP, or SCTP. Default is TCP.
ports.name (string)
name represents the name of this port. All ports in an EndpointSlice must have a unique name. If the EndpointSlice is dervied from a Kubernetes service, this corresponds to the Service.ports[].name. Name must either be an empty string or pass DNS_LABEL validation: * must be no more than 63 characters long. * must consist of lower case alphanumeric characters or '-'. * must start and end with an alphanumeric character. Default is empty string.
ports.appProtocol (string)
The application protocol for this port. This is used as a hint for implementations to offer richer behavior for protocols that they understand. This field follows standard Kubernetes label syntax. Valid values are either:
Ingress is a collection of rules that allow inbound connections to reach the endpoints defined by a backend.
apiVersion: networking.k8s.io/v1
import "k8s.io/api/networking/v1"
Ingress
Ingress is a collection of rules that allow inbound connections to reach the endpoints defined by a backend. An Ingress can be configured to give services externally-reachable urls, load balance traffic, terminate SSL, offer name based virtual hosting etc.
defaultBackend is the backend that should handle requests that don't match any rule. If Rules are not specified, DefaultBackend must be specified. If DefaultBackend is not set, the handling of requests that do not match any of the rules will be up to the Ingress controller.
ingressClassName (string)
ingressClassName is the name of an IngressClass cluster resource. Ingress controller implementations use this field to know whether they should be serving this Ingress resource, by a transitive connection (controller -> IngressClass -> Ingress resource). Although the kubernetes.io/ingress.class annotation (simple constant name) was never formally defined, it was widely supported by Ingress controllers to create a direct binding between Ingress controller and Ingress resources. Newly created Ingress resources should prefer using the field. However, even though the annotation is officially deprecated, for backwards compatibility reasons, ingress controllers should still honor that annotation if present.
rules ([]IngressRule)
Atomic: will be replaced during a merge
rules is a list of host rules used to configure the Ingress. If unspecified, or no rule matches, all traffic is sent to the default backend.
IngressRule represents the rules mapping the paths under a specified host to the related backend services. Incoming requests are first evaluated for a host match, then routed to the backend associated with the matching IngressRuleValue.
rules.host (string)
host is the fully qualified domain name of a network host, as defined by RFC 3986. Note the following deviations from the "host" part of the URI as defined in RFC 3986: 1. IPs are not allowed. Currently an IngressRuleValue can only apply to
the IP in the Spec of the parent Ingress.
2. The : delimiter is not respected because ports are not allowed.
Currently the port of an Ingress is implicitly :80 for http and
:443 for https.
Both these may change in the future. Incoming requests are matched against the host before the IngressRuleValue. If the host is unspecified, the Ingress routes all traffic based on the specified IngressRuleValue.
host can be "precise" which is a domain name without the terminating dot of a network host (e.g. "foo.bar.com") or "wildcard", which is a domain name prefixed with a single wildcard label (e.g. ".foo.com"). The wildcard character '' must appear by itself as the first DNS label and matches only a single label. You cannot have a wildcard label by itself (e.g. Host == "*"). Requests will be matched against the Host field in the following way: 1. If host is precise, the request matches this rule if the http host header is equal to Host. 2. If host is a wildcard, then the request matches this rule if the http host header is to equal to the suffix (removing the first label) of the wildcard rule.
rules.http (HTTPIngressRuleValue)
HTTPIngressRuleValue is a list of http selectors pointing to backends. In the example: http:///? -> backend where where parts of the url correspond to RFC 3986, this resource will be used to match against everything after the last '/' and before the first '?' or '#'.
rules.http.paths ([]HTTPIngressPath), required
Atomic: will be replaced during a merge
paths is a collection of paths that map requests to backends.
HTTPIngressPath associates a path with a backend. Incoming urls matching the path are forwarded to the backend.
backend defines the referenced service endpoint to which the traffic will be forwarded to.
rules.http.paths.pathType (string), required
pathType determines the interpretation of the path matching. PathType can be one of the following values: * Exact: Matches the URL path exactly. * Prefix: Matches based on a URL path prefix split by '/'. Matching is
done on a path element by element basis. A path element refers is the
list of labels in the path split by the '/' separator. A request is a
match for path p if every p is an element-wise prefix of p of the
request path. Note that if the last element of the path is a substring
of the last element in request path, it is not a match (e.g. /foo/bar
matches /foo/bar/baz, but does not match /foo/barbaz).
ImplementationSpecific: Interpretation of the Path matching is up to
the IngressClass. Implementations can treat this as a separate PathType
or treat it identically to Prefix or Exact path types.
Implementations are required to support all path types.
rules.http.paths.path (string)
path is matched against the path of an incoming request. Currently it can contain characters disallowed from the conventional "path" part of a URL as defined by RFC 3986. Paths must begin with a '/' and must be present when using PathType with value "Exact" or "Prefix".
tls ([]IngressTLS)
Atomic: will be replaced during a merge
tls represents the TLS configuration. Currently the Ingress only supports a single TLS port, 443. If multiple members of this list specify different hosts, they will be multiplexed on the same port according to the hostname specified through the SNI TLS extension, if the ingress controller fulfilling the ingress supports SNI.
IngressTLS describes the transport layer security associated with an ingress.
tls.hosts ([]string)
Atomic: will be replaced during a merge
hosts is a list of hosts included in the TLS certificate. The values in this list must match the name/s used in the tlsSecret. Defaults to the wildcard host setting for the loadbalancer controller fulfilling this Ingress, if left unspecified.
tls.secretName (string)
secretName is the name of the secret used to terminate TLS traffic on port 443. Field is left optional to allow TLS routing based on SNI hostname alone. If the SNI host in a listener conflicts with the "Host" header field used by an IngressRule, the SNI host is used for termination and value of the "Host" header is used for routing.
IngressBackend
IngressBackend describes all endpoints for a given service and port.
resource is an ObjectRef to another Kubernetes resource in the namespace of the Ingress object. If resource is specified, a service.Name and service.Port must not be specified. This is a mutually exclusive setting with "Service".
service (IngressServiceBackend)
service references a service as a backend. This is a mutually exclusive setting with "Resource".
IngressServiceBackend references a Kubernetes Service as a Backend.
service.name (string), required
name is the referenced service. The service must exist in the same namespace as the Ingress object.
service.port (ServiceBackendPort)
port of the referenced service. A port name or port number is required for a IngressServiceBackend.
ServiceBackendPort is the service port being referenced.
service.port.name (string)
name is the name of the port on the Service. This is a mutually exclusive setting with "Number".
service.port.number (int32)
number is the numerical port number (e.g. 80) on the Service. This is a mutually exclusive setting with "Name".
IngressStatus
IngressStatus describe the current state of the Ingress.
loadBalancer (IngressLoadBalancerStatus)
loadBalancer contains the current status of the load-balancer.
IngressLoadBalancerStatus represents the status of a load-balancer.
protocol is the protocol of the ingress port. The supported values are: "TCP", "UDP", "SCTP"
loadBalancer.ingress.ports.error (string)
error is to record the problem with the service port The format of the error shall comply with the following rules: - built-in error values shall be specified in this file and those shall use
CamelCase names
cloud provider specific error values must have names that comply with the
format foo.example.com/CamelCase.
IngressClass represents the class of the Ingress, referenced by the Ingress Spec.
apiVersion: networking.k8s.io/v1
import "k8s.io/api/networking/v1"
IngressClass
IngressClass represents the class of the Ingress, referenced by the Ingress Spec. The ingressclass.kubernetes.io/is-default-class annotation can be used to indicate that an IngressClass should be considered default. When a single IngressClass resource has this annotation set to true, new Ingress resources without a class specified will be assigned this default class.
IngressClassSpec provides information about the class of an Ingress.
controller (string)
controller refers to the name of the controller that should handle this class. This allows for different "flavors" that are controlled by the same controller. For example, you may have different parameters for the same implementing controller. This should be specified as a domain-prefixed path no more than 250 characters in length, e.g. "acme.io/ingress-controller". This field is immutable.
parameters (IngressClassParametersReference)
parameters is a link to a custom resource containing additional configuration for the controller. This is optional if the controller does not require extra parameters.
IngressClassParametersReference identifies an API object. This can be used to specify a cluster or namespace-scoped resource.
parameters.kind (string), required
kind is the type of resource being referenced.
parameters.name (string), required
name is the name of resource being referenced.
parameters.apiGroup (string)
apiGroup is the group for the resource being referenced. If APIGroup is not specified, the specified Kind must be in the core API group. For any other third-party types, APIGroup is required.
parameters.namespace (string)
namespace is the namespace of the resource being referenced. This field is required when scope is set to "Namespace" and must be unset when scope is set to "Cluster".
parameters.scope (string)
scope represents if this refers to a cluster or namespace scoped resource. This may be set to "Cluster" (default) or "Namespace".
IngressClassList
IngressClassList is a collection of IngressClasses.
BinaryData contains the binary data. Each key must consist of alphanumeric characters, '-', '_' or '.'. BinaryData can contain byte sequences that are not in the UTF-8 range. The keys stored in BinaryData must not overlap with the ones in the Data field, this is enforced during validation process. Using this field will require 1.10+ apiserver and kubelet.
data (map[string]string)
Data contains the configuration data. Each key must consist of alphanumeric characters, '-', '_' or '.'. Values with non-UTF-8 byte sequences must use the BinaryData field. The keys stored in Data must not overlap with the keys in the BinaryData field, this is enforced during validation process.
immutable (boolean)
Immutable, if set to true, ensures that data stored in the ConfigMap cannot be updated (only object metadata can be modified). If not set to true, the field can be modified at any time. Defaulted to nil.
ConfigMapList
ConfigMapList is a resource containing a list of ConfigMap objects.
Data contains the secret data. Each key must consist of alphanumeric characters, '-', '_' or '.'. The serialized form of the secret data is a base64 encoded string, representing the arbitrary (possibly non-string) data value here. Described in https://tools.ietf.org/html/rfc4648#section-4
immutable (boolean)
Immutable, if set to true, ensures that data stored in the Secret cannot be updated (only object metadata can be modified). If not set to true, the field can be modified at any time. Defaulted to nil.
stringData (map[string]string)
stringData allows specifying non-binary secret data in string form. It is provided as a write-only input field for convenience. All keys and values are merged into the data field on write, overwriting any existing values. The stringData field is never output when reading from the API.
PersistentVolumeClaimVolumeSource references the user's PVC in the same namespace. This volume finds the bound PV and mounts that volume for the pod. A PersistentVolumeClaimVolumeSource is, essentially, a wrapper around another type of volume that is owned by someone else (the system).
readOnly Will force the ReadOnly setting in VolumeMounts. Default false.
Projections
configMap (ConfigMapVolumeSource)
configMap represents a configMap that should populate this volume
*Adapts a ConfigMap into a volume.
The contents of the target ConfigMap's Data field will be presented in a volume as files using the keys in the Data field as the file names, unless the items element is populated with specific mappings of keys to paths. ConfigMap volumes support ownership management and SELinux relabeling.*
optional specify whether the ConfigMap or its keys must be defined
configMap.defaultMode (int32)
defaultMode is optional: mode bits used to set permissions on created files by default. Must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. Defaults to 0644. Directories within the path are not affected by this setting. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
items if unspecified, each key-value pair in the Data field of the referenced ConfigMap will be projected into the volume as a file whose name is the key and content is the value. If specified, the listed keys will be projected into the specified paths, and unlisted keys will not be present. If a key is specified which is not present in the ConfigMap, the volume setup will error unless it is marked optional. Paths must be relative and may not contain the '..' path or start with '..'.
The contents of the target Secret's Data field will be presented in a volume as files using the keys in the Data field as the file names. Secret volumes support ownership management and SELinux relabeling.*
optional field specify whether the Secret or its keys must be defined
secret.defaultMode (int32)
defaultMode is Optional: mode bits used to set permissions on created files by default. Must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. Defaults to 0644. Directories within the path are not affected by this setting. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
items If unspecified, each key-value pair in the Data field of the referenced Secret will be projected into the volume as a file whose name is the key and content is the value. If specified, the listed keys will be projected into the specified paths, and unlisted keys will not be present. If a key is specified which is not present in the Secret, the volume setup will error unless it is marked optional. Paths must be relative and may not contain the '..' path or start with '..'.
downwardAPI (DownwardAPIVolumeSource)
downwardAPI represents downward API about the pod that should populate this volume
DownwardAPIVolumeSource represents a volume containing downward API info. Downward API volumes support ownership management and SELinux relabeling.
downwardAPI.defaultMode (int32)
Optional: mode bits to use on created files by default. Must be a Optional: mode bits used to set permissions on created files by default. Must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. Defaults to 0644. Directories within the path are not affected by this setting. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
projected items for all in one resources secrets, configmaps, and downward API
Represents a projected volume source
projected.defaultMode (int32)
defaultMode are the mode bits used to set permissions on created files by default. Must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. Directories within the path are not affected by this setting. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
projected.sources ([]VolumeProjection)
sources is the list of volume projections
Projection that may be projected along with other supported volume types
projected.sources.configMap (ConfigMapProjection)
configMap information about the configMap data to project
*Adapts a ConfigMap into a projected volume.
The contents of the target ConfigMap's Data field will be presented in a projected volume as files using the keys in the Data field as the file names, unless the items element is populated with specific mappings of keys to paths. Note that this is identical to a configmap volume source without the default mode.*
items if unspecified, each key-value pair in the Data field of the referenced ConfigMap will be projected into the volume as a file whose name is the key and content is the value. If specified, the listed keys will be projected into the specified paths, and unlisted keys will not be present. If a key is specified which is not present in the ConfigMap, the volume setup will error unless it is marked optional. Paths must be relative and may not contain the '..' path or start with '..'.
downwardAPI information about the downwardAPI data to project
Represents downward API info for projecting into a projected volume. Note that this is identical to a downwardAPI volume source without the default mode.
secret information about the secret data to project
*Adapts a secret into a projected volume.
The contents of the target Secret's Data field will be presented in a projected volume as files using the keys in the Data field as the file names. Note that this is identical to a secret volume source without the default mode.*
items if unspecified, each key-value pair in the Data field of the referenced Secret will be projected into the volume as a file whose name is the key and content is the value. If specified, the listed keys will be projected into the specified paths, and unlisted keys will not be present. If a key is specified which is not present in the Secret, the volume setup will error unless it is marked optional. Paths must be relative and may not contain the '..' path or start with '..'.
serviceAccountToken is information about the serviceAccountToken data to project
ServiceAccountTokenProjection represents a projected service account token volume. This projection can be used to insert a service account token into the pods runtime filesystem for use against APIs (Kubernetes API Server or otherwise).
audience is the intended audience of the token. A recipient of a token must identify itself with an identifier specified in the audience of the token, and otherwise should reject the token. The audience defaults to the identifier of the apiserver.
expirationSeconds is the requested duration of validity of the service account token. As the token approaches expiration, the kubelet volume plugin will proactively rotate the service account token. The kubelet will start trying to rotate the token if the token is older than 80 percent of its time to live or if the token is older than 24 hours.Defaults to 1 hour and must be at least 10 minutes.
Represents an empty directory for a pod. Empty directory volumes support ownership management and SELinux relabeling.
emptyDir.medium (string)
medium represents what type of storage medium should back this directory. The default is "" which means to use the node's default medium. Must be an empty string (default) or Memory. More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir
sizeLimit is the total amount of local storage required for this EmptyDir volume. The size limit is also applicable for memory medium. The maximum usage on memory medium EmptyDir would be the minimum value between the SizeLimit specified here and the sum of memory limits of all containers in a pod. The default is nil which means that the limit is undefined. More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir
hostPath (HostPathVolumeSource)
hostPath represents a pre-existing file or directory on the host machine that is directly exposed to the container. This is generally used for system agents or other privileged things that are allowed to see the host machine. Most containers will NOT need this. More info: https://kubernetes.io/docs/concepts/storage/volumes#hostpath
Represents a host path mapped into a pod. Host path volumes do not support ownership management or SELinux relabeling.
An AWS EBS disk must exist before mounting to a container. The disk must also be in the same AWS zone as the kubelet. An AWS EBS disk can only be mounted as read/write once. AWS EBS volumes support ownership management and SELinux relabeling.*
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#awselasticblockstore
awsElasticBlockStore.partition (int32)
partition is the partition in the volume that you want to mount. If omitted, the default is to mount by volume name. Examples: For volume /dev/sda1, you specify the partition as "1". Similarly, the volume partition for /dev/sda is "0" (or you can leave the property empty).
azureDisk represents an Azure Data Disk mount on the host and bind mount to the pod.
AzureDisk represents an Azure Data Disk mount on the host and bind mount to the pod.
azureDisk.diskName (string), required
diskName is the Name of the data disk in the blob storage
azureDisk.diskURI (string), required
diskURI is the URI of data disk in the blob storage
azureDisk.cachingMode (string)
cachingMode is the Host Caching mode: None, Read Only, Read Write.
azureDisk.fsType (string)
fsType is Filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
azureDisk.kind (string)
kind expected values are Shared: multiple blob disks per storage account Dedicated: single blob disk per storage account Managed: azure managed data disk (only in managed availability set). defaults to shared
azureDisk.readOnly (boolean)
readOnly Defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
azureFile (AzureFileVolumeSource)
azureFile represents an Azure File Service mount on the host and bind mount to the pod.
AzureFile represents an Azure File Service mount on the host and bind mount to the pod.
azureFile.secretName (string), required
secretName is the name of secret that contains Azure Storage Account Name and Key
azureFile.shareName (string), required
shareName is the azure share Name
azureFile.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
cephfs (CephFSVolumeSource)
cephFS represents a Ceph FS mount on the host that shares a pod's lifetime
Represents a Ceph Filesystem mount that lasts the lifetime of a pod Cephfs volumes do not support ownership management or SELinux relabeling.
Represents a cinder volume resource in Openstack. A Cinder volume must exist before mounting to a container. The volume must also be in the same region as the kubelet. Cinder volumes support ownership management and SELinux relabeling.
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://examples.k8s.io/mysql-cinder-pd/README.md
secretRef is optional: points to a secret object containing parameters used to connect to OpenStack.
csi (CSIVolumeSource)
csi (Container Storage Interface) represents ephemeral storage that is handled by certain external CSI drivers (Beta feature).
Represents a source location of a volume to mount, managed by an external CSI driver
csi.driver (string), required
driver is the name of the CSI driver that handles this volume. Consult with your admin for the correct name as registered in the cluster.
csi.fsType (string)
fsType to mount. Ex. "ext4", "xfs", "ntfs". If not provided, the empty value is passed to the associated CSI driver which will determine the default filesystem to apply.
nodePublishSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI NodePublishVolume and NodeUnpublishVolume calls. This field is optional, and may be empty if no secret is required. If the secret object contains more than one secret, all secret references are passed.
csi.readOnly (boolean)
readOnly specifies a read-only configuration for the volume. Defaults to false (read/write).
csi.volumeAttributes (map[string]string)
volumeAttributes stores driver-specific properties that are passed to the CSI driver. Consult your driver's documentation for supported values.
ephemeral (EphemeralVolumeSource)
ephemeral represents a volume that is handled by a cluster storage driver. The volume's lifecycle is tied to the pod that defines it - it will be created before the pod starts, and deleted when the pod is removed.
Use this if: a) the volume is only needed while the pod runs, b) features of normal volumes like restoring from snapshot or capacity
tracking are needed,
c) the storage driver is specified through a storage class, and d) the storage driver supports dynamic volume provisioning through
a PersistentVolumeClaim (see EphemeralVolumeSource for more
information on the connection between this volume type
and PersistentVolumeClaim).
Use PersistentVolumeClaim or one of the vendor-specific APIs for volumes that persist for longer than the lifecycle of an individual pod.
Use CSI for light-weight local ephemeral volumes if the CSI driver is meant to be used that way - see the documentation of the driver for more information.
A pod can use both types of ephemeral volumes and persistent volumes at the same time.
Represents an ephemeral volume that is handled by a normal storage driver.
Will be used to create a stand-alone PVC to provision the volume. The pod in which this EphemeralVolumeSource is embedded will be the owner of the PVC, i.e. the PVC will be deleted together with the pod. The name of the PVC will be \<pod name>-\<volume name> where \<volume name> is the name from the PodSpec.Volumes array entry. Pod validation will reject the pod if the concatenated name is not valid for a PVC (for example, too long).
An existing PVC with that name that is not owned by the pod will not be used for the pod to avoid using an unrelated volume by mistake. Starting the pod is then blocked until the unrelated PVC is removed. If such a pre-created PVC is meant to be used by the pod, the PVC has to updated with an owner reference to the pod once the pod exists. Normally this should not be necessary, but it may be useful when manually reconstructing a broken cluster.
This field is read-only and no changes will be made by Kubernetes to the PVC after it has been created.
Required, must not be nil.
PersistentVolumeClaimTemplate is used to produce PersistentVolumeClaim objects as part of an EphemeralVolumeSource.
The specification for the PersistentVolumeClaim. The entire content is copied unchanged into the PVC that gets created from this template. The same fields as in a PersistentVolumeClaim are also valid here.
May contain labels and annotations that will be copied into the PVC when creating it. No other fields are allowed and will be rejected during validation.
fc (FCVolumeSource)
fc represents a Fibre Channel resource that is attached to a kubelet's host machine and then exposed to the pod.
Represents a Fibre Channel volume. Fibre Channel volumes can only be mounted as read/write once. Fibre Channel volumes support ownership management and SELinux relabeling.
fc.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
fc.lun (int32)
lun is Optional: FC target lun number
fc.readOnly (boolean)
readOnly is Optional: Defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
fc.targetWWNs ([]string)
targetWWNs is Optional: FC target worldwide names (WWNs)
fc.wwids ([]string)
wwids Optional: FC volume world wide identifiers (wwids) Either wwids or combination of targetWWNs and lun must be set, but not both simultaneously.
flexVolume (FlexVolumeSource)
flexVolume represents a generic volume resource that is provisioned/attached using an exec based plugin.
FlexVolume represents a generic volume resource that is provisioned/attached using an exec based plugin.
flexVolume.driver (string), required
driver is the name of the driver to use for this volume.
flexVolume.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". The default filesystem depends on FlexVolume script.
flexVolume.options (map[string]string)
options is Optional: this field holds extra command options if any.
flexVolume.readOnly (boolean)
readOnly is Optional: defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
secretRef is Optional: secretRef is reference to the secret object containing sensitive information to pass to the plugin scripts. This may be empty if no secret object is specified. If the secret object contains more than one secret, all secrets are passed to the plugin scripts.
flocker (FlockerVolumeSource)
flocker represents a Flocker volume attached to a kubelet's host machine. This depends on the Flocker control service being running
Represents a Flocker volume mounted by the Flocker agent. One and only one of datasetName and datasetUUID should be set. Flocker volumes do not support ownership management or SELinux relabeling.
flocker.datasetName (string)
datasetName is Name of the dataset stored as metadata -> name on the dataset for Flocker should be considered as deprecated
flocker.datasetUUID (string)
datasetUUID is the UUID of the dataset. This is unique identifier of a Flocker dataset
*Represents a Persistent Disk resource in Google Compute Engine.
A GCE PD must exist before mounting to a container. The disk must also be in the same GCE project and zone as the kubelet. A GCE PD can only be mounted as read/write once or read-only many times. GCE PDs support ownership management and SELinux relabeling.*
fsType is filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#gcepersistentdisk
gcePersistentDisk.partition (int32)
partition is the partition in the volume that you want to mount. If omitted, the default is to mount by volume name. Examples: For volume /dev/sda1, you specify the partition as "1". Similarly, the volume partition for /dev/sda is "0" (or you can leave the property empty). More info: https://kubernetes.io/docs/concepts/storage/volumes#gcepersistentdisk
Represents an ISCSI disk. ISCSI volumes can only be mounted as read/write once. ISCSI volumes support ownership management and SELinux relabeling.
iscsi.iqn (string), required
iqn is the target iSCSI Qualified Name.
iscsi.lun (int32), required
lun represents iSCSI Target Lun number.
iscsi.targetPortal (string), required
targetPortal is iSCSI Target Portal. The Portal is either an IP or ip_addr:port if the port is other than default (typically TCP ports 860 and 3260).
iscsi.chapAuthDiscovery (boolean)
chapAuthDiscovery defines whether support iSCSI Discovery CHAP authentication
iscsi.chapAuthSession (boolean)
chapAuthSession defines whether support iSCSI Session CHAP authentication
iscsi.fsType (string)
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#iscsi
iscsi.initiatorName (string)
initiatorName is the custom iSCSI Initiator Name. If initiatorName is specified with iscsiInterface simultaneously, new iSCSI interface <target portal>:<volume name> will be created for the connection.
iscsi.iscsiInterface (string)
iscsiInterface is the interface Name that uses an iSCSI transport. Defaults to 'default' (tcp).
iscsi.portals ([]string)
portals is the iSCSI Target Portal List. The portal is either an IP or ip_addr:port if the port is other than default (typically TCP ports 860 and 3260).
iscsi.readOnly (boolean)
readOnly here will force the ReadOnly setting in VolumeMounts. Defaults to false.
photonPersistentDisk represents a PhotonController persistent disk attached and mounted on kubelets host machine
Represents a Photon Controller persistent disk resource.
photonPersistentDisk.pdID (string), required
pdID is the ID that identifies Photon Controller persistent disk
photonPersistentDisk.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
portworxVolume (PortworxVolumeSource)
portworxVolume represents a portworx volume attached and mounted on kubelets host machine
PortworxVolumeSource represents a Portworx volume resource.
portworxVolume.volumeID (string), required
volumeID uniquely identifies a Portworx volume
portworxVolume.fsType (string)
fSType represents the filesystem type to mount Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs". Implicitly inferred to be "ext4" if unspecified.
portworxVolume.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
quobyte (QuobyteVolumeSource)
quobyte represents a Quobyte mount on the host that shares a pod's lifetime
Represents a Quobyte mount that lasts the lifetime of a pod. Quobyte volumes do not support ownership management or SELinux relabeling.
quobyte.registry (string), required
registry represents a single or multiple Quobyte Registry services specified as a string as host:port pair (multiple entries are separated with commas) which acts as the central registry for volumes
quobyte.volume (string), required
volume is a string that references an already created Quobyte volume by name.
quobyte.group (string)
group to map volume access to Default is no group
quobyte.readOnly (boolean)
readOnly here will force the Quobyte volume to be mounted with read-only permissions. Defaults to false.
quobyte.tenant (string)
tenant owning the given Quobyte volume in the Backend Used with dynamically provisioned Quobyte volumes, value is set by the plugin
quobyte.user (string)
user to map volume access to Defaults to serivceaccount user
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#rbd
secretRef references to the secret for ScaleIO user and other sensitive information. If this is not provided, Login operation will fail.
scaleIO.system (string), required
system is the name of the storage system as configured in ScaleIO.
scaleIO.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Default is "xfs".
scaleIO.protectionDomain (string)
protectionDomain is the name of the ScaleIO Protection Domain for the configured storage.
scaleIO.readOnly (boolean)
readOnly Defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
scaleIO.sslEnabled (boolean)
sslEnabled Flag enable/disable SSL communication with Gateway, default false
scaleIO.storageMode (string)
storageMode indicates whether the storage for a volume should be ThickProvisioned or ThinProvisioned. Default is ThinProvisioned.
scaleIO.storagePool (string)
storagePool is the ScaleIO Storage Pool associated with the protection domain.
scaleIO.volumeName (string)
volumeName is the name of a volume already created in the ScaleIO system that is associated with this volume source.
storageos (StorageOSVolumeSource)
storageOS represents a StorageOS volume attached and mounted on Kubernetes nodes.
Represents a StorageOS persistent volume resource.
storageos.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
storageos.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
secretRef specifies the secret to use for obtaining the StorageOS API credentials. If not specified, default values will be attempted.
storageos.volumeName (string)
volumeName is the human-readable name of the StorageOS volume. Volume names are only unique within a namespace.
storageos.volumeNamespace (string)
volumeNamespace specifies the scope of the volume within StorageOS. If no namespace is specified then the Pod's namespace will be used. This allows the Kubernetes name scoping to be mirrored within StorageOS for tighter integration. Set VolumeName to any name to override the default behaviour. Set to "default" if you are not using namespaces within StorageOS. Namespaces that do not pre-exist within StorageOS will be created.
vsphereVolume (VsphereVirtualDiskVolumeSource)
vsphereVolume represents a vSphere volume attached and mounted on kubelets host machine
Represents a vSphere volume resource.
vsphereVolume.volumePath (string), required
volumePath is the path that identifies vSphere volume vmdk
vsphereVolume.fsType (string)
fsType is filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
vsphereVolume.storagePolicyID (string)
storagePolicyID is the storage Policy Based Management (SPBM) profile ID associated with the StoragePolicyName.
vsphereVolume.storagePolicyName (string)
storagePolicyName is the storage Policy Based Management (SPBM) profile name.
Deprecated
gitRepo (GitRepoVolumeSource)
gitRepo represents a git repository at a particular revision. DEPRECATED: GitRepo is deprecated. To provision a container with a git repo, mount an EmptyDir into an InitContainer that clones the repo using git, then mount the EmptyDir into the Pod's container.
*Represents a volume that is populated with the contents of a git repository. Git repo volumes do not support ownership management. Git repo volumes support SELinux relabeling.
DEPRECATED: GitRepo is deprecated. To provision a container with a git repo, mount an EmptyDir into an InitContainer that clones the repo using git, then mount the EmptyDir into the Pod's container.*
gitRepo.repository (string), required
repository is the URL
gitRepo.directory (string)
directory is the target directory name. Must not contain or start with '..'. If '.' is supplied, the volume directory will be the git repository. Otherwise, if specified, the volume will contain the git repository in the subdirectory with the given name.
gitRepo.revision (string)
revision is the commit hash for the specified revision.
DownwardAPIVolumeFile
DownwardAPIVolumeFile represents information to create the file containing the pod field
path (string), required
Required: Path is the relative path name of the file to be created. Must not be absolute or contain the '..' path. Must be utf-8 encoded. The first item of the relative path must not start with '..'
Required: Selects a field of the pod: only annotations, labels, name and namespace are supported.
mode (int32)
Optional: mode bits used to set permissions on this file, must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. If not specified, the volume defaultMode will be used. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
Selects a resource of the container: only resources limits and requests (limits.cpu, limits.memory, requests.cpu and requests.memory) are currently supported.
KeyToPath
Maps a string key to a path within a volume.
key (string), required
key is the key to project.
path (string), required
path is the relative path of the file to map the key to. May not be an absolute path. May not contain the path element '..'. May not start with the string '..'.
mode (int32)
mode is Optional: mode bits used to set permissions on this file. Must be an octal value between 0000 and 0777 or a decimal value between 0 and 511. YAML accepts both octal and decimal values, JSON requires decimal values for mode bits. If not specified, the volume defaultMode will be used. This might be in conflict with other options that affect the file mode, like fsGroup, and the result can be other mode bits set.
5.3.4 - PersistentVolumeClaim
PersistentVolumeClaim is a user's request for and claim to a persistent volume.
apiVersion: v1
import "k8s.io/api/core/v1"
PersistentVolumeClaim
PersistentVolumeClaim is a user's request for and claim to a persistent volume
selector is a label query over volumes to consider for binding.
resources (ResourceRequirements)
resources represents the minimum resources the volume should have. If RecoverVolumeExpansionFailure feature is enabled users are allowed to specify resource requirements that are lower than previous value but must still be higher than capacity recorded in the status field of the claim. More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes#resources
ResourceRequirements describes the compute resource requirements.
resources.claims ([]ResourceClaim)
Map: unique values on key name will be kept during a merge
Claims lists the names of resources, defined in spec.resourceClaims, that are used by this container.
This is an alpha field and requires enabling the DynamicResourceAllocation feature gate.
This field is immutable. It can only be set for containers.
ResourceClaim references one entry in PodSpec.ResourceClaims.
resources.claims.name (string), required
Name must match the name of one entry in pod.spec.resourceClaims of the Pod where this field is used. It makes that resource available inside a container.
Requests describes the minimum amount of compute resources required. If Requests is omitted for a container, it defaults to Limits if that is explicitly specified, otherwise to an implementation-defined value. Requests cannot exceed Limits. More info: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
volumeName (string)
volumeName is the binding reference to the PersistentVolume backing this claim.
dataSource field can be used to specify either: * An existing VolumeSnapshot object (snapshot.storage.k8s.io/VolumeSnapshot) * An existing PVC (PersistentVolumeClaim) If the provisioner or an external controller can support the specified data source, it will create a new volume based on the contents of the specified data source. When the AnyVolumeDataSource feature gate is enabled, dataSource contents will be copied to dataSourceRef, and dataSourceRef contents will be copied to dataSource when dataSourceRef.namespace is not specified. If the namespace is specified, then dataSourceRef will not be copied to dataSource.
dataSourceRef (TypedObjectReference)
dataSourceRef specifies the object from which to populate the volume with data, if a non-empty volume is desired. This may be any object from a non-empty API group (non core object) or a PersistentVolumeClaim object. When this field is specified, volume binding will only succeed if the type of the specified object matches some installed volume populator or dynamic provisioner. This field will replace the functionality of the dataSource field and as such if both fields are non-empty, they must have the same value. For backwards compatibility, when namespace isn't specified in dataSourceRef, both fields (dataSource and dataSourceRef) will be set to the same value automatically if one of them is empty and the other is non-empty. When namespace is specified in dataSourceRef, dataSource isn't set to the same value and must be empty. There are three important differences between dataSource and dataSourceRef: * While dataSource only allows two specific types of objects, dataSourceRef
allows any non-core object, as well as PersistentVolumeClaim objects.
While dataSource ignores disallowed values (dropping them), dataSourceRef
preserves all values, and generates an error if a disallowed value is
specified.
While dataSource only allows local objects, dataSourceRef allows objects
in any namespaces.
(Beta) Using this field requires the AnyVolumeDataSource feature gate to be enabled. (Alpha) Using the namespace field of dataSourceRef requires the CrossNamespaceVolumeDataSource feature gate to be enabled.
**
dataSourceRef.kind (string), required
Kind is the type of resource being referenced
dataSourceRef.name (string), required
Name is the name of resource being referenced
dataSourceRef.apiGroup (string)
APIGroup is the group for the resource being referenced. If APIGroup is not specified, the specified Kind must be in the core API group. For any other third-party types, APIGroup is required.
dataSourceRef.namespace (string)
Namespace is the namespace of resource being referenced Note that when a namespace is specified, a gateway.networking.k8s.io/ReferenceGrant object is required in the referent namespace to allow that namespace's owner to accept the reference. See the ReferenceGrant documentation for details. (Alpha) This field requires the CrossNamespaceVolumeDataSource feature gate to be enabled.
PersistentVolumeClaimStatus
PersistentVolumeClaimStatus is the current status of a persistent volume claim.
allocatedResourceStatuses stores status of resource being resized for the given PVC. Key names follow standard Kubernetes label syntax. Valid values are either:
* Un-prefixed keys:
- storage - the capacity of the volume.
* Custom resources must use implementation-defined prefixed names such as "example.com/my-custom-resource"
Apart from above values - keys that are unprefixed or have kubernetes.io prefix are considered reserved and hence may not be used.
ClaimResourceStatus can be in any of following states:
- ControllerResizeInProgress:
State set when resize controller starts resizing the volume in control-plane.
- ControllerResizeFailed:
State set when resize has failed in resize controller with a terminal error.
- NodeResizePending:
State set when resize controller has finished resizing the volume but further resizing of
volume is needed on the node.
- NodeResizeInProgress:
State set when kubelet starts resizing the volume.
- NodeResizeFailed:
State set when resizing has failed in kubelet with a terminal error. Transient errors don't set
NodeResizeFailed.
For example: if expanding a PVC for more capacity - this field can be one of the following states:
- pvc.status.allocatedResourceStatus['storage'] = "ControllerResizeInProgress"
- pvc.status.allocatedResourceStatus['storage'] = "ControllerResizeFailed"
- pvc.status.allocatedResourceStatus['storage'] = "NodeResizePending"
- pvc.status.allocatedResourceStatus['storage'] = "NodeResizeInProgress"
- pvc.status.allocatedResourceStatus['storage'] = "NodeResizeFailed"
When this field is not set, it means that no resize operation is in progress for the given PVC.
A controller that receives PVC update with previously unknown resourceName or ClaimResourceStatus should ignore the update for the purpose it was designed. For example - a controller that only is responsible for resizing capacity of the volume, should ignore PVC updates that change other valid resources associated with PVC.
This is an alpha field and requires enabling RecoverVolumeExpansionFailure feature.
allocatedResources tracks the resources allocated to a PVC including its capacity. Key names follow standard Kubernetes label syntax. Valid values are either:
* Un-prefixed keys:
- storage - the capacity of the volume.
* Custom resources must use implementation-defined prefixed names such as "example.com/my-custom-resource"
Apart from above values - keys that are unprefixed or have kubernetes.io prefix are considered reserved and hence may not be used.
Capacity reported here may be larger than the actual capacity when a volume expansion operation is requested. For storage quota, the larger value from allocatedResources and PVC.spec.resources is used. If allocatedResources is not set, PVC.spec.resources alone is used for quota calculation. If a volume expansion capacity request is lowered, allocatedResources is only lowered if there are no expansion operations in progress and if the actual volume capacity is equal or lower than the requested capacity.
A controller that receives PVC update with previously unknown resourceName should ignore the update for the purpose it was designed. For example - a controller that only is responsible for resizing capacity of the volume, should ignore PVC updates that change other valid resources associated with PVC.
This is an alpha field and requires enabling RecoverVolumeExpansionFailure feature.
capacity represents the actual resources of the underlying volume.
conditions ([]PersistentVolumeClaimCondition)
Patch strategy: merge on key type
conditions is the current Condition of persistent volume claim. If underlying persistent volume is being resized then the Condition will be set to 'ResizeStarted'.
PersistentVolumeClaimCondition contains details about state of pvc
conditions.status (string), required
conditions.type (string), required
conditions.lastProbeTime (Time)
lastProbeTime is the time we probed the condition.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastTransitionTime (Time)
lastTransitionTime is the time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message is the human-readable message indicating details about last transition.
conditions.reason (string)
reason is a unique, this should be a short, machine understandable string that gives the reason for condition's last transition. If it reports "ResizeStarted" that means the underlying persistent volume is being resized.
phase (string)
phase represents the current phase of PersistentVolumeClaim.
PersistentVolumeClaimList
PersistentVolumeClaimList is a list of PersistentVolumeClaim items.
nodeAffinity defines constraints that limit what nodes this volume can be accessed from. This field influences the scheduling of pods that use this volume.
VolumeNodeAffinity defines constraints that limit what nodes this volume can be accessed from.
nodeAffinity.required (NodeSelector)
required specifies hard node constraints that must be met.
A node selector represents the union of the results of one or more label queries over a set of nodes; that is, it represents the OR of the selectors represented by the node selector terms.
Required. A list of node selector terms. The terms are ORed.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
A list of node selector requirements by node's fields.
persistentVolumeReclaimPolicy (string)
persistentVolumeReclaimPolicy defines what happens to a persistent volume when released from its claim. Valid options are Retain (default for manually created PersistentVolumes), Delete (default for dynamically provisioned PersistentVolumes), and Recycle (deprecated). Recycle must be supported by the volume plugin underlying this PersistentVolume. More info: https://kubernetes.io/docs/concepts/storage/persistent-volumes#reclaiming
storageClassName (string)
storageClassName is the name of StorageClass to which this persistent volume belongs. Empty value means that this volume does not belong to any StorageClass.
volumeMode (string)
volumeMode defines if a volume is intended to be used with a formatted filesystem or to remain in raw block state. Value of Filesystem is implied when not included in spec.
Local
hostPath (HostPathVolumeSource)
hostPath represents a directory on the host. Provisioned by a developer or tester. This is useful for single-node development and testing only! On-host storage is not supported in any way and WILL NOT WORK in a multi-node cluster. More info: https://kubernetes.io/docs/concepts/storage/volumes#hostpath
Represents a host path mapped into a pod. Host path volumes do not support ownership management or SELinux relabeling.
local represents directly-attached storage with node affinity
Local represents directly-attached storage with node affinity (Beta feature)
local.path (string), required
path of the full path to the volume on the node. It can be either a directory or block device (disk, partition, ...).
local.fsType (string)
fsType is the filesystem type to mount. It applies only when the Path is a block device. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". The default value is to auto-select a filesystem if unspecified.
An AWS EBS disk must exist before mounting to a container. The disk must also be in the same AWS zone as the kubelet. An AWS EBS disk can only be mounted as read/write once. AWS EBS volumes support ownership management and SELinux relabeling.*
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#awselasticblockstore
awsElasticBlockStore.partition (int32)
partition is the partition in the volume that you want to mount. If omitted, the default is to mount by volume name. Examples: For volume /dev/sda1, you specify the partition as "1". Similarly, the volume partition for /dev/sda is "0" (or you can leave the property empty).
azureDisk represents an Azure Data Disk mount on the host and bind mount to the pod.
AzureDisk represents an Azure Data Disk mount on the host and bind mount to the pod.
azureDisk.diskName (string), required
diskName is the Name of the data disk in the blob storage
azureDisk.diskURI (string), required
diskURI is the URI of data disk in the blob storage
azureDisk.cachingMode (string)
cachingMode is the Host Caching mode: None, Read Only, Read Write.
azureDisk.fsType (string)
fsType is Filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
azureDisk.kind (string)
kind expected values are Shared: multiple blob disks per storage account Dedicated: single blob disk per storage account Managed: azure managed data disk (only in managed availability set). defaults to shared
azureDisk.readOnly (boolean)
readOnly Defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
azureFile (AzureFilePersistentVolumeSource)
azureFile represents an Azure File Service mount on the host and bind mount to the pod.
AzureFile represents an Azure File Service mount on the host and bind mount to the pod.
azureFile.secretName (string), required
secretName is the name of secret that contains Azure Storage Account Name and Key
azureFile.shareName (string), required
shareName is the azure Share Name
azureFile.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
azureFile.secretNamespace (string)
secretNamespace is the namespace of the secret that contains Azure Storage Account Name and Key default is the same as the Pod
cephfs (CephFSPersistentVolumeSource)
cephFS represents a Ceph FS mount on the host that shares a pod's lifetime
Represents a Ceph Filesystem mount that lasts the lifetime of a pod Cephfs volumes do not support ownership management or SELinux relabeling.
Represents a cinder volume resource in Openstack. A Cinder volume must exist before mounting to a container. The volume must also be in the same region as the kubelet. Cinder volumes support ownership management and SELinux relabeling.
fsType Filesystem type to mount. Must be a filesystem type supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://examples.k8s.io/mysql-cinder-pd/README.md
secretRef is Optional: points to a secret object containing parameters used to connect to OpenStack.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
cinder.secretRef.name (string)
name is unique within a namespace to reference a secret resource.
cinder.secretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi (CSIPersistentVolumeSource)
csi represents storage that is handled by an external CSI driver (Beta feature).
Represents storage that is managed by an external CSI volume driver (Beta feature)
csi.driver (string), required
driver is the name of the driver to use for this volume. Required.
csi.volumeHandle (string), required
volumeHandle is the unique volume name returned by the CSI volume plugin’s CreateVolume to refer to the volume on all subsequent calls. Required.
csi.controllerExpandSecretRef (SecretReference)
controllerExpandSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI ControllerExpandVolume call. This field is optional, and may be empty if no secret is required. If the secret object contains more than one secret, all secrets are passed.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
csi.controllerExpandSecretRef.name (string)
name is unique within a namespace to reference a secret resource.
csi.controllerExpandSecretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi.controllerPublishSecretRef (SecretReference)
controllerPublishSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI ControllerPublishVolume and ControllerUnpublishVolume calls. This field is optional, and may be empty if no secret is required. If the secret object contains more than one secret, all secrets are passed.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
csi.controllerPublishSecretRef.name (string)
name is unique within a namespace to reference a secret resource.
csi.controllerPublishSecretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi.fsType (string)
fsType to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs".
csi.nodeExpandSecretRef (SecretReference)
nodeExpandSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI NodeExpandVolume call. This is a beta field which is enabled default by CSINodeExpandSecret feature gate. This field is optional, may be omitted if no secret is required. If the secret object contains more than one secret, all secrets are passed.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
csi.nodeExpandSecretRef.name (string)
name is unique within a namespace to reference a secret resource.
csi.nodeExpandSecretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi.nodePublishSecretRef (SecretReference)
nodePublishSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI NodePublishVolume and NodeUnpublishVolume calls. This field is optional, and may be empty if no secret is required. If the secret object contains more than one secret, all secrets are passed.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
csi.nodePublishSecretRef.name (string)
name is unique within a namespace to reference a secret resource.
csi.nodePublishSecretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi.nodeStageSecretRef (SecretReference)
nodeStageSecretRef is a reference to the secret object containing sensitive information to pass to the CSI driver to complete the CSI NodeStageVolume and NodeStageVolume and NodeUnstageVolume calls. This field is optional, and may be empty if no secret is required. If the secret object contains more than one secret, all secrets are passed.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
csi.nodeStageSecretRef.name (string)
name is unique within a namespace to reference a secret resource.
csi.nodeStageSecretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
csi.readOnly (boolean)
readOnly value to pass to ControllerPublishVolumeRequest. Defaults to false (read/write).
csi.volumeAttributes (map[string]string)
volumeAttributes of the volume to publish.
fc (FCVolumeSource)
fc represents a Fibre Channel resource that is attached to a kubelet's host machine and then exposed to the pod.
Represents a Fibre Channel volume. Fibre Channel volumes can only be mounted as read/write once. Fibre Channel volumes support ownership management and SELinux relabeling.
fc.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
fc.lun (int32)
lun is Optional: FC target lun number
fc.readOnly (boolean)
readOnly is Optional: Defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
fc.targetWWNs ([]string)
targetWWNs is Optional: FC target worldwide names (WWNs)
fc.wwids ([]string)
wwids Optional: FC volume world wide identifiers (wwids) Either wwids or combination of targetWWNs and lun must be set, but not both simultaneously.
flexVolume (FlexPersistentVolumeSource)
flexVolume represents a generic volume resource that is provisioned/attached using an exec based plugin.
FlexPersistentVolumeSource represents a generic persistent volume resource that is provisioned/attached using an exec based plugin.
flexVolume.driver (string), required
driver is the name of the driver to use for this volume.
flexVolume.fsType (string)
fsType is the Filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". The default filesystem depends on FlexVolume script.
flexVolume.options (map[string]string)
options is Optional: this field holds extra command options if any.
flexVolume.readOnly (boolean)
readOnly is Optional: defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
flexVolume.secretRef (SecretReference)
secretRef is Optional: SecretRef is reference to the secret object containing sensitive information to pass to the plugin scripts. This may be empty if no secret object is specified. If the secret object contains more than one secret, all secrets are passed to the plugin scripts.
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
flexVolume.secretRef.name (string)
name is unique within a namespace to reference a secret resource.
flexVolume.secretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
flocker (FlockerVolumeSource)
flocker represents a Flocker volume attached to a kubelet's host machine and exposed to the pod for its usage. This depends on the Flocker control service being running
Represents a Flocker volume mounted by the Flocker agent. One and only one of datasetName and datasetUUID should be set. Flocker volumes do not support ownership management or SELinux relabeling.
flocker.datasetName (string)
datasetName is Name of the dataset stored as metadata -> name on the dataset for Flocker should be considered as deprecated
flocker.datasetUUID (string)
datasetUUID is the UUID of the dataset. This is unique identifier of a Flocker dataset
*Represents a Persistent Disk resource in Google Compute Engine.
A GCE PD must exist before mounting to a container. The disk must also be in the same GCE project and zone as the kubelet. A GCE PD can only be mounted as read/write once or read-only many times. GCE PDs support ownership management and SELinux relabeling.*
fsType is filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#gcepersistentdisk
gcePersistentDisk.partition (int32)
partition is the partition in the volume that you want to mount. If omitted, the default is to mount by volume name. Examples: For volume /dev/sda1, you specify the partition as "1". Similarly, the volume partition for /dev/sda is "0" (or you can leave the property empty). More info: https://kubernetes.io/docs/concepts/storage/volumes#gcepersistentdisk
iscsi represents an ISCSI Disk resource that is attached to a kubelet's host machine and then exposed to the pod. Provisioned by an admin.
ISCSIPersistentVolumeSource represents an ISCSI disk. ISCSI volumes can only be mounted as read/write once. ISCSI volumes support ownership management and SELinux relabeling.
iscsi.iqn (string), required
iqn is Target iSCSI Qualified Name.
iscsi.lun (int32), required
lun is iSCSI Target Lun number.
iscsi.targetPortal (string), required
targetPortal is iSCSI Target Portal. The Portal is either an IP or ip_addr:port if the port is other than default (typically TCP ports 860 and 3260).
iscsi.chapAuthDiscovery (boolean)
chapAuthDiscovery defines whether support iSCSI Discovery CHAP authentication
iscsi.chapAuthSession (boolean)
chapAuthSession defines whether support iSCSI Session CHAP authentication
iscsi.fsType (string)
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#iscsi
iscsi.initiatorName (string)
initiatorName is the custom iSCSI Initiator Name. If initiatorName is specified with iscsiInterface simultaneously, new iSCSI interface <target portal>:<volume name> will be created for the connection.
iscsi.iscsiInterface (string)
iscsiInterface is the interface Name that uses an iSCSI transport. Defaults to 'default' (tcp).
iscsi.portals ([]string)
portals is the iSCSI Target Portal List. The Portal is either an IP or ip_addr:port if the port is other than default (typically TCP ports 860 and 3260).
iscsi.readOnly (boolean)
readOnly here will force the ReadOnly setting in VolumeMounts. Defaults to false.
iscsi.secretRef (SecretReference)
secretRef is the CHAP Secret for iSCSI target and initiator authentication
SecretReference represents a Secret Reference. It has enough information to retrieve secret in any namespace
iscsi.secretRef.name (string)
name is unique within a namespace to reference a secret resource.
iscsi.secretRef.namespace (string)
namespace defines the space within which the secret name must be unique.
photonPersistentDisk represents a PhotonController persistent disk attached and mounted on kubelets host machine
Represents a Photon Controller persistent disk resource.
photonPersistentDisk.pdID (string), required
pdID is the ID that identifies Photon Controller persistent disk
photonPersistentDisk.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
portworxVolume (PortworxVolumeSource)
portworxVolume represents a portworx volume attached and mounted on kubelets host machine
PortworxVolumeSource represents a Portworx volume resource.
portworxVolume.volumeID (string), required
volumeID uniquely identifies a Portworx volume
portworxVolume.fsType (string)
fSType represents the filesystem type to mount Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs". Implicitly inferred to be "ext4" if unspecified.
portworxVolume.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
quobyte (QuobyteVolumeSource)
quobyte represents a Quobyte mount on the host that shares a pod's lifetime
Represents a Quobyte mount that lasts the lifetime of a pod. Quobyte volumes do not support ownership management or SELinux relabeling.
quobyte.registry (string), required
registry represents a single or multiple Quobyte Registry services specified as a string as host:port pair (multiple entries are separated with commas) which acts as the central registry for volumes
quobyte.volume (string), required
volume is a string that references an already created Quobyte volume by name.
quobyte.group (string)
group to map volume access to Default is no group
quobyte.readOnly (boolean)
readOnly here will force the Quobyte volume to be mounted with read-only permissions. Defaults to false.
quobyte.tenant (string)
tenant owning the given Quobyte volume in the Backend Used with dynamically provisioned Quobyte volumes, value is set by the plugin
quobyte.user (string)
user to map volume access to Defaults to serivceaccount user
fsType is the filesystem type of the volume that you want to mount. Tip: Ensure that the filesystem type is supported by the host operating system. Examples: "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified. More info: https://kubernetes.io/docs/concepts/storage/volumes#rbd
Represents a StorageOS persistent volume resource.
storageos.fsType (string)
fsType is the filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
storageos.readOnly (boolean)
readOnly defaults to false (read/write). ReadOnly here will force the ReadOnly setting in VolumeMounts.
secretRef specifies the secret to use for obtaining the StorageOS API credentials. If not specified, default values will be attempted.
storageos.volumeName (string)
volumeName is the human-readable name of the StorageOS volume. Volume names are only unique within a namespace.
storageos.volumeNamespace (string)
volumeNamespace specifies the scope of the volume within StorageOS. If no namespace is specified then the Pod's namespace will be used. This allows the Kubernetes name scoping to be mirrored within StorageOS for tighter integration. Set VolumeName to any name to override the default behaviour. Set to "default" if you are not using namespaces within StorageOS. Namespaces that do not pre-exist within StorageOS will be created.
vsphereVolume (VsphereVirtualDiskVolumeSource)
vsphereVolume represents a vSphere volume attached and mounted on kubelets host machine
Represents a vSphere volume resource.
vsphereVolume.volumePath (string), required
volumePath is the path that identifies vSphere volume vmdk
vsphereVolume.fsType (string)
fsType is filesystem type to mount. Must be a filesystem type supported by the host operating system. Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
vsphereVolume.storagePolicyID (string)
storagePolicyID is the storage Policy Based Management (SPBM) profile ID associated with the StoragePolicyName.
vsphereVolume.storagePolicyName (string)
storagePolicyName is the storage Policy Based Management (SPBM) profile name.
PersistentVolumeStatus
PersistentVolumeStatus is the current status of a persistent volume.
lastPhaseTransitionTime (Time)
lastPhaseTransitionTime is the time the phase transitioned from one to another and automatically resets to current time everytime a volume phase transitions. This is an alpha field and requires enabling PersistentVolumeLastPhaseTransitionTime feature.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
message (string)
message is a human-readable message indicating details about why the volume is in this state.
provisioner indicates the type of the provisioner.
allowVolumeExpansion (boolean)
allowVolumeExpansion shows whether the storage class allow volume expand.
allowedTopologies ([]TopologySelectorTerm)
Atomic: will be replaced during a merge
allowedTopologies restrict the node topologies where volumes can be dynamically provisioned. Each volume plugin defines its own supported topology specifications. An empty TopologySelectorTerm list means there is no topology restriction. This field is only honored by servers that enable the VolumeScheduling feature.
A topology selector term represents the result of label queries. A null or empty topology selector term matches no objects. The requirements of them are ANDed. It provides a subset of functionality as NodeSelectorTerm. This is an alpha feature and may change in the future.
An array of string values. One value must match the label to be selected. Each entry in Values is ORed.
mountOptions ([]string)
mountOptions controls the mountOptions for dynamically provisioned PersistentVolumes of this storage class. e.g. ["ro", "soft"]. Not validated - mount of the PVs will simply fail if one is invalid.
parameters (map[string]string)
parameters holds the parameters for the provisioner that should create volumes of this storage class.
reclaimPolicy (string)
reclaimPolicy controls the reclaimPolicy for dynamically provisioned PersistentVolumes of this storage class. Defaults to Delete.
volumeBindingMode (string)
volumeBindingMode indicates how PersistentVolumeClaims should be provisioned and bound. When unset, VolumeBindingImmediate is used. This field is only honored by servers that enable the VolumeScheduling feature.
StorageClassList
StorageClassList is a collection of storage classes.
status represents status of the VolumeAttachment request. Populated by the entity completing the attach or detach operation, i.e. the external-attacher.
VolumeAttachmentSpec
VolumeAttachmentSpec is the specification of a VolumeAttachment request.
attacher (string), required
attacher indicates the name of the volume driver that MUST handle this request. This is the name returned by GetPluginName().
nodeName (string), required
nodeName represents the node that the volume should be attached to.
source (VolumeAttachmentSource), required
source represents the volume that should be attached.
VolumeAttachmentSource represents a volume that should be attached. Right now only PersistenVolumes can be attached via external attacher, in future we may allow also inline volumes in pods. Exactly one member can be set.
inlineVolumeSpec contains all the information necessary to attach a persistent volume defined by a pod's inline VolumeSource. This field is populated only for the CSIMigration feature. It contains translated fields from a pod's inline VolumeSource to a PersistentVolumeSpec. This field is beta-level and is only honored by servers that enabled the CSIMigration feature.
source.persistentVolumeName (string)
persistentVolumeName represents the name of the persistent volume to attach.
VolumeAttachmentStatus
VolumeAttachmentStatus is the status of a VolumeAttachment request.
attached (boolean), required
attached indicates the volume is successfully attached. This field must only be set by the entity completing the attach operation, i.e. the external-attacher.
attachError (VolumeError)
attachError represents the last error encountered during attach operation, if any. This field must only be set by the entity completing the attach operation, i.e. the external-attacher.
VolumeError captures an error encountered during a volume operation.
attachError.message (string)
message represents the error encountered during Attach or Detach operation. This string may be logged, so it should not contain sensitive information.
attachError.time (Time)
time represents the time the error was encountered.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
attachmentMetadata (map[string]string)
attachmentMetadata is populated with any information returned by the attach operation, upon successful attach, that must be passed into subsequent WaitForAttach or Mount calls. This field must only be set by the entity completing the attach operation, i.e. the external-attacher.
detachError (VolumeError)
detachError represents the last error encountered during detach operation, if any. This field must only be set by the entity completing the detach operation, i.e. the external-attacher.
VolumeError captures an error encountered during a volume operation.
detachError.message (string)
message represents the error encountered during Attach or Detach operation. This string may be logged, so it should not contain sensitive information.
detachError.time (Time)
time represents the time the error was encountered.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
VolumeAttachmentList
VolumeAttachmentList is a collection of VolumeAttachment objects.
CSIDriver captures information about a Container Storage Interface (CSI) volume driver deployed on the cluster.
apiVersion: storage.k8s.io/v1
import "k8s.io/api/storage/v1"
CSIDriver
CSIDriver captures information about a Container Storage Interface (CSI) volume driver deployed on the cluster. Kubernetes attach detach controller uses this object to determine whether attach is required. Kubelet uses this object to determine whether pod information needs to be passed on mount. CSIDriver objects are non-namespaced.
Standard object metadata. metadata.Name indicates the name of the CSI driver that this object refers to; it MUST be the same name returned by the CSI GetPluginName() call for that driver. The driver name must be 63 characters or less, beginning and ending with an alphanumeric character ([a-z0-9A-Z]) with dashes (-), dots (.), and alphanumerics between. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
spec represents the specification of the CSI Driver.
CSIDriverSpec
CSIDriverSpec is the specification of a CSIDriver.
attachRequired (boolean)
attachRequired indicates this CSI volume driver requires an attach operation (because it implements the CSI ControllerPublishVolume() method), and that the Kubernetes attach detach controller should call the attach volume interface which checks the volumeattachment status and waits until the volume is attached before proceeding to mounting. The CSI external-attacher coordinates with CSI volume driver and updates the volumeattachment status when the attach operation is complete. If the CSIDriverRegistry feature gate is enabled and the value is specified to false, the attach operation will be skipped. Otherwise the attach operation will be called.
This field is immutable.
fsGroupPolicy (string)
fsGroupPolicy defines if the underlying volume supports changing ownership and permission of the volume before being mounted. Refer to the specific FSGroupPolicy values for additional details.
This field is immutable.
Defaults to ReadWriteOnceWithFSType, which will examine each volume to determine if Kubernetes should modify ownership and permissions of the volume. With the default policy the defined fsGroup will only be applied if a fstype is defined and the volume's access mode contains ReadWriteOnce.
podInfoOnMount (boolean)
podInfoOnMount indicates this CSI volume driver requires additional pod information (like podName, podUID, etc.) during mount operations, if set to true. If set to false, pod information will not be passed on mount. Default is false.
The CSI driver specifies podInfoOnMount as part of driver deployment. If true, Kubelet will pass pod information as VolumeContext in the CSI NodePublishVolume() calls. The CSI driver is responsible for parsing and validating the information passed in as VolumeContext.
The following VolumeConext will be passed if podInfoOnMount is set to true. This list might grow, but the prefix will be used. "csi.storage.k8s.io/pod.name": pod.Name "csi.storage.k8s.io/pod.namespace": pod.Namespace "csi.storage.k8s.io/pod.uid": string(pod.UID) "csi.storage.k8s.io/ephemeral": "true" if the volume is an ephemeral inline volume
defined by a CSIVolumeSource, otherwise "false"
"csi.storage.k8s.io/ephemeral" is a new feature in Kubernetes 1.16. It is only required for drivers which support both the "Persistent" and "Ephemeral" VolumeLifecycleMode. Other drivers can leave pod info disabled and/or ignore this field. As Kubernetes 1.15 doesn't support this field, drivers can only support one mode when deployed on such a cluster and the deployment determines which mode that is, for example via a command line parameter of the driver.
This field is immutable.
requiresRepublish (boolean)
requiresRepublish indicates the CSI driver wants NodePublishVolume being periodically called to reflect any possible change in the mounted volume. This field defaults to false.
Note: After a successful initial NodePublishVolume call, subsequent calls to NodePublishVolume should only update the contents of the volume. New mount points will not be seen by a running container.
seLinuxMount (boolean)
seLinuxMount specifies if the CSI driver supports "-o context" mount option.
When "true", the CSI driver must ensure that all volumes provided by this CSI driver can be mounted separately with different -o context options. This is typical for storage backends that provide volumes as filesystems on block devices or as independent shared volumes. Kubernetes will call NodeStage / NodePublish with "-o context=xyz" mount option when mounting a ReadWriteOncePod volume used in Pod that has explicitly set SELinux context. In the future, it may be expanded to other volume AccessModes. In any case, Kubernetes will ensure that the volume is mounted only with a single SELinux context.
When "false", Kubernetes won't pass any special SELinux mount options to the driver. This is typical for volumes that represent subdirectories of a bigger shared filesystem.
Default is "false".
storageCapacity (boolean)
storageCapacity indicates that the CSI volume driver wants pod scheduling to consider the storage capacity that the driver deployment will report by creating CSIStorageCapacity objects with capacity information, if set to true.
The check can be enabled immediately when deploying a driver. In that case, provisioning new volumes with late binding will pause until the driver deployment has published some suitable CSIStorageCapacity object.
Alternatively, the driver can be deployed with the field unset or false and it can be flipped later when storage capacity information has been published.
This field was immutable in Kubernetes <= 1.22 and now is mutable.
tokenRequests ([]TokenRequest)
Atomic: will be replaced during a merge
tokenRequests indicates the CSI driver needs pods' service account tokens it is mounting volume for to do necessary authentication. Kubelet will pass the tokens in VolumeContext in the CSI NodePublishVolume calls. The CSI driver should parse and validate the following VolumeContext: "csi.storage.k8s.io/serviceAccount.tokens": {
"<audience>": {
"token": <token>,
"expirationTimestamp": <expiration timestamp in RFC3339>,
},
...
}
Note: Audience in each TokenRequest should be different and at most one token is empty string. To receive a new token after expiry, RequiresRepublish can be used to trigger NodePublishVolume periodically.
TokenRequest contains parameters of a service account token.
tokenRequests.audience (string), required
audience is the intended audience of the token in "TokenRequestSpec". It will default to the audiences of kube apiserver.
tokenRequests.expirationSeconds (int64)
expirationSeconds is the duration of validity of the token in "TokenRequestSpec". It has the same default value of "ExpirationSeconds" in "TokenRequestSpec".
volumeLifecycleModes ([]string)
Set: unique values will be kept during a merge
volumeLifecycleModes defines what kind of volumes this CSI volume driver supports. The default if the list is empty is "Persistent", which is the usage defined by the CSI specification and implemented in Kubernetes via the usual PV/PVC mechanism.
The other mode is "Ephemeral". In this mode, volumes are defined inline inside the pod spec with CSIVolumeSource and their lifecycle is tied to the lifecycle of that pod. A driver has to be aware of this because it is only going to get a NodePublishVolume call for such a volume.
CSINode holds information about all CSI drivers installed on a node.
apiVersion: storage.k8s.io/v1
import "k8s.io/api/storage/v1"
CSINode
CSINode holds information about all CSI drivers installed on a node. CSI drivers do not need to create the CSINode object directly. As long as they use the node-driver-registrar sidecar container, the kubelet will automatically populate the CSINode object for the CSI driver as part of kubelet plugin registration. CSINode has the same name as a node. If the object is missing, it means either there are no CSI Drivers available on the node, or the Kubelet version is low enough that it doesn't create this object. CSINode has an OwnerReference that points to the corresponding node object.
CSINodeSpec holds information about the specification of all CSI drivers installed on a node
drivers ([]CSINodeDriver), required
Patch strategy: merge on key name
drivers is a list of information of all CSI Drivers existing on a node. If all drivers in the list are uninstalled, this can become empty.
CSINodeDriver holds information about the specification of one CSI driver installed on a node
drivers.name (string), required
name represents the name of the CSI driver that this object refers to. This MUST be the same name returned by the CSI GetPluginName() call for that driver.
drivers.nodeID (string), required
nodeID of the node from the driver point of view. This field enables Kubernetes to communicate with storage systems that do not share the same nomenclature for nodes. For example, Kubernetes may refer to a given node as "node1", but the storage system may refer to the same node as "nodeA". When Kubernetes issues a command to the storage system to attach a volume to a specific node, it can use this field to refer to the node name using the ID that the storage system will understand, e.g. "nodeA" instead of "node1". This field is required.
drivers.allocatable (VolumeNodeResources)
allocatable represents the volume resources of a node that are available for scheduling. This field is beta.
VolumeNodeResources is a set of resource limits for scheduling of volumes.
drivers.allocatable.count (int32)
count indicates the maximum number of unique volumes managed by the CSI driver that can be used on a node. A volume that is both attached and mounted on a node is considered to be used once, not twice. The same rule applies for a unique volume that is shared among multiple pods on the same node. If this field is not specified, then the supported number of volumes on this node is unbounded.
drivers.topologyKeys ([]string)
topologyKeys is the list of keys supported by the driver. When a driver is initialized on a cluster, it provides a set of topology keys that it understands (e.g. "company.com/zone", "company.com/region"). When a driver is initialized on a node, it provides the same topology keys along with values. Kubelet will expose these topology keys as labels on its own node object. When Kubernetes does topology aware provisioning, it can use this list to determine which labels it should retrieve from the node object and pass back to the driver. It is possible for different nodes to use different topology keys. This can be empty if driver does not support topology.
CSIStorageCapacity stores the result of one CSI GetCapacity call.
apiVersion: storage.k8s.io/v1
import "k8s.io/api/storage/v1"
CSIStorageCapacity
CSIStorageCapacity stores the result of one CSI GetCapacity call. For a given StorageClass, this describes the available capacity in a particular topology segment. This can be used when considering where to instantiate new PersistentVolumes.
For example this can express things like: - StorageClass "standard" has "1234 GiB" available in "topology.kubernetes.io/zone=us-east1" - StorageClass "localssd" has "10 GiB" available in "kubernetes.io/hostname=knode-abc123"
The following three cases all imply that no capacity is available for a certain combination: - no object exists with suitable topology and storage class name - such an object exists, but the capacity is unset - such an object exists, but the capacity is zero
The producer of these objects can decide which approach is more suitable.
They are consumed by the kube-scheduler when a CSI driver opts into capacity-aware scheduling with CSIDriverSpec.StorageCapacity. The scheduler compares the MaximumVolumeSize against the requested size of pending volumes to filter out unsuitable nodes. If MaximumVolumeSize is unset, it falls back to a comparison against the less precise Capacity. If that is also unset, the scheduler assumes that capacity is insufficient and tries some other node.
Standard object's metadata. The name has no particular meaning. It must be a DNS subdomain (dots allowed, 253 characters). To ensure that there are no conflicts with other CSI drivers on the cluster, the recommendation is to use csisc-<uuid>, a generated name, or a reverse-domain name which ends with the unique CSI driver name.
storageClassName represents the name of the StorageClass that the reported capacity applies to. It must meet the same requirements as the name of a StorageClass object (non-empty, DNS subdomain). If that object no longer exists, the CSIStorageCapacity object is obsolete and should be removed by its creator. This field is immutable.
capacity is the value reported by the CSI driver in its GetCapacityResponse for a GetCapacityRequest with topology and parameters that match the previous fields.
The semantic is currently (CSI spec 1.2) defined as: The available capacity, in bytes, of the storage that can be used to provision volumes. If not set, that information is currently unavailable.
maximumVolumeSize is the value reported by the CSI driver in its GetCapacityResponse for a GetCapacityRequest with topology and parameters that match the previous fields.
This is defined since CSI spec 1.4.0 as the largest size that may be used in a CreateVolumeRequest.capacity_range.required_bytes field to create a volume with the same parameters as those in GetCapacityRequest. The corresponding value in the Kubernetes API is ResourceRequirements.Requests in a volume claim.
nodeTopology defines which nodes have access to the storage for which capacity was reported. If not set, the storage is not accessible from any node in the cluster. If empty, the storage is accessible from all nodes. This field is immutable.
CSIStorageCapacityList
CSIStorageCapacityList is a collection of CSIStorageCapacity objects.
ServiceAccount binds together: * a name, understood by users, and perhaps by peripheral systems, for an identity * a principal that can be authenticated and authorized * a set of secrets.
apiVersion: v1
import "k8s.io/api/core/v1"
ServiceAccount
ServiceAccount binds together: * a name, understood by users, and perhaps by peripheral systems, for an identity * a principal that can be authenticated and authorized * a set of secrets
AutomountServiceAccountToken indicates whether pods running as this service account should have an API token automatically mounted. Can be overridden at the pod level.
ImagePullSecrets is a list of references to secrets in the same namespace to use for pulling any images in pods that reference this ServiceAccount. ImagePullSecrets are distinct from Secrets because Secrets can be mounted in the pod, but ImagePullSecrets are only accessed by the kubelet. More info: https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-pod
Secrets is a list of the secrets in the same namespace that pods running using this ServiceAccount are allowed to use. Pods are only limited to this list if this service account has a "kubernetes.io/enforce-mountable-secrets" annotation set to "true". This field should not be used to find auto-generated service account token secrets for use outside of pods. Instead, tokens can be requested directly using the TokenRequest API, or service account token secrets can be manually created. More info: https://kubernetes.io/docs/concepts/configuration/secret
ServiceAccountList
ServiceAccountList is a list of ServiceAccount objects
Status is filled in by the server and indicates whether the token can be authenticated.
TokenRequestSpec
TokenRequestSpec contains client provided parameters of a token request.
audiences ([]string), required
Audiences are the intendend audiences of the token. A recipient of a token must identify themself with an identifier in the list of audiences of the token, and otherwise should reject the token. A token issued for multiple audiences may be used to authenticate against any of the audiences listed but implies a high degree of trust between the target audiences.
boundObjectRef (BoundObjectReference)
BoundObjectRef is a reference to an object that the token will be bound to. The token will only be valid for as long as the bound object exists. NOTE: The API server's TokenReview endpoint will validate the BoundObjectRef, but other audiences may not. Keep ExpirationSeconds small if you want prompt revocation.
BoundObjectReference is a reference to an object that a token is bound to.
boundObjectRef.apiVersion (string)
API version of the referent.
boundObjectRef.kind (string)
Kind of the referent. Valid kinds are 'Pod' and 'Secret'.
boundObjectRef.name (string)
Name of the referent.
boundObjectRef.uid (string)
UID of the referent.
expirationSeconds (int64)
ExpirationSeconds is the requested duration of validity of the request. The token issuer may return a token with a different validity duration so a client needs to check the 'expiration' field in a response.
TokenRequestStatus
TokenRequestStatus is the result of a token request.
expirationTimestamp (Time), required
ExpirationTimestamp is the time of expiration of the returned token.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
token (string), required
Token is the opaque bearer token.
Operations
create create token of a ServiceAccount
HTTP Request
POST /api/v1/namespaces/{namespace}/serviceaccounts/{name}/token
TokenReview attempts to authenticate a token to a known user.
apiVersion: authentication.k8s.io/v1
import "k8s.io/api/authentication/v1"
TokenReview
TokenReview attempts to authenticate a token to a known user. Note: TokenReview requests may be cached by the webhook token authenticator plugin in the kube-apiserver.
Status is filled in by the server and indicates whether the request can be authenticated.
TokenReviewSpec
TokenReviewSpec is a description of the token authentication request.
audiences ([]string)
Audiences is a list of the identifiers that the resource server presented with the token identifies as. Audience-aware token authenticators will verify that the token was intended for at least one of the audiences in this list. If no audiences are provided, the audience will default to the audience of the Kubernetes apiserver.
token (string)
Token is the opaque bearer token.
TokenReviewStatus
TokenReviewStatus is the result of the token authentication request.
audiences ([]string)
Audiences are audience identifiers chosen by the authenticator that are compatible with both the TokenReview and token. An identifier is any identifier in the intersection of the TokenReviewSpec audiences and the token's audiences. A client of the TokenReview API that sets the spec.audiences field should validate that a compatible audience identifier is returned in the status.audiences field to ensure that the TokenReview server is audience aware. If a TokenReview returns an empty status.audience field where status.authenticated is "true", the token is valid against the audience of the Kubernetes API server.
authenticated (boolean)
Authenticated indicates that the token was associated with a known user.
error (string)
Error indicates that the token couldn't be checked
user (UserInfo)
User is the UserInfo associated with the provided token.
UserInfo holds the information about the user needed to implement the user.Info interface.
user.extra (map[string][]string)
Any additional information provided by the authenticator.
user.groups ([]string)
The names of groups this user is a part of.
user.uid (string)
A unique value that identifies this user across time. If this user is deleted and another user by the same name is added, they will have different UIDs.
user.username (string)
The name that uniquely identifies this user among all active users.
CertificateSigningRequest objects provide a mechanism to obtain x509 certificates by submitting a certificate signing request, and having it asynchronously approved and issued.
apiVersion: certificates.k8s.io/v1
import "k8s.io/api/certificates/v1"
CertificateSigningRequest
CertificateSigningRequest objects provide a mechanism to obtain x509 certificates by submitting a certificate signing request, and having it asynchronously approved and issued.
Kubelets use this API to obtain:
client certificates to authenticate to kube-apiserver (with the "kubernetes.io/kube-apiserver-client-kubelet" signerName).
serving certificates for TLS endpoints kube-apiserver can connect to securely (with the "kubernetes.io/kubelet-serving" signerName).
This API can be used to request client certificates to authenticate to kube-apiserver (with the "kubernetes.io/kube-apiserver-client" signerName), or to obtain certificates from custom non-Kubernetes signers.
spec contains the certificate request, and is immutable after creation. Only the request, signerName, expirationSeconds, and usages fields can be set on creation. Other fields are derived by Kubernetes and cannot be modified by users.
status contains information about whether the request is approved or denied, and the certificate issued by the signer, or the failure condition indicating signer failure.
CertificateSigningRequestSpec
CertificateSigningRequestSpec contains the certificate request.
request ([]byte), required
Atomic: will be replaced during a merge
request contains an x509 certificate signing request encoded in a "CERTIFICATE REQUEST" PEM block. When serialized as JSON or YAML, the data is additionally base64-encoded.
signerName (string), required
signerName indicates the requested signer, and is a qualified name.
List/watch requests for CertificateSigningRequests can filter on this field using a "spec.signerName=NAME" fieldSelector.
Well-known Kubernetes signers are:
"kubernetes.io/kube-apiserver-client": issues client certificates that can be used to authenticate to kube-apiserver.
Requests for this signer are never auto-approved by kube-controller-manager, can be issued by the "csrsigning" controller in kube-controller-manager.
"kubernetes.io/kube-apiserver-client-kubelet": issues client certificates that kubelets use to authenticate to kube-apiserver.
Requests for this signer can be auto-approved by the "csrapproving" controller in kube-controller-manager, and can be issued by the "csrsigning" controller in kube-controller-manager.
"kubernetes.io/kubelet-serving" issues serving certificates that kubelets use to serve TLS endpoints, which kube-apiserver can connect to securely.
Requests for this signer are never auto-approved by kube-controller-manager, and can be issued by the "csrsigning" controller in kube-controller-manager.
Custom signerNames can also be specified. The signer defines:
Trust distribution: how trust (CA bundles) are distributed.
Permitted subjects: and behavior when a disallowed subject is requested.
Required, permitted, or forbidden x509 extensions in the request (including whether subjectAltNames are allowed, which types, restrictions on allowed values) and behavior when a disallowed extension is requested.
Required, permitted, or forbidden key usages / extended key usages.
Expiration/certificate lifetime: whether it is fixed by the signer, configurable by the admin.
Whether or not requests for CA certificates are allowed.
expirationSeconds (int32)
expirationSeconds is the requested duration of validity of the issued certificate. The certificate signer may issue a certificate with a different validity duration so a client must check the delta between the notBefore and and notAfter fields in the issued certificate to determine the actual duration.
The v1.22+ in-tree implementations of the well-known Kubernetes signers will honor this field as long as the requested duration is not greater than the maximum duration they will honor per the --cluster-signing-duration CLI flag to the Kubernetes controller manager.
Certificate signers may not honor this field for various reasons:
Old signer that is unaware of the field (such as the in-tree
implementations prior to v1.22)
Signer whose configured maximum is shorter than the requested duration
Signer whose configured minimum is longer than the requested duration
The minimum valid value for expirationSeconds is 600, i.e. 10 minutes.
extra (map[string][]string)
extra contains extra attributes of the user that created the CertificateSigningRequest. Populated by the API server on creation and immutable.
groups ([]string)
Atomic: will be replaced during a merge
groups contains group membership of the user that created the CertificateSigningRequest. Populated by the API server on creation and immutable.
uid (string)
uid contains the uid of the user that created the CertificateSigningRequest. Populated by the API server on creation and immutable.
usages ([]string)
Atomic: will be replaced during a merge
usages specifies a set of key usages requested in the issued certificate.
Requests for TLS client certificates typically request: "digital signature", "key encipherment", "client auth".
Requests for TLS serving certificates typically request: "key encipherment", "digital signature", "server auth".
username contains the name of the user that created the CertificateSigningRequest. Populated by the API server on creation and immutable.
CertificateSigningRequestStatus
CertificateSigningRequestStatus contains conditions used to indicate approved/denied/failed status of the request, and the issued certificate.
certificate ([]byte)
Atomic: will be replaced during a merge
certificate is populated with an issued certificate by the signer after an Approved condition is present. This field is set via the /status subresource. Once populated, this field is immutable.
If the certificate signing request is denied, a condition of type "Denied" is added and this field remains empty. If the signer cannot issue the certificate, a condition of type "Failed" is added and this field remains empty.
Validation requirements:
certificate must contain one or more PEM blocks.
All PEM blocks must have the "CERTIFICATE" label, contain no headers, and the encoded data
must be a BER-encoded ASN.1 Certificate structure as described in section 4 of RFC5280.
Non-PEM content may appear before or after the "CERTIFICATE" PEM blocks and is unvalidated,
to allow for explanatory text as described in section 5.2 of RFC7468.
If more than one PEM block is present, and the definition of the requested spec.signerName does not indicate otherwise, the first block is the issued certificate, and subsequent blocks should be treated as intermediate certificates and presented in TLS handshakes.
The certificate is encoded in PEM format.
When serialized as JSON or YAML, the data is additionally base64-encoded, so it consists of:
Map: unique values on key type will be kept during a merge
conditions applied to the request. Known conditions are "Approved", "Denied", and "Failed".
CertificateSigningRequestCondition describes a condition of a CertificateSigningRequest object
conditions.status (string), required
status of the condition, one of True, False, Unknown. Approved, Denied, and Failed conditions may not be "False" or "Unknown".
conditions.type (string), required
type of the condition. Known conditions are "Approved", "Denied", and "Failed".
An "Approved" condition is added via the /approval subresource, indicating the request was approved and should be issued by the signer.
A "Denied" condition is added via the /approval subresource, indicating the request was denied and should not be issued by the signer.
A "Failed" condition is added via the /status subresource, indicating the signer failed to issue the certificate.
Approved and Denied conditions are mutually exclusive. Approved, Denied, and Failed conditions cannot be removed once added.
Only one condition of a given type is allowed.
conditions.lastTransitionTime (Time)
lastTransitionTime is the time the condition last transitioned from one status to another. If unset, when a new condition type is added or an existing condition's status is changed, the server defaults this to the current time.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastUpdateTime (Time)
lastUpdateTime is the time of the last update to this condition
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message contains a human readable message with details about the request state
conditions.reason (string)
reason indicates a brief reason for the request state
CertificateSigningRequestList
CertificateSigningRequestList is a collection of CertificateSigningRequest objects
ClusterTrustBundle is a cluster-scoped container for X.
apiVersion: certificates.k8s.io/v1alpha1
import "k8s.io/api/certificates/v1alpha1"
ClusterTrustBundle
ClusterTrustBundle is a cluster-scoped container for X.509 trust anchors (root certificates).
ClusterTrustBundle objects are considered to be readable by any authenticated user in the cluster, because they can be mounted by pods using the clusterTrustBundle projection. All service accounts have read access to ClusterTrustBundles by default. Users who only have namespace-level access to a cluster can read ClusterTrustBundles by impersonating a serviceaccount that they have access to.
It can be optionally associated with a particular assigner, in which case it contains one valid set of trust anchors for that signer. Signers may have multiple associated ClusterTrustBundles; each is an independent set of trust anchors for that signer. Admission control is used to enforce that only users with permissions on the signer can create or modify the corresponding bundle.
spec contains the signer (if any) and trust anchors.
ClusterTrustBundleSpec
ClusterTrustBundleSpec contains the signer and trust anchors.
trustBundle (string), required
trustBundle contains the individual X.509 trust anchors for this bundle, as PEM bundle of PEM-wrapped, DER-formatted X.509 certificates.
The data must consist only of PEM certificate blocks that parse as valid X.509 certificates. Each certificate must include a basic constraints extension with the CA bit set. The API server will reject objects that contain duplicate certificates, or that use PEM block headers.
Users of ClusterTrustBundles, including Kubelet, are free to reorder and deduplicate certificate blocks in this file according to their own logic, as well as to drop PEM block headers and inter-block data.
signerName (string)
signerName indicates the associated signer, if any.
In order to create or update a ClusterTrustBundle that sets signerName, you must have the following cluster-scoped permission: group=certificates.k8s.io resource=signers resourceName=<the signer name> verb=attest.
If signerName is not empty, then the ClusterTrustBundle object must be named with the signer name as a prefix (translating slashes to colons). For example, for the signer name example.com/foo, valid ClusterTrustBundle object names include example.com:foo:abc and example.com:foo:v1.
If signerName is empty, then the ClusterTrustBundle object's name must not have such a prefix.
List/watch requests for ClusterTrustBundles can filter on this field using a spec.signerName=NAME field selector.
ClusterTrustBundleList
ClusterTrustBundleList is a collection of ClusterTrustBundle objects
SelfSubjectReview contains the user information that the kube-apiserver has about the user making this request.
apiVersion: authentication.k8s.io/v1
import "k8s.io/api/authentication/v1"
SelfSubjectReview
SelfSubjectReview contains the user information that the kube-apiserver has about the user making this request. When using impersonation, users will receive the user info of the user being impersonated. If impersonation or request header authentication is used, any extra keys will have their case ignored and returned as lowercase.
Status is filled in by the server with the user attributes.
SelfSubjectReviewStatus
SelfSubjectReviewStatus is filled by the kube-apiserver and sent back to a user.
userInfo (UserInfo)
User attributes of the user making this request.
UserInfo holds the information about the user needed to implement the user.Info interface.
userInfo.extra (map[string][]string)
Any additional information provided by the authenticator.
userInfo.groups ([]string)
The names of groups this user is a part of.
userInfo.uid (string)
A unique value that identifies this user across time. If this user is deleted and another user by the same name is added, they will have different UIDs.
userInfo.username (string)
The name that uniquely identifies this user among all active users.
Operations
create create a SelfSubjectReview
HTTP Request
POST /apis/authentication.k8s.io/v1/selfsubjectreviews
LocalSubjectAccessReview checks whether or not a user or group can perform an action in a given namespace.
apiVersion: authorization.k8s.io/v1
import "k8s.io/api/authorization/v1"
LocalSubjectAccessReview
LocalSubjectAccessReview checks whether or not a user or group can perform an action in a given namespace. Having a namespace scoped resource makes it much easier to grant namespace scoped policy that includes permissions checking.
Spec holds information about the request being evaluated. spec.namespace must be equal to the namespace you made the request against. If empty, it is defaulted.
SelfSubjectAccessReview checks whether or the current user can perform an action.
apiVersion: authorization.k8s.io/v1
import "k8s.io/api/authorization/v1"
SelfSubjectAccessReview
SelfSubjectAccessReview checks whether or the current user can perform an action. Not filling in a spec.namespace means "in all namespaces". Self is a special case, because users should always be able to check whether they can perform an action
Status is filled in by the server and indicates whether the request is allowed or not
SelfSubjectAccessReviewSpec
SelfSubjectAccessReviewSpec is a description of the access request. Exactly one of ResourceAuthorizationAttributes and NonResourceAuthorizationAttributes must be set
nonResourceAttributes (NonResourceAttributes)
NonResourceAttributes describes information for a non-resource access request
NonResourceAttributes includes the authorization attributes available for non-resource requests to the Authorizer interface
nonResourceAttributes.path (string)
Path is the URL path of the request
nonResourceAttributes.verb (string)
Verb is the standard HTTP verb
resourceAttributes (ResourceAttributes)
ResourceAuthorizationAttributes describes information for a resource access request
ResourceAttributes includes the authorization attributes available for resource requests to the Authorizer interface
resourceAttributes.group (string)
Group is the API Group of the Resource. "*" means all.
resourceAttributes.name (string)
Name is the name of the resource being requested for a "get" or deleted for a "delete". "" (empty) means all.
resourceAttributes.namespace (string)
Namespace is the namespace of the action being requested. Currently, there is no distinction between no namespace and all namespaces "" (empty) is defaulted for LocalSubjectAccessReviews "" (empty) is empty for cluster-scoped resources "" (empty) means "all" for namespace scoped resources from a SubjectAccessReview or SelfSubjectAccessReview
resourceAttributes.resource (string)
Resource is one of the existing resource types. "*" means all.
resourceAttributes.subresource (string)
Subresource is one of the existing resource types. "" means none.
resourceAttributes.verb (string)
Verb is a kubernetes resource API verb, like: get, list, watch, create, update, delete, proxy. "*" means all.
resourceAttributes.version (string)
Version is the API Version of the Resource. "*" means all.
Operations
create create a SelfSubjectAccessReview
HTTP Request
POST /apis/authorization.k8s.io/v1/selfsubjectaccessreviews
SelfSubjectRulesReview enumerates the set of actions the current user can perform within a namespace.
apiVersion: authorization.k8s.io/v1
import "k8s.io/api/authorization/v1"
SelfSubjectRulesReview
SelfSubjectRulesReview enumerates the set of actions the current user can perform within a namespace. The returned list of actions may be incomplete depending on the server's authorization mode, and any errors experienced during the evaluation. SelfSubjectRulesReview should be used by UIs to show/hide actions, or to quickly let an end user reason about their permissions. It should NOT Be used by external systems to drive authorization decisions as this raises confused deputy, cache lifetime/revocation, and correctness concerns. SubjectAccessReview, and LocalAccessReview are the correct way to defer authorization decisions to the API server.
Spec holds information about the request being evaluated.
status (SubjectRulesReviewStatus)
Status is filled in by the server and indicates the set of actions a user can perform.
SubjectRulesReviewStatus contains the result of a rules check. This check can be incomplete depending on the set of authorizers the server is configured with and any errors experienced during evaluation. Because authorization rules are additive, if a rule appears in a list it's safe to assume the subject has that permission, even if that list is incomplete.
status.incomplete (boolean), required
Incomplete is true when the rules returned by this call are incomplete. This is most commonly encountered when an authorizer, such as an external authorizer, doesn't support rules evaluation.
NonResourceRules is the list of actions the subject is allowed to perform on non-resources. The list ordering isn't significant, may contain duplicates, and possibly be incomplete.
NonResourceRule holds information that describes a rule for the non-resource
NonResourceURLs is a set of partial urls that a user should have access to. s are allowed, but only as the full, final step in the path. "" means all.
status.resourceRules ([]ResourceRule), required
ResourceRules is the list of actions the subject is allowed to perform on resources. The list ordering isn't significant, may contain duplicates, and possibly be incomplete.
ResourceRule is the list of actions the subject is allowed to perform on resources. The list ordering isn't significant, may contain duplicates, and possibly be incomplete.
status.resourceRules.verbs ([]string), required
Verb is a list of kubernetes resource API verbs, like: get, list, watch, create, update, delete, proxy. "*" means all.
status.resourceRules.apiGroups ([]string)
APIGroups is the name of the APIGroup that contains the resources. If multiple API groups are specified, any action requested against one of the enumerated resources in any API group will be allowed. "*" means all.
status.resourceRules.resourceNames ([]string)
ResourceNames is an optional white list of names that the rule applies to. An empty set means that everything is allowed. "*" means all.
status.resourceRules.resources ([]string)
Resources is a list of resources this rule applies to. "" means all in the specified apiGroups.
"/foo" represents the subresource 'foo' for all resources in the specified apiGroups.
status.evaluationError (string)
EvaluationError can appear in combination with Rules. It indicates an error occurred during rule evaluation, such as an authorizer that doesn't support rule evaluation, and that ResourceRules and/or NonResourceRules may be incomplete.
SelfSubjectRulesReviewSpec
SelfSubjectRulesReviewSpec defines the specification for SelfSubjectRulesReview.
namespace (string)
Namespace to evaluate rules for. Required.
Operations
create create a SelfSubjectRulesReview
HTTP Request
POST /apis/authorization.k8s.io/v1/selfsubjectrulesreviews
Status is filled in by the server and indicates whether the request is allowed or not
SubjectAccessReviewSpec
SubjectAccessReviewSpec is a description of the access request. Exactly one of ResourceAuthorizationAttributes and NonResourceAuthorizationAttributes must be set
extra (map[string][]string)
Extra corresponds to the user.Info.GetExtra() method from the authenticator. Since that is input to the authorizer it needs a reflection here.
groups ([]string)
Groups is the groups you're testing for.
nonResourceAttributes (NonResourceAttributes)
NonResourceAttributes describes information for a non-resource access request
NonResourceAttributes includes the authorization attributes available for non-resource requests to the Authorizer interface
nonResourceAttributes.path (string)
Path is the URL path of the request
nonResourceAttributes.verb (string)
Verb is the standard HTTP verb
resourceAttributes (ResourceAttributes)
ResourceAuthorizationAttributes describes information for a resource access request
ResourceAttributes includes the authorization attributes available for resource requests to the Authorizer interface
resourceAttributes.group (string)
Group is the API Group of the Resource. "*" means all.
resourceAttributes.name (string)
Name is the name of the resource being requested for a "get" or deleted for a "delete". "" (empty) means all.
resourceAttributes.namespace (string)
Namespace is the namespace of the action being requested. Currently, there is no distinction between no namespace and all namespaces "" (empty) is defaulted for LocalSubjectAccessReviews "" (empty) is empty for cluster-scoped resources "" (empty) means "all" for namespace scoped resources from a SubjectAccessReview or SelfSubjectAccessReview
resourceAttributes.resource (string)
Resource is one of the existing resource types. "*" means all.
resourceAttributes.subresource (string)
Subresource is one of the existing resource types. "" means none.
resourceAttributes.verb (string)
Verb is a kubernetes resource API verb, like: get, list, watch, create, update, delete, proxy. "*" means all.
resourceAttributes.version (string)
Version is the API Version of the Resource. "*" means all.
uid (string)
UID information about the requesting user.
user (string)
User is the user you're testing for. If you specify "User" but not "Groups", then is it interpreted as "What if User were not a member of any groups
SubjectAccessReviewStatus
SubjectAccessReviewStatus
allowed (boolean), required
Allowed is required. True if the action would be allowed, false otherwise.
denied (boolean)
Denied is optional. True if the action would be denied, otherwise false. If both allowed is false and denied is false, then the authorizer has no opinion on whether to authorize the action. Denied may not be true if Allowed is true.
evaluationError (string)
EvaluationError is an indication that some error occurred during the authorization check. It is entirely possible to get an error and be able to continue determine authorization status in spite of it. For instance, RBAC can be missing a role, but enough roles are still present and bound to reason about the request.
reason (string)
Reason is optional. It indicates why a request was allowed or denied.
Operations
create create a SubjectAccessReview
HTTP Request
POST /apis/authorization.k8s.io/v1/subjectaccessreviews
AggregationRule is an optional field that describes how to build the Rules for this ClusterRole. If AggregationRule is set, then the Rules are controller managed and direct changes to Rules will be stomped by the controller.
AggregationRule describes how to locate ClusterRoles to aggregate into the ClusterRole
ClusterRoleSelectors holds a list of selectors which will be used to find ClusterRoles and create the rules. If any of the selectors match, then the ClusterRole's permissions will be added
rules ([]PolicyRule)
Rules holds all the PolicyRules for this ClusterRole
PolicyRule holds information that describes a policy rule, but does not contain information about who the rule applies to or which namespace the rule applies to.
rules.apiGroups ([]string)
APIGroups is the name of the APIGroup that contains the resources. If multiple API groups are specified, any action requested against one of the enumerated resources in any API group will be allowed. "" represents the core API group and "*" represents all API groups.
rules.resources ([]string)
Resources is a list of resources this rule applies to. '*' represents all resources.
rules.verbs ([]string), required
Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
rules.resourceNames ([]string)
ResourceNames is an optional white list of names that the rule applies to. An empty set means that everything is allowed.
rules.nonResourceURLs ([]string)
NonResourceURLs is a set of partial urls that a user should have access to. *s are allowed, but only as the full, final step in the path Since non-resource URLs are not namespaced, this field is only applicable for ClusterRoles referenced from a ClusterRoleBinding. Rules can either apply to API resources (such as "pods" or "secrets") or non-resource URL paths (such as "/api"), but not both.
ClusterRoleBinding references a ClusterRole, but not contain it.
apiVersion: rbac.authorization.k8s.io/v1
import "k8s.io/api/rbac/v1"
ClusterRoleBinding
ClusterRoleBinding references a ClusterRole, but not contain it. It can reference a ClusterRole in the global namespace, and adds who information via Subject.
RoleRef can only reference a ClusterRole in the global namespace. If the RoleRef cannot be resolved, the Authorizer must return an error. This field is immutable.
RoleRef contains information that points to the role being used
roleRef.apiGroup (string), required
APIGroup is the group for the resource being referenced
roleRef.kind (string), required
Kind is the type of resource being referenced
roleRef.name (string), required
Name is the name of resource being referenced
subjects ([]Subject)
Subjects holds references to the objects the role applies to.
Subject contains a reference to the object or user identities a role binding applies to. This can either hold a direct API object reference, or a value for non-objects such as user and group names.
subjects.kind (string), required
Kind of object being referenced. Values defined by this API group are "User", "Group", and "ServiceAccount". If the Authorizer does not recognized the kind value, the Authorizer should report an error.
subjects.name (string), required
Name of the object being referenced.
subjects.apiGroup (string)
APIGroup holds the API group of the referenced subject. Defaults to "" for ServiceAccount subjects. Defaults to "rbac.authorization.k8s.io" for User and Group subjects.
subjects.namespace (string)
Namespace of the referenced object. If the object kind is non-namespace, such as "User" or "Group", and this value is not empty the Authorizer should report an error.
ClusterRoleBindingList
ClusterRoleBindingList is a collection of ClusterRoleBindings
PolicyRule holds information that describes a policy rule, but does not contain information about who the rule applies to or which namespace the rule applies to.
rules.apiGroups ([]string)
APIGroups is the name of the APIGroup that contains the resources. If multiple API groups are specified, any action requested against one of the enumerated resources in any API group will be allowed. "" represents the core API group and "*" represents all API groups.
rules.resources ([]string)
Resources is a list of resources this rule applies to. '*' represents all resources.
rules.verbs ([]string), required
Verbs is a list of Verbs that apply to ALL the ResourceKinds contained in this rule. '*' represents all verbs.
rules.resourceNames ([]string)
ResourceNames is an optional white list of names that the rule applies to. An empty set means that everything is allowed.
rules.nonResourceURLs ([]string)
NonResourceURLs is a set of partial urls that a user should have access to. *s are allowed, but only as the full, final step in the path Since non-resource URLs are not namespaced, this field is only applicable for ClusterRoles referenced from a ClusterRoleBinding. Rules can either apply to API resources (such as "pods" or "secrets") or non-resource URL paths (such as "/api"), but not both.
RoleBinding references a role, but does not contain it.
apiVersion: rbac.authorization.k8s.io/v1
import "k8s.io/api/rbac/v1"
RoleBinding
RoleBinding references a role, but does not contain it. It can reference a Role in the same namespace or a ClusterRole in the global namespace. It adds who information via Subjects and namespace information by which namespace it exists in. RoleBindings in a given namespace only have effect in that namespace.
RoleRef can reference a Role in the current namespace or a ClusterRole in the global namespace. If the RoleRef cannot be resolved, the Authorizer must return an error. This field is immutable.
RoleRef contains information that points to the role being used
roleRef.apiGroup (string), required
APIGroup is the group for the resource being referenced
roleRef.kind (string), required
Kind is the type of resource being referenced
roleRef.name (string), required
Name is the name of resource being referenced
subjects ([]Subject)
Subjects holds references to the objects the role applies to.
Subject contains a reference to the object or user identities a role binding applies to. This can either hold a direct API object reference, or a value for non-objects such as user and group names.
subjects.kind (string), required
Kind of object being referenced. Values defined by this API group are "User", "Group", and "ServiceAccount". If the Authorizer does not recognized the kind value, the Authorizer should report an error.
subjects.name (string), required
Name of the object being referenced.
subjects.apiGroup (string)
APIGroup holds the API group of the referenced subject. Defaults to "" for ServiceAccount subjects. Defaults to "rbac.authorization.k8s.io" for User and Group subjects.
subjects.namespace (string)
Namespace of the referenced object. If the object kind is non-namespace, such as "User" or "Group", and this value is not empty the Authorizer should report an error.
MaxLimitRequestRatio if specified, the named resource must have a request and limit that are both non-zero where limit divided by request is less than or equal to the enumerated value; this represents the max burst for the named resource.
scopeSelector is also a collection of filters like scopes that must match each object tracked by a quota but expressed using ScopeSelectorOperator in combination with possible values. For a resource to match, both scopes AND scopeSelector (if specified in spec), must be matched.
A scope selector represents the AND of the selectors represented by the scoped-resource selector requirements.
The name of the scope that the selector applies to.
scopeSelector.matchExpressions.values ([]string)
An array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
scopes ([]string)
A collection of filters that must match each object tracked by a quota. If not specified, the quota matches all objects.
ResourceQuotaStatus
ResourceQuotaStatus defines the enforced hard limits and observed use.
podSelector selects the pods to which this NetworkPolicy object applies. The array of ingress rules is applied to any pods selected by this field. Multiple network policies can select the same set of pods. In this case, the ingress rules for each are combined additively. This field is NOT optional and follows standard label selector semantics. An empty podSelector matches all pods in this namespace.
policyTypes ([]string)
policyTypes is a list of rule types that the NetworkPolicy relates to. Valid options are ["Ingress"], ["Egress"], or ["Ingress", "Egress"]. If this field is not specified, it will default based on the existence of ingress or egress rules; policies that contain an egress section are assumed to affect egress, and all policies (whether or not they contain an ingress section) are assumed to affect ingress. If you want to write an egress-only policy, you must explicitly specify policyTypes [ "Egress" ]. Likewise, if you want to write a policy that specifies that no egress is allowed, you must specify a policyTypes value that include "Egress" (since such a policy would not include an egress section and would otherwise default to just [ "Ingress" ]). This field is beta-level in 1.8
ingress ([]NetworkPolicyIngressRule)
ingress is a list of ingress rules to be applied to the selected pods. Traffic is allowed to a pod if there are no NetworkPolicies selecting the pod (and cluster policy otherwise allows the traffic), OR if the traffic source is the pod's local node, OR if the traffic matches at least one ingress rule across all of the NetworkPolicy objects whose podSelector matches the pod. If this field is empty then this NetworkPolicy does not allow any traffic (and serves solely to ensure that the pods it selects are isolated by default)
NetworkPolicyIngressRule describes a particular set of traffic that is allowed to the pods matched by a NetworkPolicySpec's podSelector. The traffic must match both ports and from.
ingress.from ([]NetworkPolicyPeer)
from is a list of sources which should be able to access the pods selected for this rule. Items in this list are combined using a logical OR operation. If this field is empty or missing, this rule matches all sources (traffic not restricted by source). If this field is present and contains at least one item, this rule allows traffic only if the traffic matches at least one item in the from list.
NetworkPolicyPeer describes a peer to allow traffic to/from. Only certain combinations of fields are allowed
ingress.from.ipBlock (IPBlock)
ipBlock defines policy on a particular IPBlock. If this field is set then neither of the other fields can be.
IPBlock describes a particular CIDR (Ex. "192.168.1.0/24","2001:db8::/64") that is allowed to the pods matched by a NetworkPolicySpec's podSelector. The except entry describes CIDRs that should not be included within this rule.
ingress.from.ipBlock.cidr (string), required
cidr is a string representing the IPBlock Valid examples are "192.168.1.0/24" or "2001:db8::/64"
ingress.from.ipBlock.except ([]string)
except is a slice of CIDRs that should not be included within an IPBlock Valid examples are "192.168.1.0/24" or "2001:db8::/64" Except values will be rejected if they are outside the cidr range
namespaceSelector selects namespaces using cluster-scoped labels. This field follows standard label selector semantics; if present but empty, it selects all namespaces.
If podSelector is also set, then the NetworkPolicyPeer as a whole selects the pods matching podSelector in the namespaces selected by namespaceSelector. Otherwise it selects all pods in the namespaces selected by namespaceSelector.
podSelector is a label selector which selects pods. This field follows standard label selector semantics; if present but empty, it selects all pods.
If namespaceSelector is also set, then the NetworkPolicyPeer as a whole selects the pods matching podSelector in the Namespaces selected by NamespaceSelector. Otherwise it selects the pods matching podSelector in the policy's own namespace.
ingress.ports ([]NetworkPolicyPort)
ports is a list of ports which should be made accessible on the pods selected for this rule. Each item in this list is combined using a logical OR. If this field is empty or missing, this rule matches all ports (traffic not restricted by port). If this field is present and contains at least one item, then this rule allows traffic only if the traffic matches at least one port in the list.
NetworkPolicyPort describes a port to allow traffic on
ingress.ports.port (IntOrString)
port represents the port on the given protocol. This can either be a numerical or named port on a pod. If this field is not provided, this matches all port names and numbers. If present, only traffic on the specified protocol AND port will be matched.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
ingress.ports.endPort (int32)
endPort indicates that the range of ports from port to endPort if set, inclusive, should be allowed by the policy. This field cannot be defined if the port field is not defined or if the port field is defined as a named (string) port. The endPort must be equal or greater than port.
ingress.ports.protocol (string)
protocol represents the protocol (TCP, UDP, or SCTP) which traffic must match. If not specified, this field defaults to TCP.
egress ([]NetworkPolicyEgressRule)
egress is a list of egress rules to be applied to the selected pods. Outgoing traffic is allowed if there are no NetworkPolicies selecting the pod (and cluster policy otherwise allows the traffic), OR if the traffic matches at least one egress rule across all of the NetworkPolicy objects whose podSelector matches the pod. If this field is empty then this NetworkPolicy limits all outgoing traffic (and serves solely to ensure that the pods it selects are isolated by default). This field is beta-level in 1.8
NetworkPolicyEgressRule describes a particular set of traffic that is allowed out of pods matched by a NetworkPolicySpec's podSelector. The traffic must match both ports and to. This type is beta-level in 1.8
egress.to ([]NetworkPolicyPeer)
to is a list of destinations for outgoing traffic of pods selected for this rule. Items in this list are combined using a logical OR operation. If this field is empty or missing, this rule matches all destinations (traffic not restricted by destination). If this field is present and contains at least one item, this rule allows traffic only if the traffic matches at least one item in the to list.
NetworkPolicyPeer describes a peer to allow traffic to/from. Only certain combinations of fields are allowed
egress.to.ipBlock (IPBlock)
ipBlock defines policy on a particular IPBlock. If this field is set then neither of the other fields can be.
IPBlock describes a particular CIDR (Ex. "192.168.1.0/24","2001:db8::/64") that is allowed to the pods matched by a NetworkPolicySpec's podSelector. The except entry describes CIDRs that should not be included within this rule.
egress.to.ipBlock.cidr (string), required
cidr is a string representing the IPBlock Valid examples are "192.168.1.0/24" or "2001:db8::/64"
egress.to.ipBlock.except ([]string)
except is a slice of CIDRs that should not be included within an IPBlock Valid examples are "192.168.1.0/24" or "2001:db8::/64" Except values will be rejected if they are outside the cidr range
namespaceSelector selects namespaces using cluster-scoped labels. This field follows standard label selector semantics; if present but empty, it selects all namespaces.
If podSelector is also set, then the NetworkPolicyPeer as a whole selects the pods matching podSelector in the namespaces selected by namespaceSelector. Otherwise it selects all pods in the namespaces selected by namespaceSelector.
podSelector is a label selector which selects pods. This field follows standard label selector semantics; if present but empty, it selects all pods.
If namespaceSelector is also set, then the NetworkPolicyPeer as a whole selects the pods matching podSelector in the Namespaces selected by NamespaceSelector. Otherwise it selects the pods matching podSelector in the policy's own namespace.
egress.ports ([]NetworkPolicyPort)
ports is a list of destination ports for outgoing traffic. Each item in this list is combined using a logical OR. If this field is empty or missing, this rule matches all ports (traffic not restricted by port). If this field is present and contains at least one item, then this rule allows traffic only if the traffic matches at least one port in the list.
NetworkPolicyPort describes a port to allow traffic on
egress.ports.port (IntOrString)
port represents the port on the given protocol. This can either be a numerical or named port on a pod. If this field is not provided, this matches all port names and numbers. If present, only traffic on the specified protocol AND port will be matched.
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
egress.ports.endPort (int32)
endPort indicates that the range of ports from port to endPort if set, inclusive, should be allowed by the policy. This field cannot be defined if the port field is not defined or if the port field is defined as a named (string) port. The endPort must be equal or greater than port.
egress.ports.protocol (string)
protocol represents the protocol (TCP, UDP, or SCTP) which traffic must match. If not specified, this field defaults to TCP.
NetworkPolicyList
NetworkPolicyList is a list of NetworkPolicy objects.
Most recently observed status of the PodDisruptionBudget.
PodDisruptionBudgetSpec
PodDisruptionBudgetSpec is a description of a PodDisruptionBudget.
maxUnavailable (IntOrString)
An eviction is allowed if at most "maxUnavailable" pods selected by "selector" are unavailable after the eviction, i.e. even in absence of the evicted pod. For example, one can prevent all voluntary evictions by specifying 0. This is a mutually exclusive setting with "minAvailable".
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
minAvailable (IntOrString)
An eviction is allowed if at least "minAvailable" pods selected by "selector" will still be available after the eviction, i.e. even in the absence of the evicted pod. So for example you can prevent all voluntary evictions by specifying "100%".
IntOrString is a type that can hold an int32 or a string. When used in JSON or YAML marshalling and unmarshalling, it produces or consumes the inner type. This allows you to have, for example, a JSON field that can accept a name or number.
Label query over pods whose evictions are managed by the disruption budget. A null selector will match no pods, while an empty ({}) selector will select all pods within the namespace.
unhealthyPodEvictionPolicy (string)
UnhealthyPodEvictionPolicy defines the criteria for when unhealthy pods should be considered for eviction. Current implementation considers healthy pods, as pods that have status.conditions item with type="Ready",status="True".
Valid policies are IfHealthyBudget and AlwaysAllow. If no policy is specified, the default behavior will be used, which corresponds to the IfHealthyBudget policy.
IfHealthyBudget policy means that running pods (status.phase="Running"), but not yet healthy can be evicted only if the guarded application is not disrupted (status.currentHealthy is at least equal to status.desiredHealthy). Healthy pods will be subject to the PDB for eviction.
AlwaysAllow policy means that all running pods (status.phase="Running"), but not yet healthy are considered disrupted and can be evicted regardless of whether the criteria in a PDB is met. This means perspective running pods of a disrupted application might not get a chance to become healthy. Healthy pods will be subject to the PDB for eviction.
Additional policies may be added in the future. Clients making eviction decisions should disallow eviction of unhealthy pods if they encounter an unrecognized policy in this field.
This field is beta-level. The eviction API uses this field when the feature gate PDBUnhealthyPodEvictionPolicy is enabled (enabled by default).
PodDisruptionBudgetStatus
PodDisruptionBudgetStatus represents information about the status of a PodDisruptionBudget. Status may trail the actual state of a system.
currentHealthy (int32), required
current number of healthy pods
desiredHealthy (int32), required
minimum desired number of healthy pods
disruptionsAllowed (int32), required
Number of pod disruptions that are currently allowed.
expectedPods (int32), required
total number of pods counted by this disruption budget
conditions ([]Condition)
Patch strategy: merge on key type
Map: unique values on key type will be kept during a merge
Conditions contain conditions for PDB. The disruption controller sets the DisruptionAllowed condition. The following are known values for the reason field (additional reasons could be added in the future): - SyncFailed: The controller encountered an error and wasn't able to compute
the number of allowed disruptions. Therefore no disruptions are
allowed and the status of the condition will be False.
InsufficientPods: The number of pods are either at or below the number
required by the PodDisruptionBudget. No disruptions are
allowed and the status of the condition will be False.
SufficientPods: There are more pods than required by the PodDisruptionBudget.
The condition will be True, and the number of allowed
disruptions are provided by the disruptionsAllowed property.
Condition contains details for one aspect of the current state of this API Resource.
conditions.lastTransitionTime (Time), required
lastTransitionTime is the last time the condition transitioned from one status to another. This should be when the underlying condition changed. If that is not known, then using the time when the API field changed is acceptable.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string), required
message is a human readable message indicating details about the transition. This may be an empty string.
conditions.reason (string), required
reason contains a programmatic identifier indicating the reason for the condition's last transition. Producers of specific condition types may define expected values and meanings for this field, and whether the values are considered a guaranteed API. The value should be a CamelCase string. This field may not be empty.
conditions.status (string), required
status of the condition, one of True, False, Unknown.
conditions.type (string), required
type of condition in CamelCase or in foo.example.com/CamelCase.
conditions.observedGeneration (int64)
observedGeneration represents the .metadata.generation that the condition was set based upon. For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date with respect to the current state of the instance.
disruptedPods (map[string]Time)
DisruptedPods contains information about pods whose eviction was processed by the API server eviction subresource handler but has not yet been observed by the PodDisruptionBudget controller. A pod will be in this map from the time when the API server processed the eviction request to the time when the pod is seen by PDB controller as having been marked for deletion (or after a timeout). The key in the map is the name of the pod and the value is the time when the API server processed the eviction request. If the deletion didn't occur and a pod is still there it will be removed from the list automatically by PodDisruptionBudget controller after some time. If everything goes smooth this map should be empty for the most of the time. Large number of entries in the map may indicate problems with pod deletions.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
observedGeneration (int64)
Most recent generation observed when updating this PDB status. DisruptionsAllowed and other status information is valid only if observedGeneration equals to PDB's object generation.
PodDisruptionBudgetList
PodDisruptionBudgetList is a collection of PodDisruptionBudgets.
IPAddress represents a single IP of a single IP Family.
apiVersion: networking.k8s.io/v1alpha1
import "k8s.io/api/networking/v1alpha1"
IPAddress
IPAddress represents a single IP of a single IP Family. The object is designed to be used by APIs that operate on IP addresses. The object is used by the Service core API for allocation of IP addresses. An IP address can be represented in different formats, to guarantee the uniqueness of the IP, the name of the object is the IP address in canonical format, four decimal digits separated by dots suppressing leading zeros for IPv4 and the representation defined by RFC 5952 for IPv6. Valid: 192.168.1.5 or 2001:db8::1 or 2001:db8:aaaa:bbbb:cccc:dddd:eeee:1 Invalid: 10.01.2.3 or 2001:db8:0:0:0::1
status indicates the actual state of the CustomResourceDefinition
CustomResourceDefinitionSpec
CustomResourceDefinitionSpec describes how a user wants their resource to appear
group (string), required
group is the API group of the defined custom resource. The custom resources are served under /apis/\<group>/.... Must match the name of the CustomResourceDefinition (in the form \<names.plural>.\<group>).
names (CustomResourceDefinitionNames), required
names specify the resource and kind names for the custom resource.
CustomResourceDefinitionNames indicates the names to serve this CustomResourceDefinition
names.kind (string), required
kind is the serialized kind of the resource. It is normally CamelCase and singular. Custom resource instances will use this value as the kind attribute in API calls.
names.plural (string), required
plural is the plural name of the resource to serve. The custom resources are served under /apis/\<group>/\<version>/.../\<plural>. Must match the name of the CustomResourceDefinition (in the form \<names.plural>.\<group>). Must be all lowercase.
names.categories ([]string)
categories is a list of grouped resources this custom resource belongs to (e.g. 'all'). This is published in API discovery documents, and used by clients to support invocations like kubectl get all.
names.listKind (string)
listKind is the serialized kind of the list for this resource. Defaults to "kindList".
names.shortNames ([]string)
shortNames are short names for the resource, exposed in API discovery documents, and used by clients to support invocations like kubectl get \<shortname>. It must be all lowercase.
names.singular (string)
singular is the singular name of the resource. It must be all lowercase. Defaults to lowercased kind.
scope (string), required
scope indicates whether the defined custom resource is cluster- or namespace-scoped. Allowed values are Cluster and Namespaced.
versions is the list of all API versions of the defined custom resource. Version names are used to compute the order in which served versions are listed in API discovery. If the version string is "kube-like", it will sort above non "kube-like" version strings, which are ordered lexicographically. "Kube-like" versions start with a "v", then are followed by a number (the major version), then optionally the string "alpha" or "beta" and another number (the minor version). These are sorted first by GA > beta > alpha (where GA is a version with no suffix such as beta or alpha), and then by comparing major version, then minor version. An example sorted list of versions: v10, v2, v1, v11beta2, v10beta3, v3beta1, v12alpha1, v11alpha2, foo1, foo10.
CustomResourceDefinitionVersion describes a version for CRD.
versions.name (string), required
name is the version name, e.g. “v1”, “v2beta1”, etc. The custom resources are served under this version at /apis/\<group>/\<version>/... if served is true.
versions.served (boolean), required
served is a flag enabling/disabling this version from being served via REST APIs
versions.storage (boolean), required
storage indicates this version should be used when persisting custom resources to storage. There must be exactly one version with storage=true.
priority is an integer defining the relative importance of this column compared to others. Lower numbers are considered higher priority. Columns that may be omitted in limited space scenarios should be given a priority greater than 0.
versions.deprecated (boolean)
deprecated indicates this version of the custom resource API is deprecated. When set to true, API requests to this version receive a warning header in the server response. Defaults to false.
versions.deprecationWarning (string)
deprecationWarning overrides the default warning returned to API clients. May only be set when deprecated is true. The default warning indicates this version is deprecated and recommends use of the newest served version of equal or greater stability, if one exists.
versions.schema (CustomResourceValidation)
schema describes the schema used for validation, pruning, and defaulting of this version of the custom resource.
CustomResourceValidation is a list of validation methods for CustomResources.
specReplicasPath defines the JSON path inside of a custom resource that corresponds to Scale spec.replicas. Only JSON paths without the array notation are allowed. Must be a JSON Path under .spec. If there is no value under the given path in the custom resource, the /scale subresource will return an error on GET.
statusReplicasPath defines the JSON path inside of a custom resource that corresponds to Scale status.replicas. Only JSON paths without the array notation are allowed. Must be a JSON Path under .status. If there is no value under the given path in the custom resource, the status.replicas value in the /scale subresource will default to 0.
labelSelectorPath defines the JSON path inside of a custom resource that corresponds to Scale status.selector. Only JSON paths without the array notation are allowed. Must be a JSON Path under .status or .spec. Must be set to work with HorizontalPodAutoscaler. The field pointed by this JSON path must be a string field (not a complex selector struct) which contains a serialized label selector in string form. More info: https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions#scale-subresource If there is no value under the given path in the custom resource, the status.selector value in the /scale subresource will default to the empty string.
status indicates the custom resource should serve a /status subresource. When enabled: 1. requests to the custom resource primary endpoint ignore changes to the status stanza of the object. 2. requests to the custom resource /status subresource ignore changes to anything other than the status stanza of the object.
CustomResourceSubresourceStatus defines how to serve the status subresource for CustomResources. Status is represented by the .status JSON path inside of a CustomResource. When set, * exposes a /status subresource for the custom resource * PUT requests to the /status subresource take a custom resource object, and ignore changes to anything except the status stanza * PUT/POST/PATCH requests to the custom resource ignore changes to the status stanza
conversion (CustomResourceConversion)
conversion defines conversion settings for the CRD.
CustomResourceConversion describes how to convert different versions of a CR.
conversion.strategy (string), required
strategy specifies how custom resources are converted between versions. Allowed values are: - "None": The converter only change the apiVersion and would not touch any other field in the custom resource. - "Webhook": API Server will call to an external webhook to do the conversion. Additional information
is needed for this option. This requires spec.preserveUnknownFields to be false, and spec.conversion.webhook to be set.
conversion.webhook (WebhookConversion)
webhook describes how to call the conversion webhook. Required when strategy is set to "Webhook".
WebhookConversion describes how to call a conversion webhook
conversionReviewVersions is an ordered list of preferred ConversionReview versions the Webhook expects. The API server will use the first version in the list which it supports. If none of the versions specified in this list are supported by API server, conversion will fail for the custom resource. If a persisted Webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail.
clientConfig is the instructions for how to call the webhook if strategy is Webhook.
WebhookClientConfig contains the information to make a TLS connection with the webhook.
conversion.webhook.clientConfig.caBundle ([]byte)
caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.
port is an optional service port at which the webhook will be contacted. port should be a valid port number (1-65535, inclusive). Defaults to 443 for backward compatibility.
conversion.webhook.clientConfig.url (string)
url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.
The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in some apiservers (e.g., kube-apiserver cannot resolve in-cluster DNS as that would be a layering violation). host may also be an IP address.
Please note that using localhost or 127.0.0.1 as a host is risky unless you take great care to run this webhook on all hosts which run an apiserver which might need to make calls to this webhook. Such installs are likely to be non-portable, i.e., not easy to turn up in a new cluster.
The scheme must be "https"; the URL must begin with "https://".
A path is optional, and if present may be any string permissible in a URL. You may use the path to pass an arbitrary string to the webhook, for example, a cluster identifier.
Attempting to use a user or basic auth e.g. "user:password@" is not allowed. Fragments ("#...") and query parameters ("?...") are not allowed, either.
preserveUnknownFields (boolean)
preserveUnknownFields indicates that object fields which are not specified in the OpenAPI schema should be preserved when persisting to storage. apiVersion, kind, metadata and known fields inside metadata are always preserved. This field is deprecated in favor of setting x-preserve-unknown-fields to true in spec.versions[*].schema.openAPIV3Schema. See https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#field-pruning for details.
default is a default value for undefined object fields. Defaulting is a beta feature under the CustomResourceDefaulting feature gate. Defaulting requires spec.preserveUnknownFields to be false.
JSON represents any valid JSON value. These types are supported: bool, int64, float64, string, []interface{}, map[string]interface{} and nil.
JSONSchemaPropsOrStringArray represents a JSONSchemaProps or a string array.
description (string)
enum ([]JSON)
JSON represents any valid JSON value. These types are supported: bool, int64, float64, string, []interface{}, map[string]interface{} and nil.
example (JSON)
JSON represents any valid JSON value. These types are supported: bool, int64, float64, string, []interface{}, map[string]interface{} and nil.
exclusiveMaximum (boolean)
exclusiveMinimum (boolean)
externalDocs (ExternalDocumentation)
ExternalDocumentation allows referencing an external resource for extended documentation.
externalDocs.description (string)
externalDocs.url (string)
format (string)
format is an OpenAPI v3 format string. Unknown formats are ignored. The following formats are validated:
bsonobjectid: a bson object ID, i.e. a 24 characters hex string - uri: an URI as parsed by Golang net/url.ParseRequestURI - email: an email address as parsed by Golang net/mail.ParseAddress - hostname: a valid representation for an Internet host name, as defined by RFC 1034, section 3.1 [RFC1034]. - ipv4: an IPv4 IP as parsed by Golang net.ParseIP - ipv6: an IPv6 IP as parsed by Golang net.ParseIP - cidr: a CIDR as parsed by Golang net.ParseCIDR - mac: a MAC address as parsed by Golang net.ParseMAC - uuid: an UUID that allows uppercase defined by the regex (?i)^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$ - uuid3: an UUID3 that allows uppercase defined by the regex (?i)^[0-9a-f]{8}-?[0-9a-f]{4}-?3[0-9a-f]{3}-?[0-9a-f]{4}-?[0-9a-f]{12}$ - uuid4: an UUID4 that allows uppercase defined by the regex (?i)^[0-9a-f]{8}-?[0-9a-f]{4}-?4[0-9a-f]{3}-?[89ab][0-9a-f]{3}-?[0-9a-f]{12}$ - uuid5: an UUID5 that allows uppercase defined by the regex (?i)^[0-9a-f]{8}-?[0-9a-f]{4}-?5[0-9a-f]{3}-?[89ab][0-9a-f]{3}-?[0-9a-f]{12}$ - isbn: an ISBN10 or ISBN13 number string like "0321751043" or "978-0321751041" - isbn10: an ISBN10 number string like "0321751043" - isbn13: an ISBN13 number string like "978-0321751041" - creditcard: a credit card number defined by the regex ^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$ with any non digit characters mixed in - ssn: a U.S. social security number following the regex ^\d{3}[- ]?\d{2}[- ]?\d{4}$ - hexcolor: an hexadecimal color code like "#FFFFFF: following the regex ^#?([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$ - rgbcolor: an RGB color code like rgb like "rgb(255,255,2559" - byte: base64 encoded binary data - password: any kind of string - date: a date string like "2006-01-02" as defined by full-date in RFC3339 - duration: a duration string like "22 ns" as parsed by Golang time.ParseDuration or compatible with Scala duration format - datetime: a date time string like "2014-12-15T19:30:20.000Z" as defined by date-time in RFC3339.
id (string)
items (JSONSchemaPropsOrArray)
JSONSchemaPropsOrArray represents a value that can either be a JSONSchemaProps or an array of JSONSchemaProps. Mainly here for serialization purposes.
x-kubernetes-embedded-resource defines that the value is an embedded Kubernetes runtime.Object, with TypeMeta and ObjectMeta. The type must be object. It is allowed to further restrict the embedded object. kind, apiVersion and metadata are validated automatically. x-kubernetes-preserve-unknown-fields is allowed to be true, but does not have to be if the object is fully specified (up to kind, apiVersion, metadata).
x-kubernetes-int-or-string (boolean)
x-kubernetes-int-or-string specifies that this value is either an integer or a string. If this is true, an empty type is allowed and type as child of anyOf is permitted if following one of the following patterns:
anyOf:
type: integer
type: string
allOf:
anyOf:
type: integer
type: string
... zero or more
x-kubernetes-list-map-keys ([]string)
x-kubernetes-list-map-keys annotates an array with the x-kubernetes-list-type map by specifying the keys used as the index of the map.
This tag MUST only be used on lists that have the "x-kubernetes-list-type" extension set to "map". Also, the values specified for this attribute must be a scalar typed field of the child structure (no nesting is supported).
The properties specified must either be required or have a default value, to ensure those properties are present for all list items.
x-kubernetes-list-type (string)
x-kubernetes-list-type annotates an array to further describe its topology. This extension must only be used on lists and may have 3 possible values:
atomic: the list is treated as a single entity, like a scalar.
Atomic lists will be entirely replaced when updated. This extension
may be used on any type of list (struct, scalar, ...).
set:
Sets are lists that must not have multiple items with the same value. Each
value must be a scalar, an object with x-kubernetes-map-type atomic or an
array with x-kubernetes-list-type atomic.
map:
These lists are like maps in that their elements have a non-index key
used to identify them. Order is preserved upon merge. The map tag
must only be used on a list with elements of type object.
Defaults to atomic for arrays.
x-kubernetes-map-type (string)
x-kubernetes-map-type annotates an object to further describe its topology. This extension must only be used when type is object and may have 2 possible values:
granular:
These maps are actual maps (key-value pairs) and each fields are independent
from each other (they can each be manipulated by separate actors). This is
the default behaviour for all maps.
atomic: the list is treated as a single entity, like a scalar.
Atomic maps will be entirely replaced when updated.
x-kubernetes-preserve-unknown-fields (boolean)
x-kubernetes-preserve-unknown-fields stops the API server decoding step from pruning fields which are not specified in the validation schema. This affects fields recursively, but switches back to normal pruning behaviour if nested properties or additionalProperties are specified in the schema. This can either be true or undefined. False is forbidden.
x-kubernetes-validations ([]ValidationRule)
Patch strategy: merge on key rule
Map: unique values on key rule will be kept during a merge
x-kubernetes-validations describes a list of validation rules written in the CEL expression language. This field is an alpha-level. Using this field requires the feature gate CustomResourceValidationExpressions to be enabled.
ValidationRule describes a validation rule written in the CEL expression language.
x-kubernetes-validations.rule (string), required
Rule represents the expression which will be evaluated by CEL. ref: https://github.com/google/cel-spec The Rule is scoped to the location of the x-kubernetes-validations extension in the schema. The self variable in the CEL expression is bound to the scoped value. Example: - Rule scoped to the root of a resource with a status subresource: {"rule": "self.status.actual <= self.spec.maxDesired"}
If the Rule is scoped to an object with properties, the accessible properties of the object are field selectable via self.field and field presence can be checked via has(self.field). Null valued fields are treated as absent fields in CEL expressions. If the Rule is scoped to an object with additionalProperties (i.e. a map) the value of the map are accessible via self[mapKey], map containment can be checked via mapKey in self and all entries of the map are accessible via CEL macros and functions such as self.all(...). If the Rule is scoped to an array, the elements of the array are accessible via self[i] and also by macros and functions. If the Rule is scoped to a scalar, self is bound to the scalar value. Examples: - Rule scoped to a map of objects: {"rule": "self.components['Widget'].priority < 10"} - Rule scoped to a list of integers: {"rule": "self.values.all(value, value >= 0 && value < 100)"} - Rule scoped to a string value: {"rule": "self.startsWith('kube')"}
The apiVersion, kind, metadata.name and metadata.generateName are always accessible from the root of the object and from any x-kubernetes-embedded-resource annotated objects. No other metadata properties are accessible.
Unknown data preserved in custom resources via x-kubernetes-preserve-unknown-fields is not accessible in CEL expressions. This includes: - Unknown field values that are preserved by object schemas with x-kubernetes-preserve-unknown-fields. - Object properties where the property schema is of an "unknown type". An "unknown type" is recursively defined as:
A schema with no type and x-kubernetes-preserve-unknown-fields set to true
An array where the items schema is of an "unknown type"
An object where the additionalProperties schema is of an "unknown type"
Only property names of the form [a-zA-Z_.-/][a-zA-Z0-9_.-/]* are accessible. Accessible property names are escaped according to the following rules when accessed in the expression: - '' escapes to 'underscores' - '.' escapes to 'dot' - '-' escapes to 'dash' - '/' escapes to 'slash' - Property names that exactly match a CEL RESERVED keyword escape to '{keyword}__'. The keywords are:
"true", "false", "null", "in", "as", "break", "const", "continue", "else", "for", "function", "if",
"import", "let", "loop", "package", "namespace", "return".
Examples:
Rule accessing a property named "namespace": {"rule": "self.namespace > 0"}
Rule accessing a property named "x-prop": {"rule": "self.x__dash__prop > 0"}
Rule accessing a property named "redact__d": {"rule": "self.redact__underscores__d > 0"}
Equality on arrays with x-kubernetes-list-type of 'set' or 'map' ignores element order, i.e. [1, 2] == [2, 1]. Concatenation on arrays with x-kubernetes-list-type use the semantics of the list type:
'set': X + Y performs a union where the array positions of all elements in X are preserved and
non-intersecting elements in Y are appended, retaining their partial order.
'map': X + Y performs a merge where the array positions of all keys in X are preserved but the values
are overwritten by values in Y when the key sets of X and Y intersect. Elements in Y with
non-intersecting keys are appended, retaining their partial order.
x-kubernetes-validations.fieldPath (string)
fieldPath represents the field path returned when the validation fails. It must be a relative JSON path (i.e. with array notation) scoped to the location of this x-kubernetes-validations extension in the schema and refer to an existing field. e.g. when validation checks if a specific attribute foo under a map testMap, the fieldPath could be set to .testMap.foo If the validation checks two lists must have unique attributes, the fieldPath could be set to either of the list: e.g. .testList It does not support list numeric index. It supports child operation to refer to an existing field currently. Refer to JSONPath support in Kubernetes for more info. Numeric index of array is not supported. For field name which contains special characters, use ['specialName'] to refer the field name. e.g. for attribute foo.34$ appears in a list testList, the fieldPath could be set to .testList['foo.34$']
x-kubernetes-validations.message (string)
Message represents the message displayed when validation fails. The message is required if the Rule contains line breaks. The message must not contain line breaks. If unset, the message is "failed rule: {Rule}". e.g. "must be a URL with the host matching spec.host"
MessageExpression declares a CEL expression that evaluates to the validation failure message that is returned when this rule fails. Since messageExpression is used as a failure message, it must evaluate to a string. If both message and messageExpression are present on a rule, then messageExpression will be used if validation fails. If messageExpression results in a runtime error, the runtime error is logged, and the validation failure message is produced as if the messageExpression field were unset. If messageExpression evaluates to an empty string, a string with only spaces, or a string that contains line breaks, then the validation failure message will also be produced as if the messageExpression field were unset, and the fact that messageExpression produced an empty string/string with only spaces/string with line breaks will be logged. messageExpression has access to all the same variables as the rule; the only difference is the return type. Example: "x must be less than max ("+string(self.max)+")"
x-kubernetes-validations.reason (string)
reason provides a machine-readable validation failure reason that is returned to the caller when a request fails this validation rule. The HTTP status code returned to the caller will match the reason of the reason of the first failed validation rule. The currently supported reasons are: "FieldValueInvalid", "FieldValueForbidden", "FieldValueRequired", "FieldValueDuplicate". If not set, default to use "FieldValueInvalid". All future added reasons must be accepted by clients when reading this value and unknown reasons should be treated as FieldValueInvalid.
CustomResourceDefinitionStatus
CustomResourceDefinitionStatus indicates the state of the CustomResourceDefinition
acceptedNames (CustomResourceDefinitionNames)
acceptedNames are the names that are actually being used to serve discovery. They may be different than the names in spec.
CustomResourceDefinitionNames indicates the names to serve this CustomResourceDefinition
acceptedNames.kind (string), required
kind is the serialized kind of the resource. It is normally CamelCase and singular. Custom resource instances will use this value as the kind attribute in API calls.
acceptedNames.plural (string), required
plural is the plural name of the resource to serve. The custom resources are served under /apis/\<group>/\<version>/.../\<plural>. Must match the name of the CustomResourceDefinition (in the form \<names.plural>.\<group>). Must be all lowercase.
acceptedNames.categories ([]string)
categories is a list of grouped resources this custom resource belongs to (e.g. 'all'). This is published in API discovery documents, and used by clients to support invocations like kubectl get all.
acceptedNames.listKind (string)
listKind is the serialized kind of the list for this resource. Defaults to "kindList".
acceptedNames.shortNames ([]string)
shortNames are short names for the resource, exposed in API discovery documents, and used by clients to support invocations like kubectl get \<shortname>. It must be all lowercase.
acceptedNames.singular (string)
singular is the singular name of the resource. It must be all lowercase. Defaults to lowercased kind.
conditions ([]CustomResourceDefinitionCondition)
Map: unique values on key type will be kept during a merge
conditions indicate state for particular aspects of a CustomResourceDefinition
CustomResourceDefinitionCondition contains details for the current condition of this pod.
conditions.status (string), required
status is the status of the condition. Can be True, False, Unknown.
conditions.type (string), required
type is the type of the condition. Types include Established, NamesAccepted and Terminating.
conditions.lastTransitionTime (Time)
lastTransitionTime last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message is a human-readable message indicating details about last transition.
conditions.reason (string)
reason is a unique, one-word, CamelCase reason for the condition's last transition.
storedVersions ([]string)
storedVersions lists all versions of CustomResources that were ever persisted. Tracking these versions allows a migration path for stored versions in etcd. The field is mutable so a migration controller can finish a migration to another version (ensuring no old objects are left in storage), and then remove the rest of the versions from this list. Versions may not be removed from spec.versions while they exist in this list.
CustomResourceDefinitionList
CustomResourceDefinitionList is a list of CustomResourceDefinition objects.
AdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.
ClientConfig defines how to communicate with the hook. Required
WebhookClientConfig contains the information to make a TLS connection with the webhook
webhooks.clientConfig.caBundle ([]byte)
caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.
webhooks.clientConfig.service (ServiceReference)
service is a reference to the service for this webhook. Either service or url must be specified.
If the webhook is running within the cluster, then you should use service.
ServiceReference holds a reference to Service.legacy.k8s.io
namespace is the namespace of the service. Required
webhooks.clientConfig.service.path (string)
path is an optional URL path which will be sent in any request to this service.
webhooks.clientConfig.service.port (int32)
If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).
webhooks.clientConfig.url (string)
url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.
The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in some apiservers (e.g., kube-apiserver cannot resolve in-cluster DNS as that would be a layering violation). host may also be an IP address.
Please note that using localhost or 127.0.0.1 as a host is risky unless you take great care to run this webhook on all hosts which run an apiserver which might need to make calls to this webhook. Such installs are likely to be non-portable, i.e., not easy to turn up in a new cluster.
The scheme must be "https"; the URL must begin with "https://".
A path is optional, and if present may be any string permissible in a URL. You may use the path to pass an arbitrary string to the webhook, for example, a cluster identifier.
Attempting to use a user or basic auth e.g. "user:password@" is not allowed. Fragments ("#...") and query parameters ("?...") are not allowed, either.
webhooks.name (string), required
The name of the admission webhook. Name should be fully qualified, e.g., imagepolicy.kubernetes.io, where "imagepolicy" is the name of the webhook, and kubernetes.io is the name of the organization. Required.
webhooks.sideEffects (string), required
SideEffects states whether this webhook has side effects. Acceptable values are: None, NoneOnDryRun (webhooks created via v1beta1 may also specify Some or Unknown). Webhooks with side effects MUST implement a reconciliation system, since a request may be rejected by a future step in the admission chain and the side effects therefore need to be undone. Requests with the dryRun attribute will be auto-rejected if they match a webhook with sideEffects == Unknown or Some.
webhooks.failurePolicy (string)
FailurePolicy defines how unrecognized errors from the admission endpoint are handled - allowed values are Ignore or Fail. Defaults to Fail.
webhooks.matchConditions ([]MatchCondition)
Patch strategy: merge on key name
Map: unique values on key name will be kept during a merge
MatchConditions is a list of conditions that must be met for a request to be sent to this webhook. Match conditions filter requests that have already been matched by the rules, namespaceSelector, and objectSelector. An empty list of matchConditions matches all requests. There are a maximum of 64 match conditions allowed.
The exact matching logic is (in order):
If ANY matchCondition evaluates to FALSE, the webhook is skipped.
If ALL matchConditions evaluate to TRUE, the webhook is called.
If any matchCondition evaluates to an error (but none are FALSE):
If failurePolicy=Fail, reject the request
If failurePolicy=Ignore, the error is ignored and the webhook is skipped
This is a beta feature and managed by the AdmissionWebhookMatchConditions feature gate.
MatchCondition represents a condition which must by fulfilled for a request to be sent to a webhook.
Expression represents the expression which will be evaluated by CEL. Must evaluate to bool. CEL expressions have access to the contents of the AdmissionRequest and Authorizer, organized into CEL variables:
'object' - The object from the incoming request. The value is null for DELETE requests. 'oldObject' - The existing object. The value is null for CREATE requests. 'request' - Attributes of the admission request(/pkg/apis/admission/types.go#AdmissionRequest). 'authorizer' - A CEL Authorizer. May be used to perform authorization checks for the principal (user or service account) of the request.
See https://pkg.go.dev/k8s.io/apiserver/pkg/cel/library#Authz
'authorizer.requestResource' - A CEL ResourceCheck constructed from the 'authorizer' and configured with the
request resource.
Documentation on CEL: https://kubernetes.io/docs/reference/using-api/cel/
Required.
webhooks.matchConditions.name (string), required
Name is an identifier for this match condition, used for strategic merging of MatchConditions, as well as providing an identifier for logging purposes. A good name should be descriptive of the associated expression. Name must be a qualified name consisting of alphanumeric characters, '-', '' or '.', and must start and end with an alphanumeric character (e.g. 'MyName', or 'my.name', or '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9.]*)?[A-Za-z0-9]') with an optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
Required.
webhooks.matchPolicy (string)
matchPolicy defines how the "rules" list is used to match incoming requests. Allowed values are "Exact" or "Equivalent".
Exact: match a request only if it exactly matches a specified rule. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, but "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would not be sent to the webhook.
Equivalent: match a request if modifies a resource listed in rules, even via another API group or version. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, and "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would be converted to apps/v1 and sent to the webhook.
NamespaceSelector decides whether to run the webhook on an object based on whether the namespace for that object matches the selector. If the object itself is a namespace, the matching is performed on object.metadata.labels. If the object is another cluster scoped resource, it never skips the webhook.
For example, to run the webhook on any objects whose namespace is not associated with "runlevel" of "0" or "1"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "runlevel",
"operator": "NotIn",
"values": [
"0",
"1"
]
}
]
}
If instead you want to only run the webhook on any objects whose namespace is associated with the "environment" of "prod" or "staging"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "environment",
"operator": "In",
"values": [
"prod",
"staging"
]
}
]
}
ObjectSelector decides whether to run the webhook based on if the object has matching labels. objectSelector is evaluated against both the oldObject and newObject that would be sent to the webhook, and is considered to match if either object matches the selector. A null object (oldObject in the case of create, or newObject in the case of delete) or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object) is not considered to match. Use the object selector only if the webhook is opt-in, because end users may skip the admission webhook by setting the labels. Default to the empty LabelSelector, which matches everything.
webhooks.reinvocationPolicy (string)
reinvocationPolicy indicates whether this webhook should be called multiple times as part of a single admission evaluation. Allowed values are "Never" and "IfNeeded".
Never: the webhook will not be called more than once in a single admission evaluation.
IfNeeded: the webhook will be called at least one additional time as part of the admission evaluation if the object being admitted is modified by other admission plugins after the initial webhook call. Webhooks that specify this option must be idempotent, able to process objects they previously admitted. Note: * the number of additional invocations is not guaranteed to be exactly one. * if additional invocations result in further modifications to the object, webhooks are not guaranteed to be invoked again. * webhooks that use this option may be reordered to minimize the number of additional invocations. * to validate an object after all mutations are guaranteed complete, use a validating admission webhook instead.
Defaults to "Never".
webhooks.rules ([]RuleWithOperations)
Rules describes what operations on what resources/subresources the webhook cares about. The webhook cares about an operation if it matches any Rule. However, in order to prevent ValidatingAdmissionWebhooks and MutatingAdmissionWebhooks from putting the cluster in a state which cannot be recovered from without completely disabling the plugin, ValidatingAdmissionWebhooks and MutatingAdmissionWebhooks are never called on admission requests for ValidatingWebhookConfiguration and MutatingWebhookConfiguration objects.
RuleWithOperations is a tuple of Operations and Resources. It is recommended to make sure that all the tuple expansions are valid.
webhooks.rules.apiGroups ([]string)
Atomic: will be replaced during a merge
APIGroups is the API groups the resources belong to. '' is all groups. If '' is present, the length of the slice must be one. Required.
webhooks.rules.apiVersions ([]string)
Atomic: will be replaced during a merge
APIVersions is the API versions the resources belong to. '' is all versions. If '' is present, the length of the slice must be one. Required.
webhooks.rules.operations ([]string)
Atomic: will be replaced during a merge
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
webhooks.rules.resources ([]string)
Atomic: will be replaced during a merge
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
webhooks.rules.scope (string)
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
webhooks.timeoutSeconds (int32)
TimeoutSeconds specifies the timeout for this webhook. After the timeout passes, the webhook call will be ignored or the API call will fail based on the failure policy. The timeout value must be between 1 and 30 seconds. Default to 10 seconds.
MutatingWebhookConfigurationList
MutatingWebhookConfigurationList is a list of MutatingWebhookConfiguration.
AdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.
ClientConfig defines how to communicate with the hook. Required
WebhookClientConfig contains the information to make a TLS connection with the webhook
webhooks.clientConfig.caBundle ([]byte)
caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.
webhooks.clientConfig.service (ServiceReference)
service is a reference to the service for this webhook. Either service or url must be specified.
If the webhook is running within the cluster, then you should use service.
ServiceReference holds a reference to Service.legacy.k8s.io
namespace is the namespace of the service. Required
webhooks.clientConfig.service.path (string)
path is an optional URL path which will be sent in any request to this service.
webhooks.clientConfig.service.port (int32)
If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).
webhooks.clientConfig.url (string)
url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.
The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in some apiservers (e.g., kube-apiserver cannot resolve in-cluster DNS as that would be a layering violation). host may also be an IP address.
Please note that using localhost or 127.0.0.1 as a host is risky unless you take great care to run this webhook on all hosts which run an apiserver which might need to make calls to this webhook. Such installs are likely to be non-portable, i.e., not easy to turn up in a new cluster.
The scheme must be "https"; the URL must begin with "https://".
A path is optional, and if present may be any string permissible in a URL. You may use the path to pass an arbitrary string to the webhook, for example, a cluster identifier.
Attempting to use a user or basic auth e.g. "user:password@" is not allowed. Fragments ("#...") and query parameters ("?...") are not allowed, either.
webhooks.name (string), required
The name of the admission webhook. Name should be fully qualified, e.g., imagepolicy.kubernetes.io, where "imagepolicy" is the name of the webhook, and kubernetes.io is the name of the organization. Required.
webhooks.sideEffects (string), required
SideEffects states whether this webhook has side effects. Acceptable values are: None, NoneOnDryRun (webhooks created via v1beta1 may also specify Some or Unknown). Webhooks with side effects MUST implement a reconciliation system, since a request may be rejected by a future step in the admission chain and the side effects therefore need to be undone. Requests with the dryRun attribute will be auto-rejected if they match a webhook with sideEffects == Unknown or Some.
webhooks.failurePolicy (string)
FailurePolicy defines how unrecognized errors from the admission endpoint are handled - allowed values are Ignore or Fail. Defaults to Fail.
webhooks.matchConditions ([]MatchCondition)
Patch strategy: merge on key name
Map: unique values on key name will be kept during a merge
MatchConditions is a list of conditions that must be met for a request to be sent to this webhook. Match conditions filter requests that have already been matched by the rules, namespaceSelector, and objectSelector. An empty list of matchConditions matches all requests. There are a maximum of 64 match conditions allowed.
The exact matching logic is (in order):
If ANY matchCondition evaluates to FALSE, the webhook is skipped.
If ALL matchConditions evaluate to TRUE, the webhook is called.
If any matchCondition evaluates to an error (but none are FALSE):
If failurePolicy=Fail, reject the request
If failurePolicy=Ignore, the error is ignored and the webhook is skipped
This is a beta feature and managed by the AdmissionWebhookMatchConditions feature gate.
MatchCondition represents a condition which must by fulfilled for a request to be sent to a webhook.
Expression represents the expression which will be evaluated by CEL. Must evaluate to bool. CEL expressions have access to the contents of the AdmissionRequest and Authorizer, organized into CEL variables:
'object' - The object from the incoming request. The value is null for DELETE requests. 'oldObject' - The existing object. The value is null for CREATE requests. 'request' - Attributes of the admission request(/pkg/apis/admission/types.go#AdmissionRequest). 'authorizer' - A CEL Authorizer. May be used to perform authorization checks for the principal (user or service account) of the request.
See https://pkg.go.dev/k8s.io/apiserver/pkg/cel/library#Authz
'authorizer.requestResource' - A CEL ResourceCheck constructed from the 'authorizer' and configured with the
request resource.
Documentation on CEL: https://kubernetes.io/docs/reference/using-api/cel/
Required.
webhooks.matchConditions.name (string), required
Name is an identifier for this match condition, used for strategic merging of MatchConditions, as well as providing an identifier for logging purposes. A good name should be descriptive of the associated expression. Name must be a qualified name consisting of alphanumeric characters, '-', '' or '.', and must start and end with an alphanumeric character (e.g. 'MyName', or 'my.name', or '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9.]*)?[A-Za-z0-9]') with an optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
Required.
webhooks.matchPolicy (string)
matchPolicy defines how the "rules" list is used to match incoming requests. Allowed values are "Exact" or "Equivalent".
Exact: match a request only if it exactly matches a specified rule. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, but "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would not be sent to the webhook.
Equivalent: match a request if modifies a resource listed in rules, even via another API group or version. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, and "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would be converted to apps/v1 and sent to the webhook.
NamespaceSelector decides whether to run the webhook on an object based on whether the namespace for that object matches the selector. If the object itself is a namespace, the matching is performed on object.metadata.labels. If the object is another cluster scoped resource, it never skips the webhook.
For example, to run the webhook on any objects whose namespace is not associated with "runlevel" of "0" or "1"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "runlevel",
"operator": "NotIn",
"values": [
"0",
"1"
]
}
]
}
If instead you want to only run the webhook on any objects whose namespace is associated with the "environment" of "prod" or "staging"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "environment",
"operator": "In",
"values": [
"prod",
"staging"
]
}
]
}
ObjectSelector decides whether to run the webhook based on if the object has matching labels. objectSelector is evaluated against both the oldObject and newObject that would be sent to the webhook, and is considered to match if either object matches the selector. A null object (oldObject in the case of create, or newObject in the case of delete) or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object) is not considered to match. Use the object selector only if the webhook is opt-in, because end users may skip the admission webhook by setting the labels. Default to the empty LabelSelector, which matches everything.
webhooks.rules ([]RuleWithOperations)
Rules describes what operations on what resources/subresources the webhook cares about. The webhook cares about an operation if it matches any Rule. However, in order to prevent ValidatingAdmissionWebhooks and MutatingAdmissionWebhooks from putting the cluster in a state which cannot be recovered from without completely disabling the plugin, ValidatingAdmissionWebhooks and MutatingAdmissionWebhooks are never called on admission requests for ValidatingWebhookConfiguration and MutatingWebhookConfiguration objects.
RuleWithOperations is a tuple of Operations and Resources. It is recommended to make sure that all the tuple expansions are valid.
webhooks.rules.apiGroups ([]string)
Atomic: will be replaced during a merge
APIGroups is the API groups the resources belong to. '' is all groups. If '' is present, the length of the slice must be one. Required.
webhooks.rules.apiVersions ([]string)
Atomic: will be replaced during a merge
APIVersions is the API versions the resources belong to. '' is all versions. If '' is present, the length of the slice must be one. Required.
webhooks.rules.operations ([]string)
Atomic: will be replaced during a merge
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
webhooks.rules.resources ([]string)
Atomic: will be replaced during a merge
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
webhooks.rules.scope (string)
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
webhooks.timeoutSeconds (int32)
TimeoutSeconds specifies the timeout for this webhook. After the timeout passes, the webhook call will be ignored or the API call will fail based on the failure policy. The timeout value must be between 1 and 30 seconds. Default to 10 seconds.
ValidatingWebhookConfigurationList
ValidatingWebhookConfigurationList is a list of ValidatingWebhookConfiguration.
Specification of the desired behavior of the ValidatingAdmissionPolicy.
ValidatingAdmissionPolicySpec is the specification of the desired behavior of the AdmissionPolicy.
spec.auditAnnotations ([]AuditAnnotation)
Atomic: will be replaced during a merge
auditAnnotations contains CEL expressions which are used to produce audit annotations for the audit event of the API request. validations and auditAnnotations may not both be empty; a least one of validations or auditAnnotations is required.
AuditAnnotation describes how to produce an audit annotation for an API request.
spec.auditAnnotations.key (string), required
key specifies the audit annotation key. The audit annotation keys of a ValidatingAdmissionPolicy must be unique. The key must be a qualified name ([A-Za-z0-9][-A-Za-z0-9_.]*) no more than 63 bytes in length.
The key is combined with the resource name of the ValidatingAdmissionPolicy to construct an audit annotation key: "{ValidatingAdmissionPolicy name}/{key}".
If an admission webhook uses the same resource name as this ValidatingAdmissionPolicy and the same audit annotation key, the annotation key will be identical. In this case, the first annotation written with the key will be included in the audit event and all subsequent annotations with the same key will be discarded.
valueExpression represents the expression which is evaluated by CEL to produce an audit annotation value. The expression must evaluate to either a string or null value. If the expression evaluates to a string, the audit annotation is included with the string value. If the expression evaluates to null or empty string the audit annotation will be omitted. The valueExpression may be no longer than 5kb in length. If the result of the valueExpression is more than 10kb in length, it will be truncated to 10kb.
If multiple ValidatingAdmissionPolicyBinding resources match an API request, then the valueExpression will be evaluated for each binding. All unique values produced by the valueExpressions will be joined together in a comma-separated list.
Required.
spec.failurePolicy (string)
failurePolicy defines how to handle failures for the admission policy. Failures can occur from CEL expression parse errors, type check errors, runtime errors and invalid or mis-configured policy definitions or bindings.
A policy is invalid if spec.paramKind refers to a non-existent Kind. A binding is invalid if spec.paramRef.name refers to a non-existent resource.
failurePolicy does not define how validations that evaluate to false are handled.
When failurePolicy is set to Fail, ValidatingAdmissionPolicyBinding validationActions define how failures are enforced.
Allowed values are Ignore or Fail. Defaults to Fail.
spec.matchConditions ([]MatchCondition)
Patch strategy: merge on key name
Map: unique values on key name will be kept during a merge
MatchConditions is a list of conditions that must be met for a request to be validated. Match conditions filter requests that have already been matched by the rules, namespaceSelector, and objectSelector. An empty list of matchConditions matches all requests. There are a maximum of 64 match conditions allowed.
If a parameter object is provided, it can be accessed via the params handle in the same manner as validation expressions.
The exact matching logic is (in order):
If ANY matchCondition evaluates to FALSE, the policy is skipped.
If ALL matchConditions evaluate to TRUE, the policy is evaluated.
If any matchCondition evaluates to an error (but none are FALSE):
If failurePolicy=Fail, reject the request
If failurePolicy=Ignore, the policy is skipped
MatchCondition represents a condition which must be fulfilled for a request to be sent to a webhook.
Expression represents the expression which will be evaluated by CEL. Must evaluate to bool. CEL expressions have access to the contents of the AdmissionRequest and Authorizer, organized into CEL variables:
'object' - The object from the incoming request. The value is null for DELETE requests. 'oldObject' - The existing object. The value is null for CREATE requests. 'request' - Attributes of the admission request(/pkg/apis/admission/types.go#AdmissionRequest). 'authorizer' - A CEL Authorizer. May be used to perform authorization checks for the principal (user or service account) of the request.
See https://pkg.go.dev/k8s.io/apiserver/pkg/cel/library#Authz
'authorizer.requestResource' - A CEL ResourceCheck constructed from the 'authorizer' and configured with the
request resource.
Documentation on CEL: https://kubernetes.io/docs/reference/using-api/cel/
Required.
spec.matchConditions.name (string), required
Name is an identifier for this match condition, used for strategic merging of MatchConditions, as well as providing an identifier for logging purposes. A good name should be descriptive of the associated expression. Name must be a qualified name consisting of alphanumeric characters, '-', '' or '.', and must start and end with an alphanumeric character (e.g. 'MyName', or 'my.name', or '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9.]*)?[A-Za-z0-9]') with an optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
Required.
spec.matchConstraints (MatchResources)
MatchConstraints specifies what resources this policy is designed to validate. The AdmissionPolicy cares about a request if it matches all Constraints. However, in order to prevent clusters from being put into an unstable state that cannot be recovered from via the API ValidatingAdmissionPolicy cannot match ValidatingAdmissionPolicy and ValidatingAdmissionPolicyBinding. Required.
MatchResources decides whether to run the admission control policy on an object based on whether it meets the match criteria. The exclude rules take precedence over include rules (if a resource matches both, it is excluded)
ExcludeResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy should not care about. The exclude rules take precedence over include rules (if a resource matches both, it is excluded)
NamedRuleWithOperations is a tuple of Operations and Resources with ResourceNames.
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
spec.matchConstraints.matchPolicy (string)
matchPolicy defines how the "MatchResources" list is used to match incoming requests. Allowed values are "Exact" or "Equivalent".
Exact: match a request only if it exactly matches a specified rule. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, but "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would not be sent to the ValidatingAdmissionPolicy.
Equivalent: match a request if modifies a resource listed in rules, even via another API group or version. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, and "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would be converted to apps/v1 and sent to the ValidatingAdmissionPolicy.
NamespaceSelector decides whether to run the admission control policy on an object based on whether the namespace for that object matches the selector. If the object itself is a namespace, the matching is performed on object.metadata.labels. If the object is another cluster scoped resource, it never skips the policy.
For example, to run the webhook on any objects whose namespace is not associated with "runlevel" of "0" or "1"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "runlevel",
"operator": "NotIn",
"values": [
"0",
"1"
]
}
]
}
If instead you want to only run the policy on any objects whose namespace is associated with the "environment" of "prod" or "staging"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "environment",
"operator": "In",
"values": [
"prod",
"staging"
]
}
]
}
ObjectSelector decides whether to run the validation based on if the object has matching labels. objectSelector is evaluated against both the oldObject and newObject that would be sent to the cel validation, and is considered to match if either object matches the selector. A null object (oldObject in the case of create, or newObject in the case of delete) or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object) is not considered to match. Use the object selector only if the webhook is opt-in, because end users may skip the admission webhook by setting the labels. Default to the empty LabelSelector, which matches everything.
ResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy matches. The policy cares about an operation if it matches any Rule.
NamedRuleWithOperations is a tuple of Operations and Resources with ResourceNames.
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
spec.paramKind (ParamKind)
ParamKind specifies the kind of resources used to parameterize this policy. If absent, there are no parameters for this policy and the param CEL variable will not be provided to validation expressions. If ParamKind refers to a non-existent kind, this policy definition is mis-configured and the FailurePolicy is applied. If paramKind is specified but paramRef is unset in ValidatingAdmissionPolicyBinding, the params variable will be null.
ParamKind is a tuple of Group Kind and Version.
spec.paramKind.apiVersion (string)
APIVersion is the API group version the resources belong to. In format of "group/version". Required.
spec.paramKind.kind (string)
Kind is the API kind the resources belong to. Required.
spec.validations ([]Validation)
Atomic: will be replaced during a merge
Validations contain CEL expressions which is used to apply the validation. Validations and AuditAnnotations may not both be empty; a minimum of one Validations or AuditAnnotations is required.
Validation specifies the CEL expression which is used to apply the validation.
spec.validations.expression (string), required
Expression represents the expression which will be evaluated by CEL. ref: https://github.com/google/cel-spec CEL expressions have access to the contents of the API request/response, organized into CEL variables as well as some other useful variables:
'object' - The object from the incoming request. The value is null for DELETE requests. - 'oldObject' - The existing object. The value is null for CREATE requests. - 'request' - Attributes of the API request(ref). - 'params' - Parameter resource referred to by the policy binding being evaluated. Only populated if the policy has a ParamKind. - 'namespaceObject' - The namespace object that the incoming object belongs to. The value is null for cluster-scoped resources. - 'variables' - Map of composited variables, from its name to its lazily evaluated value.
For example, a variable named 'foo' can be accessed as 'variables.foo'.
'authorizer.requestResource' - A CEL ResourceCheck constructed from the 'authorizer' and configured with the
request resource.
The apiVersion, kind, metadata.name and metadata.generateName are always accessible from the root of the object. No other metadata properties are accessible.
Only property names of the form [a-zA-Z_.-/][a-zA-Z0-9_.-/]* are accessible. Accessible property names are escaped according to the following rules when accessed in the expression: - '' escapes to 'underscores' - '.' escapes to 'dot' - '-' escapes to 'dash' - '/' escapes to 'slash' - Property names that exactly match a CEL RESERVED keyword escape to '{keyword}__'. The keywords are:
"true", "false", "null", "in", "as", "break", "const", "continue", "else", "for", "function", "if",
"import", "let", "loop", "package", "namespace", "return".
Examples:
Expression accessing a property named "namespace": {"Expression": "object.namespace > 0"}
Expression accessing a property named "x-prop": {"Expression": "object.x__dash__prop > 0"}
Expression accessing a property named "redact__d": {"Expression": "object.redact__underscores__d > 0"}
Equality on arrays with list type of 'set' or 'map' ignores element order, i.e. [1, 2] == [2, 1]. Concatenation on arrays with x-kubernetes-list-type use the semantics of the list type:
'set': X + Y performs a union where the array positions of all elements in X are preserved and
non-intersecting elements in Y are appended, retaining their partial order.
'map': X + Y performs a merge where the array positions of all keys in X are preserved but the values
are overwritten by values in Y when the key sets of X and Y intersect. Elements in Y with
non-intersecting keys are appended, retaining their partial order.
Required.
spec.validations.message (string)
Message represents the message displayed when validation fails. The message is required if the Expression contains line breaks. The message must not contain line breaks. If unset, the message is "failed rule: {Rule}". e.g. "must be a URL with the host matching spec.host" If the Expression contains line breaks. Message is required. The message must not contain line breaks. If unset, the message is "failed Expression: {Expression}".
spec.validations.messageExpression (string)
messageExpression declares a CEL expression that evaluates to the validation failure message that is returned when this rule fails. Since messageExpression is used as a failure message, it must evaluate to a string. If both message and messageExpression are present on a validation, then messageExpression will be used if validation fails. If messageExpression results in a runtime error, the runtime error is logged, and the validation failure message is produced as if the messageExpression field were unset. If messageExpression evaluates to an empty string, a string with only spaces, or a string that contains line breaks, then the validation failure message will also be produced as if the messageExpression field were unset, and the fact that messageExpression produced an empty string/string with only spaces/string with line breaks will be logged. messageExpression has access to all the same variables as the expression except for 'authorizer' and 'authorizer.requestResource'. Example: "object.x must be less than max ("+string(params.max)+")"
spec.validations.reason (string)
Reason represents a machine-readable description of why this validation failed. If this is the first validation in the list to fail, this reason, as well as the corresponding HTTP response code, are used in the HTTP response to the client. The currently supported reasons are: "Unauthorized", "Forbidden", "Invalid", "RequestEntityTooLarge". If not set, StatusReasonInvalid is used in the response to the client.
spec.variables ([]Variable)
Patch strategy: merge on key name
Map: unique values on key name will be kept during a merge
Variables contain definitions of variables that can be used in composition of other expressions. Each variable is defined as a named CEL expression. The variables defined here will be available under variables in other expressions of the policy except MatchConditions because MatchConditions are evaluated before the rest of the policy.
The expression of a variable can refer to other variables defined earlier in the list but not those after. Thus, Variables must be sorted by the order of first appearance and acyclic.
Variable is the definition of a variable that is used for composition. A variable is defined as a named expression.
spec.variables.expression (string), required
Expression is the expression that will be evaluated as the value of the variable. The CEL expression has access to the same identifiers as the CEL expressions in Validation.
spec.variables.name (string), required
Name is the name of the variable. The name must be a valid CEL identifier and unique among all variables. The variable can be accessed in other expressions through variables For example, if name is "foo", the variable will be available as variables.foo
status (ValidatingAdmissionPolicyStatus)
The status of the ValidatingAdmissionPolicy, including warnings that are useful to determine if the policy behaves in the expected way. Populated by the system. Read-only.
ValidatingAdmissionPolicyStatus represents the status of an admission validation policy.
status.conditions ([]Condition)
Map: unique values on key type will be kept during a merge
The conditions represent the latest available observations of a policy's current state.
Condition contains details for one aspect of the current state of this API Resource.
lastTransitionTime is the last time the condition transitioned from one status to another. This should be when the underlying condition changed. If that is not known, then using the time when the API field changed is acceptable.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
status.conditions.message (string), required
message is a human readable message indicating details about the transition. This may be an empty string.
status.conditions.reason (string), required
reason contains a programmatic identifier indicating the reason for the condition's last transition. Producers of specific condition types may define expected values and meanings for this field, and whether the values are considered a guaranteed API. The value should be a CamelCase string. This field may not be empty.
status.conditions.status (string), required
status of the condition, one of True, False, Unknown.
status.conditions.type (string), required
type of condition in CamelCase or in foo.example.com/CamelCase.
status.conditions.observedGeneration (int64)
observedGeneration represents the .metadata.generation that the condition was set based upon. For instance, if .metadata.generation is currently 12, but the .status.conditions[x].observedGeneration is 9, the condition is out of date with respect to the current state of the instance.
status.observedGeneration (int64)
The generation observed by the controller.
status.typeChecking (TypeChecking)
The results of type checking for each expression. Presence of this field indicates the completion of the type checking.
TypeChecking contains results of type checking the expressions in the ValidatingAdmissionPolicy
The path to the field that refers the expression. For example, the reference to the expression of the first item of validations is "spec.validations[0].expression"
The content of type checking information in a human-readable form. Each line of the warning contains the type that the expression is checked against, followed by the type check error from the compiler.
ValidatingAdmissionPolicyList
ValidatingAdmissionPolicyList is a list of ValidatingAdmissionPolicy.
ValidatingAdmissionPolicyBinding binds the ValidatingAdmissionPolicy with paramerized resources. ValidatingAdmissionPolicyBinding and parameter CRDs together define how cluster administrators configure policies for clusters.
For a given admission request, each binding will cause its policy to be evaluated N times, where N is 1 for policies/bindings that don't use params, otherwise N is the number of parameters selected by the binding.
The CEL expressions of a policy must have a computed CEL cost below the maximum CEL budget. Each evaluation of the policy is given an independent CEL cost budget. Adding/removing policies, bindings, or params can not affect whether a given (policy, binding, param) combination is within its own CEL budget.
Specification of the desired behavior of the ValidatingAdmissionPolicyBinding.
ValidatingAdmissionPolicyBindingSpec is the specification of the ValidatingAdmissionPolicyBinding.
spec.matchResources (MatchResources)
MatchResources declares what resources match this binding and will be validated by it. Note that this is intersected with the policy's matchConstraints, so only requests that are matched by the policy can be selected by this. If this is unset, all resources matched by the policy are validated by this binding When resourceRules is unset, it does not constrain resource matching. If a resource is matched by the other fields of this object, it will be validated. Note that this is differs from ValidatingAdmissionPolicy matchConstraints, where resourceRules are required.
MatchResources decides whether to run the admission control policy on an object based on whether it meets the match criteria. The exclude rules take precedence over include rules (if a resource matches both, it is excluded)
ExcludeResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy should not care about. The exclude rules take precedence over include rules (if a resource matches both, it is excluded)
NamedRuleWithOperations is a tuple of Operations and Resources with ResourceNames.
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
spec.matchResources.matchPolicy (string)
matchPolicy defines how the "MatchResources" list is used to match incoming requests. Allowed values are "Exact" or "Equivalent".
Exact: match a request only if it exactly matches a specified rule. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, but "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would not be sent to the ValidatingAdmissionPolicy.
Equivalent: match a request if modifies a resource listed in rules, even via another API group or version. For example, if deployments can be modified via apps/v1, apps/v1beta1, and extensions/v1beta1, and "rules" only included apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"], a request to apps/v1beta1 or extensions/v1beta1 would be converted to apps/v1 and sent to the ValidatingAdmissionPolicy.
NamespaceSelector decides whether to run the admission control policy on an object based on whether the namespace for that object matches the selector. If the object itself is a namespace, the matching is performed on object.metadata.labels. If the object is another cluster scoped resource, it never skips the policy.
For example, to run the webhook on any objects whose namespace is not associated with "runlevel" of "0" or "1"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "runlevel",
"operator": "NotIn",
"values": [
"0",
"1"
]
}
]
}
If instead you want to only run the policy on any objects whose namespace is associated with the "environment" of "prod" or "staging"; you will set the selector as follows: "namespaceSelector": {
"matchExpressions": [
{
"key": "environment",
"operator": "In",
"values": [
"prod",
"staging"
]
}
]
}
ObjectSelector decides whether to run the validation based on if the object has matching labels. objectSelector is evaluated against both the oldObject and newObject that would be sent to the cel validation, and is considered to match if either object matches the selector. A null object (oldObject in the case of create, or newObject in the case of delete) or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object) is not considered to match. Use the object selector only if the webhook is opt-in, because end users may skip the admission webhook by setting the labels. Default to the empty LabelSelector, which matches everything.
ResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy matches. The policy cares about an operation if it matches any Rule.
NamedRuleWithOperations is a tuple of Operations and Resources with ResourceNames.
Operations is the operations the admission hook cares about - CREATE, UPDATE, DELETE, CONNECT or * for all of those operations and any future admission operations that are added. If '*' is present, the length of the slice must be one. Required.
Resources is a list of resources this rule applies to.
For example: 'pods' means pods. 'pods/log' means the log subresource of pods. '' means all resources, but not subresources. 'pods/' means all subresources of pods. '/scale' means all scale subresources. '/*' means all resources and their subresources.
If wildcard is present, the validation rule will ensure resources do not overlap with each other.
Depending on the enclosing object, subresources might not be allowed. Required.
spec.matchResources.resourceRules.scope (string)
scope specifies the scope of this rule. Valid values are "Cluster", "Namespaced", and "" "Cluster" means that only cluster-scoped resources will match this rule. Namespace API objects are cluster-scoped. "Namespaced" means that only namespaced resources will match this rule. "" means that there are no scope restrictions. Subresources match the scope of their parent resource. Default is "*".
spec.paramRef (ParamRef)
paramRef specifies the parameter resource used to configure the admission control policy. It should point to a resource of the type specified in ParamKind of the bound ValidatingAdmissionPolicy. If the policy specifies a ParamKind and the resource referred to by ParamRef does not exist, this binding is considered mis-configured and the FailurePolicy of the ValidatingAdmissionPolicy applied. If the policy does not specify a ParamKind then this field is ignored, and the rules are evaluated without a param.
ParamRef describes how to locate the params to be used as input to expressions of rules applied by a policy binding.
spec.paramRef.name (string)
name is the name of the resource being referenced.
One of name or selector must be set, but name and selector are mutually exclusive properties. If one is set, the other must be unset.
A single parameter used for all admission requests can be configured by setting the name field, leaving selector blank, and setting namespace if paramKind is namespace-scoped.
spec.paramRef.namespace (string)
namespace is the namespace of the referenced resource. Allows limiting the search for params to a specific namespace. Applies to both name and selector fields.
A per-namespace parameter may be used by specifying a namespace-scoped paramKind in the policy and leaving this field empty.
If paramKind is cluster-scoped, this field MUST be unset. Setting this field results in a configuration error.
If paramKind is namespace-scoped, the namespace of the object being evaluated for admission will be used when this field is left unset. Take care that if this is left empty the binding must not match any cluster-scoped resources, which will result in an error.
spec.paramRef.parameterNotFoundAction (string)
parameterNotFoundAction controls the behavior of the binding when the resource exists, and name or selector is valid, but there are no parameters matched by the binding. If the value is set to Allow, then no matched parameters will be treated as successful validation by the binding. If set to Deny, then no matched parameters will be subject to the failurePolicy of the policy.
selector can be used to match multiple param objects based on their labels. Supply selector: {} to match all resources of the ParamKind.
If multiple params are found, they are all evaluated with the policy expressions and the results are ANDed together.
One of name or selector must be set, but name and selector are mutually exclusive properties. If one is set, the other must be unset.
spec.policyName (string)
PolicyName references a ValidatingAdmissionPolicy name which the ValidatingAdmissionPolicyBinding binds to. If the referenced resource does not exist, this binding is considered invalid and will be ignored Required.
spec.validationActions ([]string)
Set: unique values will be kept during a merge
validationActions declares how Validations of the referenced ValidatingAdmissionPolicy are enforced. If a validation evaluates to false it is always enforced according to these actions.
Failures defined by the ValidatingAdmissionPolicy's FailurePolicy are enforced according to these actions only if the FailurePolicy is set to Fail, otherwise the failures are ignored. This includes compilation errors, runtime errors and misconfigurations of the policy.
validationActions is declared as a set of action values. Order does not matter. validationActions may not contain duplicates of the same action.
The supported actions values are:
"Deny" specifies that a validation failure results in a denied request.
"Warn" specifies that a validation failure is reported to the request client in HTTP Warning headers, with a warning code of 299. Warnings can be sent both for allowed or denied admission responses.
"Audit" specifies that a validation failure is included in the published audit event for the request. The audit event will contain a validation.policy.admission.k8s.io/validation_failure audit annotation with a value containing the details of the validation failures, formatted as a JSON list of objects, each with the following fields: - message: The validation failure message string - policy: The resource name of the ValidatingAdmissionPolicy - binding: The resource name of the ValidatingAdmissionPolicyBinding - expressionIndex: The index of the failed validations in the ValidatingAdmissionPolicy - validationActions: The enforcement actions enacted for the validation failure Example audit annotation: "validation.policy.admission.k8s.io/validation_failure": "[{"message": "Invalid value", {"policy": "policy.example.com", {"binding": "policybinding.example.com", {"expressionIndex": "1", {"validationActions": ["Audit"]}]"
Clients should expect to handle additional values by ignoring any values not recognized.
"Deny" and "Warn" may not be used together since this combination needlessly duplicates the validation failure both in the API response body and the HTTP warning headers.
Required.
Operations
get read the specified ValidatingAdmissionPolicy
HTTP Request
GET /apis/admissionregistration.k8s.io/v1beta1/validatingadmissionpolicies/{name}
NodeSpec describes the attributes that a node is created with.
configSource (NodeConfigSource)
Deprecated: Previously used to specify the source of the node's configuration for the DynamicKubeletConfig feature. This feature is removed.
NodeConfigSource specifies a source of node configuration. Exactly one subfield (excluding metadata) must be non-nil. This API is deprecated since 1.22
PodCIDR represents the pod IP range assigned to the node.
podCIDRs ([]string)
podCIDRs represents the IP ranges assigned to the node for usage by Pods on that node. If this field is specified, the 0th entry must match the podCIDR field. It may contain at most 1 value for each of IPv4 and IPv6.
providerID (string)
ID of the node assigned by the cloud provider in the format: <ProviderName>://<ProviderSpecificNodeID>
taints ([]Taint)
If specified, the node's taints.
The node this Taint is attached to has the "effect" on any pod that does not tolerate the Taint.
taints.effect (string), required
Required. The effect of the taint on pods that do not tolerate the taint. Valid effects are NoSchedule, PreferNoSchedule and NoExecute.
taints.key (string), required
Required. The taint key to be applied to a node.
taints.timeAdded (Time)
TimeAdded represents the time at which the taint was added. It is only written for NoExecute taints.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
NodeStatus is information about the current status of a node.
addresses ([]NodeAddress)
Patch strategy: merge on key type
List of addresses reachable to the node. Queried from cloud provider, if available. More info: https://kubernetes.io/docs/concepts/nodes/node/#addresses Note: This field is declared as mergeable, but the merge key is not sufficiently unique, which can cause data corruption when it is merged. Callers should instead use a full-replacement patch. See https://pr.k8s.io/79391 for an example. Consumers should assume that addresses can change during the lifetime of a Node. However, there are some exceptions where this may not be possible, such as Pods that inherit a Node's address in its own status or consumers of the downward API (status.hostIP).
NodeAddress contains information for the node's address.
addresses.address (string), required
The node address.
addresses.type (string), required
Node address type, one of Hostname, ExternalIP or InternalIP.
NodeCondition contains condition information for a node.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of node condition.
conditions.lastHeartbeatTime (Time)
Last time we got an update on a given condition.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.lastTransitionTime (Time)
Last time the condition transit from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
Human readable message indicating details about last transition.
conditions.reason (string)
(brief) reason for the condition's last transition.
config (NodeConfigStatus)
Status of the config assigned to the node via the dynamic Kubelet config feature.
NodeConfigStatus describes the status of the config assigned by Node.Spec.ConfigSource.
config.active (NodeConfigSource)
Active reports the checkpointed config the node is actively using. Active will represent either the current version of the Assigned config, or the current LastKnownGood config, depending on whether attempting to use the Assigned config results in an error.
NodeConfigSource specifies a source of node configuration. Exactly one subfield (excluding metadata) must be non-nil. This API is deprecated since 1.22
Namespace is the metadata.namespace of the referenced ConfigMap. This field is required in all cases.
config.active.configMap.resourceVersion (string)
ResourceVersion is the metadata.ResourceVersion of the referenced ConfigMap. This field is forbidden in Node.Spec, and required in Node.Status.
config.active.configMap.uid (string)
UID is the metadata.UID of the referenced ConfigMap. This field is forbidden in Node.Spec, and required in Node.Status.
config.assigned (NodeConfigSource)
Assigned reports the checkpointed config the node will try to use. When Node.Spec.ConfigSource is updated, the node checkpoints the associated config payload to local disk, along with a record indicating intended config. The node refers to this record to choose its config checkpoint, and reports this record in Assigned. Assigned only updates in the status after the record has been checkpointed to disk. When the Kubelet is restarted, it tries to make the Assigned config the Active config by loading and validating the checkpointed payload identified by Assigned.
NodeConfigSource specifies a source of node configuration. Exactly one subfield (excluding metadata) must be non-nil. This API is deprecated since 1.22
ResourceVersion is the metadata.ResourceVersion of the referenced ConfigMap. This field is forbidden in Node.Spec, and required in Node.Status.
config.assigned.configMap.uid (string)
UID is the metadata.UID of the referenced ConfigMap. This field is forbidden in Node.Spec, and required in Node.Status.
config.error (string)
Error describes any problems reconciling the Spec.ConfigSource to the Active config. Errors may occur, for example, attempting to checkpoint Spec.ConfigSource to the local Assigned record, attempting to checkpoint the payload associated with Spec.ConfigSource, attempting to load or validate the Assigned config, etc. Errors may occur at different points while syncing config. Earlier errors (e.g. download or checkpointing errors) will not result in a rollback to LastKnownGood, and may resolve across Kubelet retries. Later errors (e.g. loading or validating a checkpointed config) will result in a rollback to LastKnownGood. In the latter case, it is usually possible to resolve the error by fixing the config assigned in Spec.ConfigSource. You can find additional information for debugging by searching the error message in the Kubelet log. Error is a human-readable description of the error state; machines can check whether or not Error is empty, but should not rely on the stability of the Error text across Kubelet versions.
config.lastKnownGood (NodeConfigSource)
LastKnownGood reports the checkpointed config the node will fall back to when it encounters an error attempting to use the Assigned config. The Assigned config becomes the LastKnownGood config when the node determines that the Assigned config is stable and correct. This is currently implemented as a 10-minute soak period starting when the local record of Assigned config is updated. If the Assigned config is Active at the end of this period, it becomes the LastKnownGood. Note that if Spec.ConfigSource is reset to nil (use local defaults), the LastKnownGood is also immediately reset to nil, because the local default config is always assumed good. You should not make assumptions about the node's method of determining config stability and correctness, as this may change or become configurable in the future.
NodeConfigSource specifies a source of node configuration. Exactly one subfield (excluding metadata) must be non-nil. This API is deprecated since 1.22
NamespaceStatus is information about the current status of a Namespace.
conditions ([]NamespaceCondition)
Patch strategy: merge on key type
Represents the latest available observations of a namespace's current state.
NamespaceCondition contains details about state of namespace.
conditions.status (string), required
Status of the condition, one of True, False, Unknown.
conditions.type (string), required
Type of namespace controller condition.
conditions.lastTransitionTime (Time)
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
Event is a report of an event somewhere in the cluster.
apiVersion: events.k8s.io/v1
import "k8s.io/api/events/v1"
Event
Event is a report of an event somewhere in the cluster. It generally denotes some state change in the system. Events have a limited retention time and triggers and messages may evolve with time. Event consumers should not rely on the timing of an event with a given Reason reflecting a consistent underlying trigger, or the continued existence of events with that Reason. Events should be treated as informative, best-effort, supplemental data.
eventTime is the time when this Event was first observed. It is required.
MicroTime is version of Time with microsecond level precision.
action (string)
action is what action was taken/failed regarding to the regarding object. It is machine-readable. This field cannot be empty for new Events and it can have at most 128 characters.
deprecatedCount (int32)
deprecatedCount is the deprecated field assuring backward compatibility with core.v1 Event type.
deprecatedFirstTimestamp (Time)
deprecatedFirstTimestamp is the deprecated field assuring backward compatibility with core.v1 Event type.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
deprecatedLastTimestamp (Time)
deprecatedLastTimestamp is the deprecated field assuring backward compatibility with core.v1 Event type.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
deprecatedSource (EventSource)
deprecatedSource is the deprecated field assuring backward compatibility with core.v1 Event type.
EventSource contains information for an event.
deprecatedSource.component (string)
Component from which the event is generated.
deprecatedSource.host (string)
Node name on which the event is generated.
note (string)
note is a human-readable description of the status of this operation. Maximal length of the note is 1kB, but libraries should be prepared to handle values up to 64kB.
reason (string)
reason is why the action was taken. It is human-readable. This field cannot be empty for new Events and it can have at most 128 characters.
regarding contains the object this Event is about. In most cases it's an Object reporting controller implements, e.g. ReplicaSetController implements ReplicaSets and this event is emitted because it acts on some changes in a ReplicaSet object.
related is the optional secondary object for more complex actions. E.g. when regarding object triggers a creation or deletion of related object.
reportingController (string)
reportingController is the name of the controller that emitted this Event, e.g. kubernetes.io/kubelet. This field cannot be empty for new Events.
reportingInstance (string)
reportingInstance is the ID of the controller instance, e.g. kubelet-xyzf. This field cannot be empty for new Events and it can have at most 128 characters.
series (EventSeries)
series is data about the Event series this event represents or nil if it's a singleton Event.
EventSeries contain information on series of events, i.e. thing that was/is happening continuously for some time. How often to update the EventSeries is up to the event reporters. The default event reporter in "k8s.io/client-go/tools/events/event_broadcaster.go" shows how this struct is updated on heartbeats and can guide customized reporter implementations.
series.count (int32), required
count is the number of occurrences in this series up to the last heartbeat time.
series.lastObservedTime (MicroTime), required
lastObservedTime is the time when last Event from the series was seen before last heartbeat.
MicroTime is version of Time with microsecond level precision.
type (string)
type is the type of this event (Normal, Warning), new types could be added in the future. It is machine-readable. This field cannot be empty for new Events.
Status contains derived information about an API server
APIServiceSpec
APIServiceSpec contains information for locating and communicating with a server. Only https is supported, though you are able to disable certificate verification.
groupPriorityMinimum (int32), required
GroupPriorityMininum is the priority this group should have at least. Higher priority means that the group is preferred by clients over lower priority ones. Note that other versions of this group might specify even higher GroupPriorityMininum values such that the whole group gets a higher priority. The primary sort is based on GroupPriorityMinimum, ordered highest number to lowest (20 before 10). The secondary sort is based on the alphabetical comparison of the name of the object. (v1.bar before v1.foo) We'd recommend something like: *.k8s.io (except extensions) at 18000 and PaaSes (OpenShift, Deis) are recommended to be in the 2000s
versionPriority (int32), required
VersionPriority controls the ordering of this API version inside of its group. Must be greater than zero. The primary sort is based on VersionPriority, ordered highest to lowest (20 before 10). Since it's inside of a group, the number can be small, probably in the 10s. In case of equal version priorities, the version string will be used to compute the order inside a group. If the version string is "kube-like", it will sort above non "kube-like" version strings, which are ordered lexicographically. "Kube-like" versions start with a "v", then are followed by a number (the major version), then optionally the string "alpha" or "beta" and another number (the minor version). These are sorted first by GA > beta > alpha (where GA is a version with no suffix such as beta or alpha), and then by comparing major version, then minor version. An example sorted list of versions: v10, v2, v1, v11beta2, v10beta3, v3beta1, v12alpha1, v11alpha2, foo1, foo10.
caBundle ([]byte)
Atomic: will be replaced during a merge
CABundle is a PEM encoded CA bundle which will be used to validate an API server's serving certificate. If unspecified, system trust roots on the apiserver are used.
group (string)
Group is the API group name this server hosts
insecureSkipTLSVerify (boolean)
InsecureSkipTLSVerify disables TLS certificate verification when communicating with this server. This is strongly discouraged. You should use the CABundle instead.
service (ServiceReference)
Service is a reference to the service for this API server. It must communicate on port 443. If the Service is nil, that means the handling for the API groupversion is handled locally on this server. The call will simply delegate to the normal handler chain to be fulfilled.
ServiceReference holds a reference to Service.legacy.k8s.io
service.name (string)
Name is the name of the service
service.namespace (string)
Namespace is the namespace of the service
service.port (int32)
If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).
version (string)
Version is the API version this server hosts. For example, "v1"
APIServiceStatus
APIServiceStatus contains derived information about an API server
conditions ([]APIServiceCondition)
Patch strategy: merge on key type
Map: unique values on key type will be kept during a merge
Current service state of apiService.
APIServiceCondition describes the state of an APIService at a particular point
conditions.status (string), required
Status is the status of the condition. Can be True, False, Unknown.
conditions.type (string), required
Type is the type of the condition.
conditions.lastTransitionTime (Time)
Last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
Human-readable message indicating details about last transition.
conditions.reason (string)
Unique, one-word, CamelCase reason for the condition's last transition.
acquireTime is a time when the current lease was acquired.
MicroTime is version of Time with microsecond level precision.
holderIdentity (string)
holderIdentity contains the identity of the holder of a current lease.
leaseDurationSeconds (int32)
leaseDurationSeconds is a duration that candidates for a lease need to wait to force acquire it. This is measure against time of last observed renewTime.
leaseTransitions (int32)
leaseTransitions is the number of transitions of a lease between holders.
renewTime (MicroTime)
renewTime is a time when the current holder of a lease has last updated the lease.
MicroTime is version of Time with microsecond level precision.
RuntimeClass defines a class of container runtime supported in the cluster.
apiVersion: node.k8s.io/v1
import "k8s.io/api/node/v1"
RuntimeClass
RuntimeClass defines a class of container runtime supported in the cluster. The RuntimeClass is used to determine which container runtime is used to run all containers in a pod. RuntimeClasses are manually defined by a user or cluster provisioner, and referenced in the PodSpec. The Kubelet is responsible for resolving the RuntimeClassName reference before running the pod. For more details, see https://kubernetes.io/docs/concepts/containers/runtime-class/
handler specifies the underlying runtime and configuration that the CRI implementation will use to handle pods of this class. The possible values are specific to the node & CRI configuration. It is assumed that all handlers are available on every node, and handlers of the same name are equivalent on every node. For example, a handler called "runc" might specify that the runc OCI runtime (using native Linux containers) will be used to run the containers in a pod. The Handler must be lowercase, conform to the DNS Label (RFC 1123) requirements, and is immutable.
podFixed represents the fixed resource overhead associated with running a pod.
scheduling (Scheduling)
scheduling holds the scheduling constraints to ensure that pods running with this RuntimeClass are scheduled to nodes that support it. If scheduling is nil, this RuntimeClass is assumed to be supported by all nodes.
Scheduling specifies the scheduling constraints for nodes supporting a RuntimeClass.
scheduling.nodeSelector (map[string]string)
nodeSelector lists labels that must be present on nodes that support this RuntimeClass. Pods using this RuntimeClass can only be scheduled to a node matched by this selector. The RuntimeClass nodeSelector is merged with a pod's existing nodeSelector. Any conflicts will cause the pod to be rejected in admission.
scheduling.tolerations ([]Toleration)
Atomic: will be replaced during a merge
tolerations are appended (excluding duplicates) to pods running with this RuntimeClass during admission, effectively unioning the set of nodes tolerated by the pod and the RuntimeClass.
The pod this Toleration is attached to tolerates any taint that matches the triple <key,value,effect> using the matching operator .
scheduling.tolerations.key (string)
Key is the taint key that the toleration applies to. Empty means match all taint keys. If the key is empty, operator must be Exists; this combination means to match all values and all keys.
scheduling.tolerations.operator (string)
Operator represents a key's relationship to the value. Valid operators are Exists and Equal. Defaults to Equal. Exists is equivalent to wildcard for value, so that a pod can tolerate all taints of a particular category.
scheduling.tolerations.value (string)
Value is the taint value the toleration matches to. If the operator is Exists, the value should be empty, otherwise just a regular string.
scheduling.tolerations.effect (string)
Effect indicates the taint effect to match. Empty means match all taint effects. When specified, allowed values are NoSchedule, PreferNoSchedule and NoExecute.
scheduling.tolerations.tolerationSeconds (int64)
TolerationSeconds represents the period of time the toleration (which must be of effect NoExecute, otherwise this field is ignored) tolerates the taint. By default, it is not set, which means tolerate the taint forever (do not evict). Zero and negative values will be treated as 0 (evict immediately) by the system.
RuntimeClassList
RuntimeClassList is a list of RuntimeClass objects.
FlowSchema defines the schema of a group of flows.
apiVersion: flowcontrol.apiserver.k8s.io/v1beta3
import "k8s.io/api/flowcontrol/v1beta3"
FlowSchema
FlowSchema defines the schema of a group of flows. Note that a flow is made up of a set of inbound API requests with similar attributes and is identified by a pair of strings: the name of the FlowSchema and a "flow distinguisher".
priorityLevelConfiguration should reference a PriorityLevelConfiguration in the cluster. If the reference cannot be resolved, the FlowSchema will be ignored and marked as invalid in its status. Required.
PriorityLevelConfigurationReference contains information that points to the "request-priority" being used.
name is the name of the priority level configuration being referenced Required.
distinguisherMethod (FlowDistinguisherMethod)
distinguisherMethod defines how to compute the flow distinguisher for requests that match this schema. nil specifies that the distinguisher is disabled and thus will always be the empty string.
FlowDistinguisherMethod specifies the method of a flow distinguisher.
distinguisherMethod.type (string), required
type is the type of flow distinguisher method The supported types are "ByUser" and "ByNamespace". Required.
matchingPrecedence (int32)
matchingPrecedence is used to choose among the FlowSchemas that match a given request. The chosen FlowSchema is among those with the numerically lowest (which we take to be logically highest) MatchingPrecedence. Each MatchingPrecedence value must be ranged in [1,10000]. Note that if the precedence is not specified, it will be set to 1000 as default.
rules ([]PolicyRulesWithSubjects)
Atomic: will be replaced during a merge
rules describes which requests will match this flow schema. This FlowSchema matches a request if and only if at least one member of rules matches the request. if it is an empty slice, there will be no requests matching the FlowSchema.
PolicyRulesWithSubjects prescribes a test that applies to a request to an apiserver. The test considers the subject making the request, the verb being requested, and the resource to be acted upon. This PolicyRulesWithSubjects matches a request if and only if both (a) at least one member of subjects matches the request and (b) at least one member of resourceRules or nonResourceRules matches the request.
rules.subjects ([]Subject), required
Atomic: will be replaced during a merge
subjects is the list of normal user, serviceaccount, or group that this rule cares about. There must be at least one member in this slice. A slice that includes both the system:authenticated and system:unauthenticated user groups matches every request. Required.
Subject matches the originator of a request, as identified by the request authentication system. There are three ways of matching an originator; by user, group, or service account.
rules.subjects.kind (string), required
kind indicates which one of the other fields is non-empty. Required
rules.subjects.group (GroupSubject)
group matches based on user group name.
GroupSubject holds detailed information for group-kind subject.
namespace is the namespace of matching ServiceAccount objects. Required.
rules.subjects.user (UserSubject)
user matches based on username.
UserSubject holds detailed information for user-kind subject.
rules.subjects.user.name (string), required
name is the username that matches, or "*" to match all usernames. Required.
rules.nonResourceRules ([]NonResourcePolicyRule)
Atomic: will be replaced during a merge
nonResourceRules is a list of NonResourcePolicyRules that identify matching requests according to their verb and the target non-resource URL.
NonResourcePolicyRule is a predicate that matches non-resource requests according to their verb and the target non-resource URL. A NonResourcePolicyRule matches a request if and only if both (a) at least one member of verbs matches the request and (b) at least one member of nonResourceURLs matches the request.
nonResourceURLs is a set of url prefixes that a user should have access to and may not be empty. For example:
"/healthz" is legal
"/hea*" is illegal
"/hea" is legal but matches nothing
"/hea/*" also matches nothing
"/healthz/" matches all per-component health checks.
"" matches all non-resource urls. if it is present, it must be the only entry. Required.
rules.nonResourceRules.verbs ([]string), required
Set: unique values will be kept during a merge
verbs is a list of matching verbs and may not be empty. "*" matches all verbs. If it is present, it must be the only entry. Required.
rules.resourceRules ([]ResourcePolicyRule)
Atomic: will be replaced during a merge
resourceRules is a slice of ResourcePolicyRules that identify matching requests according to their verb and the target resource. At least one of resourceRules and nonResourceRules has to be non-empty.
ResourcePolicyRule is a predicate that matches some resource requests, testing the request's verb and the target resource. A ResourcePolicyRule matches a resource request if and only if: (a) at least one member of verbs matches the request, (b) at least one member of apiGroups matches the request, (c) at least one member of resources matches the request, and (d) either (d1) the request does not specify a namespace (i.e., Namespace=="") and clusterScope is true or (d2) the request specifies a namespace and least one member of namespaces matches the request's namespace.
resources is a list of matching resources (i.e., lowercase and plural) with, if desired, subresource. For example, [ "services", "nodes/status" ]. This list may not be empty. "*" matches all resources and, if present, must be the only entry. Required.
rules.resourceRules.verbs ([]string), required
Set: unique values will be kept during a merge
verbs is a list of matching verbs and may not be empty. "*" matches all verbs and, if present, must be the only entry. Required.
rules.resourceRules.clusterScope (boolean)
clusterScope indicates whether to match requests that do not specify a namespace (which happens either because the resource is not namespaced or the request targets all namespaces). If this field is omitted or false then the namespaces field must contain a non-empty list.
rules.resourceRules.namespaces ([]string)
Set: unique values will be kept during a merge
namespaces is a list of target namespaces that restricts matches. A request that specifies a target namespace matches only if either (a) this list contains that target namespace or (b) this list contains "". Note that "" matches any specified namespace but does not match a request that does not specify a namespace (see the clusterScope field for that). This list may be empty, but only if clusterScope is true.
FlowSchemaStatus
FlowSchemaStatus represents the current state of a FlowSchema.
conditions ([]FlowSchemaCondition)
Patch strategy: merge on key type
Map: unique values on key type will be kept during a merge
conditions is a list of the current states of FlowSchema.
FlowSchemaCondition describes conditions for a FlowSchema.
conditions.lastTransitionTime (Time)
lastTransitionTime is the last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message is a human-readable message indicating details about last transition.
conditions.reason (string)
reason is a unique, one-word, CamelCase reason for the condition's last transition.
conditions.status (string)
status is the status of the condition. Can be True, False, Unknown. Required.
PriorityLevelConfigurationSpec specifies the configuration of a priority level.
type (string), required
type indicates whether this priority level is subject to limitation on request execution. A value of "Exempt" means that requests of this priority level are not subject to a limit (and thus are never queued) and do not detract from the capacity made available to other priority levels. A value of "Limited" means that (a) requests of this priority level are subject to limits and (b) some of the server's limited capacity is made available exclusively to this priority level. Required.
exempt (ExemptPriorityLevelConfiguration)
exempt specifies how requests are handled for an exempt priority level. This field MUST be empty if type is "Limited". This field MAY be non-empty if type is "Exempt". If empty and type is "Exempt" then the default values for ExemptPriorityLevelConfiguration apply.
ExemptPriorityLevelConfiguration describes the configurable aspects of the handling of exempt requests. In the mandatory exempt configuration object the values in the fields here can be modified by authorized users, unlike the rest of the spec.
exempt.lendablePercent (int32)
lendablePercent prescribes the fraction of the level's NominalCL that can be borrowed by other priority levels. This value of this field must be between 0 and 100, inclusive, and it defaults to 0. The number of seats that other levels can borrow from this level, known as this level's LendableConcurrencyLimit (LendableCL), is defined as follows.
nominalConcurrencyShares (NCS) contributes to the computation of the NominalConcurrencyLimit (NominalCL) of this level. This is the number of execution seats nominally reserved for this priority level. This DOES NOT limit the dispatching from this priority level but affects the other priority levels through the borrowing mechanism. The server's concurrency limit (ServerCL) is divided among all the priority levels in proportion to their NCS values:
Bigger numbers mean a larger nominal concurrency limit, at the expense of every other priority level. This field has a default value of zero.
limited (LimitedPriorityLevelConfiguration)
limited specifies how requests are handled for a Limited priority level. This field must be non-empty if and only if type is "Limited".
*LimitedPriorityLevelConfiguration specifies how to handle requests that are subject to limits. It addresses two issues:
How are requests for this priority level limited?
What should be done with requests that exceed the limit?*
limited.borrowingLimitPercent (int32)
borrowingLimitPercent, if present, configures a limit on how many seats this priority level can borrow from other priority levels. The limit is known as this level's BorrowingConcurrencyLimit (BorrowingCL) and is a limit on the total number of seats that this level may borrow at any one time. This field holds the ratio of that limit to the level's nominal concurrency limit. When this field is non-nil, it must hold a non-negative integer and the limit is calculated as follows.
The value of this field can be more than 100, implying that this priority level can borrow a number of seats that is greater than its own nominal concurrency limit (NominalCL). When this field is left nil, the limit is effectively infinite.
limited.lendablePercent (int32)
lendablePercent prescribes the fraction of the level's NominalCL that can be borrowed by other priority levels. The value of this field must be between 0 and 100, inclusive, and it defaults to 0. The number of seats that other levels can borrow from this level, known as this level's LendableConcurrencyLimit (LendableCL), is defined as follows.
limitResponse indicates what to do with requests that can not be executed right now
LimitResponse defines how to handle requests that can not be executed right now.
limited.limitResponse.type (string), required
type is "Queue" or "Reject". "Queue" means that requests that can not be executed upon arrival are held in a queue until they can be executed or a queuing limit is reached. "Reject" means that requests that can not be executed upon arrival are rejected. Required.
queuing holds the configuration parameters for queuing. This field may be non-empty only if type is "Queue".
QueuingConfiguration holds the configuration parameters for queuing
limited.limitResponse.queuing.handSize (int32)
handSize is a small positive number that configures the shuffle sharding of requests into queues. When enqueuing a request at this priority level the request's flow identifier (a string pair) is hashed and the hash value is used to shuffle the list of queues and deal a hand of the size specified here. The request is put into one of the shortest queues in that hand. handSize must be no larger than queues, and should be significantly smaller (so that a few heavy flows do not saturate most of the queues). See the user-facing documentation for more extensive guidance on setting this field. This field has a default value of 8.
queueLengthLimit is the maximum number of requests allowed to be waiting in a given queue of this priority level at a time; excess requests are rejected. This value must be positive. If not specified, it will be defaulted to 50.
limited.limitResponse.queuing.queues (int32)
queues is the number of queues for this priority level. The queues exist independently at each apiserver. The value must be positive. Setting it to 1 effectively precludes shufflesharding and thus makes the distinguisher method of associated flow schemas irrelevant. This field has a default value of 64.
limited.nominalConcurrencyShares (int32)
nominalConcurrencyShares (NCS) contributes to the computation of the NominalConcurrencyLimit (NominalCL) of this level. This is the number of execution seats available at this priority level. This is used both for requests dispatched from this priority level as well as requests dispatched from other priority levels borrowing seats from this level. The server's concurrency limit (ServerCL) is divided among the Limited priority levels in proportion to their NCS values:
Map: unique values on key type will be kept during a merge
conditions is the current state of "request-priority".
PriorityLevelConfigurationCondition defines the condition of priority level.
conditions.lastTransitionTime (Time)
lastTransitionTime is the last time the condition transitioned from one status to another.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
conditions.message (string)
message is a human-readable message indicating details about last transition.
conditions.reason (string)
reason is a unique, one-word, CamelCase reason for the condition's last transition.
conditions.status (string)
status is the status of the condition. Can be True, False, Unknown. Required.
conditions.type (string)
type is the type of the condition. Required.
PriorityLevelConfigurationList
PriorityLevelConfigurationList is a list of PriorityLevelConfiguration objects.
Binding ties one object to another; for example, a pod is bound to a node by a scheduler.
apiVersion: v1
import "k8s.io/api/core/v1"
Binding
Binding ties one object to another; for example, a pod is bound to a node by a scheduler. Deprecated in 1.7, please use the bindings subresource of pods instead.
ClusterCIDR represents a single configuration for per-Node Pod CIDR allocations when the MultiCIDRRangeAllocator is enabled (see the config for kube-controller-manager).
apiVersion: networking.k8s.io/v1alpha1
import "k8s.io/api/networking/v1alpha1"
ClusterCIDR
ClusterCIDR represents a single configuration for per-Node Pod CIDR allocations when the MultiCIDRRangeAllocator is enabled (see the config for kube-controller-manager). A cluster may have any number of ClusterCIDR resources, all of which will be considered when allocating a CIDR for a Node. A ClusterCIDR is eligible to be used for a given Node when the node selector matches the node in question and has free CIDRs to allocate. In case of multiple matching ClusterCIDR resources, the allocator will attempt to break ties using internal heuristics, but any ClusterCIDR whose node selector matches the Node may be used.
ClusterCIDRSpec defines the desired state of ClusterCIDR.
perNodeHostBits (int32), required
perNodeHostBits defines the number of host bits to be configured per node. A subnet mask determines how much of the address is used for network bits and host bits. For example an IPv4 address of 192.168.0.0/24, splits the address into 24 bits for the network portion and 8 bits for the host portion. To allocate 256 IPs, set this field to 8 (a /24 mask for IPv4 or a /120 for IPv6). Minimum value is 4 (16 IPs). This field is immutable.
ipv4 (string)
ipv4 defines an IPv4 IP block in CIDR notation(e.g. "10.0.0.0/8"). At least one of ipv4 and ipv6 must be specified. This field is immutable.
ipv6 (string)
ipv6 defines an IPv6 IP block in CIDR notation(e.g. "2001:db8::/64"). At least one of ipv4 and ipv6 must be specified. This field is immutable.
nodeSelector (NodeSelector)
nodeSelector defines which nodes the config is applicable to. An empty or nil nodeSelector selects all nodes. This field is immutable.
A node selector represents the union of the results of one or more label queries over a set of nodes; that is, it represents the OR of the selectors represented by the node selector terms.
Required. A list of node selector terms. The terms are ORed.
A null or empty node selector term matches no objects. The requirements of them are ANDed. The TopologySelectorTerm type implements a subset of the NodeSelectorTerm.
When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed
gracePeriodSeconds (int64)
The duration in seconds before the object should be deleted. Value must be non-negative integer. The value zero indicates delete immediately. If this value is nil, the default grace period for the specified type will be used. Defaults to a per object value if not specified. zero means delete immediately.
Deprecated: please use the PropagationPolicy, this field will be deprecated in 1.7. Should the dependent objects be orphaned. If true/false, the "orphan" finalizer will be added to/removed from the object's finalizers list. Either this field or PropagationPolicy may be set, but not both.
preconditions (Preconditions)
Must be fulfilled before a deletion is carried out. If not possible, a 409 Conflict status will be returned.
Preconditions must be fulfilled before an operation (update, delete, etc.) is carried out.
preconditions.resourceVersion (string)
Specifies the target ResourceVersion
preconditions.uid (string)
Specifies the target UID.
propagationPolicy (string)
Whether and how garbage collection will be performed. Either this field or OrphanDependents may be set, but not both. The default policy is decided by the existing finalizer set in the metadata.finalizers and the resource-specific default policy. Acceptable values are: 'Orphan' - orphan the dependents; 'Background' - allow the garbage collector to delete the dependents in the background; 'Foreground' - a cascading policy that deletes all dependents in the foreground.
5.9.2 - LabelSelector
A label selector is a label query over a set of resources.
import "k8s.io/apimachinery/pkg/apis/meta/v1"
A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects.
matchExpressions ([]LabelSelectorRequirement)
matchExpressions is a list of label selector requirements. The requirements are ANDed.
A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
matchExpressions.key (string), required
key is the label key that the selector applies to.
matchExpressions.operator (string), required
operator represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists and DoesNotExist.
matchExpressions.values ([]string)
values is an array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
matchLabels (map[string]string)
matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels map is equivalent to an element of matchExpressions, whose key field is "key", the operator is "In", and the values array contains only "value". The requirements are ANDed.
5.9.3 - ListMeta
ListMeta describes metadata that synthetic resources must have, including lists and various status objects.
import "k8s.io/apimachinery/pkg/apis/meta/v1"
ListMeta describes metadata that synthetic resources must have, including lists and various status objects. A resource may have only one of {ObjectMeta, ListMeta}.
continue (string)
continue may be set if the user set a limit on the number of items returned, and indicates that the server has more data available. The value is opaque and may be used to issue another request to the endpoint that served this list to retrieve the next set of available objects. Continuing a consistent list may not be possible if the server configuration has changed or more than a few minutes have passed. The resourceVersion field returned when using this continue value will be identical to the value in the first response, unless you have received this token from an error message.
remainingItemCount (int64)
remainingItemCount is the number of subsequent items in the list which are not included in this list response. If the list request contained label or field selectors, then the number of remaining items is unknown and the field will be left unset and omitted during serialization. If the list is complete (either because it is not chunking or because this is the last chunk), then there are no more remaining items and this field will be left unset and omitted during serialization. Servers older than v1.15 do not set this field. The intended use of the remainingItemCount is estimating the size of a collection. Clients should not rely on the remainingItemCount to be set or to be exact.
A node selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
import "k8s.io/api/core/v1"
A node selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
key (string), required
The label key that the selector applies to.
operator (string), required
Represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists, DoesNotExist. Gt, and Lt.
values ([]string)
An array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. If the operator is Gt or Lt, the values array must have a single element, which will be interpreted as an integer. This array is replaced during a strategic merge patch.
5.9.6 - ObjectFieldSelector
ObjectFieldSelector selects an APIVersioned field of an object.
import "k8s.io/api/core/v1"
ObjectFieldSelector selects an APIVersioned field of an object.
fieldPath (string), required
Path of the field to select in the specified API version.
apiVersion (string)
Version of the schema the FieldPath is written in terms of, defaults to "v1".
5.9.7 - ObjectMeta
ObjectMeta is metadata that all persisted resources must have, which includes all objects users must create.
import "k8s.io/apimachinery/pkg/apis/meta/v1"
ObjectMeta is metadata that all persisted resources must have, which includes all objects users must create.
name (string)
Name must be unique within a namespace. Is required when creating resources, although some resources may allow a client to request the generation of an appropriate name automatically. Name is primarily intended for creation idempotence and configuration definition. Cannot be updated. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/names#names
generateName (string)
GenerateName is an optional prefix, used by the server, to generate a unique name ONLY IF the Name field has not been provided. If this field is used, the name returned to the client will be different than the name passed. This value will also be combined with a unique suffix. The provided value has the same validation rules as the Name field, and may be truncated by the length of the suffix required to make the value unique on the server.
If this field is specified and the generated name exists, the server will return a 409.
Namespace defines the space within which each name must be unique. An empty namespace is equivalent to the "default" namespace, but "default" is the canonical representation. Not all objects are required to be scoped to a namespace - the value of this field for those objects will be empty.
Must be empty before the object is deleted from the registry. Each entry is an identifier for the responsible component that will remove the entry from the list. If the deletionTimestamp of the object is non-nil, entries in this list can only be removed. Finalizers may be processed and removed in any order. Order is NOT enforced because it introduces significant risk of stuck finalizers. finalizers is a shared field, any actor with permission can reorder it. If the finalizer list is processed in order, then this can lead to a situation in which the component responsible for the first finalizer in the list is waiting for a signal (field value, external system, or other) produced by a component responsible for a finalizer later in the list, resulting in a deadlock. Without enforced ordering finalizers are free to order amongst themselves and are not vulnerable to ordering changes in the list.
managedFields ([]ManagedFieldsEntry)
ManagedFields maps workflow-id and version to the set of fields that are managed by that workflow. This is mostly for internal housekeeping, and users typically shouldn't need to set or understand this field. A workflow can be the user's name, a controller's name, or the name of a specific apply path like "ci-cd". The set of fields is always in the version that the workflow used when modifying the object.
ManagedFieldsEntry is a workflow-id, a FieldSet and the group version of the resource that the fieldset applies to.
managedFields.apiVersion (string)
APIVersion defines the version of this resource that this field set applies to. The format is "group/version" just like the top-level APIVersion field. It is necessary to track the version of a field set because it cannot be automatically converted.
managedFields.fieldsType (string)
FieldsType is the discriminator for the different fields format and version. There is currently only one possible value: "FieldsV1"
managedFields.fieldsV1 (FieldsV1)
FieldsV1 holds the first JSON version format as described in the "FieldsV1" type.
*FieldsV1 stores a set of fields in a data structure like a Trie, in JSON format.
Each key is either a '.' representing the field itself, and will always map to an empty set, or a string representing a sub-field or item. The string will follow one of these four formats: 'f:', where is the name of a field in a struct, or key in a map 'v:', where is the exact json formatted value of a list item 'i:', where is position of a item in a list 'k:', where is a map of a list item's key fields to their unique values If a key maps to an empty Fields value, the field that key represents is part of the set.
The exact format is defined in sigs.k8s.io/structured-merge-diff*
managedFields.manager (string)
Manager is an identifier of the workflow managing these fields.
managedFields.operation (string)
Operation is the type of operation which lead to this ManagedFieldsEntry being created. The only valid values for this field are 'Apply' and 'Update'.
managedFields.subresource (string)
Subresource is the name of the subresource used to update that object, or empty string if the object was updated through the main resource. The value of this field is used to distinguish between managers, even if they share the same name. For example, a status update will be distinct from a regular update using the same manager name. Note that the APIVersion field is not related to the Subresource field and it always corresponds to the version of the main resource.
managedFields.time (Time)
Time is the timestamp of when the ManagedFields entry was added. The timestamp will also be updated if a field is added, the manager changes any of the owned fields value or removes a field. The timestamp does not update when a field is removed from the entry because another manager took it over.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
ownerReferences ([]OwnerReference)
Patch strategy: merge on key uid
List of objects depended by this object. If ALL objects in the list have been deleted, this object will be garbage collected. If this object is managed by a controller, then an entry in this list will point to this controller, with the controller field set to true. There cannot be more than one managing controller.
OwnerReference contains enough information to let you identify an owning object. An owning object must be in the same namespace as the dependent, or be cluster-scoped, so there is no namespace field.
If true, AND if the owner has the "foregroundDeletion" finalizer, then the owner cannot be deleted from the key-value store until this reference is removed. See https://kubernetes.io/docs/concepts/architecture/garbage-collection/#foreground-deletion for how the garbage collector interacts with this field and enforces the foreground deletion. Defaults to false. To set this field, a user needs "delete" permission of the owner, otherwise 422 (Unprocessable Entity) will be returned.
ownerReferences.controller (boolean)
If true, this reference points to the managing controller.
Read-only
creationTimestamp (Time)
CreationTimestamp is a timestamp representing the server time when this object was created. It is not guaranteed to be set in happens-before order across separate operations. Clients may not set this value. It is represented in RFC3339 form and is in UTC.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
deletionGracePeriodSeconds (int64)
Number of seconds allowed for this object to gracefully terminate before it will be removed from the system. Only set when deletionTimestamp is also set. May only be shortened. Read-only.
deletionTimestamp (Time)
DeletionTimestamp is RFC 3339 date and time at which this resource will be deleted. This field is set by the server when a graceful deletion is requested by the user, and is not directly settable by a client. The resource is expected to be deleted (no longer visible from resource lists, and not reachable by name) after the time in this field, once the finalizers list is empty. As long as the finalizers list contains items, deletion is blocked. Once the deletionTimestamp is set, this value may not be unset or be set further into the future, although it may be shortened or the resource may be deleted prior to this time. For example, a user may request that a pod is deleted in 30 seconds. The Kubelet will react by sending a graceful termination signal to the containers in the pod. After that 30 seconds, the Kubelet will send a hard termination signal (SIGKILL) to the container and after cleanup, remove the pod from the API. In the presence of network partitions, this object may still exist after this timestamp, until an administrator or automated process can determine the resource is fully terminated. If not set, graceful deletion of the object has not been requested.
Time is a wrapper around time.Time which supports correct marshaling to YAML and JSON. Wrappers are provided for many of the factory methods that the time package offers.
generation (int64)
A sequence number representing a specific generation of the desired state. Populated by the system. Read-only.
resourceVersion (string)
An opaque value that represents the internal version of this object that can be used by clients to determine when objects have changed. May be used for optimistic concurrency, change detection, and the watch operation on a resource or set of resources. Clients must treat these values as opaque and passed unmodified back to the server. They may only be valid for a particular resource or set of resources.
Deprecated: selfLink is a legacy read-only field that is no longer populated by the system.
uid (string)
UID is the unique in time and space value for this object. It is typically generated by the server on successful creation of a resource and is not allowed to change on PUT operations.
ObjectReference contains enough information to let you inspect or modify the referred object.
import "k8s.io/api/core/v1"
ObjectReference contains enough information to let you inspect or modify the referred object.
apiVersion (string)
API version of the referent.
fieldPath (string)
If referring to a piece of an object instead of an entire object, this string should contain a valid JSON/Go field access statement, such as desiredState.manifest.containers[2]. For example, if the object reference is to a container within a pod, this would take on a value like: "spec.containers{name}" (where "name" refers to the name of the container that triggered the event) or if no container name is specified "spec.containers[2]" (container with index 2 in this pod). This syntax is chosen only to have some well-defined way of referencing a part of an object.
Patch is provided to give a concrete name and type to the Kubernetes PATCH request body.
import "k8s.io/apimachinery/pkg/apis/meta/v1"
Patch is provided to give a concrete name and type to the Kubernetes PATCH request body.
5.9.10 - Quantity
Quantity is a fixed-point representation of a number.
import "k8s.io/apimachinery/pkg/api/resource"
Quantity is a fixed-point representation of a number. It provides convenient marshaling/unmarshaling in JSON and YAML, in addition to String() and AsInt64() accessors.
The serialization format is:
(Note that \<suffix> may be empty, from the "" case in \<decimalSI>.)
\<digit> ::= 0 | 1 | ... | 9 \<digits> ::= \<digit> | \<digit>\<digits> \<number> ::= \<digits> | \<digits>.\<digits> | \<digits>. | .\<digits> \<sign> ::= "+" | "-" \<signedNumber> ::= \<number> | \<sign>\<number> \<suffix> ::= \<binarySI> | \<decimalExponent> | \<decimalSI> \<binarySI> ::= Ki | Mi | Gi | Ti | Pi | Ei
(International System of units; See: http://physics.nist.gov/cuu/Units/binary.html)
\<decimalSI> ::= m | "" | k | M | G | T | P | E
(Note that 1024 = 1Ki but 1000 = 1k; I didn't choose the capitalization.)
\<decimalExponent> ::= "e" \<signedNumber> | "E" \<signedNumber> ```
No matter which of the three exponent forms is used, no quantity may represent a number greater than 2^63-1 in magnitude, nor may it have more than 3 decimal places. Numbers larger or more precise will be capped or rounded up. (E.g.: 0.1m will rounded up to 1m.) This may be extended in the future if we require larger or smaller quantities.
When a Quantity is parsed from a string, it will remember the type of suffix it had, and will use the same type again when it is serialized.
Before serializing, Quantity will be put in "canonical form". This means that Exponent/suffix will be adjusted up or down (with a corresponding increase or decrease in Mantissa) such that:
- No precision is lost - No fractional digits will be emitted - The exponent (or suffix) is as large as possible.
The sign will be omitted unless the number is negative.
Examples:
- 1.5 will be serialized as "1500m" - 1.5Gi will be serialized as "1536Mi"
Note that the quantity will NEVER be internally represented by a floating point number. That is the whole point of this exercise.
Non-canonical values will still parse as long as they are well formed, but will be re-emitted in their canonical form. (So always use canonical form, or don't diff.)
This format is intended to make it difficult to use these numbers without writing some sort of special handling code in the hopes that that will cause implementors to also use a fixed point implementation.
<hr>
5.9.11 - ResourceFieldSelector
ResourceFieldSelector represents container resources (cpu, memory) and their output format.
import "k8s.io/api/core/v1"
ResourceFieldSelector represents container resources (cpu, memory) and their output format
resource (string), required
Required: resource to select
containerName (string)
Container name: required for volumes, optional for env vars
Suggested HTTP return code for this status, 0 if not set.
details (StatusDetails)
Extended data associated with the reason. Each reason may define its own extended details. This field is optional and the data returned is not guaranteed to conform to any schema except that defined by the reason type.
StatusDetails is a set of additional properties that MAY be set by the server to provide additional information about a response. The Reason field of a Status object defines what attributes will be set. Clients must ignore fields that do not match the defined type of each attribute, and should assume that any attribute may be empty, invalid, or under defined.
details.causes ([]StatusCause)
The Causes array includes more details associated with the StatusReason failure. Not all StatusReasons may provide detailed causes.
StatusCause provides more information about an api.Status failure, including cases when multiple errors are encountered.
details.causes.field (string)
The field of the resource that has caused this error, as named by its JSON serialization. May include dot and postfix notation for nested attributes. Arrays are zero-indexed. Fields may appear more than once in an array of causes due to fields having multiple errors. Optional.
Examples:
"name" - the field "name" on the current resource
"items[0].name" - the field "name" on the first array entry in "items"
details.causes.message (string)
A human-readable description of the cause of the error. This field may be presented as-is to a reader.
details.causes.reason (string)
A machine-readable description of the cause of the error. If this value is empty there is no information available.
details.group (string)
The group attribute of the resource associated with the status StatusReason.
The name attribute of the resource associated with the status StatusReason (when there is a single name which can be described).
details.retryAfterSeconds (int32)
If specified, the time in seconds before the operation should be retried. Some errors may indicate the client must take an alternate action - for those errors this field may indicate how long to wait before taking the alternate action.
A machine-readable description of why this operation is in the "Failure" status. If this value is empty there is no information available. A Reason clarifies an HTTP status code but does not override it.
TypedLocalObjectReference contains enough information to let you locate the typed referenced object inside the same namespace.
import "k8s.io/api/core/v1"
TypedLocalObjectReference contains enough information to let you locate the typed referenced object inside the same namespace.
kind (string), required
Kind is the type of resource being referenced
name (string), required
Name is the name of resource being referenced
apiGroup (string)
APIGroup is the group for the resource being referenced. If APIGroup is not specified, the specified Kind must be in the core API group. For any other third-party types, APIGroup is required.
allowWatchBookmarks requests watch events with type "BOOKMARK". Servers that do not implement bookmarks may ignore this flag and bookmarks are sent at the server's discretion. Clients should not assume bookmarks are returned at any specific interval, nor may they assume the server will send any BOOKMARK event during a session. If this is not a watch, this field is ignored.
continue
The continue option should be set when retrieving more results from the server. Since this value is server defined, clients may only use the continue value from a previous query result with identical query parameters (except for the value of continue) and the server may reject a continue value it does not recognize. If the specified continue value is no longer valid whether due to expiration (generally five to fifteen minutes) or a configuration change on the server, the server will respond with a 410 ResourceExpired error together with a continue token. If the client needs a consistent list, it must restart their list without the continue field. Otherwise, the client may send another list request with the token received with the 410 error, the server will respond with a list starting from the next key, but from the latest snapshot, which is inconsistent from the previous list results - objects that are created, modified, or deleted after the first list request will be included in the response, as long as their keys are after the "next key".
This field is not supported when watch is true. Clients may start a watch from the last resourceVersion value returned by the server and not miss any modifications.
dryRun
When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed
fieldManager
fieldManager is a name associated with the actor or entity that is making these changes. The value must be less than or 128 characters long, and only contain printable characters, as defined by https://golang.org/pkg/unicode/#IsPrint.
fieldSelector
A selector to restrict the list of returned objects by their fields. Defaults to everything.
fieldValidation
fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered.
force
Force is going to "force" Apply requests. It means user will re-acquire conflicting fields owned by other people. Force flag must be unset for non-apply patch requests.
gracePeriodSeconds
The duration in seconds before the object should be deleted. Value must be non-negative integer. The value zero indicates delete immediately. If this value is nil, the default grace period for the specified type will be used. Defaults to a per object value if not specified. zero means delete immediately.
labelSelector
A selector to restrict the list of returned objects by their labels. Defaults to everything.
limit
limit is a maximum number of responses to return for a list call. If more items exist, the server will set the continue field on the list metadata to a value that can be used with the same initial query to retrieve the next set of results. Setting a limit may return fewer than the requested amount of items (up to zero items) in the event all requested objects are filtered out and clients should only use the presence of the continue field to determine whether more results are available. Servers may choose not to support the limit argument and will return all of the available results. If limit is specified and the continue field is empty, clients may assume that no more results are available. This field is not supported if watch is true.
The server guarantees that the objects returned when using continue will be identical to issuing a single list call without a limit - that is, no objects created, modified, or deleted after the first request is issued will be included in any subsequent continued requests. This is sometimes referred to as a consistent snapshot, and ensures that a client that is using limit to receive smaller chunks of a very large result can ensure they see all possible objects. If objects are updated during a chunked list the version of the object that was present at the time the first list result was calculated is returned.
namespace
object name and auth scope, such as for teams and projects
pretty
If 'true', then the output is pretty printed.
propagationPolicy
Whether and how garbage collection will be performed. Either this field or OrphanDependents may be set, but not both. The default policy is decided by the existing finalizer set in the metadata.finalizers and the resource-specific default policy. Acceptable values are: 'Orphan' - orphan the dependents; 'Background' - allow the garbage collector to delete the dependents in the background; 'Foreground' - a cascading policy that deletes all dependents in the foreground.
sendInitialEvents=true may be set together with watch=true. In that case, the watch stream will begin with synthetic events to produce the current state of objects in the collection. Once all such events have been sent, a synthetic "Bookmark" event will be sent. The bookmark will report the ResourceVersion (RV) corresponding to the set of objects, and be marked with "k8s.io/initial-events-end": "true" annotation. Afterwards, the watch stream will proceed as usual, sending watch events corresponding to changes (subsequent to the RV) to objects watched.
When sendInitialEvents option is set, we require resourceVersionMatch option to also be set. The semantic of the watch request is as following: - resourceVersionMatch = NotOlderThan
is interpreted as "data at least as new as the provided resourceVersion"
and the bookmark event is send when the state is synced
to a resourceVersion at least as fresh as the one provided by the ListOptions.
If resourceVersion is unset, this is interpreted as "consistent read" and the
bookmark event is send when the state is synced at least to the moment
when request started being processed.
resourceVersionMatch set to any other value or unset
Invalid error is returned.
Defaults to true if resourceVersion="" or resourceVersion="0" (for backward compatibility reasons) and to false otherwise.
timeoutSeconds
Timeout for the list/watch call. This limits the duration of the call, regardless of any activity or inactivity.
watch
Watch for changes to the described resources and return them as a stream of add, update, and remove notifications. Specify resourceVersion.
6 - Instrumentation
6.1 - Kubernetes Component SLI Metrics
FEATURE STATE:Kubernetes v1.27 [beta]
By default, Kubernetes 1.28 publishes Service Level Indicator (SLI) metrics
for each Kubernetes component binary. This metric endpoint is exposed on the serving
HTTPS port of each component, at the path /metrics/slis. The
ComponentSLIsfeature gate
defaults to enabled for each Kubernetes component as of v1.27.
SLI Metrics
With SLI metrics enabled, each Kubernetes component exposes two metrics,
labeled per healthcheck:
a gauge (which represents the current state of the healthcheck)
a counter (which records the cumulative counts observed for each healthcheck state)
You can use the metric information to calculate per-component availability statistics.
For example, the API server checks the health of etcd. You can work out and report how
available or unavailable etcd has been - as reported by its client, the API server.
The prometheus gauge data looks like this:
# HELP kubernetes_healthcheck [ALPHA] This metric records the result of a single healthcheck.
# TYPE kubernetes_healthcheck gauge
kubernetes_healthcheck{name="autoregister-completion",type="healthz"} 1
kubernetes_healthcheck{name="autoregister-completion",type="readyz"} 1
kubernetes_healthcheck{name="etcd",type="healthz"} 1
kubernetes_healthcheck{name="etcd",type="readyz"} 1
kubernetes_healthcheck{name="etcd-readiness",type="readyz"} 1
kubernetes_healthcheck{name="informer-sync",type="readyz"} 1
kubernetes_healthcheck{name="log",type="healthz"} 1
kubernetes_healthcheck{name="log",type="readyz"} 1
kubernetes_healthcheck{name="ping",type="healthz"} 1
kubernetes_healthcheck{name="ping",type="readyz"} 1
While the counter data looks like this:
# HELP kubernetes_healthchecks_total [ALPHA] This metric records the results of all healthcheck.
# TYPE kubernetes_healthchecks_total counter
kubernetes_healthchecks_total{name="autoregister-completion",status="error",type="readyz"} 1
kubernetes_healthchecks_total{name="autoregister-completion",status="success",type="healthz"} 15
kubernetes_healthchecks_total{name="autoregister-completion",status="success",type="readyz"} 14
kubernetes_healthchecks_total{name="etcd",status="success",type="healthz"} 15
kubernetes_healthchecks_total{name="etcd",status="success",type="readyz"} 15
kubernetes_healthchecks_total{name="etcd-readiness",status="success",type="readyz"} 15
kubernetes_healthchecks_total{name="informer-sync",status="error",type="readyz"} 1
kubernetes_healthchecks_total{name="informer-sync",status="success",type="readyz"} 14
kubernetes_healthchecks_total{name="log",status="success",type="healthz"} 15
kubernetes_healthchecks_total{name="log",status="success",type="readyz"} 15
kubernetes_healthchecks_total{name="ping",status="success",type="healthz"} 15
kubernetes_healthchecks_total{name="ping",status="success",type="readyz"} 15
Using this data
The component SLIs metrics endpoint is intended to be scraped at a high frequency. Scraping
at a high frequency means that you end up with greater granularity of the gauge's signal, which
can be then used to calculate SLOs. The /metrics/slis endpoint provides the raw data necessary
to calculate an availability SLO for the respective Kubernetes component.
6.2 - CRI Pod & Container Metrics
Collection of Pod & Container metrics via the CRI.
FEATURE STATE:Kubernetes v1.23 [alpha]
The kubelet collects pod and
container metrics via cAdvisor. As an alpha feature,
Kubernetes lets you configure the collection of pod and container
metrics via the Container Runtime Interface (CRI). You
must enable the PodAndContainerStatsFromCRIfeature gate and
use a compatible CRI implementation (containerd >= 1.6.0, CRI-O >= 1.23.0) to
use the CRI based collection mechanism.
CRI Pod & Container Metrics
With PodAndContainerStatsFromCRI enabled, the kubelet polls the underlying container
runtime for pod and container stats instead of inspecting the host system directly using cAdvisor.
The benefits of relying on the container runtime for this information as opposed to direct
collection with cAdvisor include:
Potential improved performance if the container runtime already collects this information
during normal operations. In this case, the data can be re-used instead of being aggregated
again by the kubelet.
It further decouples the kubelet and the container runtime allowing collection of metrics for
container runtimes that don't run processes directly on the host with kubelet where they are
observable by cAdvisor (for example: container runtimes that use virtualization).
6.3 - Node metrics data
Mechanisms for accessing metrics at node, volume, pod and container level, as seen by the kubelet.
The kubelet
gathers metric statistics at the node, volume, pod and container level,
and emits this information in the
Summary API.
You can send a proxied request to the stats summary API via the
Kubernetes API server.
Here is an example of a Summary API request for a node named minikube:
kubectl get --raw "/api/v1/nodes/minikube/proxy/stats/summary"
Here is the same API call using curl:
# You need to run "kubectl proxy" first# Change 8080 to the port that "kubectl proxy" assignscurl http://localhost:8080/api/v1/nodes/minikube/proxy/stats/summary
Note: Beginning with metrics-server 0.6.x, metrics-server queries the /metrics/resource
kubelet endpoint, and not /stats/summary.
The task pages for Troubleshooting Clusters discuss
how to use a metrics pipeline that rely on these data.
6.4 - Kubernetes Metrics Reference
Details of the metric data that Kubernetes components export.
Metrics (v1.29)
This page details the metrics that different Kubernetes components export. You can query the metrics endpoint for these
components using an HTTP scrape, and fetch the current metrics data in Prometheus format.
List of Stable Kubernetes Metrics
Stable metrics observe strict API contracts and no labels can be added or removed from stable metrics during their lifetime.
Admission webhook latency histogram in seconds, identified by name and broken out for each operation and API resource and type (validate or admit).
STABLE
Histogram
nameoperationrejectedtype
apiserver_current_inflight_requests
Maximal number of currently used inflight request limit of this apiserver per request kind in last second.
STABLE
Gauge
request_kind
apiserver_longrunning_requests
Gauge of all active long-running apiserver requests broken out by verb, group, version, resource, scope and component. Not all requests are tracked this way.
STABLE
Gauge
componentgroupresourcescopesubresourceverbversion
apiserver_request_duration_seconds
Response latency distribution in seconds for each verb, dry run value, group, version, resource, subresource, scope and component.
Time between when a cronjob is scheduled to be run, and when the corresponding job is created
STABLE
Histogram
job_controller_job_pods_finished_total
The number of finished Pods that are fully tracked
STABLE
Counter
completion_moderesult
job_controller_job_sync_duration_seconds
The time it took to sync a job
STABLE
Histogram
actioncompletion_moderesult
job_controller_job_syncs_total
The number of job syncs
STABLE
Counter
actioncompletion_moderesult
job_controller_jobs_finished_total
The number of finished jobs
STABLE
Counter
completion_modereasonresult
kube_pod_resource_limit
Resources limit for workloads on the cluster, broken down by pod. This shows the resource usage the scheduler and kubelet expect per pod for resources along with the unit for the resource if any.
STABLE
Custom
namespacepodnodeschedulerpriorityresourceunit
kube_pod_resource_request
Resources requested by workloads on the cluster, broken down by pod. This shows the resource usage the scheduler and kubelet expect per pod for resources along with the unit for the resource if any.
STABLE
Custom
namespacepodnodeschedulerpriorityresourceunit
node_collector_evictions_total
Number of Node evictions that happened since current instance of NodeController started.
STABLE
Counter
zone
node_cpu_usage_seconds_total
Cumulative cpu time consumed by the node in core-seconds
STABLE
Custom
node_memory_working_set_bytes
Current working set of the node in bytes
STABLE
Custom
pod_cpu_usage_seconds_total
Cumulative cpu time consumed by the pod in core-seconds
STABLE
Custom
podnamespace
pod_memory_working_set_bytes
Current working set of the pod in bytes
STABLE
Custom
podnamespace
resource_scrape_error
1 if there was an error while getting container metrics, 0 otherwise
Latency for running all plugins of a specific extension point.
STABLE
Histogram
extension_pointprofilestatus
scheduler_pending_pods
Number of pending pods, by the queue type. 'active' means number of pods in activeQ; 'backoff' means number of pods in backoffQ; 'unschedulable' means number of pods in unschedulablePods that the scheduler attempted to schedule and failed; 'gated' is the number of unschedulable pods that the scheduler never attempted to schedule because they are gated.
STABLE
Gauge
queue
scheduler_pod_scheduling_attempts
Number of attempts to successfully schedule a pod.
STABLE
Histogram
scheduler_pod_scheduling_duration_seconds
E2e latency for a pod being scheduled which may include multiple scheduling attempts.
STABLE
Histogram
attempts
1.28.0
scheduler_preemption_attempts_total
Total preemption attempts in the cluster till now
STABLE
Counter
scheduler_preemption_victims
Number of selected preemption victims
STABLE
Histogram
scheduler_queue_incoming_pods_total
Number of pods added to scheduling queues by event and queue type.
STABLE
Counter
eventqueue
scheduler_schedule_attempts_total
Number of attempts to schedule pods, by the result. 'unschedulable' means a pod could not be scheduled, while 'error' means an internal scheduler problem.
STABLE
Counter
profileresult
scheduler_scheduling_attempt_duration_seconds
Scheduling attempt latency in seconds (scheduling algorithm + binding)
STABLE
Histogram
profileresult
List of Beta Kubernetes Metrics
Beta metrics observe a looser API contract than its stable counterparts. No labels can be removed from beta metrics during their lifetime, however, labels can be added while the metric is in the beta stage. This offers the assurance that beta metrics will honor existing dashboards and alerts, while allowing for amendments in the future.
apiserver_flowcontrol_current_executing_requests
Number of requests in initial (for a WATCH) or any (for a non-WATCH) execution stage in the API Priority and Fairness subsystem
BETA
Gauge
flow_schemapriority_level
apiserver_flowcontrol_current_executing_seats
Concurrency (number of seats) occupied by the currently executing (initial stage for a WATCH, any stage otherwise) requests in the API Priority and Fairness subsystem
BETA
Gauge
flow_schemapriority_level
apiserver_flowcontrol_current_inqueue_requests
Number of requests currently pending in queues of the API Priority and Fairness subsystem
BETA
Gauge
flow_schemapriority_level
apiserver_flowcontrol_dispatched_requests_total
Number of requests executed by API Priority and Fairness subsystem
BETA
Counter
flow_schemapriority_level
apiserver_flowcontrol_nominal_limit_seats
Nominal number of execution seats configured for each priority level
BETA
Gauge
priority_level
apiserver_flowcontrol_rejected_requests_total
Number of requests rejected by API Priority and Fairness subsystem
Length of time a request spent waiting in its queue
BETA
Histogram
executeflow_schemapriority_level
disabled_metrics_total
The count of disabled metrics.
BETA
Counter
hidden_metrics_total
The count of hidden metrics.
BETA
Counter
kubernetes_feature_enabled
This metric records the data about the stage and enablement of a k8s feature.
BETA
Gauge
namestage
kubernetes_healthcheck
This metric records the result of a single healthcheck.
BETA
Gauge
nametype
kubernetes_healthchecks_total
This metric records the results of all healthcheck.
BETA
Counter
namestatustype
registered_metrics_total
The count of registered metrics broken by stability level and deprecation version.
BETA
Counter
deprecated_versionstability_level
scheduler_pod_scheduling_sli_duration_seconds
E2e latency for a pod being scheduled, from the time the pod enters the scheduling queue an d might involve multiple scheduling attempts.
BETA
Histogram
attempts
List of Alpha Kubernetes Metrics
Alpha metrics do not have any API guarantees. These metrics must be used at your own risk, subsequent versions of Kubernetes may remove these metrics altogether, or mutate the API in such a way that breaks existing dashboards and alerts.
aggregator_discovery_aggregation_count_total
Counter of number of times discovery was aggregated
ALPHA
Counter
aggregator_openapi_v2_regeneration_count
Counter of OpenAPI v2 spec regeneration count broken down by causing APIService name and reason.
ALPHA
Counter
apiservicereason
aggregator_openapi_v2_regeneration_duration
Gauge of OpenAPI v2 spec regeneration duration in seconds.
ALPHA
Gauge
reason
aggregator_unavailable_apiservice
Gauge of APIServices which are marked as unavailable broken down by APIService name.
ALPHA
Custom
name
aggregator_unavailable_apiservice_total
Counter of APIServices which are marked as unavailable broken down by APIService name and reason.
ALPHA
Counter
namereason
apiextensions_openapi_v2_regeneration_count
Counter of OpenAPI v2 spec regeneration count broken down by causing CRD name and reason.
ALPHA
Counter
crdreason
apiextensions_openapi_v3_regeneration_count
Counter of OpenAPI v3 spec regeneration count broken down by group, version, causing CRD and reason.
Admission match condition evaluation errors count, identified by name of resource containing the match condition and broken out for each kind containing matchConditions (webhook or policy), operation and admission type (validate or admit).
Admission match condition evaluation time in seconds, identified by name and broken out for each kind containing matchConditions (webhook or policy), operation and type (validate or admit).
Admission match condition evaluation exclusions count, identified by name of resource containing the match condition and broken out for each kind containing matchConditions (webhook or policy), operation and admission type (validate or admit).
Admission sub-step latency summary in seconds, broken out for each operation and API resource and step type (validate or admit).
ALPHA
Summary
operationrejectedtype
apiserver_admission_webhook_fail_open_count
Admission webhook fail open count, identified by name and broken out for each admission type (validating or mutating).
ALPHA
Counter
nametype
apiserver_admission_webhook_rejection_count
Admission webhook rejection count, identified by name and broken out for each admission type (validating or admit) and operation. Additional labels specify an error type (calling_webhook_error or apiserver_internal_error if an error occurred; no_error otherwise) and optionally a non-zero rejection code if the webhook rejects the request with an HTTP status code (honored by the apiserver when the code is greater or equal to 400). Codes greater than 600 are truncated to 600, to keep the metrics cardinality bounded.
ALPHA
Counter
error_typenameoperationrejection_codetype
apiserver_admission_webhook_request_total
Admission webhook request total, identified by name and broken out for each admission type (validating or mutating) and operation. Additional labels specify whether the request was rejected or not and an HTTP status code. Codes greater than 600 are truncated to 600, to keep the metrics cardinality bounded.
ALPHA
Counter
codenameoperationrejectedtype
apiserver_audit_error_total
Counter of audit events that failed to be audited properly. Plugin identifies the plugin affected by the error.
ALPHA
Counter
plugin
apiserver_audit_event_total
Counter of audit events generated and sent to the audit backend.
ALPHA
Counter
apiserver_audit_level_total
Counter of policy levels for audit events (1 per request).
ALPHA
Counter
level
apiserver_audit_requests_rejected_total
Counter of apiserver requests rejected due to an error in audit logging backend.
ALPHA
Counter
apiserver_cache_list_fetched_objects_total
Number of objects read from watch cache in the course of serving a LIST request
ALPHA
Counter
indexresource_prefix
apiserver_cache_list_returned_objects_total
Number of objects returned for a LIST request from watch cache
Request latency in seconds. Broken down by status code.
ALPHA
Histogram
code
apiserver_delegated_authz_request_total
Number of HTTP requests partitioned by status code.
ALPHA
Counter
code
apiserver_egress_dialer_dial_duration_seconds
Dial latency histogram in seconds, labeled by the protocol (http-connect or grpc), transport (tcp or uds)
ALPHA
Histogram
protocoltransport
apiserver_egress_dialer_dial_failure_count
Dial failure count, labeled by the protocol (http-connect or grpc), transport (tcp or uds), and stage (connect or proxy). The stage indicates at which stage the dial failed
ALPHA
Counter
protocolstagetransport
apiserver_egress_dialer_dial_start_total
Dial starts, labeled by the protocol (http-connect or grpc) and transport (tcp or uds).
Number of records in data encryption key (DEK) source cache. On a restart, this value is an approximation of the number of decrypt RPC calls the server will make to the KMS plugin.
Observations, at the end of every nanosecond, of number of requests (as a fraction of the relevant limit) waiting or in any stage of execution (but only initial stage for WATCHes)
Observations, at the end of every nanosecond, of the number of requests (as a fraction of the relevant limit) waiting or in regular stage of execution
ALPHA
TimingRatioHistogram
phaserequest_kind
apiserver_flowcontrol_request_concurrency_in_use
Concurrency (number of seats) occupied by the currently executing (initial stage for a WATCH, any stage otherwise) requests in the API Priority and Fairness subsystem
ALPHA
Gauge
flow_schemapriority_level
1.31.0
apiserver_flowcontrol_request_concurrency_limit
Nominal number of execution seats configured for each priority level
Counts the number of requests to servers with insecure SHA1 signatures in their serving certificate OR the number of connection failures due to the insecure SHA1 signatures (either/or, based on the runtime environment)
ALPHA
Counter
apiserver_kube_aggregator_x509_missing_san_total
Counts the number of requests to servers missing SAN extension in their serving certificate OR the number of connection failures due to the lack of x509 certificate SAN extension missing (either/or, based on the runtime environment)
ALPHA
Counter
apiserver_request_aborts_total
Number of requests which apiserver aborted possibly due to a timeout, for each group, version, verb, resource, subresource and scope
ALPHA
Counter
groupresourcescopesubresourceverbversion
apiserver_request_body_sizes
Apiserver request body sizes broken out by size.
ALPHA
Histogram
resourceverb
apiserver_request_filter_duration_seconds
Request filter latency distribution in seconds, for each filter type
ALPHA
Histogram
filter
apiserver_request_post_timeout_total
Tracks the activity of the request handlers after the associated requests have been timed out by the apiserver
ALPHA
Counter
sourcestatus
apiserver_request_sli_duration_seconds
Response latency distribution (not counting webhook duration and priority & fairness queue wait times) in seconds for each verb, group, version, resource, subresource, scope and component.
ALPHA
Histogram
componentgroupresourcescopesubresourceverbversion
apiserver_request_slo_duration_seconds
Response latency distribution (not counting webhook duration and priority & fairness queue wait times) in seconds for each verb, group, version, resource, subresource, scope and component.
ALPHA
Histogram
componentgroupresourcescopesubresourceverbversion
1.27.0
apiserver_request_terminations_total
Number of requests which apiserver terminated in self-defense.
Total number of cache misses while accessing key decryption key(KEK).
ALPHA
Counter
apiserver_storage_events_received_total
Number of etcd events received split by kind.
ALPHA
Counter
resource
apiserver_storage_list_evaluated_objects_total
Number of objects tested in the course of serving a LIST request from storage
ALPHA
Counter
resource
apiserver_storage_list_fetched_objects_total
Number of objects read from storage in the course of serving a LIST request
ALPHA
Counter
resource
apiserver_storage_list_returned_objects_total
Number of objects returned for a LIST request from storage
ALPHA
Counter
resource
apiserver_storage_list_total
Number of LIST requests served from storage
ALPHA
Counter
resource
apiserver_storage_size_bytes
Size of the storage database file physically allocated in bytes.
ALPHA
Custom
cluster
apiserver_storage_transformation_duration_seconds
Latencies in seconds of value transformation operations.
ALPHA
Histogram
transformation_typetransformer_prefix
apiserver_storage_transformation_operations_total
Total number of transformations. Successful transformation will have a status 'OK' and a varied status string when the transformation fails. This status and transformation_type fields may be used for alerting on encryption/decryption failure using transformation_type from_storage for decryption and to_storage for encryption
ALPHA
Counter
statustransformation_typetransformer_prefix
apiserver_terminated_watchers_total
Counter of watchers closed due to unresponsiveness broken by resource type.
ALPHA
Counter
resource
apiserver_tls_handshake_errors_total
Number of requests dropped with 'TLS handshake error from' error
Validation admission latency for individual validation expressions in seconds, labeled by policy and further including binding, state and enforcement action taken.
ALPHA
Histogram
enforcement_actionpolicypolicy_bindingstate
apiserver_validating_admission_policy_check_total
Validation admission policy check total, labeled by policy and further identified by binding, enforcement action taken, and state.
Validation admission policy count total, labeled by state and enforcement action.
ALPHA
Counter
enforcement_actionstate
apiserver_watch_cache_events_dispatched_total
Counter of events dispatched in watch cache broken by resource type.
ALPHA
Counter
resource
apiserver_watch_cache_events_received_total
Counter of events received in watch cache broken by resource type.
ALPHA
Counter
resource
apiserver_watch_cache_initializations_total
Counter of watch cache initializations broken by resource type.
ALPHA
Counter
resource
apiserver_watch_events_sizes
Watch event size distribution in bytes
ALPHA
Histogram
groupkindversion
apiserver_watch_events_total
Number of events sent in watch clients
ALPHA
Counter
groupkindversion
apiserver_webhooks_x509_insecure_sha1_total
Counts the number of requests to servers with insecure SHA1 signatures in their serving certificate OR the number of connection failures due to the insecure SHA1 signatures (either/or, based on the runtime environment)
ALPHA
Counter
apiserver_webhooks_x509_missing_san_total
Counts the number of requests to servers missing SAN extension in their serving certificate OR the number of connection failures due to the lack of x509 certificate SAN extension missing (either/or, based on the runtime environment)
The number of volumes that failed force cleanup after their reconstruction failed during kubelet startup.
ALPHA
Counter
force_cleaned_failed_volume_operations_total
The number of volumes that were force cleaned after their reconstruction failed during kubelet startup. This includes both successful and failed cleanups.
The time(seconds) that the HPA controller takes to calculate one metric. The label 'action' should be either 'scale_down', 'scale_up', or 'none'. The label 'error' should be either 'spec', 'internal', or 'none'. The label 'metric_type' corresponds to HPA.spec.metrics[*].type
Number of metric computations. The label 'action' should be either 'scale_down', 'scale_up', or 'none'. Also, the label 'error' should be either 'spec', 'internal', or 'none'. The label 'metric_type' corresponds to HPA.spec.metrics[*].type
The time(seconds) that the HPA controller takes to reconcile once. The label 'action' should be either 'scale_down', 'scale_up', or 'none'. Also, the label 'error' should be either 'spec', 'internal', or 'none'. Note that if both spec and internal errors happen during a reconciliation, the first one to occur is reported in `error` label.
Number of reconciliations of HPA controller. The label 'action' should be either 'scale_down', 'scale_up', or 'none'. Also, the label 'error' should be either 'spec', 'internal', or 'none'. Note that if both spec and internal errors happen during a reconciliation, the first one to occur is reported in `error` label.
`The number of failed Pods handled by failure policy with, respect to the failure policy action applied based on the matched, rule. Possible values of the action label correspond to the, possible values for the failure policy rule action, which are:, "FailJob", "Ignore" and "Count".`
`The number of terminated pods (phase=Failed|Succeeded), that have the finalizer batch.kubernetes.io/job-tracking, The event label can be "add" or "delete".`
ALPHA
Counter
event
kube_apiserver_clusterip_allocator_allocated_ips
Gauge measuring the number of allocated IPs for Services
Total number of requests for pods/logs sliced by usage type: enforce_tls, skip_tls_allowed, skip_tls_denied
ALPHA
Counter
usage
1.27.0
kubelet_active_pods
The number of pods the kubelet considers active and which are being considered when admitting new pods. static is true if the pod is not from the apiserver.
Gauge of the TTL (time-to-live) of the Kubelet's client certificate. The value is in seconds until certificate expiry (negative if already expired). If client certificate is invalid or unused, the value will be +INF.
Histogram of the number of seconds the previous certificate lived before being rotated.
ALPHA
Histogram
kubelet_certificate_manager_server_ttl_seconds
Gauge of the shortest TTL (time-to-live) of the Kubelet's serving certificate. The value is in seconds until certificate expiry (negative if already expired). If serving certificate is invalid or unused, the value will be +INF.
ALPHA
Gauge
kubelet_cgroup_manager_duration_seconds
Duration in seconds for cgroup manager operations. Broken down by method.
ALPHA
Histogram
operation_type
kubelet_container_log_filesystem_used_bytes
Bytes used by the container's logs on the filesystem.
ALPHA
Custom
uidnamespacepodcontainer
kubelet_containers_per_pod_count
The number of containers per pod.
ALPHA
Histogram
kubelet_cpu_manager_pinning_errors_total
The number of cpu core allocations which required pinning failed.
ALPHA
Counter
kubelet_cpu_manager_pinning_requests_total
The number of cpu core allocations which required pinning.
ALPHA
Counter
kubelet_credential_provider_plugin_duration
Duration of execution in seconds for credential provider plugin
ALPHA
Histogram
plugin_name
kubelet_credential_provider_plugin_errors
Number of errors from credential provider plugin
ALPHA
Counter
plugin_name
kubelet_desired_pods
The number of pods the kubelet is being instructed to run. static is true if the pod is not from the apiserver.
ALPHA
Gauge
static
kubelet_device_plugin_alloc_duration_seconds
Duration in seconds to serve a device plugin Allocation request. Broken down by resource name.
ALPHA
Histogram
resource_name
kubelet_device_plugin_registration_total
Cumulative number of device plugin registrations. Broken down by resource name.
ALPHA
Counter
resource_name
kubelet_evented_pleg_connection_error_count
The number of errors encountered during the establishment of streaming connection with the CRI runtime.
ALPHA
Counter
kubelet_evented_pleg_connection_latency_seconds
The latency of streaming connection with the CRI runtime, measured in seconds.
ALPHA
Histogram
kubelet_evented_pleg_connection_success_count
The number of times a streaming client was obtained to receive CRI Events.
ALPHA
Counter
kubelet_eviction_stats_age_seconds
Time between when stats are collected, and when pod is evicted based on those stats by eviction signal
ALPHA
Histogram
eviction_signal
kubelet_evictions
Cumulative number of pod evictions by eviction signal
ALPHA
Counter
eviction_signal
kubelet_graceful_shutdown_end_time_seconds
Last graceful shutdown start time since unix epoch in seconds
ALPHA
Gauge
kubelet_graceful_shutdown_start_time_seconds
Last graceful shutdown start time since unix epoch in seconds
ALPHA
Gauge
kubelet_http_inflight_requests
Number of the inflight http requests
ALPHA
Gauge
long_runningmethodpathserver_type
kubelet_http_requests_duration_seconds
Duration in seconds to serve http requests
ALPHA
Histogram
long_runningmethodpathserver_type
kubelet_http_requests_total
Number of the http requests received since the server started
ALPHA
Counter
long_runningmethodpathserver_type
kubelet_lifecycle_handler_http_fallbacks_total
The number of times lifecycle handlers successfully fell back to http from https.
ALPHA
Counter
kubelet_managed_ephemeral_containers
Current number of ephemeral containers in pods managed by this kubelet.
ALPHA
Gauge
kubelet_mirror_pods
The number of mirror pods the kubelet will try to create (one per admitted static pod)
ALPHA
Gauge
kubelet_node_name
The node's name. The count is always 1.
ALPHA
Gauge
node
kubelet_orphan_pod_cleaned_volumes
The total number of orphaned Pods whose volumes were cleaned in the last periodic sweep.
ALPHA
Gauge
kubelet_orphan_pod_cleaned_volumes_errors
The number of orphaned Pods whose volumes failed to be cleaned in the last periodic sweep.
ALPHA
Gauge
kubelet_orphaned_runtime_pods_total
Number of pods that have been detected in the container runtime without being already known to the pod worker. This typically indicates the kubelet was restarted while a pod was force deleted in the API or in the local configuration, which is unusual.
ALPHA
Counter
kubelet_pleg_discard_events
The number of discard events in PLEG.
ALPHA
Counter
kubelet_pleg_last_seen_seconds
Timestamp in seconds when PLEG was last seen active.
ALPHA
Gauge
kubelet_pleg_relist_duration_seconds
Duration in seconds for relisting pods in PLEG.
ALPHA
Histogram
kubelet_pleg_relist_interval_seconds
Interval in seconds between relisting in PLEG.
ALPHA
Histogram
kubelet_pod_resources_endpoint_errors_get
Number of requests to the PodResource Get endpoint which returned error. Broken down by server api version.
Number of requests to the PodResource GetAllocatableResources endpoint. Broken down by server api version.
ALPHA
Counter
server_api_version
kubelet_pod_resources_endpoint_requests_list
Number of requests to the PodResource List endpoint. Broken down by server api version.
ALPHA
Counter
server_api_version
kubelet_pod_resources_endpoint_requests_total
Cumulative number of requests to the PodResource endpoint. Broken down by server api version.
ALPHA
Counter
server_api_version
kubelet_pod_start_duration_seconds
Duration in seconds from kubelet seeing a pod for the first time to the pod starting to run
ALPHA
Histogram
kubelet_pod_start_sli_duration_seconds
Duration in seconds to start a pod, excluding time to pull images and run init containers, measured from pod creation timestamp to when all its containers are reported as started and observed via watch
ALPHA
Histogram
kubelet_pod_status_sync_duration_seconds
Duration in seconds to sync a pod status update. Measures time from detection of a change to pod status until the API is successfully updated for that pod, even if multiple intevening changes to pod status occur.
ALPHA
Histogram
kubelet_pod_worker_duration_seconds
Duration in seconds to sync a single pod. Broken down by operation type: create, update, or sync
ALPHA
Histogram
operation_type
kubelet_pod_worker_start_duration_seconds
Duration in seconds from kubelet seeing a pod to starting a worker.
ALPHA
Histogram
kubelet_preemptions
Cumulative number of pod preemptions by preemption resource
ALPHA
Counter
preemption_signal
kubelet_restarted_pods_total
Number of pods that have been restarted because they were deleted and recreated with the same UID while the kubelet was watching them (common for static pods, extremely uncommon for API pods)
ALPHA
Counter
static
kubelet_run_podsandbox_duration_seconds
Duration in seconds of the run_podsandbox operations. Broken down by RuntimeClass.Handler.
ALPHA
Histogram
runtime_handler
kubelet_run_podsandbox_errors_total
Cumulative number of the run_podsandbox operation errors by RuntimeClass.Handler.
ALPHA
Counter
runtime_handler
kubelet_running_containers
Number of containers currently running
ALPHA
Gauge
container_state
kubelet_running_pods
Number of pods that have a running pod sandbox
ALPHA
Gauge
kubelet_runtime_operations_duration_seconds
Duration in seconds of runtime operations. Broken down by operation type.
ALPHA
Histogram
operation_type
kubelet_runtime_operations_errors_total
Cumulative number of runtime operation errors by operation type.
ALPHA
Counter
operation_type
kubelet_runtime_operations_total
Cumulative number of runtime operations by operation type.
ALPHA
Counter
operation_type
kubelet_server_expiration_renew_errors
Counter of certificate renewal errors.
ALPHA
Counter
kubelet_started_containers_errors_total
Cumulative number of errors when starting containers
Cumulative number of errors when starting hostprocess containers. This metric will only be collected on Windows.
ALPHA
Counter
codecontainer_type
kubelet_started_host_process_containers_total
Cumulative number of hostprocess containers started. This metric will only be collected on Windows.
ALPHA
Counter
container_type
kubelet_started_pods_errors_total
Cumulative number of errors when starting pods
ALPHA
Counter
kubelet_started_pods_total
Cumulative number of pods started
ALPHA
Counter
kubelet_topology_manager_admission_duration_ms
Duration in milliseconds to serve a pod admission request.
ALPHA
Histogram
kubelet_topology_manager_admission_errors_total
The number of admission request failures where resources could not be aligned.
ALPHA
Counter
kubelet_topology_manager_admission_requests_total
The number of admission requests where resources have to be aligned.
ALPHA
Counter
kubelet_volume_metric_collection_duration_seconds
Duration in seconds to calculate volume stats
ALPHA
Histogram
metric_source
kubelet_volume_stats_available_bytes
Number of available bytes in the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_capacity_bytes
Capacity in bytes of the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_health_status_abnormal
Abnormal volume health status. The count is either 1 or 0. 1 indicates the volume is unhealthy, 0 indicates volume is healthy
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_inodes
Maximum number of inodes in the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_inodes_free
Number of free inodes in the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_inodes_used
Number of used inodes in the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_volume_stats_used_bytes
Number of used bytes in the volume
ALPHA
Custom
namespacepersistentvolumeclaim
kubelet_working_pods
Number of pods the kubelet is actually running, broken down by lifecycle phase, whether the pod is desired, orphaned, or runtime only (also orphaned), and whether the pod is static. An orphaned pod has been removed from local configuration or force deleted in the API and consumes resources that are not otherwise visible.
ALPHA
Gauge
configlifecyclestatic
kubeproxy_network_programming_duration_seconds
In Cluster Network Programming Latency in seconds
ALPHA
Histogram
kubeproxy_proxy_healthz_total
Cumulative proxy healthz HTTP status
ALPHA
Counter
code
kubeproxy_proxy_livez_total
Cumulative proxy livez HTTP status
ALPHA
Counter
code
kubeproxy_sync_full_proxy_rules_duration_seconds
SyncProxyRules latency in seconds for full resyncs
A metric with a constant '1' value labeled by major, minor, git version, git commit, git tree state, build date, Go version, and compiler from which Kubernetes was built, and platform on which it is running.
Gauge of if the reporting system is master of the relevant lease, 0 indicates backup, 1 indicates master. 'name' is the string used to identify the lease. Please make sure to group by name.
ALPHA
Gauge
name
node_authorizer_graph_actions_duration_seconds
Histogram of duration of graph actions in node authorizer.
ALPHA
Histogram
operation
node_collector_unhealthy_nodes_in_zone
Gauge measuring number of not Ready Nodes per zones.
Number of exempt requests, not counting ignored or out of scope requests.
ALPHA
Counter
request_operationresourcesubresource
pod_swap_usage_bytes
Current amount of the pod swap usage in bytes. Reported only on non-windows systems
ALPHA
Custom
podnamespace
prober_probe_duration_seconds
Duration in seconds for a probe response.
ALPHA
Histogram
containernamespacepodprobe_type
prober_probe_total
Cumulative number of a liveness, readiness or startup probe for a container by result.
ALPHA
Counter
containernamespacepodpod_uidprobe_typeresult
pv_collector_bound_pv_count
Gauge measuring number of persistent volume currently bound
ALPHA
Custom
storage_class
pv_collector_bound_pvc_count
Gauge measuring number of persistent volume claim currently bound
ALPHA
Custom
namespace
pv_collector_total_pv_count
Gauge measuring total number of persistent volumes
ALPHA
Custom
plugin_namevolume_mode
pv_collector_unbound_pv_count
Gauge measuring number of persistent volume currently unbound
ALPHA
Custom
storage_class
pv_collector_unbound_pvc_count
Gauge measuring number of persistent volume claim currently unbound
ALPHA
Custom
namespace
reconstruct_volume_operations_errors_total
The number of volumes that failed reconstruction from the operating system during kubelet startup.
ALPHA
Counter
reconstruct_volume_operations_total
The number of volumes that were attempted to be reconstructed from the operating system during kubelet startup. This includes both successful and failed reconstruction.
ALPHA
Counter
replicaset_controller_sorting_deletion_age_ratio
The ratio of chosen deleted pod's ages to the current youngest pod's age (at the time). Should be <2.The intent of this metric is to measure the rough efficacy of the LogarithmicScaleDown feature gate's effect onthe sorting (and deletion) of pods when a replicaset scales down. This only considers Ready pods when calculating and reporting.
ALPHA
Histogram
resourceclaim_controller_create_attempts_total
Number of ResourceClaims creation requests
ALPHA
Counter
resourceclaim_controller_create_failures_total
Number of ResourceClaims creation request failures
ALPHA
Counter
rest_client_dns_resolution_duration_seconds
DNS resolver latency in seconds. Broken down by host.
ALPHA
Histogram
host
rest_client_exec_plugin_call_total
Number of calls to an exec plugin, partitioned by the type of event encountered (no_error, plugin_execution_error, plugin_not_found_error, client_internal_error) and an optional exit code. The exit code will be set to 0 if and only if the plugin call was successful.
ALPHA
Counter
call_statuscode
rest_client_exec_plugin_certificate_rotation_age
Histogram of the number of seconds the last auth exec plugin client certificate lived before being rotated. If auth exec plugin client certificates are unused, histogram will contain no data.
ALPHA
Histogram
rest_client_exec_plugin_ttl_seconds
Gauge of the shortest TTL (time-to-live) of the client certificate(s) managed by the auth exec plugin. The value is in seconds until certificate expiry (negative if already expired). If auth exec plugins are unused or manage no TLS certificates, the value will be +INF.
ALPHA
Gauge
rest_client_rate_limiter_duration_seconds
Client side rate limiter latency in seconds. Broken down by verb, and host.
ALPHA
Histogram
hostverb
rest_client_request_duration_seconds
Request latency in seconds. Broken down by verb, and host.
ALPHA
Histogram
hostverb
rest_client_request_retries_total
Number of request retries, partitioned by status code, verb, and host.
ALPHA
Counter
codehostverb
rest_client_request_size_bytes
Request size in bytes. Broken down by verb and host.
ALPHA
Histogram
hostverb
rest_client_requests_total
Number of HTTP requests, partitioned by status code, method, and host.
ALPHA
Counter
codehostmethod
rest_client_response_size_bytes
Response size in bytes. Broken down by verb and host.
ALPHA
Histogram
hostverb
rest_client_transport_cache_entries
Number of transport entries in the internal cache.
ALPHA
Gauge
rest_client_transport_create_calls_total
Number of calls to get a new transport, partitioned by the result of the operation hit: obtained from the cache, miss: created and added to the cache, uncacheable: created and not cached
ALPHA
Counter
result
retroactive_storageclass_errors_total
Total number of failed retroactive StorageClass assignments to persistent volume claim
ALPHA
Counter
retroactive_storageclass_total
Total number of retroactive StorageClass assignments to persistent volume claim
ALPHA
Counter
root_ca_cert_publisher_sync_duration_seconds
Number of namespace syncs happened in root ca cert publisher.
ALPHA
Histogram
code
root_ca_cert_publisher_sync_total
Number of namespace syncs happened in root ca cert publisher.
ALPHA
Counter
code
running_managed_controllers
Indicates where instances of a controller are currently running
ALPHA
Gauge
managername
scheduler_goroutines
Number of running goroutines split by the work they do such as binding.
ALPHA
Gauge
operation
scheduler_permit_wait_duration_seconds
Duration of waiting on permit.
ALPHA
Histogram
result
scheduler_plugin_evaluation_total
Number of attempts to schedule pods by each plugin and the extension point (available only in PreFilter and Filter.).
ALPHA
Counter
extension_pointpluginprofile
scheduler_plugin_execution_duration_seconds
Duration for running a plugin at a specific extension point.
ALPHA
Histogram
extension_pointpluginstatus
scheduler_scheduler_cache_size
Number of nodes, pods, and assumed (bound) pods in the scheduler cache.
ALPHA
Gauge
type
scheduler_scheduling_algorithm_duration_seconds
Scheduling algorithm latency in seconds
ALPHA
Histogram
scheduler_unschedulable_pods
The number of unschedulable pods broken down by plugin name. A pod will increment the gauge for all plugins that caused it to not schedule and so this metric have meaning only when broken down by plugin.
ALPHA
Gauge
pluginprofile
scheduler_volume_binder_cache_requests_total
Total number for request volume binding cache
ALPHA
Counter
operation
scheduler_volume_scheduling_stage_error_total
Volume scheduling stage error count
ALPHA
Counter
operation
scrape_error
1 if there was an error while getting container metrics, 0 otherwise
ALPHA
Custom
1.29.0
service_controller_loadbalancer_sync_total
A metric counting the amount of times any load balancer has been configured, as an effect of service/node changes on the cluster
ALPHA
Counter
service_controller_nodesync_error_total
A metric counting the amount of times any load balancer has been configured and errored, as an effect of node changes on the cluster
ALPHA
Counter
service_controller_nodesync_latency_seconds
A metric measuring the latency for nodesync which updates loadbalancer hosts on cluster node updates.
The time it took to delete the job since it became eligible for deletion
ALPHA
Histogram
volume_manager_selinux_container_errors_total
Number of errors when kubelet cannot compute SELinux context for a container. Kubelet can't start such a Pod then and it will retry, therefore value of this metric may not represent the actual nr. of containers.
ALPHA
Gauge
volume_manager_selinux_container_warnings_total
Number of errors when kubelet cannot compute SELinux context for a container that are ignored. They will become real errors when SELinuxMountReadWriteOncePod feature is expanded to all volume access modes.
Number of errors when a Pod defines different SELinux contexts for its containers that use the same volume. Kubelet can't start such a Pod then and it will retry, therefore value of this metric may not represent the actual nr. of Pods.
Number of errors when a Pod defines different SELinux contexts for its containers that use the same volume. They are not errors yet, but they will become real errors when SELinuxMountReadWriteOncePod feature is expanded to all volume access modes.
Number of errors when a Pod uses a volume that is already mounted with a different SELinux context than the Pod needs. Kubelet can't start such a Pod then and it will retry, therefore value of this metric may not represent the actual nr. of Pods.
Number of errors when a Pod uses a volume that is already mounted with a different SELinux context than the Pod needs. They are not errors yet, but they will become real errors when SELinuxMountReadWriteOncePod feature is expanded to all volume access modes.
ALPHA
Gauge
volume_manager_selinux_volumes_admitted_total
Number of volumes whose SELinux context was fine and will be mounted with mount -o context option.
ALPHA
Gauge
volume_manager_total_volumes
Number of volumes in Volume Manager
ALPHA
Custom
plugin_namestate
volume_operation_total_errors
Total volume operation errors
ALPHA
Counter
operation_nameplugin_name
volume_operation_total_seconds
Storage operation end to end duration in seconds
ALPHA
Histogram
operation_nameplugin_name
watch_cache_capacity
Total capacity of watch cache broken by resource type.
ALPHA
Gauge
resource
watch_cache_capacity_decrease_total
Total number of watch cache capacity decrease events broken by resource type.
ALPHA
Counter
resource
watch_cache_capacity_increase_total
Total number of watch cache capacity increase events broken by resource type.
ALPHA
Counter
resource
workqueue_adds_total
Total number of adds handled by workqueue
ALPHA
Counter
name
workqueue_depth
Current depth of workqueue
ALPHA
Gauge
name
workqueue_longest_running_processor_seconds
How many seconds has the longest running processor for workqueue been running.
ALPHA
Gauge
name
workqueue_queue_duration_seconds
How long in seconds an item stays in workqueue before being requested.
ALPHA
Histogram
name
workqueue_retries_total
Total number of retries handled by workqueue
ALPHA
Counter
name
workqueue_unfinished_work_seconds
How many seconds of work has done that is in progress and hasn't been observed by work_duration. Large values indicate stuck threads. One can deduce the number of stuck threads by observing the rate at which this increases.
ALPHA
Gauge
name
workqueue_work_duration_seconds
How long in seconds processing an item from workqueue takes.
We're extremely grateful for security researchers and users that report vulnerabilities to
the Kubernetes Open Source Community. All reports are thoroughly investigated by a set of community volunteers.
To make a report, submit your vulnerability to the Kubernetes bug bounty program.
This allows triage and handling of the vulnerability with standardized response times.
You may encrypt your email to this list using the GPG keys of the
Security Response Committee members.
Encryption using GPG is NOT required to make a disclosure.
When Should I Report a Vulnerability?
You think you discovered a potential security vulnerability in Kubernetes
You are unsure how a vulnerability affects Kubernetes
You think you discovered a vulnerability in another project that Kubernetes depends on
For projects with their own vulnerability reporting and disclosure process, please report it directly there
When Should I NOT Report a Vulnerability?
You need help tuning Kubernetes components for security
You need help applying security related updates
Your issue is not security related
Security Vulnerability Response
Each report is acknowledged and analyzed by Security Response Committee members within 3 working days.
This will set off the Security Release Process.
Any vulnerability information shared with Security Response Committee stays within Kubernetes project
and will not be disseminated to other projects unless it is necessary to get the issue fixed.
As the security issue moves from triage, to identified fix, to release planning we will keep the reporter updated.
Public Disclosure Timing
A public disclosure date is negotiated by the Kubernetes Security Response Committee and the bug submitter.
We prefer to fully disclose the bug as soon as possible once a user mitigation is available. It is reasonable
to delay disclosure when the bug or the fix is not yet fully understood, the solution is not well-tested,
or for vendor coordination. The timeframe for disclosure is from immediate (especially if it's already publicly known)
to a few weeks. For a vulnerability with a straightforward mitigation, we expect report date to disclosure date
to be on the order of 7 days. The Kubernetes Security Response Committee holds the final say when setting a disclosure date.
The Kubernetes project publishes a programmatically accessible feed of published
security issues in JSON feed
and RSS feed
formats. You can access it by executing the following commands:
This feed is auto-refreshing with a noticeable but small lag (minutes to hours)
from the time a CVE is announced to the time it is accessible in this feed.
The source of truth of this feed is a set of GitHub Issues, filtered by a controlled and
restricted label official-cve-feed. The raw data is stored in a Google Cloud
Bucket which is writable only by a small number of trusted members of the
Community.
8 - Node Reference Information
This section contains the following reference topics about nodes:
Checkpointing a container is the functionality to create a stateful copy of a
running container. Once you have a stateful copy of a container, you could
move it to a different computer for debugging or similar purposes.
If you move the checkpointed container data to a computer that's able to restore
it, that restored container continues to run at exactly the same
point it was checkpointed. You can also inspect the saved data, provided that you
have suitable tools for doing so.
Creating a checkpoint of a container might have security implications. Typically
a checkpoint contains all memory pages of all processes in the checkpointed
container. This means that everything that used to be in memory is now available
on the local disk. This includes all private data and possibly keys used for
encryption. The underlying CRI implementations (the container runtime on that node)
should create the checkpoint archive to be only accessible by the root user. It
is still important to remember if the checkpoint archive is transferred to another
system all memory pages will be readable by the owner of the checkpoint archive.
Operations
post checkpoint the specified container
Tell the kubelet to checkpoint a specific container from the specified Pod.
The kubelet will request a checkpoint from the underlying
CRI implementation. In the checkpoint
request the kubelet will specify the name of the checkpoint archive as
checkpoint-<podFullName>-<containerName>-<timestamp>.tar and also request to
store the checkpoint archive in the checkpoints directory below its root
directory (as defined by --root-dir). This defaults to
/var/lib/kubelet/checkpoints.
The checkpoint archive is in tar format, and could be listed using an implementation of
tar. The contents of the
archive depend on the underlying CRI implementation (the container runtime on that node).
Timeout in seconds to wait until the checkpoint creation is finished.
If zero or no timeout is specfied the default CRI timeout value will be used. Checkpoint
creation time depends directly on the used memory of the container.
The more memory a container uses the more time is required to create
the corresponding checkpoint.
Response
200: OK
401: Unauthorized
404: Not Found (if the ContainerCheckpoint feature gate is disabled)
404: Not Found (if the specified namespace, pod or container cannot be found)
500: Internal Server Error (if the CRI implementation encounter an error during checkpointing (see error message for further details))
500: Internal Server Error (if the CRI implementation does not implement the checkpoint CRI API (see error message for further details))
8.2 - Articles on dockershim Removal and on Using CRI-compatible Runtimes
This is a list of articles and other pages that are either
about the Kubernetes' deprecation and removal of dockershim,
or about using CRI-compatible container runtimes,
in connection with that removal.
topology.kubernetes.io/zone
(if known to the kubelet – Kubernetes may not have this information to set the label)
Note: The value of these labels is cloud provider specific and is not guaranteed to be reliable.
For example, the value of kubernetes.io/hostname may be the same as the node name in some environments
and a different value in other environments.
This page provides details of version compatibility between the Kubernetes
device plugin API,
and different versions of Kubernetes itself.
Compatibility matrix
v1alpha1
v1beta1
Kubernetes 1.21
-
✓
Kubernetes 1.22
-
✓
Kubernetes 1.23
-
✓
Kubernetes 1.24
-
✓
Kubernetes 1.25
-
✓
Kubernetes 1.26
-
✓
Key:
✓ Exactly the same features / API objects in both device plugin API and
the Kubernetes version.
+ The device plugin API has features or API objects that may not be present in the
Kubernetes cluster, either because the device plugin API has added additional new API
calls, or that the server has removed an old API call. However, everything they have in
common (most other APIs) will work. Note that alpha APIs may vanish or
change significantly between one minor release and the next.
- The Kubernetes cluster has features the device plugin API can't use,
either because server has added additional API calls, or that device plugin API has
removed an old API call. However, everything they share in common (most APIs) will work.
8.5 - Node Status
The status of a node in Kubernetes is a critical
aspect of managing a Kubernetes cluster. In this article, we'll cover the basics of
monitoring and maintaining node status to ensure a healthy and stable cluster.
Node status fields
A Node's status contains the following information:
You can use kubectl to view a Node's status and other details:
kubectl describe node <insert-node-name-here>
Each section of the output is described below.
Addresses
The usage of these fields varies depending on your cloud provider or bare metal configuration.
HostName: The hostname as reported by the node's kernel. Can be overridden via the kubelet
--hostname-override parameter.
ExternalIP: Typically the IP address of the node that is externally routable (available from
outside the cluster).
InternalIP: Typically the IP address of the node that is routable only within the cluster.
Conditions
The conditions field describes the status of all Running nodes. Examples of conditions include:
Node conditions, and a description of when each condition applies.
Node Condition
Description
Ready
True if the node is healthy and ready to accept pods, False if the node is not healthy and is not accepting pods, and Unknown if the node controller has not heard from the node in the last node-monitor-grace-period (default is 40 seconds)
DiskPressure
True if pressure exists on the disk size—that is, if the disk capacity is low; otherwise False
MemoryPressure
True if pressure exists on the node memory—that is, if the node memory is low; otherwise False
PIDPressure
True if pressure exists on the processes—that is, if there are too many processes on the node; otherwise False
NetworkUnavailable
True if the network for the node is not correctly configured, otherwise False
Note: If you use command-line tools to print details of a cordoned Node, the Condition includes
SchedulingDisabled. SchedulingDisabled is not a Condition in the Kubernetes API; instead,
cordoned nodes are marked Unschedulable in their spec.
In the Kubernetes API, a node's condition is represented as part of the .status
of the Node resource. For example, the following JSON structure describes a healthy node:
When problems occur on nodes, the Kubernetes control plane automatically creates
taints that match the conditions
affecting the node. An example of this is when the status of the Ready condition
remains Unknown or False for longer than the kube-controller-manager's NodeMonitorGracePeriod,
which defaults to 40 seconds. This will cause either an node.kubernetes.io/unreachable taint, for an Unknown status,
or a node.kubernetes.io/not-ready taint, for a False status, to be added to the Node.
These taints affect pending pods as the scheduler takes the Node's taints into consideration when
assigning a pod to a Node. Existing pods scheduled to the node may be evicted due to the application
of NoExecute taints. Pods may also have tolerations that let
them schedule to and continue running on a Node even though it has a specific taint.
Describes the resources available on the node: CPU, memory, and the maximum
number of pods that can be scheduled onto the node.
The fields in the capacity block indicate the total amount of resources that a
Node has. The allocatable block indicates the amount of resources on a
Node that is available to be consumed by normal Pods.
You may read more about capacity and allocatable resources while learning how
to reserve compute resources
on a Node.
Info
Describes general information about the node, such as kernel version, Kubernetes
version (kubelet and kube-proxy version), container runtime details, and which
operating system the node uses.
The kubelet gathers this information from the node and publishes it into
the Kubernetes API.
Heartbeats
Heartbeats, sent by Kubernetes nodes, help your cluster determine the
availability of each node, and to take action when failures are detected.
For nodes there are two forms of heartbeats:
updates to the .status of a Node
Lease objects
within the kube-node-leasenamespace.
Each Node has an associated Lease object.
Compared to updates to .status of a Node, a Lease is a lightweight resource.
Using Leases for heartbeats reduces the performance impact of these updates
for large clusters.
The kubelet is responsible for creating and updating the .status of Nodes,
and for updating their related Leases.
The kubelet updates the node's .status either when there is change in status
or if there has been no update for a configured interval. The default interval
for .status updates to Nodes is 5 minutes, which is much longer than the 40
second default timeout for unreachable nodes.
The kubelet creates and then updates its Lease object every 10 seconds
(the default update interval). Lease updates occur independently from
updates to the Node's .status. If the Lease update fails, the kubelet retries,
using exponential backoff that starts at 200 milliseconds and capped at 7 seconds.
9 - Networking Reference
This section of the Kubernetes documentation provides reference details
of Kubernetes networking.
9.1 - Protocols for Services
If you configure a Service,
you can select from any network protocol that Kubernetes supports.
Kubernetes supports the following protocols with Services:
There are 3 valid values for the protocol of a port for a Service:
SCTP
FEATURE STATE:Kubernetes v1.20 [stable]
When using a network plugin that supports SCTP traffic, you can use SCTP for
most Services. For type: LoadBalancer Services, SCTP support depends on the cloud
provider offering this facility. (Most do not).
SCTP is not supported on nodes that run Windows.
Support for multihomed SCTP associations
The support of multihomed SCTP associations requires that the CNI plugin can support the assignment of multiple interfaces and IP addresses to a Pod.
NAT for multihomed SCTP associations requires special logic in the corresponding kernel modules.
TCP
You can use TCP for any kind of Service, and it's the default network protocol.
UDP
You can use UDP for most Services. For type: LoadBalancer Services,
UDP support depends on the cloud provider offering this facility.
Special cases
HTTP
If your cloud provider supports it, you can use a Service in LoadBalancer mode to
configure a load balancer outside of your Kubernetes cluster, in a special mode
where your cloud provider's load balancer implements HTTP / HTTPS reverse proxying,
with traffic forwarded to the backend endpoints for that Service.
Typically, you set the protocol for the Service to TCP and add an
annotation
(usually specific to your cloud provider) that configures the load balancer
to handle traffic at the HTTP level.
This configuration might also include serving HTTPS (HTTP over TLS) and
reverse-proxying plain HTTP to your workload.
Note: You can also use an Ingress to expose
HTTP/HTTPS Services.
You might additionally want to specify that the
application protocol
of the connection is http or https. Use http if the session from the
load balancer to your workload is HTTP without TLS, and use https if the
session from the load balancer to your workload uses TLS encryption.
PROXY protocol
If your cloud provider supports it, you can use a Service set to type: LoadBalancer
to configure a load balancer outside of Kubernetes itself, that will forward connections
wrapped with the
PROXY protocol.
The load balancer then sends an initial series of octets describing the
incoming connection, similar to this example (PROXY protocol v1):
PROXY TCP4 192.0.2.202 10.0.42.7 12345 7\r\n
The data after the proxy protocol preamble are the original
data from the client. When either side closes the connection,
the load balancer also triggers a connection close and sends
any remaining data where feasible.
Typically, you define a Service with the protocol to TCP.
You also set an annotation, specific to your
cloud provider, that configures the load balancer to wrap each incoming connection in the PROXY protocol.
TLS
If your cloud provider supports it, you can use a Service set to type: LoadBalancer as
a way to set up external reverse proxying, where the connection from client to load
balancer is TLS encrypted and the load balancer is the TLS server peer.
The connection from the load balancer to your workload can also be TLS,
or might be plain text. The exact options available to you depend on your
cloud provider or custom Service implementation.
Typically, you set the protocol to TCP and set an annotation
(usually specific to your cloud provider) that configures the load balancer
to act as a TLS server. You would configure the TLS identity (as server,
and possibly also as a client that connects to your workload) using
mechanisms that are specific to your cloud provider.
9.2 - Ports and Protocols
When running Kubernetes in an environment with strict network boundaries, such
as on-premises datacenter with physical network firewalls or Virtual
Networks in Public Cloud, it is useful to be aware of the ports and protocols
used by Kubernetes components.
Control plane
Protocol
Direction
Port Range
Purpose
Used By
TCP
Inbound
6443
Kubernetes API server
All
TCP
Inbound
2379-2380
etcd server client API
kube-apiserver, etcd
TCP
Inbound
10250
Kubelet API
Self, Control plane
TCP
Inbound
10259
kube-scheduler
Self
TCP
Inbound
10257
kube-controller-manager
Self
Although etcd ports are included in control plane section, you can also host your own
etcd cluster externally or on custom ports.
All default port numbers can be overridden. When custom ports are used those
ports need to be open instead of defaults mentioned here.
One common example is API server port that is sometimes switched
to 443. Alternatively, the default port is kept as is and API server is put
behind a load balancer that listens on 443 and routes the requests to API server
on the default port.
9.3 - Virtual IPs and Service Proxies
Every node in a Kubernetes
cluster runs a
kube-proxy
(unless you have deployed your own alternative component in place of kube-proxy).
The kube-proxy component is responsible for implementing a virtual IP
mechanism for Services
of type other than
ExternalName.
A question that pops up every now and then is why Kubernetes relies on
proxying to forward inbound traffic to backends. What about other
approaches? For example, would it be possible to configure DNS records that
have multiple A values (or AAAA for IPv6), and rely on round-robin name
resolution?
There are a few reasons for using proxying for Services:
There is a long history of DNS implementations not respecting record TTLs,
and caching the results of name lookups after they should have expired.
Some apps do DNS lookups only once and cache the results indefinitely.
Even if apps and libraries did proper re-resolution, the low or zero TTLs
on the DNS records could impose a high load on DNS that then becomes
difficult to manage.
Later in this page you can read about how various kube-proxy implementations work.
Overall, you should note that, when running kube-proxy, kernel level rules may be modified
(for example, iptables rules might get created), which won't get cleaned up, in some
cases until you reboot. Thus, running kube-proxy is something that should only be done
by an administrator which understands the consequences of having a low level, privileged
network proxying service on a computer. Although the kube-proxy executable supports a
cleanup function, this function is not an official feature and thus is only available
to use as-is.
Some of the details in this reference refer to an example: the backend
Pods for a stateless
image-processing workloads, running with
three replicas. Those replicas are
fungible—frontends do not care which backend they use. While the actual Pods that
compose the backend set may change, the frontend clients should not need to be aware of that,
nor should they need to keep track of the set of backends themselves.
Proxy modes
The kube-proxy starts up in different modes, which are determined by its configuration.
On Linux nodes, the available modes for kube-proxy are:
a mode where the kube-proxy configures packet forwarding rules in the Windows kernel
iptables proxy mode
This proxy mode is only available on Linux nodes.
In this mode, kube-proxy watches the Kubernetes
control plane for the addition and
removal of Service and EndpointSlice objects.
For each Service, it installs
iptables rules, which capture traffic to the Service's clusterIP and port,
and redirect that traffic to one of the Service's
backend sets. For each endpoint, it installs iptables rules which
select a backend Pod.
By default, kube-proxy in iptables mode chooses a backend at random.
Using iptables to handle traffic has a lower system overhead, because traffic
is handled by Linux netfilter without the need to switch between userspace and the
kernel space. This approach is also likely to be more reliable.
If kube-proxy is running in iptables mode and the first Pod that's selected
does not respond, the connection fails. This is different from the old userspace
mode: in that scenario, kube-proxy would detect that the connection to the first
Pod had failed and would automatically retry with a different backend Pod.
You can use Pod readiness probes
to verify that backend Pods are working OK, so that kube-proxy in iptables mode
only sees backends that test out as healthy. Doing this means you avoid
having traffic sent via kube-proxy to a Pod that's known to have failed.
Virtual IP mechanism for Services, using iptables mode
Example
As an example, consider the image processing application described earlier
in the page.
When the backend Service is created, the Kubernetes control plane assigns a virtual
IP address, for example 10.0.0.1. For this example, assume that the
Service port is 1234.
All of the kube-proxy instances in the cluster observe the creation of the new
Service.
When kube-proxy on a node sees a new Service, it installs a series of iptables rules
which redirect from the virtual IP address to more iptables rules, defined per Service.
The per-Service rules link to further rules for each backend endpoint, and the per-
endpoint rules redirect traffic (using destination NAT) to the backends.
When a client connects to the Service's virtual IP address the iptables rule kicks in.
A backend is chosen (either based on session affinity or randomly) and packets are
redirected to the backend without rewriting the client IP address.
This same basic flow executes when traffic comes in through a node-port or
through a load-balancer, though in those cases the client IP address does get altered.
Optimizing iptables mode performance
In large clusters (with tens of thousands of Pods and Services), the
iptables mode of kube-proxy may take a long time to update the rules
in the kernel when Services (or their EndpointSlices) change. You can adjust the syncing
behavior of kube-proxy via options in the iptables section
of the
kube-proxy configuration file
(which you specify via kube-proxy --config <path>):
...iptables:minSyncPeriod:1ssyncPeriod:30s...
minSyncPeriod
The minSyncPeriod parameter sets the minimum duration between
attempts to resynchronize iptables rules with the kernel. If it is
0s, then kube-proxy will always immediately synchronize the rules
every time any Service or Endpoint changes. This works fine in very
small clusters, but it results in a lot of redundant work when lots of
things change in a small time period. For example, if you have a
Service backed by a Deployment
with 100 pods, and you delete the
Deployment, then with minSyncPeriod: 0s, kube-proxy would end up
removing the Service's endpoints from the iptables rules one by one,
for a total of 100 updates. With a larger minSyncPeriod, multiple
Pod deletion events would get aggregated
together, so kube-proxy might
instead end up making, say, 5 updates, each removing 20 endpoints,
which will be much more efficient in terms of CPU, and result in the
full set of changes being synchronized faster.
The larger the value of minSyncPeriod, the more work that can be
aggregated, but the downside is that each individual change may end up
waiting up to the full minSyncPeriod before being processed, meaning
that the iptables rules spend more time being out-of-sync with the
current API server state.
The default value of 1s should work well in most clusters, but in very
large clusters it may be necessary to set it to a larger value.
Especially, if kube-proxy's sync_proxy_rules_duration_seconds metric
indicates an average time much larger than 1 second, then bumping up
minSyncPeriod may make updates more efficient.
Updating legacy minSyncPeriod configuration
Older versions of kube-proxy updated all the rules for all Services on
every sync; this led to performance issues (update lag) in large
clusters, and the recommended solution was to set a larger
minSyncPeriod. Since Kubernetes v1.28, the iptables mode of
kube-proxy uses a more minimal approach, only making updates where
Services or EndpointSlices have actually changed.
If you were previously overriding minSyncPeriod, you should try
removing that override and letting kube-proxy use the default value
(1s) or at least a smaller value than you were using before upgrading.
If you are not running kube-proxy from Kubernetes 1.28, check
the behavior and associated advice for the version that you are actually running.
syncPeriod
The syncPeriod parameter controls a handful of synchronization
operations that are not directly related to changes in individual
Services and EndpointSlices. In particular, it controls how quickly
kube-proxy notices if an external component has interfered with
kube-proxy's iptables rules. In large clusters, kube-proxy also only
performs certain cleanup operations once every syncPeriod to avoid
unnecessary work.
For the most part, increasing syncPeriod is not expected to have much
impact on performance, but in the past, it was sometimes useful to set
it to a very large value (eg, 1h). This is no longer recommended,
and is likely to hurt functionality more than it improves performance.
IPVS proxy mode
This proxy mode is only available on Linux nodes.
In ipvs mode, kube-proxy watches Kubernetes Services and EndpointSlices,
calls netlink interface to create IPVS rules accordingly and synchronizes
IPVS rules with Kubernetes Services and EndpointSlices periodically.
This control loop ensures that IPVS status matches the desired state.
When accessing a Service, IPVS directs traffic to one of the backend Pods.
The IPVS proxy mode is based on netfilter hook function that is similar to
iptables mode, but uses a hash table as the underlying data structure and works
in the kernel space.
That means kube-proxy in IPVS mode redirects traffic with lower latency than
kube-proxy in iptables mode, with much better performance when synchronizing
proxy rules. Compared to the other proxy modes, IPVS mode also supports a
higher throughput of network traffic.
IPVS provides more options for balancing traffic to backend Pods;
these are:
rr (Round Robin): Traffic is equally distributed amongst the backing servers.
wrr (Weighted Round Robin): Traffic is routed to the backing servers based on
the weights of the servers. Servers with higher weights receive new connections
and get more requests than servers with lower weights.
lc (Least Connection): More traffic is assigned to servers with fewer active connections.
wlc (Weighted Least Connection): More traffic is routed to servers with fewer connections
relative to their weights, that is, connections divided by weight.
lblc (Locality based Least Connection): Traffic for the same IP address is sent to the
same backing server if the server is not overloaded and available; otherwise the traffic
is sent to servers with fewer connections, and keep it for future assignment.
lblcr (Locality Based Least Connection with Replication): Traffic for the same IP
address is sent to the server with least connections. If all the backing servers are
overloaded, it picks up one with fewer connections and add it to the target set.
If the target set has not changed for the specified time, the most loaded server
is removed from the set, in order to avoid high degree of replication.
sh (Source Hashing): Traffic is sent to a backing server by looking up a statically
assigned hash table based on the source IP addresses.
dh (Destination Hashing): Traffic is sent to a backing server by looking up a
statically assigned hash table based on their destination addresses.
sed (Shortest Expected Delay): Traffic forwarded to a backing server with the shortest
expected delay. The expected delay is (C + 1) / U if sent to a server, where C is
the number of connections on the server and U is the fixed service rate (weight) of
the server.
nq (Never Queue): Traffic is sent to an idle server if there is one, instead of
waiting for a fast one; if all servers are busy, the algorithm falls back to the sed
behavior.
Note:
To run kube-proxy in IPVS mode, you must make IPVS available on
the node before starting kube-proxy.
When kube-proxy starts in IPVS proxy mode, it verifies whether IPVS
kernel modules are available. If the IPVS kernel modules are not detected, then kube-proxy
falls back to running in iptables proxy mode.
Virtual IP address mechanism for Services, using IPVS mode
kernelspace proxy mode
This proxy mode is only available on Windows nodes.
The kube-proxy configures packet filtering rules in the Windows Virtual Filtering Platform (VFP),
an extension to Windows vSwitch. These rules process encapsulated packets within the node-level
virtual networks, and rewrite packets so that the destination IP address (and layer 2 information)
is correct for getting the packet routed to the correct destination.
The Windows VFP is analogous to tools such as Linux nftables or iptables. The Windows VFP extends
the Hyper-V Switch, which was initially implemented to support virtual machine networking.
When a Pod on a node sends traffic to a virtual IP address, and the kube-proxy selects a Pod on
a different node as the load balancing target, the kernelspace proxy mode rewrites that packet
to be destined to the target backend Pod. The Windows Host Networking Service (HNS) ensures that
packet rewriting rules are configured so that the return traffic appears to come from the virtual
IP address and not the specific backend Pod.
Direct server return for kernelspace mode
FEATURE STATE:Kubernetes v1.14 [alpha]
As an alternative to the basic operation, a node that hosts the backend Pod for a Service can
apply the packet rewriting directly, rather than placing this burden on the node where the client
Pod is running. This is called direct server return.
To use this, you must run kube-proxy with the --enable-dsr command line argument and
enable the WinDSRfeature gate.
Direct server return also optimizes the case for Pod return traffic even when both Pods
are running on the same node.
Session affinity
In these proxy models, the traffic bound for the Service's IP:Port is
proxied to an appropriate backend without the clients knowing anything
about Kubernetes or Services or Pods.
If you want to make sure that connections from a particular client
are passed to the same Pod each time, you can select the session affinity based
on the client's IP addresses by setting .spec.sessionAffinity to ClientIP
for a Service (the default is None).
Session stickiness timeout
You can also set the maximum session sticky time by setting
.spec.sessionAffinityConfig.clientIP.timeoutSeconds appropriately for a Service.
(the default value is 10800, which works out to be 3 hours).
Note: On Windows, setting the maximum session sticky time for Services is not supported.
IP address assignment to Services
Unlike Pod IP addresses, which actually route to a fixed destination,
Service IPs are not actually answered by a single host. Instead, kube-proxy
uses packet processing logic (such as Linux iptables) to define virtual IP
addresses which are transparently redirected as needed.
When clients connect to the VIP, their traffic is automatically transported to an
appropriate endpoint. The environment variables and DNS for Services are actually
populated in terms of the Service's virtual IP address (and port).
Avoiding collisions
One of the primary philosophies of Kubernetes is that you should not be
exposed to situations that could cause your actions to fail through no fault
of your own. For the design of the Service resource, this means not making
you choose your own IP address if that choice might collide with
someone else's choice. That is an isolation failure.
In order to allow you to choose an IP address for your Services, we must
ensure that no two Services can collide. Kubernetes does that by allocating each
Service its own IP address from within the service-cluster-ip-range
CIDR range that is configured for the API Server.
IP address allocation tracking
To ensure each Service receives a unique IP, an internal allocator atomically
updates a global allocation map in etcd
prior to creating each Service. The map object must exist in the registry for
Services to get IP address assignments, otherwise creations will
fail with a message indicating an IP address could not be allocated.
In the control plane, a background controller is responsible for creating that
map (needed to support migrating from older versions of Kubernetes that used
in-memory locking). Kubernetes also uses controllers to check for invalid
assignments (e.g. due to administrator intervention) and for cleaning up allocated
IP addresses that are no longer used by any Services.
FEATURE STATE:Kubernetes v1.27 [alpha]
If you enable the MultiCIDRServiceAllocatorfeature gate and the
networking.k8s.io/v1alpha1 API group,
the control plane replaces the existing etcd allocator with a new one, using IPAddress
objects instead of an internal global allocation map. The ClusterIP address
associated to each Service will have a referenced IPAddress object.
The background controller is also replaced by a new one to handle the new IPAddress
objects and the migration from the old allocator model.
One of the main benefits of the new allocator is that it removes the size limitations
for the service-cluster-ip-range, there is no limitations for IPv4 and for IPv6
users can use masks equal or larger than /64 (previously it was /108).
Users now will be able to inspect the IP addresses assigned to their Services, and
Kubernetes extensions such as the Gateway API, can use this new
IPAddress object kind to enhance the Kubernetes networking capabilities, going beyond the limitations of
the built-in Service API.
kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 2001:db8:1:2::1 <none> 443/TCP 3d1h
kubectl get ipaddresses
NAME PARENTREF
2001:db8:1:2::1 services/default/kubernetes
2001:db8:1:2::a services/kube-system/kube-dns
IP address ranges for Service virtual IP addresses
FEATURE STATE:Kubernetes v1.26 [stable]
Kubernetes divides the ClusterIP range into two bands, based on
the size of the configured service-cluster-ip-range by using the following formula
min(max(16, cidrSize / 16), 256). That formula paraphrases as never less than 16 or
more than 256, with a graduated step function between them.
Kubernetes prefers to allocate dynamic IP addresses to Services by choosing from the upper band,
which means that if you want to assign a specific IP address to a type: ClusterIP
Service, you should manually assign an IP address from the lower band. That approach
reduces the risk of a conflict over allocation.
If you disable the ServiceIPStaticSubrangefeature gate then Kubernetes
uses a single shared pool for both manually and dynamically assigned IP addresses,
that are used for type: ClusterIP Services.
Traffic policies
You can set the .spec.internalTrafficPolicy and .spec.externalTrafficPolicy fields
to control how Kubernetes routes traffic to healthy (“ready”) backends.
Internal traffic policy
FEATURE STATE:Kubernetes v1.26 [stable]
You can set the .spec.internalTrafficPolicy field to control how traffic from
internal sources is routed. Valid values are Cluster and Local. Set the field to
Cluster to route internal traffic to all ready endpoints and Local to only route
to ready node-local endpoints. If the traffic policy is Local and there are no
node-local endpoints, traffic is dropped by kube-proxy.
External traffic policy
You can set the .spec.externalTrafficPolicy field to control how traffic from
external sources is routed. Valid values are Cluster and Local. Set the field
to Cluster to route external traffic to all ready endpoints and Local to only
route to ready node-local endpoints. If the traffic policy is Local and there are
are no node-local endpoints, the kube-proxy does not forward any traffic for the
relevant Service.
Traffic to terminating endpoints
FEATURE STATE:Kubernetes v1.28 [stable]
If the ProxyTerminatingEndpointsfeature gate
is enabled in kube-proxy and the traffic policy is Local, that node's
kube-proxy uses a more complicated algorithm to select endpoints for a Service.
With the feature enabled, kube-proxy checks if the node
has local endpoints and whether or not all the local endpoints are marked as terminating.
If there are local endpoints and all of them are terminating, then kube-proxy
will forward traffic to those terminating endpoints. Otherwise, kube-proxy will always
prefer forwarding traffic to endpoints that are not terminating.
This forwarding behavior for terminating endpoints exist to allow NodePort and LoadBalancer
Services to gracefully drain connections when using externalTrafficPolicy: Local.
As a deployment goes through a rolling update, nodes backing a load balancer may transition from
N to 0 replicas of that deployment. In some cases, external load balancers can send traffic to
a node with 0 replicas in between health check probes. Routing traffic to terminating endpoints
ensures that Node's that are scaling down Pods can gracefully receive and drain traffic to
those terminating Pods. By the time the Pod completes termination, the external load balancer
should have seen the node's health check failing and fully removed the node from the backend
pool.
Kubeadm is a tool built to provide kubeadm init and kubeadm join as best-practice "fast paths" for creating Kubernetes clusters.
kubeadm performs the actions necessary to get a minimum viable cluster up and running. By design, it cares only about bootstrapping, not about provisioning machines. Likewise, installing various nice-to-have addons, like the Kubernetes Dashboard, monitoring solutions, and cloud-specific addons, is not in scope.
Instead, we expect higher-level and more tailored tooling to be built on top of kubeadm, and ideally, using kubeadm as the basis of all deployments will make it easier to create conformant clusters.
kubeadm alpha to preview a set of features made available for gathering feedback from the community
10.1.1 - Kubeadm Generated
10.1.1.1 -
kubeadm: easily bootstrap a secure Kubernetes cluster
Synopsis
┌──────────────────────────────────────────────────────────┐
│ KUBEADM │
│ Easily bootstrap a secure Kubernetes cluster │
│ │
│ Please give us feedback at: │
│ https://github.com/kubernetes/kubeadm/issues │
└──────────────────────────────────────────────────────────┘
Example usage:
Create a two-machine cluster with one control-plane node
(which controls the cluster), and one worker node
(where your workloads, like Pods and Deployments run).
┌──────────────────────────────────────────────────────────┐
│ On the first machine: │
├──────────────────────────────────────────────────────────┤
│ control-plane# kubeadm init │
└──────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────┐
│ On the second machine: │
├──────────────────────────────────────────────────────────┤
│ worker# kubeadm join <arguments-returned-from-init> │
└──────────────────────────────────────────────────────────┘
You can then repeat the second step on as many other machines as you like.
Options
-h, --help
help for kubeadm
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.2 -
Commands related to handling kubernetes certificates
Synopsis
Commands related to handling kubernetes certificates
kubeadm certs [flags]
Options
-h, --help
help for certs
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.3 -
Generate certificate keys
Synopsis
This command will print out a secure randomly-generated certificate key that can be used with
the "init" command.
You can also use "kubeadm init --upload-certs" without specifying a certificate key and it will
generate and print one for you.
kubeadm certs certificate-key [flags]
Options
-h, --help
help for certificate-key
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.4 -
Check certificates expiration for a Kubernetes cluster
Synopsis
Checks expiration for the certificates in the local PKI managed by kubeadm.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.5 -
Generate keys and certificate signing requests
Synopsis
Generates keys and certificate signing requests (CSRs) for all the certificates required to run the control plane. This command also generates partial kubeconfig files with private key data in the "users > user > client-key-data" field, and for each kubeconfig file an accompanying ".csr" file is created.
This command is designed for use in Kubeadm External CA Mode. It generates CSRs which you can then submit to your external certificate authority for signing.
The PEM encoded signed certificates should then be saved alongside the key files, using ".crt" as the file extension, or in the case of kubeconfig files, the PEM encoded signed certificate should be base64 encoded and added to the kubeconfig file in the "users > user > client-certificate-data" field.
kubeadm certs generate-csr [flags]
Examples
# The following command will generate keys and CSRs for all control-plane certificates and kubeconfig files:
kubeadm certs generate-csr --kubeconfig-dir /tmp/etc-k8s --cert-dir /tmp/etc-k8s/pki
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.6 -
Renew certificates for a Kubernetes cluster
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm certs renew [flags]
Options
-h, --help
help for renew
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.7 -
Renew the certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself
Synopsis
Renew the certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.8 -
Renew all available certificates
Synopsis
Renew all known certificates necessary to run the control plane. Renewals are run unconditionally, regardless of expiration date. Renewals can also be run individually for more control.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.9 -
Renew the certificate the apiserver uses to access etcd
Synopsis
Renew the certificate the apiserver uses to access etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.10 -
Renew the certificate for the API server to connect to kubelet
Synopsis
Renew the certificate for the API server to connect to kubelet.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.11 -
Renew the certificate for serving the Kubernetes API
Synopsis
Renew the certificate for serving the Kubernetes API.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.12 -
Renew the certificate embedded in the kubeconfig file for the controller manager to use
Synopsis
Renew the certificate embedded in the kubeconfig file for the controller manager to use.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.13 -
Renew the certificate for liveness probes to healthcheck etcd
Synopsis
Renew the certificate for liveness probes to healthcheck etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.14 -
Renew the certificate for etcd nodes to communicate with each other
Synopsis
Renew the certificate for etcd nodes to communicate with each other.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.15 -
Renew the certificate for serving etcd
Synopsis
Renew the certificate for serving etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.16 -
Renew the certificate for the front proxy client
Synopsis
Renew the certificate for the front proxy client.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.17 -
Renew the certificate embedded in the kubeconfig file for the scheduler manager to use
Synopsis
Renew the certificate embedded in the kubeconfig file for the scheduler manager to use.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.18 -
Output shell completion code for the specified shell (bash or zsh)
Synopsis
Output shell completion code for the specified shell (bash or zsh).
The shell code must be evaluated to provide interactive
completion of kubeadm commands. This can be done by sourcing it from
the .bash_profile.
Note: this requires the bash-completion framework.
To install it on Mac use homebrew:
$ brew install bash-completion
Once installed, bash_completion must be evaluated. This can be done by adding the
following line to the .bash_profile
$ source $(brew --prefix)/etc/bash_completion
If bash-completion is not installed on Linux, please install the 'bash-completion' package
via your distribution's package manager.
Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2
kubeadm completion SHELL [flags]
Examples
# Install bash completion on a Mac using homebrew
brew install bash-completion
printf "\n# Bash completion support\nsource $(brew --prefix)/etc/bash_completion\n" >> $HOME/.bash_profile
source $HOME/.bash_profile
# Load the kubeadm completion code for bash into the current shell
source <(kubeadm completion bash)
# Write bash completion code to a file and source it from .bash_profile
kubeadm completion bash > ~/.kube/kubeadm_completion.bash.inc
printf "\n# Kubeadm shell completion\nsource '$HOME/.kube/kubeadm_completion.bash.inc'\n" >> $HOME/.bash_profile
source $HOME/.bash_profile
# Load the kubeadm completion code for zsh[1] into the current shell
source <(kubeadm completion zsh)
Options
-h, --help
help for completion
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.19 -
Manage configuration for a kubeadm cluster persisted in a ConfigMap in the cluster
Synopsis
There is a ConfigMap in the kube-system namespace called "kubeadm-config" that kubeadm uses to store internal configuration about the
cluster. kubeadm CLI v1.8.0+ automatically creates this ConfigMap with the config used with 'kubeadm init', but if you
initialized your cluster using kubeadm v1.7.x or lower, you must use the 'config upload' command to create this
ConfigMap. This is required so that 'kubeadm upgrade' can configure your upgraded cluster correctly.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.21 -
Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized
Synopsis
Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized
kubeadm config images list [flags]
Options
--allow-missing-template-keys Default: true
If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.
--config string
Path to a kubeadm configuration file.
-o, --experimental-output string Default: "text"
Output format. One of: text|json|yaml|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-as-json|jsonpath-file.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.22 -
Pull images used by kubeadm
Synopsis
Pull images used by kubeadm
kubeadm config images pull [flags]
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.23 -
Read an older version of the kubeadm configuration API types from a file, and output the similar config object for the newer version
Synopsis
This command lets you convert configuration objects of older versions to the latest supported version,
locally in the CLI tool without ever touching anything in the cluster.
In this version of kubeadm, the following API versions are supported:
kubeadm.k8s.io/v1beta3
Further, kubeadm can only write out config of version "kubeadm.k8s.io/v1beta3", but read both types.
So regardless of what version you pass to the --old-config parameter here, the API object will be
read, deserialized, defaulted, converted, validated, and re-serialized when written to stdout or
--new-config if specified.
In other words, the output of this command is what kubeadm actually would read internally if you
submitted this file to "kubeadm init"
kubeadm config migrate [flags]
Options
--allow-experimental-api
Allow migration to experimental, unreleased APIs.
-h, --help
help for migrate
--new-config string
Path to the resulting equivalent kubeadm config file using the new API version. Optional, if not specified output will be sent to STDOUT.
--old-config string
Path to the kubeadm config file that is using an old API version and should be converted. This flag is mandatory.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.25 -
Print default init configuration, that can be used for 'kubeadm init'
Synopsis
This command prints objects such as the default init configuration that is used for 'kubeadm init'.
Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like "abcdef.0123456789abcdef" in order to pass validation but
not perform the real computation for creating a token.
kubeadm config print init-defaults [flags]
Options
--component-configs strings
A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.26 -
Print default join configuration, that can be used for 'kubeadm join'
Synopsis
This command prints objects such as the default join configuration that is used for 'kubeadm join'.
Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like "abcdef.0123456789abcdef" in order to pass validation but
not perform the real computation for creating a token.
kubeadm config print join-defaults [flags]
Options
--component-configs strings
A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.27 -
Print default reset configuration, that can be used for 'kubeadm reset'
Synopsis
This command prints objects such as the default reset configuration that is used for 'kubeadm reset'.
Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like "abcdef.0123456789abcdef" in order to pass validation but
not perform the real computation for creating a token.
kubeadm config print reset-defaults [flags]
Options
--component-configs strings
A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.28 -
Read a file containing the kubeadm configuration API and report any validation problems
Synopsis
This command lets you validate a kubeadm configuration API file and report any warnings and errors.
If there are no errors the exit status will be zero, otherwise it will be non-zero.
Any unmarshaling problems such as unknown API fields will trigger errors. Unknown API versions and
fields with invalid values will also trigger errors. Any other errors or warnings may be reported
depending on contents of the input file.
In this version of kubeadm, the following API versions are supported:
kubeadm.k8s.io/v1beta3
kubeadm config validate [flags]
Options
--allow-experimental-api
Allow validation of experimental, unreleased APIs.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.29 -
Run this command in order to set up the Kubernetes control plane
Synopsis
Run this command in order to set up the Kubernetes control plane
The "init" command executes the following phases:
preflight Run pre-flight checks
certs Certificate generation
/ca Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components
/apiserver Generate the certificate for serving the Kubernetes API
/apiserver-kubelet-client Generate the certificate for the API server to connect to kubelet
/front-proxy-ca Generate the self-signed CA to provision identities for front proxy
/front-proxy-client Generate the certificate for the front proxy client
/etcd-ca Generate the self-signed CA to provision identities for etcd
/etcd-server Generate the certificate for serving etcd
/etcd-peer Generate the certificate for etcd nodes to communicate with each other
/etcd-healthcheck-client Generate the certificate for liveness probes to healthcheck etcd
/apiserver-etcd-client Generate the certificate the apiserver uses to access etcd
/sa Generate a private key for signing service account tokens along with its public key
kubeconfig Generate all kubeconfig files necessary to establish the control plane and the admin kubeconfig file
/admin Generate a kubeconfig file for the admin to use and for kubeadm itself
/kubelet Generate a kubeconfig file for the kubelet to use *only* for cluster bootstrapping purposes
/controller-manager Generate a kubeconfig file for the controller manager to use
/scheduler Generate a kubeconfig file for the scheduler to use
etcd Generate static Pod manifest file for local etcd
/local Generate the static Pod manifest file for a local, single-node local etcd instance
control-plane Generate all static Pod manifest files necessary to establish the control plane
/apiserver Generates the kube-apiserver static Pod manifest
/controller-manager Generates the kube-controller-manager static Pod manifest
/scheduler Generates the kube-scheduler static Pod manifest
kubelet-start Write kubelet settings and (re)start the kubelet
upload-config Upload the kubeadm and kubelet configuration to a ConfigMap
/kubeadm Upload the kubeadm ClusterConfiguration to a ConfigMap
/kubelet Upload the kubelet component config to a ConfigMap
upload-certs Upload certificates to kubeadm-certs
mark-control-plane Mark a node as a control-plane
bootstrap-token Generates bootstrap tokens used to join a node to a cluster
kubelet-finalize Updates settings relevant to the kubelet after TLS bootstrap
/experimental-cert-rotation Enable kubelet client certificate rotation
addon Install required addons for passing conformance tests
/coredns Install the CoreDNS addon to a Kubernetes cluster
/kube-proxy Install the kube-proxy addon to a Kubernetes cluster
show-join-command Show the join command for control-plane and worker node
kubeadm init [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--apiserver-cert-extra-sans strings
Optional extra Subject Alternative Names (SANs) to use for the API Server serving certificate. Can be both IP addresses and DNS names.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--certificate-key string
Key used to encrypt the control-plane certificates in the kubeadm-certs Secret.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-h, --help
help for init
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Use alternative domain for services, e.g. "myorg.internal".
--skip-certificate-key-print
Don't print the key used to encrypt the control-plane certificates.
--skip-phases strings
List of phases to be skipped
--skip-token-print
Skip printing of the default bootstrap token generated by 'kubeadm init'.
--token string
The token to use for establishing bidirectional trust between nodes and control-plane nodes. The format is [a-z0-9]{6}.[a-z0-9]{16} - e.g. abcdef.0123456789abcdef
--token-ttl duration Default: 24h0m0s
The duration before the token is automatically deleted (e.g. 1s, 2m, 3h). If set to '0', the token will never expire
--upload-certs
Upload control-plane certificates to the kubeadm-certs Secret.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.30 -
Use this command to invoke single phase of the init workflow
Synopsis
Use this command to invoke single phase of the init workflow
Options
-h, --help
help for phase
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.31 -
Install required addons for passing conformance tests
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase addon [flags]
Options
-h, --help
help for addon
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.32 -
Install all the addons
Synopsis
Install all the addons
kubeadm init phase addon all [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Use alternative domain for services, e.g. "myorg.internal".
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.33 -
Install the CoreDNS addon to a Kubernetes cluster
Synopsis
Install the CoreDNS addon components via the API server. Please note that although the DNS server is deployed, it will not be scheduled until CNI is installed.
kubeadm init phase addon coredns [flags]
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--print-manifest
Print the addon manifests to STDOUT instead of installing them
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--print-manifest
Print the addon manifests to STDOUT instead of installing them
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.35 -
Generates bootstrap tokens used to join a node to a cluster
Synopsis
Bootstrap tokens are used for establishing bidirectional trust between a node joining the cluster and a control-plane node.
This command makes all the configurations required to make bootstrap tokens works and then creates an initial token.
kubeadm init phase bootstrap-token [flags]
Examples
# Make all the bootstrap token configurations and create an initial token, functionally
# equivalent to what generated by kubeadm init.
kubeadm init phase bootstrap-token
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-token-print
Skip printing of the default bootstrap token generated by 'kubeadm init'.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.36 -
Certificate generation
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase certs [flags]
Options
-h, --help
help for certs
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.37 -
Generate all certificates
Synopsis
Generate all certificates
kubeadm init phase certs all [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-cert-extra-sans strings
Optional extra Subject Alternative Names (SANs) to use for the API Server serving certificate. Can be both IP addresses and DNS names.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for all
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for apiserver-etcd-client
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.39 -
Generate the certificate for the API server to connect to kubelet
Synopsis
Generate the certificate for the API server to connect to kubelet, and save them into apiserver-kubelet-client.crt and apiserver-kubelet-client.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
Use alternative domain for services, e.g. "myorg.internal".
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.41 -
Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components
Synopsis
Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components, and save them into ca.crt and ca.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs ca [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for ca
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.42 -
Generate the self-signed CA to provision identities for etcd
Synopsis
Generate the self-signed CA to provision identities for etcd, and save them into etcd/ca.crt and etcd/ca.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs etcd-ca [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd-ca
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.43 -
Generate the certificate for liveness probes to healthcheck etcd
Synopsis
Generate the certificate for liveness probes to healthcheck etcd, and save them into etcd/healthcheck-client.crt and etcd/healthcheck-client.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for front-proxy-client
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.48 -
Generate a private key for signing service account tokens along with its public key
Synopsis
Generate the private key for signing service account tokens along with its public key, and save them into sa.key and sa.pub files. If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs sa [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
-h, --help
help for sa
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.49 -
Generate all static Pod manifest files necessary to establish the control plane
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase control-plane [flags]
Options
-h, --help
help for control-plane
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.50 -
Generate all static Pod manifest files
Synopsis
Generate all static Pod manifest files
kubeadm init phase control-plane all [flags]
Examples
# Generates all static Pod manifest files for control plane components,
# functionally equivalent to what is generated by kubeadm init.
kubeadm init phase control-plane all
# Generates all static Pod manifest files using options read from a configuration file.
kubeadm init phase control-plane all --config config.yaml
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
A set of extra flags to pass to the Controller Manager or override default ones in form of <flagname>=<value>
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
A set of extra flags to pass to the API Server or override default ones in form of <flagname>=<value>
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.52 -
Generates the kube-controller-manager static Pod manifest
Synopsis
Generates the kube-controller-manager static Pod manifest
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
A set of extra flags to pass to the Scheduler or override default ones in form of <flagname>=<value>
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.54 -
Generate static Pod manifest file for local etcd
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase etcd [flags]
Options
-h, --help
help for etcd
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.55 -
Generate the static Pod manifest file for a local, single-node local etcd instance
Synopsis
Generate the static Pod manifest file for a local, single-node local etcd instance
kubeadm init phase etcd local [flags]
Examples
# Generates the static Pod manifest file for etcd, functionally
# equivalent to what is generated by kubeadm init.
kubeadm init phase etcd local
# Generates the static Pod manifest file for etcd using options
# read from a configuration file.
kubeadm init phase etcd local --config config.yaml
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
Choose a container registry to pull control plane images from
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.56 -
Generate all kubeconfig files necessary to establish the control plane and the admin kubeconfig file
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase kubeconfig [flags]
Options
-h, --help
help for kubeconfig
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.57 -
Generate a kubeconfig file for the admin to use and for kubeadm itself
Synopsis
Generate the kubeconfig file for the admin and for kubeadm itself, and save it to admin.conf file.
kubeadm init phase kubeconfig admin [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.60 -
Generate a kubeconfig file for the kubelet to use only for cluster bootstrapping purposes
Synopsis
Generate the kubeconfig file for the kubelet to use and save it to kubelet.conf file.
Please note that this should only be used for cluster bootstrapping purposes. After your control plane is up, you should request all kubelet credentials from the CSR API.
kubeadm init phase kubeconfig kubelet [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for experimental-cert-rotation
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.65 -
Write kubelet settings and (re)start the kubelet
Synopsis
Write a file with KubeletConfiguration and an environment file with node specific kubelet settings, and then (re)start kubelet.
kubeadm init phase kubelet-start [flags]
Examples
# Writes a dynamic environment file with kubelet flags from a InitConfiguration file.
kubeadm init phase kubelet-start --config config.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for kubelet-start
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.66 -
Mark a node as a control-plane
Synopsis
Mark a node as a control-plane
kubeadm init phase mark-control-plane [flags]
Examples
# Applies control-plane label and taint to the current node, functionally equivalent to what executed by kubeadm init.
kubeadm init phase mark-control-plane --config config.yaml
# Applies control-plane label and taint to a specific node
kubeadm init phase mark-control-plane --node-name myNode
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for mark-control-plane
--node-name string
Specify the node name.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.67 -
Run pre-flight checks
Synopsis
Run pre-flight checks for kubeadm init.
kubeadm init phase preflight [flags]
Examples
# Run pre-flight checks for kubeadm init using a config file.
kubeadm init phase preflight --config kubeadm-config.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.68 -
Show the join command for control-plane and worker node
Synopsis
Show the join command for control-plane and worker node
kubeadm init phase show-join-command [flags]
Options
-h, --help
help for show-join-command
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.69 -
Upload certificates to kubeadm-certs
Synopsis
Upload control plane certificates to the kubeadm-certs Secret
kubeadm init phase upload-certs [flags]
Options
--certificate-key string
Key used to encrypt the control-plane certificates in the kubeadm-certs Secret.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-certificate-key-print
Don't print the key used to encrypt the control-plane certificates.
--upload-certs
Upload control-plane certificates to the kubeadm-certs Secret.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.70 -
Upload the kubeadm and kubelet configuration to a ConfigMap
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase upload-config [flags]
Options
-h, --help
help for upload-config
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.71 -
Upload all configuration to a config map
Synopsis
Upload all configuration to a config map
kubeadm init phase upload-config all [flags]
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.72 -
Upload the kubeadm ClusterConfiguration to a ConfigMap
Synopsis
Upload the kubeadm ClusterConfiguration to a ConfigMap called kubeadm-config in the kube-system namespace. This enables correct configuration of system components and a seamless user experience when upgrading.
Alternatively, you can use kubeadm config.
kubeadm init phase upload-config kubeadm [flags]
Examples
# upload the configuration of your cluster
kubeadm init phase upload-config --config=myConfig.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.73 -
Upload the kubelet component config to a ConfigMap
Synopsis
Upload the kubelet configuration extracted from the kubeadm InitConfiguration object to a kubelet-config ConfigMap in the cluster
kubeadm init phase upload-config kubelet [flags]
Examples
# Upload the kubelet configuration from the kubeadm Config file to a ConfigMap in the cluster.
kubeadm init phase upload-config kubelet --config kubeadm.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.74 -
Run this on any machine you wish to join an existing cluster
Synopsis
When joining a kubeadm initialized cluster, we need to establish
bidirectional trust. This is split into discovery (having the Node
trust the Kubernetes Control Plane) and TLS bootstrap (having the
Kubernetes Control Plane trust the Node).
There are 2 main schemes for discovery. The first is to use a shared
token along with the IP address of the API server. The second is to
provide a file - a subset of the standard kubeconfig file. The
discovery/kubeconfig file supports token, client-go authentication
plugins ("exec"), "tokenFile", and "authProvider". This file can be a
local file or downloaded via an HTTPS URL. The forms are
kubeadm join --discovery-token abcdef.1234567890abcdef 1.2.3.4:6443,
kubeadm join --discovery-file path/to/file.conf, or kubeadm join
--discovery-file https://url/file.conf. Only one form can be used. If
the discovery information is loaded from a URL, HTTPS must be used.
Also, in that case the host installed CA bundle is used to verify
the connection.
If you use a shared token for discovery, you should also pass the
--discovery-token-ca-cert-hash flag to validate the public key of the
root certificate authority (CA) presented by the Kubernetes Control Plane.
The value of this flag is specified as "<hash-type>:<hex-encoded-value>",
where the supported hash type is "sha256". The hash is calculated over
the bytes of the Subject Public Key Info (SPKI) object (as in RFC7469).
This value is available in the output of "kubeadm init" or can be
calculated using standard tools. The --discovery-token-ca-cert-hash flag
may be repeated multiple times to allow more than one public key.
If you cannot know the CA public key hash ahead of time, you can pass
the --discovery-token-unsafe-skip-ca-verification flag to disable this
verification. This weakens the kubeadm security model since other nodes
can potentially impersonate the Kubernetes Control Plane.
The TLS bootstrap mechanism is also driven via a shared token. This is
used to temporarily authenticate with the Kubernetes Control Plane to submit a
certificate signing request (CSR) for a locally created key pair. By
default, kubeadm will set up the Kubernetes Control Plane to automatically
approve these signing requests. This token is passed in with the
--tls-bootstrap-token abcdef.1234567890abcdef flag.
Often times the same token is used for both parts. In this case, the
--token flag can be used instead of specifying each token individually.
The "join [api-server-endpoint]" command executes the following phases:
preflight Run join pre-flight checks
control-plane-prepare Prepare the machine for serving a control plane
/download-certs [EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
/certs Generate the certificates for the new control plane components
/kubeconfig Generate the kubeconfig for the new control plane components
/control-plane Generate the manifests for the new control plane components
kubelet-start Write kubelet settings, certificates and (re)start the kubelet
control-plane-join Join a machine as a control plane instance
/etcd Add a new local etcd member
/update-status Register the new control-plane node into the ClusterStatus maintained in the kubeadm-config ConfigMap (DEPRECATED)
/mark-control-plane Mark a node as a control-plane
kubeadm join [api-server-endpoint] [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for join
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--skip-phases strings
List of phases to be skipped
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.75 -
Use this command to invoke single phase of the join workflow
Synopsis
Use this command to invoke single phase of the join workflow
Options
-h, --help
help for phase
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.76 -
Join a machine as a control plane instance
Synopsis
Join a machine as a control plane instance
kubeadm join phase control-plane-join [flags]
Examples
# Joins a machine as a control plane instance
kubeadm join phase control-plane-join all
Options
-h, --help
help for control-plane-join
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.77 -
Join a machine as a control plane instance
Synopsis
Join a machine as a control plane instance
kubeadm join phase control-plane-join all [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for all
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
-h, --help
help for update-status
--node-name string
Specify the node name.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.81 -
Prepare the machine for serving a control plane
Synopsis
Prepare the machine for serving a control plane
kubeadm join phase control-plane-prepare [flags]
Examples
# Prepares the machine for serving a control plane
kubeadm join phase control-plane-prepare all
Options
-h, --help
help for control-plane-prepare
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.82 -
Prepare the machine for serving a control plane
Synopsis
Prepare the machine for serving a control plane
kubeadm join phase control-plane-prepare all [api-server-endpoint] [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for all
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.83 -
Generate the certificates for the new control plane components
Synopsis
Generate the certificates for the new control plane components
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for certs
--node-name string
Specify the node name.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.84 -
Generate the manifests for the new control plane components
Synopsis
Generate the manifests for the new control plane components
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for control-plane
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.85 -
[EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
Synopsis
[EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for kubelet-start
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
# Run join pre-flight checks using a config file.
kubeadm join phase preflight --config kubeadm-config.yaml
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
--node-name string
Specify the node name.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.89 -
Kubeconfig file utilities
Synopsis
Kubeconfig file utilities.
Options
-h, --help
help for kubeconfig
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.90 -
Output a kubeconfig file for an additional user
Synopsis
Output a kubeconfig file for an additional user.
kubeadm kubeconfig user [flags]
Examples
# Output a kubeconfig file for an additional user named foo
kubeadm kubeconfig user --client-name=foo
# Output a kubeconfig file for an additional user named foo using a kubeadm config file bar
kubeadm kubeconfig user --client-name=foo --config=bar
Options
--client-name string
The name of user. It will be used as the CN if client certificates are created
--config string
Path to a kubeadm configuration file.
-h, --help
help for user
--org strings
The organizations of the client certificate. It will be used as the O if client certificates are created
--token string
The token that should be used as the authentication mechanism for this kubeconfig, instead of client certificates
--validity-period duration Default: 8760h0m0s
The validity period of the client certificate. It is an offset from the current time.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.91 -
Performs a best effort revert of changes made to this host by 'kubeadm init' or 'kubeadm join'
Synopsis
Performs a best effort revert of changes made to this host by 'kubeadm init' or 'kubeadm join'
The "reset" command executes the following phases:
preflight Run reset pre-flight checks
remove-etcd-member Remove a local etcd member.
cleanup-node Run cleanup node.
kubeadm reset [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path to the directory where the certificates are stored. If specified, clean this directory.
--cleanup-tmp-dir
Cleanup the "/etc/kubernetes/tmp" directory
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-f, --force
Reset the node without prompting for confirmation.
-h, --help
help for reset
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-phases strings
List of phases to be skipped
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.92 -
Use this command to invoke single phase of the reset workflow
Synopsis
Use this command to invoke single phase of the reset workflow
Options
-h, --help
help for phase
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.93 -
Run cleanup node.
Synopsis
Run cleanup node.
kubeadm reset phase cleanup-node [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path to the directory where the certificates are stored. If specified, clean this directory.
--cleanup-tmp-dir
Cleanup the "/etc/kubernetes/tmp" directory
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for cleanup-node
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.94 -
Run reset pre-flight checks
Synopsis
Run pre-flight checks for kubeadm reset.
kubeadm reset phase preflight [flags]
Options
--dry-run
Don't apply any changes; just output what would be done.
-f, --force
Reset the node without prompting for confirmation.
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.95 -
Remove a local etcd member.
Synopsis
Remove a local etcd member for a control plane node.
kubeadm reset phase remove-etcd-member [flags]
Options
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.96 -
Manage bootstrap tokens
Synopsis
This command manages bootstrap tokens. It is optional and needed only for advanced use cases.
In short, bootstrap tokens are used for establishing bidirectional trust between a client and a server.
A bootstrap token can be used when a client (for example a node that is about to join the cluster) needs
to trust the server it is talking to. Then a bootstrap token with the "signing" usage can be used.
bootstrap tokens can also function as a way to allow short-lived authentication to the API Server
(the token serves as a way for the API Server to trust the client), for example for doing the TLS Bootstrap.
What is a bootstrap token more exactly?
It is a Secret in the kube-system namespace of type "bootstrap.kubernetes.io/token".
A bootstrap token must be of the form "[a-z0-9]{6}.[a-z0-9]{16}". The former part is the public token ID,
while the latter is the Token Secret and it must be kept private at all circumstances!
The name of the Secret must be named "bootstrap-token-(token-id)".
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.97 -
Create bootstrap tokens on the server
Synopsis
This command will create a bootstrap token for you.
You can specify the usages for this token, the "time to live" and an optional human friendly description.
The [token] is the actual token to write.
This should be a securely generated random token of the form "[a-z0-9]{6}.[a-z0-9]{16}".
If no [token] is given, kubeadm will generate a random token instead.
kubeadm token create [token]
Options
--certificate-key string
When used together with '--print-join-command', print the full 'kubeadm join' flag needed to join the cluster as a control-plane. To create a new certificate key you must use 'kubeadm init phase upload-certs --upload-certs'.
--config string
Path to a kubeadm configuration file.
--description string
A human friendly description of how this token is used.
Describes the ways in which this token can be used. You can pass --usages multiple times or provide a comma separated list of options. Valid options: [signing,authentication]
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.98 -
Delete bootstrap tokens on the server
Synopsis
This command will delete a list of bootstrap tokens for you.
The [token-value] is the full Token of the form "[a-z0-9]{6}.[a-z0-9]{16}" or the
Token ID of the form "[a-z0-9]{6}" to delete.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.99 -
Generate and print a bootstrap token, but do not create it on the server
Synopsis
This command will print out a randomly-generated bootstrap token that can be used with
the "init" and "join" commands.
You don't have to use this command in order to generate a token. You can do so
yourself as long as it is in the format "[a-z0-9]{6}.[a-z0-9]{16}". This
command is provided for convenience to generate tokens in the given format.
You can also use "kubeadm init" without specifying a token and it will
generate and print one for you.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.100 -
List bootstrap tokens on the server
Synopsis
This command will list all bootstrap tokens for you.
kubeadm token list [flags]
Options
--allow-missing-template-keys Default: true
If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.
-o, --experimental-output string Default: "text"
Output format. One of: text|json|yaml|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-as-json|jsonpath-file.
-h, --help
help for list
--show-managed-fields
If true, keep the managedFields when printing objects in JSON or YAML format.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.101 -
Upgrade your cluster smoothly to a newer version with this command
Synopsis
Upgrade your cluster smoothly to a newer version with this command
kubeadm upgrade [flags]
Options
-h, --help
help for upgrade
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.102 -
Upgrade your Kubernetes cluster to the specified version
Synopsis
Upgrade your Kubernetes cluster to the specified version
kubeadm upgrade apply [version]
Options
--allow-experimental-upgrades
Show unstable versions of Kubernetes as an upgrade alternative and allow upgrading to an alpha/beta/release candidate versions of Kubernetes.
--allow-release-candidate-upgrades
Show release candidate versions of Kubernetes as an upgrade alternative and allow upgrading to a release candidate versions of Kubernetes.
--certificate-renewal Default: true
Perform the renewal of certificates used by component changed during upgrades.
--config string
Path to a kubeadm configuration file.
--dry-run
Do not change any state, just output what actions would be performed.
--etcd-upgrade Default: true
Perform the upgrade of etcd.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-f, --force
Force upgrading although some requirements might not be met. This also implies non-interactive mode.
-h, --help
help for apply
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--print-config
Specifies whether the configuration file that will be used in the upgrade should be printed or not.
-y, --yes
Perform the upgrade and do not prompt for confirmation (non-interactive mode).
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.103 -
Show what differences would be applied to existing static pod manifests. See also: kubeadm upgrade apply --dry-run
Synopsis
Show what differences would be applied to existing static pod manifests. See also: kubeadm upgrade apply --dry-run
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.104 -
Upgrade commands for a node in the cluster
Synopsis
Upgrade commands for a node in the cluster
The "node" command executes the following phases:
preflight Run upgrade node pre-flight checks
control-plane Upgrade the control plane instance deployed on this node, if any
kubelet-config Upgrade the kubelet configuration for this node
kubeadm upgrade node [flags]
Options
--certificate-renewal Default: true
Perform the renewal of certificates used by component changed during upgrades.
--dry-run
Do not change any state, just output the actions that would be performed.
--etcd-upgrade Default: true
Perform the upgrade of etcd.
-h, --help
help for node
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--skip-phases strings
List of phases to be skipped
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.105 -
Use this command to invoke single phase of the node workflow
Synopsis
Use this command to invoke single phase of the node workflow
Options
-h, --help
help for phase
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.106 -
Upgrade the control plane instance deployed on this node, if any
Synopsis
Upgrade the control plane instance deployed on this node, if any
kubeadm upgrade node phase control-plane [flags]
Options
--certificate-renewal Default: true
Perform the renewal of certificates used by component changed during upgrades.
--dry-run
Do not change any state, just output the actions that would be performed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.107 -
Upgrade the kubelet configuration for this node
Synopsis
Download the kubelet configuration from the kubelet-config ConfigMap stored in the cluster
kubeadm upgrade node phase kubelet-config [flags]
Options
--dry-run
Do not change any state, just output the actions that would be performed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.108 -
Run upgrade node pre-flight checks
Synopsis
Run pre-flight checks for kubeadm upgrade node.
kubeadm upgrade node phase preflight [flags]
Options
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.109 -
Check which versions are available to upgrade to and validate whether your current cluster is upgradeable. To skip the internet check, pass in the optional [version] parameter
Synopsis
Check which versions are available to upgrade to and validate whether your current cluster is upgradeable. To skip the internet check, pass in the optional [version] parameter
kubeadm upgrade plan [version] [flags]
Options
--allow-experimental-upgrades
Show unstable versions of Kubernetes as an upgrade alternative and allow upgrading to an alpha/beta/release candidate versions of Kubernetes.
--allow-release-candidate-upgrades
Show release candidate versions of Kubernetes as an upgrade alternative and allow upgrading to a release candidate versions of Kubernetes.
--config string
Path to a kubeadm configuration file.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-h, --help
help for plan
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
-o, --output string Default: "text"
EXPERIMENTAL: Output format. One of: text|json|yaml.
--print-config
Specifies whether the configuration file that will be used in the upgrade should be printed or not.
--show-managed-fields
If true, keep the managedFields when printing objects in JSON or YAML format.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.110 -
Print the version of kubeadm
Synopsis
Print the version of kubeadm
kubeadm version [flags]
Options
-h, --help
help for version
-o, --output string
Output format; available options are 'yaml', 'json' and 'short'
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.1.111 -
All files in this directory are auto-generated from other repos. Do not edit them manually. You must edit them in their upstream repo.
10.1.2 - kubeadm init
This command initializes a Kubernetes control-plane node.
Run this command in order to set up the Kubernetes control plane
Synopsis
Run this command in order to set up the Kubernetes control plane
The "init" command executes the following phases:
preflight Run pre-flight checks
certs Certificate generation
/ca Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components
/apiserver Generate the certificate for serving the Kubernetes API
/apiserver-kubelet-client Generate the certificate for the API server to connect to kubelet
/front-proxy-ca Generate the self-signed CA to provision identities for front proxy
/front-proxy-client Generate the certificate for the front proxy client
/etcd-ca Generate the self-signed CA to provision identities for etcd
/etcd-server Generate the certificate for serving etcd
/etcd-peer Generate the certificate for etcd nodes to communicate with each other
/etcd-healthcheck-client Generate the certificate for liveness probes to healthcheck etcd
/apiserver-etcd-client Generate the certificate the apiserver uses to access etcd
/sa Generate a private key for signing service account tokens along with its public key
kubeconfig Generate all kubeconfig files necessary to establish the control plane and the admin kubeconfig file
/admin Generate a kubeconfig file for the admin to use and for kubeadm itself
/kubelet Generate a kubeconfig file for the kubelet to use *only* for cluster bootstrapping purposes
/controller-manager Generate a kubeconfig file for the controller manager to use
/scheduler Generate a kubeconfig file for the scheduler to use
etcd Generate static Pod manifest file for local etcd
/local Generate the static Pod manifest file for a local, single-node local etcd instance
control-plane Generate all static Pod manifest files necessary to establish the control plane
/apiserver Generates the kube-apiserver static Pod manifest
/controller-manager Generates the kube-controller-manager static Pod manifest
/scheduler Generates the kube-scheduler static Pod manifest
kubelet-start Write kubelet settings and (re)start the kubelet
upload-config Upload the kubeadm and kubelet configuration to a ConfigMap
/kubeadm Upload the kubeadm ClusterConfiguration to a ConfigMap
/kubelet Upload the kubelet component config to a ConfigMap
upload-certs Upload certificates to kubeadm-certs
mark-control-plane Mark a node as a control-plane
bootstrap-token Generates bootstrap tokens used to join a node to a cluster
kubelet-finalize Updates settings relevant to the kubelet after TLS bootstrap
/experimental-cert-rotation Enable kubelet client certificate rotation
addon Install required addons for passing conformance tests
/coredns Install the CoreDNS addon to a Kubernetes cluster
/kube-proxy Install the kube-proxy addon to a Kubernetes cluster
show-join-command Show the join command for control-plane and worker node
kubeadm init [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--apiserver-cert-extra-sans strings
Optional extra Subject Alternative Names (SANs) to use for the API Server serving certificate. Can be both IP addresses and DNS names.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--certificate-key string
Key used to encrypt the control-plane certificates in the kubeadm-certs Secret.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-h, --help
help for init
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Use alternative domain for services, e.g. "myorg.internal".
--skip-certificate-key-print
Don't print the key used to encrypt the control-plane certificates.
--skip-phases strings
List of phases to be skipped
--skip-token-print
Skip printing of the default bootstrap token generated by 'kubeadm init'.
--token string
The token to use for establishing bidirectional trust between nodes and control-plane nodes. The format is [a-z0-9]{6}.[a-z0-9]{16} - e.g. abcdef.0123456789abcdef
--token-ttl duration Default: 24h0m0s
The duration before the token is automatically deleted (e.g. 1s, 2m, 3h). If set to '0', the token will never expire
--upload-certs
Upload control-plane certificates to the kubeadm-certs Secret.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Init workflow
kubeadm init bootstraps a Kubernetes control-plane node by executing the
following steps:
Runs a series of pre-flight checks to validate the system state
before making changes. Some checks only trigger warnings, others are
considered errors and will exit kubeadm until the problem is corrected or the
user specifies --ignore-preflight-errors=<list-of-errors>.
Generates a self-signed CA to set up identities for each component in the cluster. The user can provide their
own CA cert and/or key by dropping it in the cert directory configured via --cert-dir
(/etc/kubernetes/pki by default).
The APIServer certs will have additional SAN entries for any --apiserver-cert-extra-sans
arguments, lowercased if necessary.
Writes kubeconfig files in /etc/kubernetes/ for the kubelet, the controller-manager and the
scheduler to use to connect to the API server, each with its own identity, as well as an
additional kubeconfig file for administration named admin.conf.
Generates static Pod manifests for the API server,
controller-manager and scheduler. In case an external etcd is not provided,
an additional static Pod manifest is generated for etcd.
Static Pod manifests are written to /etc/kubernetes/manifests; the kubelet
watches this directory for Pods to create on startup.
Once control plane Pods are up and running, the kubeadm init sequence can continue.
Apply labels and taints to the control-plane node so that no additional workloads will
run there.
Generates the token that additional nodes can use to register
themselves with a control-plane in the future. Optionally, the user can provide a
token via --token, as described in the
kubeadm token docs.
Makes all the necessary configurations for allowing node joining with the
Bootstrap Tokens and
TLS Bootstrap
mechanism:
Write a ConfigMap for making available all the information required
for joining, and set up related RBAC access rules.
Installs a DNS server (CoreDNS) and the kube-proxy addon components via the API server.
In Kubernetes version 1.11 and later CoreDNS is the default DNS server.
Please note that although the DNS server is deployed, it will not be scheduled until CNI is installed.
Warning: kube-dns usage with kubeadm is deprecated as of v1.18 and is removed in v1.21.
Using init phases with kubeadm
Kubeadm allows you to create a control-plane node in phases using the kubeadm init phase command.
To view the ordered list of phases and sub-phases you can call kubeadm init --help. The list
will be located at the top of the help screen and each phase will have a description next to it.
Note that by calling kubeadm init all of the phases and sub-phases will be executed in this exact order.
Some phases have unique flags, so if you want to have a look at the list of available options add
--help, for example:
You can also use --help to see the list of sub-phases for a certain parent phase:
sudo kubeadm init phase control-plane --help
kubeadm init also exposes a flag called --skip-phases that can be used to skip certain phases.
The flag accepts a list of phase names and the names can be taken from the above ordered list.
An example:
sudo kubeadm init phase control-plane all --config=configfile.yaml
sudo kubeadm init phase etcd local --config=configfile.yaml
# you can now modify the control plane and etcd manifest filessudo kubeadm init --skip-phases=control-plane,etcd --config=configfile.yaml
What this example would do is write the manifest files for the control plane and etcd in
/etc/kubernetes/manifests based on the configuration in configfile.yaml. This allows you to
modify the files and then skip these phases using --skip-phases. By calling the last command you
will create a control plane node with the custom manifest files.
FEATURE STATE:Kubernetes v1.22 [beta]
Alternatively, you can use the skipPhases field under InitConfiguration.
Using kubeadm init with a configuration file
Caution: The config file is still considered beta and may change in future versions.
It's possible to configure kubeadm init with a configuration file instead of command
line flags, and some more advanced features may only be available as
configuration file options. This file is passed using the --config flag and it must
contain a ClusterConfiguration structure and optionally more structures separated by ---\n
Mixing --config with others flags may not be allowed in some cases.
The default configuration can be printed out using the
kubeadm config print command.
If your configuration is not using the latest version it is recommended that you migrate using
the kubeadm config migrate command.
For more information on the fields and usage of the configuration you can navigate to our
API reference page.
Using kubeadm init with feature gates
Kubeadm supports a set of feature gates that are unique to kubeadm and can only be applied
during cluster creation with kubeadm init. These features can control the behavior
of the cluster. Feature gates are removed after a feature graduates to GA.
To pass a feature gate you can either use the --feature-gates flag for
kubeadm init, or you can add items into the featureGates field when you pass
a configuration file
using --config.
Note: Once a feature gate goes GA its value becomes locked to true by default.
Feature gate descriptions:
PublicKeysECDSA
Can be used to create a cluster that uses ECDSA certificates instead of the default RSA algorithm.
Renewal of existing ECDSA certificates is also supported using kubeadm certs renew, but you cannot
switch between the RSA and ECDSA algorithms on the fly or during upgrades.
RootlessControlPlane
Setting this flag configures the kubeadm deployed control plane component static Pod containers
for kube-apiserver, kube-controller-manager, kube-scheduler and etcd to run as non-root users.
If the flag is not set, those components run as root. You can change the value of this feature gate before
you upgrade to a newer version of Kubernetes.
EtcdLearnerMode
With this feature gate enabled, when joining a new control plane node, a new etcd member will be created
as a learner and promoted to a voting member only after the etcd data are fully aligned.
List of deprecated feature gates:
kubeadm deprecated feature gates
Feature
Default
UpgradeAddonsBeforeControlPlane
false
Feature gate descriptions:
UpgradeAddonsBeforeControlPlane
This is as a disabled feature gate that was introduced for Kubernetes v1.28, in order to allow reactivating a legacy
and deprecated behavior during cluster upgrade. For kubeadm versions prior to v1.28, kubeadm upgrades cluster addons (including
CoreDNS and kube-proxy) immediately during kubeadm upgrade apply, regardless of whether there are other control plane
instances that have not been upgraded. This may cause compatibility problems. Since v1.28, kubeadm defaults to a mode that
always checks whether all the control plane instances have been upgraded before starting to upgrade the addons. This behavior
is applied to both kubeadm upgrade apply and kubeadm upgrade node. kubeadm determines whether a control plane instance
has been upgraded by checking whether the image of the kube-apiserver Pod has been upgraded. You must perform control plane
instances upgrade sequentially or at least ensure that the last control plane instance upgrade is not started until all the
other control plane instances have been upgraded completely, and the addons upgrade will be performed after the last control plane
instance is upgraded. The deprecated UpgradeAddonsBeforeControlPlane feature gate gives you a chance to keep the old upgrade
behavior. You should not need this old behavior; if you do, you should consider changing your cluster or upgrade processes, as this
feature gate will be removed in a future release.
List of removed feature gates:
kubeadm removed feature gates
Feature
Alpha
Beta
GA
Removed
UnversionedKubeletConfigMap
1.22
1.23
1.25
1.26
IPv6DualStack
1.16
1.21
1.23
1.24
Feature gate descriptions:
UnversionedKubeletConfigMap
This flag controls the name of the ConfigMap where kubeadm stores
kubelet configuration data. With this flag not specified or set to true, the ConfigMap is named kubelet-config.
If you set this flag to false, the name of the ConfigMap includes the major and minor version for Kubernetes
(for example: kubelet-config-1.28). Kubeadm ensures that RBAC rules for reading and writing
that ConfigMap are appropriate for the value you set. When kubeadm writes this ConfigMap (during kubeadm init
or kubeadm upgrade apply), kubeadm respects the value of UnversionedKubeletConfigMap. When reading that ConfigMap
(during kubeadm join, kubeadm reset, kubeadm upgrade ...), kubeadm attempts to use unversioned ConfigMap name first;
if that does not succeed, kubeadm falls back to using the legacy (versioned) name for that ConfigMap.
IPv6DualStack
This flag helps to configure components dual stack when the feature is in progress. For more details on Kubernetes
dual-stack support see Dual-stack support with kubeadm.
Adding kube-proxy parameters
For information about kube-proxy parameters in the kubeadm configuration see:
For running kubeadm without an Internet connection you have to pre-pull the required control-plane images.
You can list and pull the images using the kubeadm config images sub-command:
kubeadm config images list
kubeadm config images pull
You can pass --config to the above commands with a kubeadm configuration file
to control the kubernetesVersion and imageRepository fields.
All default registry.k8s.io images that kubeadm requires support multiple architectures.
Using custom images
By default, kubeadm pulls images from registry.k8s.io. If the
requested Kubernetes version is a CI label (such as ci/latest)
gcr.io/k8s-staging-ci-images is used.
To provide kubernetesVersion which affects the version of the images.
To provide an alternative imageRepository to be used instead of
registry.k8s.io.
To provide a specific imageRepository and imageTag for etcd or CoreDNS.
Image paths between the default registry.k8s.io and a custom repository specified using
imageRepository may differ for backwards compatibility reasons. For example,
one image might have a subpath at registry.k8s.io/subpath/image, but be defaulted
to my.customrepository.io/image when using a custom repository.
To ensure you push the images to your custom repository in paths that kubeadm
can consume, you must:
Pull images from the defaults paths at registry.k8s.io using kubeadm config images {list|pull}.
Push images to the paths from kubeadm config images list --config=config.yaml,
where config.yaml contains the custom imageRepository, and/or imageTag
for etcd and CoreDNS.
Pass the same config.yaml to kubeadm init.
Custom sandbox (pause) images
To set a custom image for these you need to configure this in your
container runtime
to use the image.
Consult the documentation for your container runtime to find out how to change this setting;
for selected container runtimes, you can also find advice within the
Container Runtimes topic.
Uploading control-plane certificates to the cluster
By adding the flag --upload-certs to kubeadm init you can temporary upload
the control-plane certificates to a Secret in the cluster. Please note that this Secret
will expire automatically after 2 hours. The certificates are encrypted using
a 32byte key that can be specified using --certificate-key. The same key can be used
to download the certificates when additional control-plane nodes are joining, by passing
--control-plane and --certificate-key to kubeadm join.
The following phase command can be used to re-upload the certificates after expiration:
Note: A predefined certificateKey can be provided in InitConfiguration when passing the
configuration file with --config.
If a predefined certificate key is not passed to kubeadm init and
kubeadm init phase upload-certs a new key will be generated automatically.
The following command can be used to generate a new key on demand:
kubeadm certs certificate-key
Certificate management with kubeadm
For detailed information on certificate management with kubeadm see
Certificate Management with kubeadm.
The document includes information about using external CA, custom certificates
and certificate renewal.
Managing the kubeadm drop-in file for the kubelet
The kubeadm package ships with a configuration file for running the kubelet by systemd.
Note that the kubeadm CLI never touches this drop-in file. This drop-in file is part of the kubeadm
DEB/RPM package.
By default kubeadm attempts to detect your container runtime. For more details on this detection,
see the kubeadm CRI installation guide.
Setting the node name
By default, kubeadm assigns a node name based on a machine's host address.
You can override this setting with the --node-name flag.
The flag passes the appropriate --hostname-override
value to the kubelet.
Rather than copying the token you obtained from kubeadm init to each node, as
in the basic kubeadm tutorial,
you can parallelize the token distribution for easier automation. To implement this automation,
you must know the IP address that the control-plane node will have after it is started, or use a
DNS name or an address of a load balancer.
Generate a token. This token must have the form <6 character string>.<16 character string>. More formally, it must match the regex:
[a-z0-9]{6}\.[a-z0-9]{16}.
kubeadm can generate a token for you:
kubeadm token generate
Start both the control-plane node and the worker nodes concurrently with this token.
As they come up they should find each other and form the cluster. The same
--token argument can be used on both kubeadm init and kubeadm join.
Similar can be done for --certificate-key when joining additional control-plane
nodes. The key can be generated using:
kubeadm certs certificate-key
Once the cluster is up, you can grab the admin credentials from the control-plane node
at /etc/kubernetes/admin.conf and use that to talk to the cluster.
Note that this style of bootstrap has some relaxed security guarantees because
it does not allow the root CA hash to be validated with
--discovery-token-ca-cert-hash (since it's not generated when the nodes are
provisioned). For details, see the kubeadm join.
kubeadm join to bootstrap a Kubernetes
worker node and join it to the cluster
kubeadm upgrade to upgrade a Kubernetes
cluster to a newer version
kubeadm reset to revert any changes made
to this host by kubeadm init or kubeadm join
10.1.3 - kubeadm join
This command initializes a Kubernetes worker node and joins it to the cluster.
Run this on any machine you wish to join an existing cluster
Synopsis
When joining a kubeadm initialized cluster, we need to establish
bidirectional trust. This is split into discovery (having the Node
trust the Kubernetes Control Plane) and TLS bootstrap (having the
Kubernetes Control Plane trust the Node).
There are 2 main schemes for discovery. The first is to use a shared
token along with the IP address of the API server. The second is to
provide a file - a subset of the standard kubeconfig file. The
discovery/kubeconfig file supports token, client-go authentication
plugins ("exec"), "tokenFile", and "authProvider". This file can be a
local file or downloaded via an HTTPS URL. The forms are
kubeadm join --discovery-token abcdef.1234567890abcdef 1.2.3.4:6443,
kubeadm join --discovery-file path/to/file.conf, or kubeadm join
--discovery-file https://url/file.conf. Only one form can be used. If
the discovery information is loaded from a URL, HTTPS must be used.
Also, in that case the host installed CA bundle is used to verify
the connection.
If you use a shared token for discovery, you should also pass the
--discovery-token-ca-cert-hash flag to validate the public key of the
root certificate authority (CA) presented by the Kubernetes Control Plane.
The value of this flag is specified as "<hash-type>:<hex-encoded-value>",
where the supported hash type is "sha256". The hash is calculated over
the bytes of the Subject Public Key Info (SPKI) object (as in RFC7469).
This value is available in the output of "kubeadm init" or can be
calculated using standard tools. The --discovery-token-ca-cert-hash flag
may be repeated multiple times to allow more than one public key.
If you cannot know the CA public key hash ahead of time, you can pass
the --discovery-token-unsafe-skip-ca-verification flag to disable this
verification. This weakens the kubeadm security model since other nodes
can potentially impersonate the Kubernetes Control Plane.
The TLS bootstrap mechanism is also driven via a shared token. This is
used to temporarily authenticate with the Kubernetes Control Plane to submit a
certificate signing request (CSR) for a locally created key pair. By
default, kubeadm will set up the Kubernetes Control Plane to automatically
approve these signing requests. This token is passed in with the
--tls-bootstrap-token abcdef.1234567890abcdef flag.
Often times the same token is used for both parts. In this case, the
--token flag can be used instead of specifying each token individually.
The "join [api-server-endpoint]" command executes the following phases:
preflight Run join pre-flight checks
control-plane-prepare Prepare the machine for serving a control plane
/download-certs [EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
/certs Generate the certificates for the new control plane components
/kubeconfig Generate the kubeconfig for the new control plane components
/control-plane Generate the manifests for the new control plane components
kubelet-start Write kubelet settings, certificates and (re)start the kubelet
control-plane-join Join a machine as a control plane instance
/etcd Add a new local etcd member
/update-status Register the new control-plane node into the ClusterStatus maintained in the kubeadm-config ConfigMap (DEPRECATED)
/mark-control-plane Mark a node as a control-plane
kubeadm join [api-server-endpoint] [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for join
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--skip-phases strings
List of phases to be skipped
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
The join workflow
kubeadm join bootstraps a Kubernetes worker node or a control-plane node and adds it to the cluster.
This action consists of the following steps for worker nodes:
kubeadm downloads necessary cluster information from the API server.
By default, it uses the bootstrap token and the CA key hash to verify the
authenticity of that data. The root CA can also be discovered directly via a
file or URL.
Once the cluster information is known, kubelet can start the TLS bootstrapping
process.
The TLS bootstrap uses the shared token to temporarily authenticate
with the Kubernetes API server to submit a certificate signing request (CSR); by
default the control plane signs this CSR request automatically.
Finally, kubeadm configures the local kubelet to connect to the API
server with the definitive identity assigned to the node.
For control-plane nodes additional steps are performed:
Downloading certificates shared among control-plane nodes from the cluster
(if explicitly requested by the user).
Generating control-plane component manifests, certificates and kubeconfig.
Adding new local etcd member.
Using join phases with kubeadm
Kubeadm allows you join a node to the cluster in phases using kubeadm join phase.
To view the ordered list of phases and sub-phases you can call kubeadm join --help. The list will be located
at the top of the help screen and each phase will have a description next to it.
Note that by calling kubeadm join all of the phases and sub-phases will be executed in this exact order.
Some phases have unique flags, so if you want to have a look at the list of available options add --help, for example:
kubeadm join phase kubelet-start --help
Similar to the kubeadm init phase
command, kubeadm join phase allows you to skip a list of phases using the --skip-phases flag.
Alternatively, you can use the skipPhases field in JoinConfiguration.
Discovering what cluster CA to trust
The kubeadm discovery has several options, each with security tradeoffs.
The right method for your environment depends on how you provision nodes and the
security expectations you have about your network and node lifecycles.
Token-based discovery with CA pinning
This is the default mode in kubeadm. In this mode, kubeadm downloads
the cluster configuration (including root CA) and validates it using the token
as well as validating that the root CA public key matches the provided hash and
that the API server certificate is valid under the root CA.
The CA key hash has the format sha256:<hex_encoded_hash>.
By default, the hash value is printed at the end of the kubeadm init command or
in the output from the kubeadm token create --print-join-command command.
It is in a standard format (see RFC7469)
and can also be calculated by 3rd party tools or provisioning systems.
For example, using the OpenSSL CLI:
You can also call join for a control-plane node with --certificate-key to copy certificates to this node,
if the kubeadm init command was called with --upload-certs.
Advantages:
Allows bootstrapping nodes to securely discover a root of trust for the
control-plane node even if other worker nodes or the network are compromised.
Convenient to execute manually since all of the information required fits
into a single kubeadm join command.
Disadvantages:
The CA hash is not normally known until the control-plane node has been provisioned,
which can make it more difficult to build automated provisioning tools that
use kubeadm. By generating your CA in beforehand, you may workaround this
limitation.
Token-based discovery without CA pinning
This mode relies only on the symmetric token to sign
(HMAC-SHA256) the discovery information that establishes the root of trust for
the control-plane. To use the mode the joining nodes must skip the hash validation of the
CA public key, using --discovery-token-unsafe-skip-ca-verification. You should consider
using one of the other modes if possible.
Still protects against many network-level attacks.
The token can be generated ahead of time and shared with the control-plane node and
worker nodes, which can then bootstrap in parallel without coordination. This
allows it to be used in many provisioning scenarios.
Disadvantages:
If an attacker is able to steal a bootstrap token via some vulnerability,
they can use that token (along with network-level access) to impersonate the
control-plane node to other bootstrapping nodes. This may or may not be an appropriate
tradeoff in your environment.
File or HTTPS-based discovery
This provides an out-of-band way to establish a root of trust between the control-plane node
and bootstrapping nodes. Consider using this mode if you are building automated provisioning
using kubeadm. The format of the discovery file is a regular Kubernetes
kubeconfig file.
In case the discovery file does not contain credentials, the TLS discovery token will be used.
Allows bootstrapping nodes to securely discover a root of trust for the
control-plane node even if the network or other worker nodes are compromised.
Disadvantages:
Requires that you have some way to carry the discovery information from
the control-plane node to the bootstrapping nodes. If the discovery file contains credentials
you must keep it secret and transfer it over a secure channel. This might be possible with your
cloud provider or provisioning tool.
Use of custom kubelet credentials with kubeadm join
To allow kubeadm join to use predefined kubelet credentials and skip client TLS bootstrap
and CSR approval for a new node:
From a working control plane node in the cluster that has /etc/kubernetes/pki/ca.key
execute kubeadm kubeconfig user --org system:nodes --client-name system:node:$NODE > kubelet.conf.
$NODE must be set to the name of the new node.
Modify the resulted kubelet.conf manually to adjust the cluster name and the server endpoint,
or run kubeadm kubeconfig user --config (it accepts InitConfiguration).
If your cluster does not have the ca.key file, you must sign the embedded certificates in
the kubelet.conf externally.
Copy the resulting kubelet.conf to /etc/kubernetes/kubelet.conf on the new node.
Execute kubeadm join with the flag
--ignore-preflight-errors=FileAvailable--etc-kubernetes-kubelet.conf on the new node.
Securing your installation even more
The defaults for kubeadm may not work for everyone. This section documents how to tighten up a kubeadm installation
at the cost of some usability.
Turning off auto-approval of node client certificates
By default, there is a CSR auto-approver enabled that basically approves any client certificate request
for a kubelet when a Bootstrap Token was used when authenticating. If you don't want the cluster to
automatically approve kubelet client certs, you can turn it off by executing this command:
After that, kubeadm join will block until the admin has manually approved the CSR in flight:
Using kubectl get csr, you can see that the original CSR is in the Pending state.
kubectl get csr
The output is similar to this:
NAME AGE REQUESTOR CONDITION
node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ 18s system:bootstrap:878f07 Pending
kubectl certificate approve allows the admin to approve CSR.This action tells a certificate signing
controller to issue a certificate to the requestor with the attributes requested in the CSR.
This would change the CRS resource to Active state.
kubectl get csr
The output is similar to this:
NAME AGE REQUESTOR CONDITION
node-csr-c69HXe7aYcqkS1bKmH4faEnHAWxn6i2bHZ2mD04jZyQ 1m system:bootstrap:878f07 Approved,Issued
This forces the workflow that kubeadm join will only succeed if kubectl certificate approve has been run.
Turning off public access to the cluster-info ConfigMap
In order to achieve the joining flow using the token as the only piece of validation information, a
ConfigMap with some data needed for validation of the control-plane node's identity is exposed publicly by
default. While there is no private data in this ConfigMap, some users might wish to turn
it off regardless. Doing so will disable the ability to use the --discovery-token flag of the
kubeadm join flow. Here are the steps to do so:
Fetch the cluster-info file from the API Server:
kubectl -n kube-public get cm cluster-info -o jsonpath='{.data.kubeconfig}' | tee cluster-info.yaml
These commands should be run after kubeadm init but before kubeadm join.
Using kubeadm join with a configuration file
Caution: The config file is still considered beta and may change in future versions.
It's possible to configure kubeadm join with a configuration file instead of command
line flags, and some more advanced features may only be available as
configuration file options. This file is passed using the --config flag and it must
contain a JoinConfiguration structure. Mixing --config with others flags may not be
allowed in some cases.
The default configuration can be printed out using the
kubeadm config print command.
If your configuration is not using the latest version it is recommended that you migrate using
the kubeadm config migrate command.
For more information on the fields and usage of the configuration you can navigate to our
API reference.
What's next
kubeadm init to bootstrap a Kubernetes control-plane node.
kubeadm reset to revert any changes made to this host by kubeadm init or kubeadm join.
10.1.4 - kubeadm upgrade
kubeadm upgrade is a user-friendly command that wraps complex upgrading logic
behind one command, with support for both planning an upgrade and actually performing it.
kubeadm upgrade guidance
The steps for performing an upgrade using kubeadm are outlined in this document.
For older versions of kubeadm, please refer to older documentation sets of the Kubernetes website.
You can use kubeadm upgrade diff to see the changes that would be applied to static pod manifests.
In Kubernetes v1.15.0 and later, kubeadm upgrade apply and kubeadm upgrade node will also
automatically renew the kubeadm managed certificates on this node, including those stored in kubeconfig files.
To opt-out, it is possible to pass the flag --certificate-renewal=false. For more details about certificate
renewal see the certificate management documentation.
Note: The commands kubeadm upgrade apply and kubeadm upgrade plan have a legacy --config
flag which makes it possible to reconfigure the cluster, while performing planning or upgrade of that particular
control-plane node. Please be aware that the upgrade workflow was not designed for this scenario and there are
reports of unexpected results.
kubeadm upgrade plan
Check which versions are available to upgrade to and validate whether your current cluster is upgradeable. To skip the internet check, pass in the optional [version] parameter
Synopsis
Check which versions are available to upgrade to and validate whether your current cluster is upgradeable. To skip the internet check, pass in the optional [version] parameter
kubeadm upgrade plan [version] [flags]
Options
--allow-experimental-upgrades
Show unstable versions of Kubernetes as an upgrade alternative and allow upgrading to an alpha/beta/release candidate versions of Kubernetes.
--allow-release-candidate-upgrades
Show release candidate versions of Kubernetes as an upgrade alternative and allow upgrading to a release candidate versions of Kubernetes.
--config string
Path to a kubeadm configuration file.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-h, --help
help for plan
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
-o, --output string Default: "text"
EXPERIMENTAL: Output format. One of: text|json|yaml.
--print-config
Specifies whether the configuration file that will be used in the upgrade should be printed or not.
--show-managed-fields
If true, keep the managedFields when printing objects in JSON or YAML format.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm upgrade apply
Upgrade your Kubernetes cluster to the specified version
Synopsis
Upgrade your Kubernetes cluster to the specified version
kubeadm upgrade apply [version]
Options
--allow-experimental-upgrades
Show unstable versions of Kubernetes as an upgrade alternative and allow upgrading to an alpha/beta/release candidate versions of Kubernetes.
--allow-release-candidate-upgrades
Show release candidate versions of Kubernetes as an upgrade alternative and allow upgrading to a release candidate versions of Kubernetes.
--certificate-renewal Default: true
Perform the renewal of certificates used by component changed during upgrades.
--config string
Path to a kubeadm configuration file.
--dry-run
Do not change any state, just output what actions would be performed.
--etcd-upgrade Default: true
Perform the upgrade of etcd.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
-f, --force
Force upgrading although some requirements might not be met. This also implies non-interactive mode.
-h, --help
help for apply
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--print-config
Specifies whether the configuration file that will be used in the upgrade should be printed or not.
-y, --yes
Perform the upgrade and do not prompt for confirmation (non-interactive mode).
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm upgrade diff
Show what differences would be applied to existing static pod manifests. See also: kubeadm upgrade apply --dry-run
Synopsis
Show what differences would be applied to existing static pod manifests. See also: kubeadm upgrade apply --dry-run
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm upgrade node
Upgrade commands for a node in the cluster
Synopsis
Upgrade commands for a node in the cluster
The "node" command executes the following phases:
preflight Run upgrade node pre-flight checks
control-plane Upgrade the control plane instance deployed on this node, if any
kubelet-config Upgrade the kubelet configuration for this node
kubeadm upgrade node [flags]
Options
--certificate-renewal Default: true
Perform the renewal of certificates used by component changed during upgrades.
--dry-run
Do not change any state, just output the actions that would be performed.
--etcd-upgrade Default: true
Perform the upgrade of etcd.
-h, --help
help for node
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--skip-phases strings
List of phases to be skipped
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
What's next
kubeadm config if you initialized your cluster using kubeadm v1.7.x or lower, to configure your cluster for kubeadm upgrade
10.1.5 - kubeadm config
During kubeadm init, kubeadm uploads the ClusterConfiguration object to your cluster
in a ConfigMap called kubeadm-config in the kube-system namespace. This configuration is then read during
kubeadm join, kubeadm reset and kubeadm upgrade.
You can use kubeadm config print to print the default static configuration that kubeadm
uses for kubeadm init and kubeadm join.
Note: The output of the command is meant to serve as an example. You must manually edit the output
of this command to adapt to your setup. Remove the fields that you are not certain about and kubeadm
will try to default them on runtime by examining the host.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config print init-defaults
Print default init configuration, that can be used for 'kubeadm init'
Synopsis
This command prints objects such as the default init configuration that is used for 'kubeadm init'.
Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like "abcdef.0123456789abcdef" in order to pass validation but
not perform the real computation for creating a token.
kubeadm config print init-defaults [flags]
Options
--component-configs strings
A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config print join-defaults
Print default join configuration, that can be used for 'kubeadm join'
Synopsis
This command prints objects such as the default join configuration that is used for 'kubeadm join'.
Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like "abcdef.0123456789abcdef" in order to pass validation but
not perform the real computation for creating a token.
kubeadm config print join-defaults [flags]
Options
--component-configs strings
A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config migrate
Read an older version of the kubeadm configuration API types from a file, and output the similar config object for the newer version
Synopsis
This command lets you convert configuration objects of older versions to the latest supported version,
locally in the CLI tool without ever touching anything in the cluster.
In this version of kubeadm, the following API versions are supported:
kubeadm.k8s.io/v1beta3
Further, kubeadm can only write out config of version "kubeadm.k8s.io/v1beta3", but read both types.
So regardless of what version you pass to the --old-config parameter here, the API object will be
read, deserialized, defaulted, converted, validated, and re-serialized when written to stdout or
--new-config if specified.
In other words, the output of this command is what kubeadm actually would read internally if you
submitted this file to "kubeadm init"
kubeadm config migrate [flags]
Options
--allow-experimental-api
Allow migration to experimental, unreleased APIs.
-h, --help
help for migrate
--new-config string
Path to the resulting equivalent kubeadm config file using the new API version. Optional, if not specified output will be sent to STDOUT.
--old-config string
Path to the kubeadm config file that is using an old API version and should be converted. This flag is mandatory.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config validate
Read a file containing the kubeadm configuration API and report any validation problems
Synopsis
This command lets you validate a kubeadm configuration API file and report any warnings and errors.
If there are no errors the exit status will be zero, otherwise it will be non-zero.
Any unmarshaling problems such as unknown API fields will trigger errors. Unknown API versions and
fields with invalid values will also trigger errors. Any other errors or warnings may be reported
depending on contents of the input file.
In this version of kubeadm, the following API versions are supported:
kubeadm.k8s.io/v1beta3
kubeadm config validate [flags]
Options
--allow-experimental-api
Allow validation of experimental, unreleased APIs.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config images list
Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized
Synopsis
Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized
kubeadm config images list [flags]
Options
--allow-missing-template-keys Default: true
If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.
--config string
Path to a kubeadm configuration file.
-o, --experimental-output string Default: "text"
Output format. One of: text|json|yaml|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-as-json|jsonpath-file.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm config images pull
Pull images used by kubeadm
Synopsis
Pull images used by kubeadm
kubeadm config images pull [flags]
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
What's next
kubeadm upgrade to upgrade a Kubernetes cluster to a newer version
10.1.6 - kubeadm reset
Performs a best effort revert of changes made by kubeadm init or kubeadm join.
Performs a best effort revert of changes made to this host by 'kubeadm init' or 'kubeadm join'
Synopsis
Performs a best effort revert of changes made to this host by 'kubeadm init' or 'kubeadm join'
The "reset" command executes the following phases:
preflight Run reset pre-flight checks
remove-etcd-member Remove a local etcd member.
cleanup-node Run cleanup node.
kubeadm reset [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path to the directory where the certificates are stored. If specified, clean this directory.
--cleanup-tmp-dir
Cleanup the "/etc/kubernetes/tmp" directory
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-f, --force
Reset the node without prompting for confirmation.
-h, --help
help for reset
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-phases strings
List of phases to be skipped
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Reset workflow
kubeadm reset is responsible for cleaning up a node local file system from files that were created using
the kubeadm init or kubeadm join commands. For control-plane nodes reset also removes the local stacked
etcd member of this node from the etcd cluster.
kubeadm reset phase can be used to execute the separate phases of the above workflow.
To skip a list of phases you can use the --skip-phases flag, which works in a similar way to
the kubeadm join and kubeadm init phase runners.
External etcd clean up
kubeadm reset will not delete any etcd data if external etcd is used. This means that if you run kubeadm init again using the same etcd endpoints, you will see state from previous clusters.
To wipe etcd data it is recommended you use a client like etcdctl, such as:
kubeadm init to bootstrap a Kubernetes control-plane node
kubeadm join to bootstrap a Kubernetes worker node and join it to the cluster
10.1.7 - kubeadm token
Bootstrap tokens are used for establishing bidirectional trust between a node joining
the cluster and a control-plane node, as described in authenticating with bootstrap tokens.
kubeadm init creates an initial token with a 24-hour TTL. The following commands allow you to manage
such a token and also to create and manage new ones.
kubeadm token create
Create bootstrap tokens on the server
Synopsis
This command will create a bootstrap token for you.
You can specify the usages for this token, the "time to live" and an optional human friendly description.
The [token] is the actual token to write.
This should be a securely generated random token of the form "[a-z0-9]{6}.[a-z0-9]{16}".
If no [token] is given, kubeadm will generate a random token instead.
kubeadm token create [token]
Options
--certificate-key string
When used together with '--print-join-command', print the full 'kubeadm join' flag needed to join the cluster as a control-plane. To create a new certificate key you must use 'kubeadm init phase upload-certs --upload-certs'.
--config string
Path to a kubeadm configuration file.
--description string
A human friendly description of how this token is used.
Describes the ways in which this token can be used. You can pass --usages multiple times or provide a comma separated list of options. Valid options: [signing,authentication]
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm token delete
Delete bootstrap tokens on the server
Synopsis
This command will delete a list of bootstrap tokens for you.
The [token-value] is the full Token of the form "[a-z0-9]{6}.[a-z0-9]{16}" or the
Token ID of the form "[a-z0-9]{6}" to delete.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm token generate
Generate and print a bootstrap token, but do not create it on the server
Synopsis
This command will print out a randomly-generated bootstrap token that can be used with
the "init" and "join" commands.
You don't have to use this command in order to generate a token. You can do so
yourself as long as it is in the format "[a-z0-9]{6}.[a-z0-9]{16}". This
command is provided for convenience to generate tokens in the given format.
You can also use "kubeadm init" without specifying a token and it will
generate and print one for you.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm token list
List bootstrap tokens on the server
Synopsis
This command will list all bootstrap tokens for you.
kubeadm token list [flags]
Options
--allow-missing-template-keys Default: true
If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.
-o, --experimental-output string Default: "text"
Output format. One of: text|json|yaml|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-as-json|jsonpath-file.
-h, --help
help for list
--show-managed-fields
If true, keep the managedFields when printing objects in JSON or YAML format.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
What's next
kubeadm join to bootstrap a Kubernetes worker node and join it to the cluster
10.1.8 - kubeadm version
This command prints the version of kubeadm.
Print the version of kubeadm
Synopsis
Print the version of kubeadm
kubeadm version [flags]
Options
-h, --help
help for version
-o, --output string
Output format; available options are 'yaml', 'json' and 'short'
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.9 - kubeadm alpha
Caution:kubeadm alpha provides a preview of a set of features made available for gathering feedback
from the community. Please try it out and give us feedback!
Currently there are no experimental commands under kubeadm alpha.
What's next
kubeadm init to bootstrap a Kubernetes control-plane node
kubeadm reset to revert any changes made to this host by kubeadm init or kubeadm join
10.1.10 - kubeadm certs
kubeadm certs provides utilities for managing certificates.
For more details on how these commands can be used, see
Certificate Management with kubeadm.
kubeadm certs
A collection of operations for operating Kubernetes certificates.
This command is not meant to be run on its own. See list of available subcommands.
kubeadm certs renew [flags]
Options
-h, --help
help for renew
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew all available certificates
Synopsis
Renew all known certificates necessary to run the control plane. Renewals are run unconditionally, regardless of expiration date. Renewals can also be run individually for more control.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself
Synopsis
Renew the certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate the apiserver uses to access etcd
Synopsis
Renew the certificate the apiserver uses to access etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for the API server to connect to kubelet
Synopsis
Renew the certificate for the API server to connect to kubelet.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for serving the Kubernetes API
Synopsis
Renew the certificate for serving the Kubernetes API.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate embedded in the kubeconfig file for the controller manager to use
Synopsis
Renew the certificate embedded in the kubeconfig file for the controller manager to use.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for liveness probes to healthcheck etcd
Synopsis
Renew the certificate for liveness probes to healthcheck etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for etcd nodes to communicate with each other
Synopsis
Renew the certificate for etcd nodes to communicate with each other.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for serving etcd
Synopsis
Renew the certificate for serving etcd.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate for the front proxy client
Synopsis
Renew the certificate for the front proxy client.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Renew the certificate embedded in the kubeconfig file for the scheduler manager to use
Synopsis
Renew the certificate embedded in the kubeconfig file for the scheduler manager to use.
Renewals run unconditionally, regardless of certificate expiration date; extra attributes such as SANs will be based on the existing file/certificates, there is no need to resupply them.
Renewal by default tries to use the certificate authority in the local PKI managed by kubeadm; as alternative it is possible to use K8s certificate API for certificate renewal, or as a last option, to generate a CSR request.
After renewal, in order to make changes effective, is required to restart control-plane components and eventually re-distribute the renewed certificate in case the file is used elsewhere.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm certs certificate-key
This command can be used to generate a new control-plane certificate key.
The key can be passed as --certificate-key to kubeadm init
and kubeadm join
to enable the automatic copy of certificates when joining additional control-plane nodes.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm certs generate-csr
This command can be used to generate keys and CSRs for all control-plane certificates and kubeconfig files.
The user can then sign the CSRs with a CA of their choice.
Generates keys and certificate signing requests (CSRs) for all the certificates required to run the control plane. This command also generates partial kubeconfig files with private key data in the "users > user > client-key-data" field, and for each kubeconfig file an accompanying ".csr" file is created.
This command is designed for use in Kubeadm External CA Mode. It generates CSRs which you can then submit to your external certificate authority for signing.
The PEM encoded signed certificates should then be saved alongside the key files, using ".crt" as the file extension, or in the case of kubeconfig files, the PEM encoded signed certificate should be base64 encoded and added to the kubeconfig file in the "users > user > client-certificate-data" field.
kubeadm certs generate-csr [flags]
Examples
# The following command will generate keys and CSRs for all control-plane certificates and kubeconfig files:
kubeadm certs generate-csr --kubeconfig-dir /tmp/etc-k8s --cert-dir /tmp/etc-k8s/pki
kubeadm reset to revert any changes made to this host by kubeadm init or kubeadm join
10.1.11 - kubeadm init phase
kubeadm init phase enables you to invoke atomic steps of the bootstrap process.
Hence, you can let kubeadm do some of the work and you can fill in the gaps
if you wish to apply customization.
kubeadm init phase is consistent with the kubeadm init workflow,
and behind the scene both use the same code.
kubeadm init phase preflight
Using this command you can execute preflight checks on a control-plane node.
# Run pre-flight checks for kubeadm init using a config file.
kubeadm init phase preflight --config kubeadm-config.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase kubelet-start
This phase will write the kubelet configuration file and environment file and then start the kubelet.
Write a file with KubeletConfiguration and an environment file with node specific kubelet settings, and then (re)start kubelet.
kubeadm init phase kubelet-start [flags]
Examples
# Writes a dynamic environment file with kubelet flags from a InitConfiguration file.
kubeadm init phase kubelet-start --config config.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for kubelet-start
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase certs
Can be used to create all required certificates by kubeadm.
Use alternative domain for services, e.g. "myorg.internal".
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the certificate for the API server to connect to kubelet
Synopsis
Generate the certificate for the API server to connect to kubelet, and save them into apiserver-kubelet-client.crt and apiserver-kubelet-client.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for front-proxy-client
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the self-signed CA to provision identities for etcd
Synopsis
Generate the self-signed CA to provision identities for etcd, and save them into etcd/ca.crt and etcd/ca.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs etcd-ca [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd-ca
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the certificate for serving etcd
Synopsis
Generate the certificate for serving etcd, and save them into etcd/server.crt and etcd/server.key files.
Default SANs are localhost, 127.0.0.1, 127.0.0.1, ::1
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs etcd-server [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd-server
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the certificate for etcd nodes to communicate with each other
Synopsis
Generate the certificate for etcd nodes to communicate with each other, and save them into etcd/peer.crt and etcd/peer.key files.
Default SANs are localhost, 127.0.0.1, 127.0.0.1, ::1
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs etcd-peer [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd-peer
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the certificate for liveness probes to healthcheck etcd
Synopsis
Generate the certificate for liveness probes to healthcheck etcd, and save them into etcd/healthcheck-client.crt and etcd/healthcheck-client.key files.
If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for apiserver-etcd-client
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate a private key for signing service account tokens along with its public key
Synopsis
Generate the private key for signing service account tokens along with its public key, and save them into sa.key and sa.pub files. If both files already exist, kubeadm skips the generation step and existing files will be used.
Alpha Disclaimer: this command is currently alpha.
kubeadm init phase certs sa [flags]
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
-h, --help
help for sa
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase kubeconfig
You can create all required kubeconfig files by calling the all subcommand or call them individually.
Choose a specific Kubernetes version for the control plane.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate a kubeconfig file for the kubelet to use only for cluster bootstrapping purposes
Synopsis
Generate the kubeconfig file for the kubelet to use and save it to kubelet.conf file.
Please note that this should only be used for cluster bootstrapping purposes. After your control plane is up, you should request all kubelet credentials from the CSR API.
kubeadm init phase kubeconfig kubelet [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
Generate all static Pod manifest files necessary to establish the control plane
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase control-plane [flags]
Options
-h, --help
help for control-plane
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate all static Pod manifest files
Synopsis
Generate all static Pod manifest files
kubeadm init phase control-plane all [flags]
Examples
# Generates all static Pod manifest files for control plane components,
# functionally equivalent to what is generated by kubeadm init.
kubeadm init phase control-plane all
# Generates all static Pod manifest files using options read from a configuration file.
kubeadm init phase control-plane all --config config.yaml
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
A set of extra flags to pass to the Controller Manager or override default ones in form of <flagname>=<value>
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
A set of extra flags to pass to the API Server or override default ones in form of <flagname>=<value>
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generates the kube-controller-manager static Pod manifest
Synopsis
Generates the kube-controller-manager static Pod manifest
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Choose a container registry to pull control plane images from
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase etcd [flags]
Options
-h, --help
help for etcd
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the static Pod manifest file for a local, single-node local etcd instance
Synopsis
Generate the static Pod manifest file for a local, single-node local etcd instance
kubeadm init phase etcd local [flags]
Examples
# Generates the static Pod manifest file for etcd, functionally
# equivalent to what is generated by kubeadm init.
kubeadm init phase etcd local
# Generates the static Pod manifest file for etcd using options
# read from a configuration file.
kubeadm init phase etcd local --config config.yaml
Options
--cert-dir string Default: "/etc/kubernetes/pki"
The path where to save and store the certificates.
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
Choose a container registry to pull control plane images from
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase upload-config
You can use this command to upload the kubeadm configuration to your cluster.
Alternatively, you can use kubeadm config.
Upload the kubeadm and kubelet configuration to a ConfigMap
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase upload-config [flags]
Options
-h, --help
help for upload-config
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Upload all configuration to a config map
Synopsis
Upload all configuration to a config map
kubeadm init phase upload-config all [flags]
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Upload the kubeadm ClusterConfiguration to a ConfigMap
Synopsis
Upload the kubeadm ClusterConfiguration to a ConfigMap called kubeadm-config in the kube-system namespace. This enables correct configuration of system components and a seamless user experience when upgrading.
Alternatively, you can use kubeadm config.
kubeadm init phase upload-config kubeadm [flags]
Examples
# upload the configuration of your cluster
kubeadm init phase upload-config --config=myConfig.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Upload the kubelet component config to a ConfigMap
Synopsis
Upload the kubelet configuration extracted from the kubeadm InitConfiguration object to a kubelet-config ConfigMap in the cluster
kubeadm init phase upload-config kubelet [flags]
Examples
# Upload the kubelet configuration from the kubeadm Config file to a ConfigMap in the cluster.
kubeadm init phase upload-config kubelet --config kubeadm.yaml
Options
--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase upload-certs
Use the following phase to upload control-plane certificates to the cluster.
By default the certs and encryption key expire after two hours.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-certificate-key-print
Don't print the key used to encrypt the control-plane certificates.
--upload-certs
Upload control-plane certificates to the kubeadm-certs Secret.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase mark-control-plane
Use the following phase to label and taint the node as a control plane node.
# Applies control-plane label and taint to the current node, functionally equivalent to what executed by kubeadm init.
kubeadm init phase mark-control-plane --config config.yaml
# Applies control-plane label and taint to a specific node
kubeadm init phase mark-control-plane --node-name myNode
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for mark-control-plane
--node-name string
Specify the node name.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase bootstrap-token
Use the following phase to configure bootstrap tokens.
Generates bootstrap tokens used to join a node to a cluster
Synopsis
Bootstrap tokens are used for establishing bidirectional trust between a node joining the cluster and a control-plane node.
This command makes all the configurations required to make bootstrap tokens works and then creates an initial token.
kubeadm init phase bootstrap-token [flags]
Examples
# Make all the bootstrap token configurations and create an initial token, functionally
# equivalent to what generated by kubeadm init.
kubeadm init phase bootstrap-token
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--skip-token-print
Skip printing of the default bootstrap token generated by 'kubeadm init'.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm init phase kubelet-finalize
Use the following phase to update settings relevant to the kubelet after TLS
bootstrap. You can use the all subcommand to run all kubelet-finalize
phases.
Install required addons for passing conformance tests
Synopsis
This command is not meant to be run on its own. See list of available subcommands.
kubeadm init phase addon [flags]
Options
-h, --help
help for addon
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Install all the addons
Synopsis
Install all the addons
kubeadm init phase addon all [flags]
Options
--apiserver-advertise-address string
The IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
Port for the API Server to bind to.
--config string
Path to a kubeadm configuration file.
--control-plane-endpoint string
Specify a stable IP address or DNS name for the control plane.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
Use alternative domain for services, e.g. "myorg.internal".
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Install the CoreDNS addon to a Kubernetes cluster
Synopsis
Install the CoreDNS addon components via the API server. Please note that although the DNS server is deployed, it will not be scheduled until CNI is installed.
kubeadm init phase addon coredns [flags]
Options
--config string
Path to a kubeadm configuration file.
--dry-run
Don't apply any changes; just output what would be done.
--feature-gates string
A set of key=value pairs that describe feature gates for various features. Options are: EtcdLearnerMode=true|false (ALPHA - default=false) PublicKeysECDSA=true|false (ALPHA - default=false) RootlessControlPlane=true|false (ALPHA - default=false) UpgradeAddonsBeforeControlPlane=true|false (DEPRECATED - default=false)
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--print-manifest
Print the addon manifests to STDOUT instead of installing them
--service-cidr string Default: "10.96.0.0/12"
Use alternative range of IP address for service VIPs.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--kubernetes-version string Default: "stable-1"
Choose a specific Kubernetes version for the control plane.
--pod-network-cidr string
Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--print-manifest
Print the addon manifests to STDOUT instead of installing them
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
For more details on each field in the v1beta3 configuration you can navigate to our
API reference pages.
What's next
kubeadm init to bootstrap a Kubernetes control-plane node
kubeadm join phase enables you to invoke atomic steps of the join process.
Hence, you can let kubeadm do some of the work and you can fill in the gaps
if you wish to apply customization.
kubeadm join phase is consistent with the kubeadm join workflow,
and behind the scene both use the same code.
# Run join pre-flight checks using a config file.
kubeadm join phase preflight --config kubeadm-config.yaml
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for preflight
--ignore-preflight-errors strings
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
--node-name string
Specify the node name.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm join phase control-plane-prepare
Using this phase you can prepare a node for serving a control-plane.
# Prepares the machine for serving a control plane
kubeadm join phase control-plane-prepare all
Options
-h, --help
help for control-plane-prepare
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Prepare the machine for serving a control plane
Synopsis
Prepare the machine for serving a control plane
kubeadm join phase control-plane-prepare all [api-server-endpoint] [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string
Use this key to decrypt the certificate secrets uploaded by init.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for all
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
[EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
Synopsis
[EXPERIMENTAL] Download certificates shared among control-plane nodes from the kubeadm-certs Secret
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for certs
--node-name string
Specify the node name.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Generate the kubeconfig for the new control plane components
Synopsis
Generate the kubeconfig for the new control plane components
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32 Default: 6443
If the node should host a new control plane instance, the port for the API Server to bind to.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for control-plane
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm join phase kubelet-start
Using this phase you can write the kubelet settings, certificates and (re)start the kubelet.
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--discovery-file string
For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string
For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings
For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification
For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for kubelet-start
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string
Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string
Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm join phase control-plane-join
Using this phase you can join a node as a control-plane instance.
# Joins a machine as a control plane instance
kubeadm join phase control-plane-join all
Options
-h, --help
help for control-plane-join
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Join a machine as a control plane instance
Synopsis
Join a machine as a control plane instance
kubeadm join phase control-plane-join all [flags]
Options
--apiserver-advertise-address string
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for all
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for etcd
--node-name string
Specify the node name.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Register the new control-plane node into the ClusterStatus maintained in the kubeadm-config ConfigMap (DEPRECATED)
Synopsis
Register the new control-plane node into the ClusterStatus maintained in the kubeadm-config ConfigMap (DEPRECATED)
If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string
Path to a kubeadm configuration file.
--control-plane
Create a new control plane instance on this node
-h, --help
help for update-status
--node-name string
Specify the node name.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
# Output a kubeconfig file for an additional user named foo
kubeadm kubeconfig user --client-name=foo
# Output a kubeconfig file for an additional user named foo using a kubeadm config file bar
kubeadm kubeconfig user --client-name=foo --config=bar
Options
--client-name string
The name of user. It will be used as the CN if client certificates are created
--config string
Path to a kubeadm configuration file.
-h, --help
help for user
--org strings
The organizations of the client certificate. It will be used as the O if client certificates are created
--token string
The token that should be used as the authentication mechanism for this kubeconfig, instead of client certificates
--validity-period duration Default: 8760h0m0s
The validity period of the client certificate. It is an offset from the current time.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
10.1.14 - kubeadm reset phase
kubeadm reset phase enables you to invoke atomic steps of the node reset process.
Hence, you can let kubeadm do some of the work and you can fill in the gaps
if you wish to apply customization.
kubeadm reset phase is consistent with the kubeadm reset workflow,
and behind the scene both use the same code.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
kubeadm reset phase cleanup-node
Using this phase you can perform cleanup on this node.
The path to the directory where the certificates are stored. If specified, clean this directory.
--cleanup-tmp-dir
Cleanup the "/etc/kubernetes/tmp" directory
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
--dry-run
Don't apply any changes; just output what would be done.
-h, --help
help for cleanup-node
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
What's next
kubeadm init to bootstrap a Kubernetes control-plane node
In v1.15.0, kubeadm introduced preliminary support for kubeadm upgrade node phases.
Phases for other kubeadm upgrade sub-commands such as apply, could be added in the
following releases.
kubeadm upgrade node phase
Using this phase you can choose to execute the separate steps of the upgrade of
secondary control-plane or worker nodes. Please note that kubeadm upgrade apply still has to
be called on a primary control-plane node.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
Upgrade the kubelet configuration for this node
Synopsis
Download the kubelet configuration from the kubelet-config ConfigMap stored in the cluster
kubeadm upgrade node phase kubelet-config [flags]
Options
--dry-run
Do not change any state, just output the actions that would be performed.
The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.
--patches string
Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
Options inherited from parent commands
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
What's next
kubeadm init to bootstrap a Kubernetes control-plane node
kubeadm init and kubeadm join together provides a nice user experience for creating a
best-practice but bare Kubernetes cluster from scratch.
However, it might not be obvious how kubeadm does that.
This document provides additional details on what happen under the hood, with the aim of sharing
knowledge on Kubernetes cluster best practices.
Core design principles
The cluster that kubeadm init and kubeadm join set up should be:
Secure: It should adopt latest best-practices like:
enforcing RBAC
using the Node Authorizer
using secure communication between the control plane components
using secure communication between the API server and the kubelets
lock-down the kubelet API
locking down access to the API for system components like the kube-proxy and CoreDNS
locking down what a Bootstrap Token can access
User-friendly: The user should not have to run anything more than a couple of commands:
kubeadm init
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl apply -f <network-of-choice.yaml>
kubeadm join --token <token> <endpoint>:<port>
Extendable:
It should not favor any particular network provider. Configuring the cluster network is out-of-scope
It should provide the possibility to use a config file for customizing various parameters
Constants and well-known values and paths
In order to reduce complexity and to simplify development of higher level tools that build on top of kubeadm, it uses a
limited set of constant values for well-known paths and file names.
The Kubernetes directory /etc/kubernetes is a constant in the application, since it is clearly the given path
in a majority of cases, and the most intuitive location; other constants paths and file names are:
/etc/kubernetes/manifests as the path where kubelet should look for static Pod manifests.
Names of static Pod manifests are:
etcd.yaml
kube-apiserver.yaml
kube-controller-manager.yaml
kube-scheduler.yaml
/etc/kubernetes/ as the path where kubeconfig files with identities for control plane
components are stored. Names of kubeconfig files are:
kubelet.conf (bootstrap-kubelet.conf during TLS bootstrap)
controller-manager.conf
scheduler.conf
admin.conf for the cluster admin and kubeadm itself
Names of certificates and key files :
ca.crt, ca.key for the Kubernetes certificate authority
apiserver.crt, apiserver.key for the API server certificate
apiserver-kubelet-client.crt, apiserver-kubelet-client.key for the client certificate used
by the API server to connect to the kubelets securely
sa.pub, sa.key for the key used by the controller manager when signing ServiceAccount
front-proxy-ca.crt, front-proxy-ca.key for the front proxy certificate authority
front-proxy-client.crt, front-proxy-client.key for the front proxy client
kubeadm init workflow internal design
The kubeadm initinternal workflow
consists of a sequence of atomic work tasks to perform,
as described in kubeadm init.
The kubeadm init phase command allows
users to invoke each task individually, and ultimately offers a reusable and composable
API/toolbox that can be used by other Kubernetes bootstrap tools, by any IT automation tool or by
an advanced user for creating custom clusters.
Preflight checks
Kubeadm executes a set of preflight checks before starting the init, with the aim to verify
preconditions and avoid common cluster startup problems.
The user can skip specific preflight checks or all of them with the --ignore-preflight-errors option.
[warning] If the Kubernetes version to use (specified with the --kubernetes-version flag) is
at least one minor version higher than the kubeadm CLI version.
Kubernetes system requirements:
if running on linux:
[error] if Kernel is older than the minimum required version
[error] if required cgroups subsystem aren't set up
[error] if the CRI endpoint does not answer
[error] if user is not root
[error] if the machine hostname is not a valid DNS subdomain
[warning] if the host name cannot be reached via network lookup
[error] if kubelet version is lower that the minimum kubelet version supported by kubeadm (current minor -1)
[error] if kubelet version is at least one minor higher than the required controlplane version (unsupported version skew)
[warning] if kubelet service does not exist or if it is disabled
[warning] if firewalld is active
[error] if API server bindPort or ports 10250/10251/10252 are used
[Error] if /etc/kubernetes/manifest folder already exists and it is not empty
[Error] if /proc/sys/net/bridge/bridge-nf-call-iptables file does not exist/does not contain 1
[Error] if advertise address is ipv6 and /proc/sys/net/bridge/bridge-nf-call-ip6tables does not exist/does not contain 1.
[Error] if swap is on
[Error] if conntrack, ip, iptables, mount, nsenter commands are not present in the command path
[warning] if ebtables, ethtool, socat, tc, touch, crictl commands are not present in the command path
[warning] if extra arg flags for API server, controller manager, scheduler contains some invalid options
[warning] if connection to https://API.AdvertiseAddress:API.BindPort goes through proxy
[warning] if connection to services subnet goes through proxy (only first address checked)
[warning] if connection to Pods subnet goes through proxy (only first address checked)
If external etcd is provided:
[Error] if etcd version is older than the minimum required version
[Error] if etcd certificates or keys are specified, but not provided
If external etcd is NOT provided (and thus local etcd will be installed):
[Error] if ports 2379 is used
[Error] if Etcd.DataDir folder already exists and it is not empty
Kubeadm generates certificate and private key pairs for different purposes:
A self signed certificate authority for the Kubernetes cluster saved into ca.crt file and
ca.key private key file
A serving certificate for the API server, generated using ca.crt as the CA, and saved into
apiserver.crt file with its private key apiserver.key. This certificate should contain
following alternative names:
The Kubernetes service's internal clusterIP (the first address in the services CIDR, e.g.
10.96.0.1 if service subnet is 10.96.0.0/12)
Kubernetes DNS names, e.g. kubernetes.default.svc.cluster.local if --service-dns-domain
flag value is cluster.local, plus default DNS names kubernetes.default.svc,
kubernetes.default, kubernetes
The node-name
The --apiserver-advertise-address
Additional alternative names specified by the user
A client certificate for the API server to connect to the kubelets securely, generated using
ca.crt as the CA and saved into apiserver-kubelet-client.crt file with its private key
apiserver-kubelet-client.key.
This certificate should be in the system:masters organization
A private key for signing ServiceAccount Tokens saved into sa.key file along with its public key sa.pub
A certificate authority for the front proxy saved into front-proxy-ca.crt file with its key
front-proxy-ca.key
A client cert for the front proxy client, generate using front-proxy-ca.crt as the CA and
saved into front-proxy-client.crt file with its private keyfront-proxy-client.key
Certificates are stored by default in /etc/kubernetes/pki, but this directory is configurable
using the --cert-dir flag.
Please note that:
If a given certificate and private key pair both exist, and its content is evaluated compliant with the above specs, the existing files will
be used and the generation phase for the given certificate skipped. This means the user can, for example, copy an existing CA to
/etc/kubernetes/pki/ca.{crt,key}, and then kubeadm will use those files for signing the rest of the certs.
See also using custom certificates
Only for the CA, it is possible to provide the ca.crt file but not the ca.key file, if all other certificates and kubeconfig files
already are in place kubeadm recognize this condition and activates the ExternalCA , which also implies the csrsignercontroller in
controller-manager won't be started
If kubeadm is running in external CA mode;
all the certificates must be provided by the user, because kubeadm cannot generate them by itself
In case of kubeadm is executed in the --dry-run mode, certificates files are written in a temporary folder
Generate kubeconfig files for control plane components
Kubeadm generates kubeconfig files with identities for control plane components:
A kubeconfig file for the kubelet to use during TLS bootstrap -
/etc/kubernetes/bootstrap-kubelet.conf. Inside this file there is a bootstrap-token or embedded
client certificates for authenticating this node with the cluster.
This client cert should:
Be in the system:nodes organization, as required by the
Node Authorization module
Have the Common Name (CN) system:node:<hostname-lowercased>
A kubeconfig file for controller-manager, /etc/kubernetes/controller-manager.conf; inside this
file is embedded a client certificate with controller-manager identity. This client cert should
have the CN system:kube-controller-manager, as defined by default
RBAC core components roles
A kubeconfig file for scheduler, /etc/kubernetes/scheduler.conf; inside this file is embedded
a client certificate with scheduler identity.
This client cert should have the CN system:kube-scheduler, as defined by default
RBAC core components roles
Additionally, a kubeconfig file for kubeadm itself and the admin is generated and saved into the
/etc/kubernetes/admin.conf file. The "admin" here is defined as the actual person(s) that is
administering the cluster and wants to have full control (root) over the cluster. The
embedded client certificate for admin should be in the system:masters organization, as defined
by default RBAC user facing role bindings.
It should also include a CN. Kubeadm uses the kubernetes-admin CN.
Please note that:
ca.crt certificate is embedded in all the kubeconfig files.
If a given kubeconfig file exists, and its content is evaluated compliant with the above specs,
the existing file will be used and the generation phase for the given kubeconfig skipped
If kubeadm is running in ExternalCA mode,
all the required kubeconfig must be provided by the user as well, because kubeadm cannot
generate any of them by itself
In case of kubeadm is executed in the --dry-run mode, kubeconfig files are written in a temporary folder
Generate static Pod manifests for control plane components
Kubeadm writes static Pod manifest files for control plane components to
/etc/kubernetes/manifests. The kubelet watches this directory for Pods to create on startup.
Static Pod manifest share a set of common properties:
All static Pods are deployed on kube-system namespace
All static Pods get tier:control-plane and component:{component-name} labels
All static Pods use the system-node-critical priority class
hostNetwork: true is set on all static Pods to allow control plane startup before a network is
configured; as a consequence:
The address that the controller-manager and the scheduler use to refer the API server is 127.0.0.1
If using a local etcd server, etcd-servers address will be set to 127.0.0.1:2379
Leader election is enabled for both the controller-manager and the scheduler
Controller-manager and the scheduler will reference kubeconfig files with their respective, unique identities
The static Pod manifest for the API server is affected by following parameters provided by the users:
The apiserver-advertise-address and apiserver-bind-port to bind to; if not provided, those
value defaults to the IP address of the default network interface on the machine and port 6443
The service-cluster-ip-range to use for services
If an external etcd server is specified, the etcd-servers address and related TLS settings
(etcd-cafile, etcd-certfile, etcd-keyfile);
if an external etcd server is not be provided, a local etcd will be used (via host network)
If a cloud provider is specified, the corresponding --cloud-provider is configured, together
with the --cloud-config path if such file exists (this is experimental, alpha and will be
removed in a future version)
Other API server flags that are set unconditionally are:
--insecure-port=0 to avoid insecure connections to the api server
--enable-bootstrap-token-auth=true to enable the BootstrapTokenAuthenticator authentication module.
See TLS Bootstrapping for more details
--allow-privileged to true (required e.g. by kube proxy)
--requestheader-client-ca-file to front-proxy-ca.crt
PersistentVolumeLabel
attaches region or zone labels to PersistentVolumes as defined by the cloud provider (This
admission controller is deprecated and will be removed in a future version.
It is not deployed by kubeadm by default with v1.9 onwards when not explicitly opting into
using gce or aws as cloud providers)
DefaultStorageClass
to enforce default storage class on PersistentVolumeClaim objects
NodeRestriction
to limit what a kubelet can modify (e.g. only pods on this node)
--kubelet-preferred-address-types to InternalIP,ExternalIP,Hostname; this makes kubectl logs and other API server-kubelet communication work in environments where the hostnames of the
nodes aren't resolvable
Flags for using certificates generated in previous steps:
--client-ca-file to ca.crt
--tls-cert-file to apiserver.crt
--tls-private-key-file to apiserver.key
--kubelet-client-certificate to apiserver-kubelet-client.crt
--kubelet-client-key to apiserver-kubelet-client.key
The static Pod manifest for the controller manager is affected by following parameters provided by
the users:
If kubeadm is invoked specifying a --pod-network-cidr, the subnet manager feature required for
some CNI network plugins is enabled by setting:
--allocate-node-cidrs=true
--cluster-cidr and --node-cidr-mask-size flags according to the given CIDR
If a cloud provider is specified, the corresponding --cloud-provider is specified, together
with the --cloud-config path if such configuration file exists (this is experimental, alpha
and will be removed in a future version)
Other flags that are set unconditionally are:
--controllers enabling all the default controllers plus BootstrapSigner and TokenCleaner
controllers for TLS bootstrap. See TLS Bootstrapping
for more details
--use-service-account-credentials to true
Flags for using certificates generated in previous steps:
--root-ca-file to ca.crt
--cluster-signing-cert-file to ca.crt, if External CA mode is disabled, otherwise to ""
--cluster-signing-key-file to ca.key, if External CA mode is disabled, otherwise to ""
--service-account-private-key-file to sa.key
Scheduler
The static Pod manifest for the scheduler is not affected by parameters provided by the users.
Generate static Pod manifest for local etcd
If you specified an external etcd this step will be skipped, otherwise kubeadm generates a
static Pod manifest file for creating a local etcd instance running in a Pod with following attributes:
listen on localhost:2379 and use HostNetwork=true
make a hostPath mount out from the dataDir to the host's filesystem
Any extra flags specified by the user
Please note that:
The etcd container image will be pulled from registry.gcr.io by default. See
using custom images
for customizing the image repository.
If you run kubeadm in --dry-run mode, the etcd static Pod manifest is written
into a temporary folder.
You can directly invoke static Pod manifest generation for local etcd, using the
kubeadm init phase etcd local
command.
Wait for the control plane to come up
kubeadm waits (upto 4m0s) until localhost:6443/healthz (kube-apiserver liveness) returns ok.
However in order to detect deadlock conditions, kubeadm fails fast if localhost:10255/healthz
(kubelet liveness) or localhost:10255/healthz/syncloop (kubelet readiness) don't return ok
within 40s and 60s respectively.
kubeadm relies on the kubelet to pull the control plane images and run them properly as static Pods.
After the control plane is up, kubeadm completes the tasks described in following paragraphs.
Save the kubeadm ClusterConfiguration in a ConfigMap for later reference
kubeadm saves the configuration passed to kubeadm init in a ConfigMap named kubeadm-config
under kube-system namespace.
This will ensure that kubeadm actions executed in future (e.g kubeadm upgrade) will be able to
determine the actual/current cluster state and make new decisions based on that data.
Please note that:
Before saving the ClusterConfiguration, sensitive information like the token is stripped from the configuration
kubeadm init ensures that everything is properly configured for this process, and this includes
following steps as well as setting API server and controller flags as already described in
previous paragraphs.
Please note that:
TLS bootstrapping for nodes can be configured with the command
kubeadm init phase bootstrap-token,
executing all the configuration steps described in following paragraphs;
alternatively, each step can be invoked individually
Create a bootstrap token
kubeadm init create a first bootstrap token, either generated automatically or provided by the
user with the --token flag; as documented in bootstrap token specification, token should be
saved as secrets with name bootstrap-token-<token-id> under kube-system namespace.
Please note that:
The default token created by kubeadm init will be used to validate temporary user during TLS
bootstrap process; those users will be member of
system:bootstrappers:kubeadm:default-node-token group
The token has a limited validity, default 24 hours (the interval may be changed with the —token-ttl flag)
Additional tokens can be created with the kubeadm token
command, that provide as well other useful functions for token management.
Allow joining nodes to call CSR API
Kubeadm ensures that users in system:bootstrappers:kubeadm:default-node-token group are able to
access the certificate signing API.
This is implemented by creating a ClusterRoleBinding named kubeadm:kubelet-bootstrap between the
group above and the default RBAC role system:node-bootstrapper.
Set up auto approval for new bootstrap tokens
Kubeadm ensures that the Bootstrap Token will get its CSR request automatically approved by the
csrapprover controller.
This is implemented by creating ClusterRoleBinding named kubeadm:node-autoapprove-bootstrap
between the system:bootstrappers:kubeadm:default-node-token group and the default role
system:certificates.k8s.io:certificatesigningrequests:nodeclient.
The role system:certificates.k8s.io:certificatesigningrequests:nodeclient should be created as
well, granting POST permission to
/apis/certificates.k8s.io/certificatesigningrequests/nodeclient.
Set up nodes certificate rotation with auto approval
Kubeadm ensures that certificate rotation is enabled for nodes, and that new certificate request
for nodes will get its CSR request automatically approved by the csrapprover controller.
This is implemented by creating ClusterRoleBinding named
kubeadm:node-autoapprove-certificate-rotation between the system:nodes group and the default
role system:certificates.k8s.io:certificatesigningrequests:selfnodeclient.
Create the public cluster-info ConfigMap
This phase creates the cluster-info ConfigMap in the kube-public namespace.
Additionally it creates a Role and a RoleBinding granting access to the ConfigMap for
unauthenticated users (i.e. users in RBAC group system:unauthenticated).
Please note that:
The access to the cluster-info ConfigMap is not rate-limited. This may or may not be a
problem if you expose your cluster's API server to the internet; worst-case scenario here is a
DoS attack where an attacker uses all the in-flight requests the kube-apiserver can handle to
serving the cluster-info ConfigMap.
Install addons
Kubeadm installs the internal DNS server and the kube-proxy addon components via the API server.
A ServiceAccount for kube-proxy is created in the kube-system namespace; then kube-proxy is
deployed as a DaemonSet:
The credentials (ca.crt and token) to the control plane come from the ServiceAccount
The location (URL) of the API server comes from a ConfigMap
The kube-proxy ServiceAccount is bound to the privileges in the system:node-proxier ClusterRole
DNS
The CoreDNS service is named kube-dns. This is done to prevent any interruption
in service when the user is switching the cluster DNS from kube-dns to CoreDNS
the --config method described here.
A ServiceAccount for CoreDNS is created in the kube-system namespace.
The coredns ServiceAccount is bound to the privileges in the system:coredns ClusterRole
In Kubernetes version 1.21, support for using kube-dns with kubeadm was removed.
You can use CoreDNS with kubeadm even when the related Service is named kube-dns.
kubeadm join phases internal design
Similarly to kubeadm init, also kubeadm join internal workflow consists of a sequence of
atomic work tasks to perform.
This is split into discovery (having the Node trust the Kubernetes Master) and TLS bootstrap
(having the Kubernetes Master trust the Node).
kubeadm executes a set of preflight checks before starting the join, with the aim to verify
preconditions and avoid common cluster startup problems.
Please note that:
kubeadm join preflight checks are basically a subset kubeadm init preflight checks
Starting from 1.24, kubeadm uses crictl to communicate to all known CRI endpoints.
Starting from 1.9, kubeadm provides support for joining nodes running on Windows; in that case,
linux specific controls are skipped.
In any case the user can skip specific preflight checks (or eventually all preflight checks)
with the --ignore-preflight-errors option.
Discovery cluster-info
There are 2 main schemes for discovery. The first is to use a shared token along with the IP
address of the API server.
The second is to provide a file (that is a subset of the standard kubeconfig file).
Shared token discovery
If kubeadm join is invoked with --discovery-token, token discovery is used; in this case the
node basically retrieves the cluster CA certificates from the cluster-info ConfigMap in the
kube-public namespace.
In order to prevent "man in the middle" attacks, several steps are taken:
First, the CA certificate is retrieved via insecure connection (this is possible because
kubeadm init granted access to cluster-info users for system:unauthenticated )
Then the CA certificate goes trough following validation steps:
Basic validation: using the token ID against a JWT signature
Pub key validation: using provided --discovery-token-ca-cert-hash. This value is available
in the output of kubeadm init or can be calculated using standard tools (the hash is
calculated over the bytes of the Subject Public Key Info (SPKI) object as in RFC7469). The
--discovery-token-ca-cert-hash flag may be repeated multiple times to allow more than one public key.
As a additional validation, the CA certificate is retrieved via secure connection and then
compared with the CA retrieved initially
Please note that:
Pub key validation can be skipped passing --discovery-token-unsafe-skip-ca-verification flag;
This weakens the kubeadm security model since others can potentially impersonate the Kubernetes Master.
File/https discovery
If kubeadm join is invoked with --discovery-file, file discovery is used; this file can be a
local file or downloaded via an HTTPS URL; in case of HTTPS, the host installed CA bundle is used
to verify the connection.
With file discovery, the cluster CA certificates is provided into the file itself; in fact, the
discovery file is a kubeconfig file with only server and certificate-authority-data attributes
set, as described in kubeadm join
reference doc; when the connection with the cluster is established, kubeadm try to access the
cluster-info ConfigMap, and if available, uses it.
TLS Bootstrap
Once the cluster info are known, the file bootstrap-kubelet.conf is written, thus allowing
kubelet to do TLS Bootstrapping.
The TLS bootstrap mechanism uses the shared token to temporarily authenticate with the Kubernetes
API server to submit a certificate signing request (CSR) for a locally created key pair.
The request is then automatically approved and the operation completes saving ca.crt file and
kubelet.conf file to be used by kubelet for joining the cluster, whilebootstrap-kubelet.conf
is deleted.
Please note that:
The temporary authentication is validated against the token saved during the kubeadm init
process (or with additional tokens created with kubeadm token)
The temporary authentication resolve to a user member of
system:bootstrappers:kubeadm:default-node-token group which was granted access to CSR api
during the kubeadm init process
The automatic CSR approval is managed by the csrapprover controller, according with
configuration done the kubeadm init process
11 - Command line tool (kubectl)
Kubernetes provides a command line tool for communicating with a Kubernetes cluster's
control plane,
using the Kubernetes API.
This tool is named kubectl.
For configuration, kubectl looks for a file named config in the $HOME/.kube directory.
You can specify other kubeconfig
files by setting the KUBECONFIG environment variable or by setting the
--kubeconfig flag.
This overview covers kubectl syntax, describes the command operations, and provides common examples.
For details about each command, including all the supported flags and subcommands, see the
kubectl reference documentation.
For installation instructions, see Installing kubectl;
for a quick guide, see the cheat sheet.
If you're used to using the docker command-line tool,
kubectl for Docker Users explains some equivalent commands for Kubernetes.
Syntax
Use the following syntax to run kubectl commands from your terminal window:
kubectl [command][TYPE][NAME][flags]
where command, TYPE, NAME, and flags are:
command: Specifies the operation that you want to perform on one or more resources,
for example create, get, describe, delete.
TYPE: Specifies the resource type. Resource types are case-insensitive and
you can specify the singular, plural, or abbreviated forms.
For example, the following commands produce the same output:
kubectl get pod pod1
kubectl get pods pod1
kubectl get po pod1
NAME: Specifies the name of the resource. Names are case-sensitive. If the name is omitted,
details for all resources are displayed, for example kubectl get pods.
When performing an operation on multiple resources, you can specify each resource by
type and name or specify one or more files:
To specify resources by type and name:
To group resources if they are all the same type: TYPE1 name1 name2 name<#>.
Example: kubectl get pod example-pod1 example-pod2
To specify multiple resource types individually: TYPE1/name1 TYPE1/name2 TYPE2/name3 TYPE<#>/name<#>.
Example: kubectl get pod/example-pod1 replicationcontroller/example-rc1
To specify resources with one or more files: -f file1 -f file2 -f file<#>
Use YAML rather than JSON
since YAML tends to be more user-friendly, especially for configuration files.
Example: kubectl get -f ./pod.yaml
flags: Specifies optional flags. For example, you can use the -s or --server flags
to specify the address and port of the Kubernetes API server.
Caution: Flags that you specify from the command line override default values and any corresponding environment variables.
If you need help, run kubectl help from the terminal window.
In-cluster authentication and namespace overrides
By default kubectl will first determine if it is running within a pod, and thus in a cluster.
It starts by checking for the KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT environment
variables and the existence of a service account token file at /var/run/secrets/kubernetes.io/serviceaccount/token.
If all three are found in-cluster authentication is assumed.
To maintain backwards compatibility, if the POD_NAMESPACE environment variable is set
during in-cluster authentication it will override the default namespace from the
service account token. Any manifests or tools relying on namespace defaulting will be affected by this.
POD_NAMESPACE environment variable
If the POD_NAMESPACE environment variable is set, cli operations on namespaced resources
will default to the variable value. For example, if the variable is set to seattle,
kubectl get pods would return pods in the seattle namespace. This is because pods are
a namespaced resource, and no namespace was provided in the command. Review the output
of kubectl api-resources to determine if a resource is namespaced.
Explicit use of --namespace <value> overrides this behavior.
How kubectl handles ServiceAccount tokens
If:
there is Kubernetes service account token file mounted at
/var/run/secrets/kubernetes.io/serviceaccount/token, and
the KUBERNETES_SERVICE_HOST environment variable is set, and
the KUBERNETES_SERVICE_PORT environment variable is set, and
you don't explicitly specify a namespace on the kubectl command line
then kubectl assumes it is running in your cluster. The kubectl tool looks up the
namespace of that ServiceAccount (this is the same as the namespace of the Pod)
and acts against that namespace. This is different from what happens outside of a
cluster; when kubectl runs outside a cluster and you don't specify a namespace,
the kubectl command acts against the namespace set for the current context in your
client configuration. To change the default namespace for your kubectl you can use the
following command:
Get documentation of various resources. For instance pods, nodes, services, etc.
expose
kubectl expose (-f FILENAME | TYPE NAME | TYPE/NAME) [--port=port] [--protocol=TCP|UDP] [--target-port=number-or-name] [--name=name] [--external-ip=external-ip-of-service] [--type=type] [flags]
Expose a replication controller, service, or pod as a new Kubernetes service.
get
kubectl get (-f FILENAME | TYPE [NAME | /NAME | -l label]) [--watch] [--sort-by=FIELD] [[-o | --output]=OUTPUT_FORMAT] [flags]
List one or more resources.
kustomize
kubectl kustomize <dir> [flags] [options]
List a set of API resources generated from instructions in a kustomization.yaml file. The argument must be the path to the directory containing the file, or a git repository URL with a path suffix specifying same with respect to the repository root.
label
kubectl label (-f FILENAME | TYPE NAME | TYPE/NAME) KEY_1=VAL_1 ... KEY_N=VAL_N [--overwrite] [--all] [--resource-version=version] [flags]
Add or update the labels of one or more resources.
logs
kubectl logs POD [-c CONTAINER] [--follow] [flags]
Print the logs for a container in a pod.
options
kubectl options
List of global command-line options, which apply to all commands.
patch
kubectl patch (-f FILENAME | TYPE NAME | TYPE/NAME) --patch PATCH [flags]
Update one or more fields of a resource by using the strategic merge patch process.
plugin
kubectl plugin [flags] [options]
Provides utilities for interacting with plugins.
port-forward
kubectl port-forward POD [LOCAL_PORT:]REMOTE_PORT [...[LOCAL_PORT_N:]REMOTE_PORT_N] [flags]
Experimental: Wait for a specific condition on one or many resources.
To learn more about command operations, see the kubectl reference documentation.
Resource types
The following table includes a list of all the supported resource types and their abbreviated aliases.
(This output can be retrieved from kubectl api-resources, and was accurate as of Kubernetes 1.25.0)
NAME
SHORTNAMES
APIVERSION
NAMESPACED
KIND
bindings
v1
true
Binding
componentstatuses
cs
v1
false
ComponentStatus
configmaps
cm
v1
true
ConfigMap
endpoints
ep
v1
true
Endpoints
events
ev
v1
true
Event
limitranges
limits
v1
true
LimitRange
namespaces
ns
v1
false
Namespace
nodes
no
v1
false
Node
persistentvolumeclaims
pvc
v1
true
PersistentVolumeClaim
persistentvolumes
pv
v1
false
PersistentVolume
pods
po
v1
true
Pod
podtemplates
v1
true
PodTemplate
replicationcontrollers
rc
v1
true
ReplicationController
resourcequotas
quota
v1
true
ResourceQuota
secrets
v1
true
Secret
serviceaccounts
sa
v1
true
ServiceAccount
services
svc
v1
true
Service
mutatingwebhookconfigurations
admissionregistration.k8s.io/v1
false
MutatingWebhookConfiguration
validatingwebhookconfigurations
admissionregistration.k8s.io/v1
false
ValidatingWebhookConfiguration
customresourcedefinitions
crd,crds
apiextensions.k8s.io/v1
false
CustomResourceDefinition
apiservices
apiregistration.k8s.io/v1
false
APIService
controllerrevisions
apps/v1
true
ControllerRevision
daemonsets
ds
apps/v1
true
DaemonSet
deployments
deploy
apps/v1
true
Deployment
replicasets
rs
apps/v1
true
ReplicaSet
statefulsets
sts
apps/v1
true
StatefulSet
tokenreviews
authentication.k8s.io/v1
false
TokenReview
localsubjectaccessreviews
authorization.k8s.io/v1
true
LocalSubjectAccessReview
selfsubjectaccessreviews
authorization.k8s.io/v1
false
SelfSubjectAccessReview
selfsubjectrulesreviews
authorization.k8s.io/v1
false
SelfSubjectRulesReview
subjectaccessreviews
authorization.k8s.io/v1
false
SubjectAccessReview
horizontalpodautoscalers
hpa
autoscaling/v2
true
HorizontalPodAutoscaler
cronjobs
cj
batch/v1
true
CronJob
jobs
batch/v1
true
Job
certificatesigningrequests
csr
certificates.k8s.io/v1
false
CertificateSigningRequest
leases
coordination.k8s.io/v1
true
Lease
endpointslices
discovery.k8s.io/v1
true
EndpointSlice
events
ev
events.k8s.io/v1
true
Event
flowschemas
flowcontrol.apiserver.k8s.io/v1beta2
false
FlowSchema
prioritylevelconfigurations
flowcontrol.apiserver.k8s.io/v1beta2
false
PriorityLevelConfiguration
ingressclasses
networking.k8s.io/v1
false
IngressClass
ingresses
ing
networking.k8s.io/v1
true
Ingress
networkpolicies
netpol
networking.k8s.io/v1
true
NetworkPolicy
runtimeclasses
node.k8s.io/v1
false
RuntimeClass
poddisruptionbudgets
pdb
policy/v1
true
PodDisruptionBudget
podsecuritypolicies
psp
policy/v1beta1
false
PodSecurityPolicy
clusterrolebindings
rbac.authorization.k8s.io/v1
false
ClusterRoleBinding
clusterroles
rbac.authorization.k8s.io/v1
false
ClusterRole
rolebindings
rbac.authorization.k8s.io/v1
true
RoleBinding
roles
rbac.authorization.k8s.io/v1
true
Role
priorityclasses
pc
scheduling.k8s.io/v1
false
PriorityClass
csidrivers
storage.k8s.io/v1
false
CSIDriver
csinodes
storage.k8s.io/v1
false
CSINode
csistoragecapacities
storage.k8s.io/v1
true
CSIStorageCapacity
storageclasses
sc
storage.k8s.io/v1
false
StorageClass
volumeattachments
storage.k8s.io/v1
false
VolumeAttachment
Output options
Use the following sections for information about how you can format or sort the output
of certain commands. For details about which commands support the various output options,
see the kubectl reference documentation.
Formatting output
The default output format for all kubectl commands is the human readable plain-text format.
To output details to your terminal window in a specific format, you can add either the -o
or --output flags to a supported kubectl command.
Syntax
kubectl [command][TYPE][NAME] -o <output_format>
Depending on the kubectl operation, the following output formats are supported:
Output format
Description
-o custom-columns=<spec>
Print a table using a comma separated list of custom columns.
-o custom-columns-file=<filename>
Print a table using the custom columns template in the <filename> file.
-o json
Output a JSON formatted API object.
-o jsonpath=<template>
Print the fields defined in a jsonpath expression.
-o jsonpath-file=<filename>
Print the fields defined by the jsonpath expression in the <filename> file.
-o name
Print only the resource name and nothing else.
-o wide
Output in the plain-text format with any additional information. For pods, the node name is included.
-o yaml
Output a YAML formatted API object.
Example
In this example, the following command outputs the details for a single pod as a YAML formatted object:
kubectl get pod web-pod-13je7 -o yaml
Remember: See the kubectl reference documentation
for details about which output format is supported by each command.
Custom columns
To define custom columns and output only the details that you want into a table, you can use the custom-columns option.
You can choose to define the custom columns inline or use a template file: -o custom-columns=<spec> or -o custom-columns-file=<filename>.
Examples
Inline:
kubectl get pods <pod-name> -o custom-columns=NAME:.metadata.name,RSRC:.metadata.resourceVersion
Template file:
kubectl get pods <pod-name> -o custom-columns-file=template.txt
where the template.txt file contains:
NAME RSRC
metadata.name metadata.resourceVersion
The result of running either command is similar to:
NAME RSRC
submit-queue 610995
Server-side columns
kubectl supports receiving specific column information from the server about objects.
This means that for any given resource, the server will return columns and rows relevant to that resource, for the client to print.
This allows for consistent human-readable output across clients used against the same cluster, by having the server encapsulate the details of printing.
This feature is enabled by default. To disable it, add the
--server-print=false flag to the kubectl get command.
Examples
To print information about the status of a pod, use a command like the following:
kubectl get pods <pod-name> --server-print=false
The output is similar to:
NAME AGE
pod-name 1m
Sorting list objects
To output objects to a sorted list in your terminal window, you can add the --sort-by flag
to a supported kubectl command. Sort your objects by specifying any numeric or string field
with the --sort-by flag. To specify a field, use a jsonpath expression.
Use the following set of examples to help you familiarize yourself with running the commonly used kubectl operations:
kubectl apply - Apply or Update a resource from a file or stdin.
# Create a service using the definition in example-service.yaml.kubectl apply -f example-service.yaml
# Create a replication controller using the definition in example-controller.yaml.kubectl apply -f example-controller.yaml
# Create the objects that are defined in any .yaml, .yml, or .json file within the <directory> directory.kubectl apply -f <directory>
kubectl get - List one or more resources.
# List all pods in plain-text output format.kubectl get pods
# List all pods in plain-text output format and include additional information (such as node name).kubectl get pods -o wide
# List the replication controller with the specified name in plain-text output format. Tip: You can shorten and replace the 'replicationcontroller' resource type with the alias 'rc'.kubectl get replicationcontroller <rc-name>
# List all replication controllers and services together in plain-text output format.kubectl get rc,services
# List all daemon sets in plain-text output format.kubectl get ds
# List all pods running on node server01kubectl get pods --field-selector=spec.nodeName=server01
kubectl describe - Display detailed state of one or more resources, including the uninitialized ones by default.
# Display the details of the node with name <node-name>.kubectl describe nodes <node-name>
# Display the details of the pod with name <pod-name>.kubectl describe pods/<pod-name>
# Display the details of all the pods that are managed by the replication controller named <rc-name>.# Remember: Any pods that are created by the replication controller get prefixed with the name of the replication controller.kubectl describe pods <rc-name>
# Describe all podskubectl describe pods
Note: The kubectl get command is usually used for retrieving one or more
resources of the same resource type. It features a rich set of flags that allows
you to customize the output format using the -o or --output flag, for example.
You can specify the -w or --watch flag to start watching updates to a particular
object. The kubectl describe command is more focused on describing the many
related aspects of a specified resource. It may invoke several API calls to the
API server to build a view for the user. For example, the kubectl describe node
command retrieves not only the information about the node, but also a summary of
the pods running on it, the events generated for the node etc.
kubectl delete - Delete resources either from a file, stdin, or specifying label selectors, names, resource selectors, or resources.
# Delete a pod using the type and name specified in the pod.yaml file.kubectl delete -f pod.yaml
# Delete all the pods and services that have the label '<label-key>=<label-value>'.kubectl delete pods,services -l <label-key>=<label-value>
# Delete all pods, including uninitialized ones.kubectl delete pods --all
kubectl exec - Execute a command against a container in a pod.
# Get output from running 'date' from pod <pod-name>. By default, output is from the first container.kubectl exec <pod-name> -- date
# Get output from running 'date' in container <container-name> of pod <pod-name>.kubectl exec <pod-name> -c <container-name> -- date
# Get an interactive TTY and run /bin/bash from pod <pod-name>. By default, output is from the first container.kubectl exec -ti <pod-name> -- /bin/bash
kubectl logs - Print the logs for a container in a pod.
# Return a snapshot of the logs from pod <pod-name>.kubectl logs <pod-name>
# Start streaming the logs from pod <pod-name>. This is similar to the 'tail -f' Linux command.kubectl logs -f <pod-name>
kubectl diff - View a diff of the proposed updates to a cluster.
# Diff resources included in "pod.json".kubectl diff -f pod.json
# Diff file read from stdin.cat service.yaml | kubectl diff -f -
Examples: Creating and using plugins
Use the following set of examples to help you familiarize yourself with writing and using kubectl plugins:
# create a simple plugin in any language and name the resulting executable file# so that it begins with the prefix "kubectl-"cat ./kubectl-hello
#!/bin/sh
# this plugin prints the words "hello world"echo"hello world"
With a plugin written, let's make it executable:
chmod a+x ./kubectl-hello
# and move it to a location in our PATHsudo mv ./kubectl-hello /usr/local/bin
sudo chown root:root /usr/local/bin
# You have now created and "installed" a kubectl plugin.# You can begin using this plugin by invoking it from kubectl as if it were a regular commandkubectl hello
hello world
# You can "uninstall" a plugin, by removing it from the folder in your# $PATH where you placed itsudo rm /usr/local/bin/kubectl-hello
In order to view all of the plugins that are available to kubectl, use
the kubectl plugin list subcommand:
kubectl plugin list
The output is similar to:
The following kubectl-compatible plugins are available:
/usr/local/bin/kubectl-hello
/usr/local/bin/kubectl-foo
/usr/local/bin/kubectl-bar
kubectl plugin list also warns you about plugins that are not
executable, or that are shadowed by other plugins; for example:
sudo chmod -x /usr/local/bin/kubectl-foo # remove execute permissionkubectl plugin list
The following kubectl-compatible plugins are available:
/usr/local/bin/kubectl-hello
/usr/local/bin/kubectl-foo
- warning: /usr/local/bin/kubectl-foo identified as a plugin, but it is not executable
/usr/local/bin/kubectl-bar
error: one plugin warning was found
You can think of plugins as a means to build more complex functionality on top
of the existing kubectl commands:
cat ./kubectl-whoami
The next few examples assume that you already made kubectl-whoami have
the following contents:
#!/bin/bash
# this plugin makes use of the `kubectl config` command in order to output# information about the current user, based on the currently selected contextkubectl config view --template='{{ range .contexts }}{{ if eq .name "'$(kubectl config current-context)'" }}Current user: {{ printf "%s\n" .context.user }}{{ end }}{{ end }}'
Running the above command gives you an output containing the user for the
current context in your KUBECONFIG file:
# make the file executablesudo chmod +x ./kubectl-whoami
# and move it into your PATHsudo mv ./kubectl-whoami /usr/local/bin
kubectl whoami
Current user: plugins-user
This page contains a list of commonly used kubectl commands and flags.
Note: These instructions are for Kubernetes v1.28. To check the version, use the kubectl version command.
Kubectl autocomplete
BASH
source <(kubectl completion bash)# set up autocomplete in bash into the current shell, bash-completion package should be installed first.echo"source <(kubectl completion bash)" >> ~/.bashrc # add autocomplete permanently to your bash shell.
You can also use a shorthand alias for kubectl that also works with completion:
aliask=kubectl
complete -o default -F __start_kubectl k
ZSH
source <(kubectl completion zsh)# set up autocomplete in zsh into the current shellecho'[[ $commands[kubectl] ]] && source <(kubectl completion zsh)' >> ~/.zshrc # add autocomplete permanently to your zsh shell
FISH
Require kubectl version 1.23 or above.
echo'kubectl completion fish | source' >> ~/.config/fish/config.fish # add kubectl autocompletion permanently to your fish shell
A note on --all-namespaces
Appending --all-namespaces happens frequently enough that you should be aware of the shorthand for --all-namespaces:
kubectl -A
Kubectl context and configuration
Set which Kubernetes cluster kubectl communicates with and modifies configuration
information. See Authenticating Across Clusters with kubeconfig documentation for
detailed config file information.
kubectl config view # Show Merged kubeconfig settings.# use multiple kubeconfig files at the same time and view merged configKUBECONFIG=~/.kube/config:~/.kube/kubconfig2
kubectl config view
# get the password for the e2e userkubectl config view -o jsonpath='{.users[?(@.name == "e2e")].user.password}'kubectl config view -o jsonpath='{.users[].name}'# display the first userkubectl config view -o jsonpath='{.users[*].name}'# get a list of userskubectl config get-contexts # display list of contextskubectl config current-context # display the current-contextkubectl config use-context my-cluster-name # set the default context to my-cluster-namekubectl config set-cluster my-cluster-name # set a cluster entry in the kubeconfig# configure the URL to a proxy server to use for requests made by this client in the kubeconfigkubectl config set-cluster my-cluster-name --proxy-url=my-proxy-url
# add a new user to your kubeconf that supports basic authkubectl config set-credentials kubeuser/foo.kubernetes.com --username=kubeuser --password=kubepassword
# permanently save the namespace for all subsequent kubectl commands in that context.kubectl config set-context --current --namespace=ggckad-s2
# set a context utilizing a specific username and namespace.kubectl config set-context gce --user=cluster-admin --namespace=foo \
&& kubectl config use-context gce
kubectl config unset users.foo # delete user foo# short alias to set/show context/namespace (only works for bash and bash-compatible shells, current context to be set before using kn to set namespace)aliaskx='f() { [ "$1" ] && kubectl config use-context $1 || kubectl config current-context ; } ; f'aliaskn='f() { [ "$1" ] && kubectl config set-context --current --namespace $1 || kubectl config view --minify | grep namespace | cut -d" " -f6 ; } ; f'
Kubectl apply
apply manages applications through files defining Kubernetes resources. It creates and updates resources in a cluster through running kubectl apply. This is the recommended way of managing Kubernetes applications on production. See Kubectl Book.
Creating objects
Kubernetes manifests can be defined in YAML or JSON. The file extension .yaml,
.yml, and .json can be used.
kubectl apply -f ./my-manifest.yaml # create resource(s)kubectl apply -f ./my1.yaml -f ./my2.yaml # create from multiple fileskubectl apply -f ./dir # create resource(s) in all manifest files in dirkubectl apply -f https://git.io/vPieo # create resource(s) from urlkubectl create deployment nginx --image=nginx # start a single instance of nginx# create a Job which prints "Hello World"kubectl create job hello --image=busybox:1.28 -- echo"Hello World"# create a CronJob that prints "Hello World" every minutekubectl create cronjob hello --image=busybox:1.28 --schedule="*/1 * * * *" -- echo"Hello World"kubectl explain pods # get the documentation for pod manifests# Create multiple YAML objects from stdinkubectl apply -f - <<EOF
apiVersion: v1
kind: Pod
metadata:
name: busybox-sleep
spec:
containers:
- name: busybox
image: busybox:1.28
args:
- sleep
- "1000000"
---
apiVersion: v1
kind: Pod
metadata:
name: busybox-sleep-less
spec:
containers:
- name: busybox
image: busybox:1.28
args:
- sleep
- "1000"
EOF# Create a secret with several keyskubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
name: mysecret
type: Opaque
data:
password: $(echo -n "s33msi4" | base64 -w0)
username: $(echo -n "jane" | base64 -w0)
EOF
Viewing and finding resources
# Get commands with basic outputkubectl get services # List all services in the namespacekubectl get pods --all-namespaces # List all pods in all namespaceskubectl get pods -o wide # List all pods in the current namespace, with more detailskubectl get deployment my-dep # List a particular deploymentkubectl get pods # List all pods in the namespacekubectl get pod my-pod -o yaml # Get a pod's YAML# Describe commands with verbose outputkubectl describe nodes my-node
kubectl describe pods my-pod
# List Services Sorted by Namekubectl get services --sort-by=.metadata.name
# List pods Sorted by Restart Countkubectl get pods --sort-by='.status.containerStatuses[0].restartCount'# List PersistentVolumes sorted by capacitykubectl get pv --sort-by=.spec.capacity.storage
# Get the version label of all pods with label app=cassandrakubectl get pods --selector=app=cassandra -o \
jsonpath='{.items[*].metadata.labels.version}'# Retrieve the value of a key with dots, e.g. 'ca.crt'kubectl get configmap myconfig \
-o jsonpath='{.data.ca\.crt}'# Retrieve a base64 encoded value with dashes instead of underscores.kubectl get secret my-secret --template='{{index .data "key-name-with-dashes"}}'# Get all worker nodes (use a selector to exclude results that have a label# named 'node-role.kubernetes.io/control-plane')kubectl get node --selector='!node-role.kubernetes.io/control-plane'# Get all running pods in the namespacekubectl get pods --field-selector=status.phase=Running
# Get ExternalIPs of all nodeskubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="ExternalIP")].address}'# List Names of Pods that belong to Particular RC# "jq" command useful for transformations that are too complex for jsonpath, it can be found at https://jqlang.github.io/jq/sel=${$(kubectl get rc my-rc --output=json | jq -j '.spec.selector | to_entries | .[] | "\(.key)=\(.value),"')%?}echo$(kubectl get pods --selector=$sel --output=jsonpath={.items..metadata.name})# Show labels for all pods (or any other Kubernetes object that supports labelling)kubectl get pods --show-labels
# Check which nodes are readyJSONPATH='{range .items[*]}{@.metadata.name}:{range @.status.conditions[*]}{@.type}={@.status};{end}{end}'\
&& kubectl get nodes -o jsonpath="$JSONPATH" | grep "Ready=True"# Check which nodes are ready with custom-columnskubectl get node -o custom-columns='NODE_NAME:.metadata.name,STATUS:.status.conditions[?(@.type=="Ready")].status'# Output decoded secrets without external toolskubectl get secret my-secret -o go-template='{{range $k,$v := .data}}{{"### "}}{{$k}}{{"\n"}}{{$v|base64decode}}{{"\n\n"}}{{end}}'# List all Secrets currently in use by a podkubectl get pods -o json | jq '.items[].spec.containers[].env[]?.valueFrom.secretKeyRef.name' | grep -v null | sort | uniq
# List all containerIDs of initContainer of all pods# Helpful when cleaning up stopped containers, while avoiding removal of initContainers.kubectl get pods --all-namespaces -o jsonpath='{range .items[*].status.initContainerStatuses[*]}{.containerID}{"\n"}{end}' | cut -d/ -f3
# List Events sorted by timestampkubectl get events --sort-by=.metadata.creationTimestamp
# List all warning eventskubectl events --types=Warning
# Compares the current state of the cluster against the state that the cluster would be in if the manifest was applied.kubectl diff -f ./my-manifest.yaml
# Produce a period-delimited tree of all keys returned for nodes# Helpful when locating a key within a complex nested JSON structurekubectl get nodes -o json | jq -c 'paths|join(".")'# Produce a period-delimited tree of all keys returned for pods, etckubectl get pods -o json | jq -c 'paths|join(".")'# Produce ENV for all pods, assuming you have a default container for the pods, default namespace and the `env` command is supported.# Helpful when running any supported command across all pods, not just `env`for pod in $(kubectl get po --output=jsonpath={.items..metadata.name}); doecho$pod&& kubectl exec -it $pod -- env; done# Get a deployment's status subresourcekubectl get deployment nginx-deployment --subresource=status
Updating resources
kubectl set image deployment/frontend www=image:v2 # Rolling update "www" containers of "frontend" deployment, updating the imagekubectl rollout history deployment/frontend # Check the history of deployments including the revisionkubectl rollout undo deployment/frontend # Rollback to the previous deploymentkubectl rollout undo deployment/frontend --to-revision=2# Rollback to a specific revisionkubectl rollout status -w deployment/frontend # Watch rolling update status of "frontend" deployment until completionkubectl rollout restart deployment/frontend # Rolling restart of the "frontend" deploymentcat pod.json | kubectl replace -f - # Replace a pod based on the JSON passed into stdin# Force replace, delete and then re-create the resource. Will cause a service outage.kubectl replace --force -f ./pod.json
# Create a service for a replicated nginx, which serves on port 80 and connects to the containers on port 8000kubectl expose rc nginx --port=80 --target-port=8000# Update a single-container pod's image version (tag) to v4kubectl get pod mypod -o yaml | sed 's/\(image: myimage\):.*$/\1:v4/' | kubectl replace -f -
kubectl label pods my-pod new-label=awesome # Add a Labelkubectl label pods my-pod new-label- # Remove a labelkubectl label pods my-pod new-label=new-value --overwrite # Overwrite an existing valuekubectl annotate pods my-pod icon-url=http://goo.gl/XXBTWq # Add an annotationkubectl annotate pods my-pod icon- # Remove annotationkubectl autoscale deployment foo --min=2 --max=10# Auto scale a deployment "foo"
Patching resources
# Partially update a nodekubectl patch node k8s-node-1 -p '{"spec":{"unschedulable":true}}'# Update a container's image; spec.containers[*].name is required because it's a merge keykubectl patch pod valid-pod -p '{"spec":{"containers":[{"name":"kubernetes-serve-hostname","image":"new image"}]}}'# Update a container's image using a json patch with positional arrayskubectl patch pod valid-pod --type='json' -p='[{"op": "replace", "path": "/spec/containers/0/image", "value":"new image"}]'# Disable a deployment livenessProbe using a json patch with positional arrayskubectl patch deployment valid-deployment --type json -p='[{"op": "remove", "path": "/spec/template/spec/containers/0/livenessProbe"}]'# Add a new element to a positional arraykubectl patch sa default --type='json' -p='[{"op": "add", "path": "/secrets/1", "value": {"name": "whatever" } }]'# Update a deployment's replica count by patching its scale subresourcekubectl patch deployment nginx-deployment --subresource='scale' --type='merge' -p '{"spec":{"replicas":2}}'
Editing resources
Edit any API resource in your preferred editor.
kubectl edit svc/docker-registry # Edit the service named docker-registryKUBE_EDITOR="nano" kubectl edit svc/docker-registry # Use an alternative editor
Scaling resources
kubectl scale --replicas=3 rs/foo # Scale a replicaset named 'foo' to 3kubectl scale --replicas=3 -f foo.yaml # Scale a resource specified in "foo.yaml" to 3kubectl scale --current-replicas=2 --replicas=3 deployment/mysql # If the deployment named mysql's current size is 2, scale mysql to 3kubectl scale --replicas=5 rc/foo rc/bar rc/baz # Scale multiple replication controllers
Deleting resources
kubectl delete -f ./pod.json # Delete a pod using the type and name specified in pod.jsonkubectl delete pod unwanted --now # Delete a pod with no grace periodkubectl delete pod,service baz foo # Delete pods and services with same names "baz" and "foo"kubectl delete pods,services -l name=myLabel # Delete pods and services with label name=myLabelkubectl -n my-ns delete pod,svc --all # Delete all pods and services in namespace my-ns,# Delete all pods matching the awk pattern1 or pattern2kubectl get pods -n mynamespace --no-headers=true | awk '/pattern1|pattern2/{print $1}' | xargs kubectl delete -n mynamespace pod
Interacting with running Pods
kubectl logs my-pod # dump pod logs (stdout)kubectl logs -l name=myLabel # dump pod logs, with label name=myLabel (stdout)kubectl logs my-pod --previous # dump pod logs (stdout) for a previous instantiation of a containerkubectl logs my-pod -c my-container # dump pod container logs (stdout, multi-container case)kubectl logs -l name=myLabel -c my-container # dump pod logs, with label name=myLabel (stdout)kubectl logs my-pod -c my-container --previous # dump pod container logs (stdout, multi-container case) for a previous instantiation of a containerkubectl logs -f my-pod # stream pod logs (stdout)kubectl logs -f my-pod -c my-container # stream pod container logs (stdout, multi-container case)kubectl logs -f -l name=myLabel --all-containers # stream all pods logs with label name=myLabel (stdout)kubectl run -i --tty busybox --image=busybox:1.28 -- sh # Run pod as interactive shellkubectl run nginx --image=nginx -n mynamespace # Start a single instance of nginx pod in the namespace of mynamespacekubectl run nginx --image=nginx --dry-run=client -o yaml > pod.yaml
# Generate spec for running pod nginx and write it into a file called pod.yamlkubectl attach my-pod -i # Attach to Running Containerkubectl port-forward my-pod 5000:6000 # Listen on port 5000 on the local machine and forward to port 6000 on my-podkubectl exec my-pod -- ls / # Run command in existing pod (1 container case)kubectl exec --stdin --tty my-pod -- /bin/sh # Interactive shell access to a running pod (1 container case)kubectl exec my-pod -c my-container -- ls / # Run command in existing pod (multi-container case)kubectl top pod POD_NAME --containers # Show metrics for a given pod and its containerskubectl top pod POD_NAME --sort-by=cpu # Show metrics for a given pod and sort it by 'cpu' or 'memory'
Copying files and directories to and from containers
kubectl cp /tmp/foo_dir my-pod:/tmp/bar_dir # Copy /tmp/foo_dir local directory to /tmp/bar_dir in a remote pod in the current namespacekubectl cp /tmp/foo my-pod:/tmp/bar -c my-container # Copy /tmp/foo local file to /tmp/bar in a remote pod in a specific containerkubectl cp /tmp/foo my-namespace/my-pod:/tmp/bar # Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace my-namespacekubectl cp my-namespace/my-pod:/tmp/foo /tmp/bar # Copy /tmp/foo from a remote pod to /tmp/bar locally
Note:kubectl cp requires that the 'tar' binary is present in your container image. If 'tar' is not present, kubectl cp will fail.
For advanced use cases, such as symlinks, wildcard expansion or file mode preservation consider using kubectl exec.
tar cf - /tmp/foo | kubectl exec -i -n my-namespace my-pod -- tar xf - -C /tmp/bar # Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace my-namespacekubectl exec -n my-namespace my-pod -- tar cf - /tmp/foo | tar xf - -C /tmp/bar # Copy /tmp/foo from a remote pod to /tmp/bar locally
Interacting with Deployments and Services
kubectl logs deploy/my-deployment # dump Pod logs for a Deployment (single-container case)kubectl logs deploy/my-deployment -c my-container # dump Pod logs for a Deployment (multi-container case)kubectl port-forward svc/my-service 5000# listen on local port 5000 and forward to port 5000 on Service backendkubectl port-forward svc/my-service 5000:my-service-port # listen on local port 5000 and forward to Service target port with name <my-service-port>kubectl port-forward deploy/my-deployment 5000:6000 # listen on local port 5000 and forward to port 6000 on a Pod created by <my-deployment>kubectl exec deploy/my-deployment -- ls # run command in first Pod and first container in Deployment (single- or multi-container cases)
Interacting with Nodes and cluster
kubectl cordon my-node # Mark my-node as unschedulablekubectl drain my-node # Drain my-node in preparation for maintenancekubectl uncordon my-node # Mark my-node as schedulablekubectl top node my-node # Show metrics for a given nodekubectl cluster-info # Display addresses of the master and serviceskubectl cluster-info dump # Dump current cluster state to stdoutkubectl cluster-info dump --output-directory=/path/to/cluster-state # Dump current cluster state to /path/to/cluster-state# View existing taints on which exist on current nodes.kubectl get nodes -o='custom-columns=NodeName:.metadata.name,TaintKey:.spec.taints[*].key,TaintValue:.spec.taints[*].value,TaintEffect:.spec.taints[*].effect'# If a taint with that key and effect already exists, its value is replaced as specified.kubectl taint nodes foo dedicated=special-user:NoSchedule
Resource types
List all supported resource types along with their shortnames, API group, whether they are namespaced, and kind:
kubectl api-resources
Other operations for exploring API resources:
kubectl api-resources --namespaced=true# All namespaced resourceskubectl api-resources --namespaced=false# All non-namespaced resourceskubectl api-resources -o name # All resources with simple output (only the resource name)kubectl api-resources -o wide # All resources with expanded (aka "wide") outputkubectl api-resources --verbs=list,get # All resources that support the "list" and "get" request verbskubectl api-resources --api-group=extensions # All resources in the "extensions" API group
Formatting output
To output details to your terminal window in a specific format, add the -o (or --output) flag to a supported kubectl command.
Output format
Description
-o=custom-columns=<spec>
Print a table using a comma separated list of custom columns
-o=custom-columns-file=<filename>
Print a table using the custom columns template in the <filename> file
Print the fields defined by the jsonpath expression in the <filename> file
-o=name
Print only the resource name and nothing else
-o=wide
Output in the plain-text format with any additional information, and for pods, the node name is included
-o=yaml
Output a YAML formatted API object
Examples using -o=custom-columns:
# All images running in a clusterkubectl get pods -A -o=custom-columns='DATA:spec.containers[*].image'# All images running in namespace: default, grouped by Podkubectl get pods --namespace default --output=custom-columns="NAME:.metadata.name,IMAGE:.spec.containers[*].image"# All images excluding "registry.k8s.io/coredns:1.6.2"kubectl get pods -A -o=custom-columns='DATA:spec.containers[?(@.image!="registry.k8s.io/coredns:1.6.2")].image'# All fields under metadata regardless of namekubectl get pods -A -o=custom-columns='DATA:metadata.*'
Kubectl verbosity is controlled with the -v or --v flags followed by an integer representing the log level. General Kubernetes logging conventions and the associated log levels are described here.
Verbosity
Description
--v=0
Generally useful for this to always be visible to a cluster operator.
--v=1
A reasonable default log level if you don't want verbosity.
--v=2
Useful steady state information about the service and important log messages that may correlate to significant changes in the system. This is the recommended default log level for most systems.
--v=3
Extended information about changes.
--v=4
Debug level verbosity.
--v=5
Trace level verbosity.
--v=6
Display requested resources.
--v=7
Display HTTP request headers.
--v=8
Display HTTP request contents.
--v=9
Display HTTP request contents without truncation of contents.
CIDRs opened in GCE firewall for L4 LB traffic proxy & health checks
--cluster string
The name of the kubeconfig cluster to use
--context string
The name of the kubeconfig context to use
--default-not-ready-toleration-seconds int Default: 300
Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.
--default-unreachable-toleration-seconds int Default: 300
Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.
-h, --help
help for kubectl
--insecure-skip-tls-verify
If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure
--kubeconfig string
Path to the kubeconfig file to use for CLI requests.
--log-backtrace-at traceLocation Default: :0
when logging hits line file:N, emit a stack trace
--log-dir string
If non-empty, write log files in this directory
--log-file string
If non-empty, use this log file
--log-file-max-size uint Default: 1800
Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited.
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes
--logtostderr Default: true
log to standard error instead of files
--match-server-version
Require server version to match client version
-n, --namespace string
If present, the namespace scope for this CLI request
--one-output
If true, only write logs to their native severity level (vs also writing to each lower severity level
--password string
Password for basic authentication to the API server
--profile string Default: "none"
Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)
--profile-output string Default: "profile.pprof"
Name of the file to write the profile to
--request-timeout string Default: "0"
The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.
-s, --server string
The address and port of the Kubernetes API server
--skip-headers
If true, avoid header prefixes in the log messages
--skip-log-headers
If true, avoid headers when opening log files
--stderrthreshold severity Default: 2
logs at or above this threshold go to stderr
--tls-server-name string
Server name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used
--token string
Bearer token for authentication to the API server
--user string
The name of the kubeconfig user to use
--username string
Username for basic authentication to the API server
-v, --v Level
number for the log level verbosity
--version version[=true]
Print version information and quit
--vmodule moduleSpec
comma-separated list of pattern=N settings for file-filtered logging
--warnings-as-errors
Treat warnings received from the server as errors and exit with a non-zero exit code
Environment variables
KUBECONFIG
Path to the kubectl configuration ("kubeconfig") file. Default: "$HOME/.kube/config"
KUBECTL_COMMAND_HEADERS
When set to false, turns off extra HTTP headers detailing invoked kubectl command (Kubernetes version v1.22 or later)
KUBECTL_EXPLAIN_OPENAPIV3
Toggles whether calls to `kubectl explain` use the new OpenAPIv3 data source available. OpenAPIV3 is enabled by default since Kubernetes 1.24.
KUBECTL_ENABLE_CMD_SHADOW
When set to true, external plugins can be used as subcommands for builtin commands if subcommand does not exist. In alpha stage, this feature can only be used for create command(e.g. kubectl create networkpolicy).
KUBECTL_INTERACTIVE_DELETE
When set to true, the --interactive flag in the kubectl delete command will be activated, allowing users to preview and confirm resources before proceeding to delete by passing this flag.
kubectl version - Print the client and server version information
kubectl wait - Experimental: Wait for a specific condition on one or many resources.
11.4 - JSONPath Support
Kubectl supports JSONPath template.
JSONPath template is composed of JSONPath expressions enclosed by curly braces {}.
Kubectl uses JSONPath expressions to filter on specific fields in the JSON object and format the output.
In addition to the original JSONPath template syntax, the following functions and syntax are valid:
Use double quotes to quote text inside JSONPath expressions.
Use the range, end operators to iterate lists.
Use negative slice indices to step backwards through a list. Negative indices do not "wrap around" a list and are valid as long as -index + listLength >= 0.
Note:
The $ operator is optional since the expression always starts from the root object by default.
The result object is printed as its String() function.
kubectl get pods -o json
kubectl get pods -o=jsonpath='{@}'kubectl get pods -o=jsonpath='{.items[0]}'kubectl get pods -o=jsonpath='{.items[0].metadata.name}'kubectl get pods -o=jsonpath="{.items[*]['metadata.name', 'status.capacity']}"kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.status.startTime}{"\n"}{end}'kubectl get pods -o=jsonpath='{.items[0].metadata.labels.kubernetes\.io/hostname}'
Note:
On Windows, you must double quote any JSONPath template that contains spaces (not single quote as shown above for bash). This in turn means that you must use a single quote or escaped double quote around any literals in the template. For example:
kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.name}{'\t'}{.status.startTime}{'\n'}{end}"kubectl get pods -o=jsonpath="{range .items[*]}{.metadata.name}{\"\t\"}{.status.startTime}{\"\n\"}{end}"
Note:
JSONPath regular expressions are not supported. If you want to match using regular expressions, you can use a tool such as jq.
# kubectl does not support regular expressions for JSONpath output# The following command does not workkubectl get pods -o jsonpath='{.items[?(@.metadata.name=~/^test$/)].metadata.name}'# The following command achieves the desired resultkubectl get pods -o json | jq -r '.items[] | select(.metadata.name | test("test-")).metadata.name'
11.5 - kubectl for Docker Users
You can use the Kubernetes command line tool kubectl to interact with the API Server. Using kubectl is straightforward if you are familiar with the Docker command line tool. However, there are a few differences between the Docker commands and the kubectl commands. The following sections show a Docker sub-command and describe the equivalent kubectl command.
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
55c103fa1296 nginx "nginx -g 'daemon of…" 9 seconds ago Up 9 seconds 0.0.0.0:80->80/tcp nginx-app
kubectl:
# start the pod running nginxkubectl create deployment --image=nginx nginx-app
deployment.apps/nginx-app created
# add env to nginx-appkubectl set env deployment/nginx-app DOMAIN=cluster
deployment.apps/nginx-app env updated
Note:kubectl commands print the type and name of the resource created or mutated, which can then be used in subsequent commands. You can expose a new Service after a Deployment is created.
# expose a port through with a servicekubectl expose deployment nginx-app --port=80 --name=nginx-http
service "nginx-http" exposed
By using kubectl, you can create a Deployment to ensure that N pods are running nginx, where N is the number of replicas stated in the spec and defaults to 1. You can also create a service with a selector that matches the pod labels. For more information, see Use a Service to Access an Application in a Cluster.
By default images run in the background, similar to docker run -d .... To run things in the foreground, use kubectl run to create pod:
kubectl run [-i][--tty] --attach <name> --image=<image>
Unlike docker run ..., if you specify --attach, then you attach stdin, stdout and stderr. You cannot control which streams are attached (docker -a ...).
To detach from the container, you can type the escape sequence Ctrl+P followed by Ctrl+Q.
docker ps
To list what is currently running, see kubectl get.
docker:
docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
14636241935f ubuntu:16.04 "echo test" 5 seconds ago Exited (0) 5 seconds ago cocky_fermi
55c103fa1296 nginx "nginx -g 'daemon of…" About a minute ago Up About a minute 0.0.0.0:80->80/tcp nginx-app
kubectl:
kubectl get po
NAME READY STATUS RESTARTS AGE
nginx-app-8df569cb7-4gd89 1/1 Running 0 3m
ubuntu 0/1 Completed 0 20s
docker attach
To attach a process that is already running in a container, see kubectl attach.
docker:
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
55c103fa1296 nginx "nginx -g 'daemon of…" 5 minutes ago Up 5 minutes 0.0.0.0:80->80/tcp nginx-app
docker attach 55c103fa1296
...
kubectl:
kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-app-5jyvm 1/1 Running 0 10m
kubectl attach -it nginx-app-5jyvm
...
To detach from the container, you can type the escape sequence Ctrl+P followed by Ctrl+Q.
docker exec
To execute a command in a container, see kubectl exec.
docker:
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
55c103fa1296 nginx "nginx -g 'daemon of…" 6 minutes ago Up 6 minutes 0.0.0.0:80->80/tcp nginx-app
docker exec 55c103fa1296 cat /etc/hostname
55c103fa1296
kubectl:
kubectl get po
NAME READY STATUS RESTARTS AGE
nginx-app-5jyvm 1/1 Running 0 10m
There is a slight difference between pods and containers; by default pods do not terminate if their processes exit. Instead the pods restart the process. This is similar to the docker run option --restart=always with one major difference. In docker, the output for each invocation of the process is concatenated, but for Kubernetes, each invocation is separate. To see the output from a previous run in Kubernetes, do this:
To stop and delete a running process, see kubectl delete.
docker:
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a9ec34d98787 nginx "nginx -g 'daemon of" 22 hours ago Up 22 hours 0.0.0.0:80->80/tcp, 443/tcp nginx-app
docker stop a9ec34d98787
a9ec34d98787
docker rm a9ec34d98787
a9ec34d98787
kubectl:
kubectl get deployment nginx-app
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-app 1/1 1 1 2m
kubectl get po -l app=nginx-app
NAME READY STATUS RESTARTS AGE
nginx-app-2883164633-aklf7 1/1 Running 0 2m
kubectl delete deployment nginx-app
deployment "nginx-app" deleted
kubectl get po -l app=nginx-app
# Return nothing
Note: When you use kubectl, you don't delete the pod directly. You have to first delete the Deployment that owns the pod. If you delete the pod directly, the Deployment recreates the pod.
docker login
There is no direct analog of docker login in kubectl. If you are interested in using Kubernetes with a private registry, see Using a Private Registry.
docker version
To get the version of client and server, see kubectl version.
docker:
docker version
Client version: 1.7.0
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 0baf609
OS/Arch (client): linux/amd64
Server version: 1.7.0
Server API version: 1.19
Go version (server): go1.4.2
Git commit (server): 0baf609
OS/Arch (server): linux/amd64
Kubernetes master is running at https://203.0.113.141
KubeDNS is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/kube-dns/proxy
kubernetes-dashboard is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
Grafana is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
Heapster is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-heapster/proxy
InfluxDB is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
11.6 - kubectl Usage Conventions
Recommended usage conventions for kubectl.
Using kubectl in Reusable Scripts
For a stable output in a script:
Request one of the machine-oriented output forms, such as -o name, -o json, -o yaml, -o go-template, or -o jsonpath.
Fully-qualify the version. For example, jobs.v1.batch/myjob. This will ensure that kubectl does not use its default version that can change over time.
Don't rely on context, preferences, or other implicit states.
Subresources
You can use the --subresource beta flag for kubectl commands like get, patch,
edit and replace to fetch and update subresources for all resources that
support them. Currently, only the status and scale subresources are supported.
For kubectl edit, the scale subresource is not supported. If you use --subresource with
kubectl edit and specify scale as the subresource, the command will error out.
The API contract against a subresource is identical to a full resource. While updating the
status subresource to a new value, keep in mind that the subresource could be potentially
reconciled by a controller to a different value.
Best Practices
kubectl run
For kubectl run to satisfy infrastructure as code:
Tag the image with a version-specific tag and don't move that tag to a new version. For example, use :v1234, v1.2.3, r03062016-1-4, rather than :latest (For more information, see Best Practices for Configuration).
Check in the script for an image that is heavily parameterized.
Switch to configuration files checked into source control for features that are needed, but not expressible via kubectl run flags.
You can use the --dry-run=client flag to preview the object that would be sent to your cluster, without really submitting it.
kubectl apply
You can use kubectl apply to create or update resources. For more information about using kubectl apply to update resources, see Kubectl Book.
12 - Component tools
12.1 - Feature Gates
This page contains an overview of the various feature gates an administrator
can specify on different Kubernetes components.
See feature stages for an explanation of the stages for a feature.
Overview
Feature gates are a set of key=value pairs that describe Kubernetes features.
You can turn these features on or off using the --feature-gates command line flag
on each Kubernetes component.
Each Kubernetes component lets you enable or disable a set of feature gates that
are relevant to that component.
Use -h flag to see a full set of feature gates for all components.
To set feature gates for a component, such as kubelet, use the --feature-gates
flag assigned to a list of feature pairs:
--feature-gates=...,GracefulNodeShutdown=true
The following tables are a summary of the feature gates that you can set on
different Kubernetes components.
The "Since" column contains the Kubernetes release when a feature is introduced
or its release stage is changed.
The "Until" column, if not empty, contains the last Kubernetes release in which
you can still use a feature gate.
The feature is well tested. Enabling the feature is considered safe.
Support for the overall feature will not be dropped, though details may change.
The schema and/or semantics of objects may change in incompatible ways in a
subsequent beta or stable release. When this happens, we will provide instructions
for migrating to the next version. This may require deleting, editing, and
re-creating API objects. The editing process may require some thought.
This may require downtime for applications that rely on the feature.
Recommended for only non-business-critical uses because of potential for
incompatible changes in subsequent releases. If you have multiple clusters
that can be upgraded independently, you may be able to relax this restriction.
Note: Please do try Beta features and give feedback on them!
After they exit beta, it may not be practical for us to make more changes.
A General Availability (GA) feature is also referred to as a stable feature. It means:
The feature is always enabled; you cannot disable it.
The corresponding feature gate is no longer needed.
Stable versions of features will appear in released software for many subsequent versions.
List of feature gates
Each feature gate is designed for enabling/disabling a specific feature:
AdmissionWebhookMatchConditions: Enable match conditions
on mutating & validating admission webhooks.
APIListChunking: Enable the API clients to retrieve (LIST or GET)
resources from API server in chunks.
APIPriorityAndFairness: Enable managing request concurrency with
prioritization and fairness at each server. (Renamed from RequestManagement)
APIResponseCompression: Compress the API responses for LIST or GET requests.
AggregatedDiscoveryEndpoint: Enable a single HTTP endpoint /discovery/<version> which
supports native HTTP caching with ETags containing all APIResources known to the API server.
AnyVolumeDataSource: Enable use of any custom resource as the DataSource of a
PVC.
AppArmor: Enable use of AppArmor mandatory access control for Pods running on Linux nodes.
See AppArmor Tutorial for more details.
CPUManagerPolicyAlphaOptions: This allows fine-tuning of CPUManager policies,
experimental, Alpha-quality options.
This feature gate guards a group of CPUManager options whose quality level is alpha.
This feature gate will never graduate to beta or stable.
CPUManagerPolicyBetaOptions: This allows fine-tuning of CPUManager policies,
experimental, Beta-quality options.
This feature gate guards a group of CPUManager options whose quality level is beta.
This feature gate will never graduate to stable.
CPUManagerPolicyOptions: Allow fine-tuning of CPUManager policies.
CSIMigrationAzureFile: Enables shims and translation logic to route volume
operations from the Azure-File in-tree plugin to AzureFile CSI plugin.
Supports falling back to in-tree AzureFile plugin for mount operations to
nodes that have the feature disabled or that do not have AzureFile CSI plugin
installed and configured. Does not support falling back for provision
operations, for those the CSI plugin must be installed and configured.
Requires CSIMigration feature flag enabled.
CSIMigrationRBD: Enables shims and translation logic to route volume
operations from the RBD in-tree plugin to Ceph RBD CSI plugin. Requires
CSIMigration and csiMigrationRBD feature flags enabled and Ceph CSI plugin
installed and configured in the cluster. This flag has been deprecated in
favor of the InTreePluginRBDUnregister feature flag which prevents the registration of
in-tree RBD plugin.
CSIMigrationvSphere: Enables shims and translation logic to route volume operations
from the vSphere in-tree plugin to vSphere CSI plugin. Supports falling back
to in-tree vSphere plugin for mount operations to nodes that have the feature
disabled or that do not have vSphere CSI plugin installed and configured.
Does not support falling back for provision operations, for those the CSI
plugin must be installed and configured. Requires CSIMigration feature flag
enabled.
CSIMigrationPortworx: Enables shims and translation logic to route volume operations
from the Portworx in-tree plugin to Portworx CSI plugin.
Requires Portworx CSI driver to be installed and configured in the cluster.
CSINodeExpandSecret: Enable passing secret authentication data to a CSI driver for use
during a NodeExpandVolume CSI operation.
CSIVolumeHealth: Enable support for CSI volume health monitoring on node.
CloudControllerManagerWebhook: Enable webhooks in cloud controller manager.
CloudDualStackNodeIPs: Enables dual-stack kubelet --node-ip with external cloud providers.
See Configure IPv4/IPv6 dual-stack
for more details.
ClusterTrustBundle: Enable ClusterTrustBundle objects and kubelet integration.
ComponentSLIs: Enable the /metrics/slis endpoint on Kubernetes components like
kubelet, kube-scheduler, kube-proxy, kube-controller-manager, cloud-controller-manager
allowing you to scrape health check metrics.
ConsistentHTTPGetHandlers: Normalize HTTP get URL and Header passing for lifecycle
handlers with probers.
ConsistentListFromCache: Allow the API server to serve consistent lists from cache.
ContainerCheckpoint: Enables the kubelet checkpoint API.
See Kubelet Checkpoint API for more details.
ContextualLogging: When you enable this feature gate, Kubernetes components that support
contextual logging add extra detail to log output.
CronJobsScheduledAnnotation: Set the scheduled job time as an
annotation on Jobs that were created
on behalf of a CronJob.
CronJobTimeZone: Allow the use of the timeZone optional field in CronJobs.
CRDValidationRatcheting: Enable updates to custom resources to contain
violations of their OpenAPI schema if the offending portions of the resource
update did not change. See Validation Ratcheting
for more details.
CrossNamespaceVolumeDataSource: Enable the usage of cross namespace volume data source
to allow you to specify a source namespace in the dataSourceRef field of a
PersistentVolumeClaim.
CustomCPUCFSQuotaPeriod: Enable nodes to change cpuCFSQuotaPeriod in
kubelet config.
CustomResourceValidationExpressions: Enable expression language validation in CRD
which will validate customer resource based on validation rules written in
the x-kubernetes-validations extension.
DefaultHostNetworkHostPortsInPodTemplates: Changes when the default value of
PodSpec.containers[*].ports[*].hostPort
is assigned. The default is to only set a default value in Pods.
Enabling this means a default will be assigned even to embedded
PodSpecs (e.g. in a Deployment), which is the historical default.
DevicePluginCDIDevices: Enable support to CDI device IDs in the
Device Plugin API.
DisableCloudProviders: Disables any functionality in kube-apiserver,
kube-controller-manager and kubelet related to the --cloud-provider
component flag.
DisableKubeletCloudCredentialProviders: Disable the in-tree functionality in kubelet
to authenticate to a cloud provider container registry for image pull credentials.
DownwardAPIHugePages: Enables usage of hugepages in
downward API.
DynamicResourceAllocation: Enables support for resources with custom parameters and a lifecycle
that is independent of a Pod.
ElasticIndexedJob: Enables Indexed Jobs to be scaled up or down by mutating both
spec.completions and spec.parallelism together such that spec.completions == spec.parallelism.
See docs on elastic Indexed Jobs
for more details.
EfficientWatchResumption: Allows for storage-originated bookmark (progress
notify) events to be delivered to the users. This is only applied to watch operations.
EventedPLEG: Enable support for the kubelet to receive container life cycle events from the
container runtime via
an extension to CRI.
(PLEG is an abbreviation for “Pod lifecycle event generator”).
For this feature to be useful, you also need to enable support for container lifecycle events
in each container runtime running in your cluster. If the container runtime does not announce
support for container lifecycle events then the kubelet automatically switches to the legacy
generic PLEG mechanism, even if you have this feature gate enabled.
ExecProbeTimeout: Ensure kubelet respects exec probe timeouts.
This feature gate exists in case any of your existing workloads depend on a
now-corrected fault where Kubernetes ignored exec probe timeouts. See
readiness probes.
ExpandedDNSConfig: Enable kubelet and kube-apiserver to allow more DNS
search paths and longer list of DNS search paths. This feature requires container
runtime support (containerd: v1.5.6 or higher, CRI-O: v1.22 or higher). See
Expanded DNS Configuration.
ExperimentalHostUserNamespaceDefaulting: Enabling the defaulting user
namespace to host. This is for containers that are using other host namespaces,
host mounts, or containers that are privileged or using specific non-namespaced
capabilities (e.g. MKNODE, SYS_MODULE etc.). This should only be enabled
if user namespace remapping is enabled in the Docker daemon.
GracefulNodeShutdown: Enables support for graceful shutdown in kubelet.
During a system shutdown, kubelet will attempt to detect the shutdown event
and gracefully terminate pods running on the node. See
Graceful Node Shutdown
for more details.
GracefulNodeShutdownBasedOnPodPriority: Enables the kubelet to check Pod priorities
when shutting down a node gracefully.
HonorPVReclaimPolicy: Honor persistent volume reclaim policy when it is Delete irrespective of PV-PVC deletion ordering.
For more details, check the
PersistentVolume deletion protection finalizer
documentation.
HPAContainerMetrics: Enable the HorizontalPodAutoscaler to scale based on
metrics from individual containers in target pods.
HPAScaleToZero: Enables setting minReplicas to 0 for HorizontalPodAutoscaler
resources when using custom or external metrics.
IPTablesOwnershipCleanup: This causes kubelet to no longer create legacy iptables rules.
InPlacePodVerticalScaling: Enables in-place Pod vertical scaling.
InTreePluginAWSUnregister: Stops registering the aws-ebs in-tree plugin in kubelet
and volume controllers.
InTreePluginAzureDiskUnregister: Stops registering the azuredisk in-tree plugin in kubelet
and volume controllers.
InTreePluginAzureFileUnregister: Stops registering the azurefile in-tree plugin in kubelet
and volume controllers.
InTreePluginGCEUnregister: Stops registering the gce-pd in-tree plugin in kubelet
and volume controllers.
InTreePluginOpenStackUnregister: Stops registering the OpenStack cinder in-tree plugin in kubelet
and volume controllers.
InTreePluginPortworxUnregister: Stops registering the Portworx in-tree plugin in kubelet
and volume controllers.
InTreePluginRBDUnregister: Stops registering the RBD in-tree plugin in kubelet
and volume controllers.
InTreePluginvSphereUnregister: Stops registering the vSphere in-tree plugin in kubelet
and volume controllers.
JobMutableNodeSchedulingDirectives: Allows updating node scheduling directives in
the pod template of Job.
JobBackoffLimitPerIndex: Allows specifying the maximal number of pod
retries per index in Indexed jobs.
JobPodFailurePolicy: Allow users to specify handling of pod failures based on container
exit codes and pod conditions.
JobPodReplacementPolicy: Allows you to specify pod replacement for terminating pods in a
Job.
JobReadyPods: Enables tracking the number of Pods that have a Readycondition.
The count of Ready pods is recorded in the
status
of a Job status.
JobTrackingWithFinalizers: Enables tracking Job
completions without relying on Pods remaining in the cluster indefinitely.
The Job controller uses Pod finalizers and a field in the Job status to keep
track of the finished Pods to count towards completion.
KMSv2KDF: Enables KMS v2 to generate single use data encryption keys.
See Using a KMS Provider for data encryption
for more details. If the KMSv2 feature gate is not enabled in your cluster, the value of
the KMSv2KDF feature gate has no effect.
KubeProxyDrainingTerminatingNodes: Implement connection draining for
terminating nodes for externalTrafficPolicy: Cluster services.
KubeletCgroupDriverFromCRI: Enable detection of the kubelet cgroup driver
configuration option from the CRI.
You can use this feature gate on nodes with a kubelet that supports the feature gate
and where there is a CRI container runtime that supports the RuntimeConfig
CRI call. If both CRI and kubelet support this feature, the kubelet ignores the
cgroupDriver configuration setting (or deprecated --cgroup-driver command
line argument). If you enable this feature gate and the container runtime
doesn't support it, the kubelet falls back to using the driver configured using
the cgroupDriver configuration setting.
See Configuring a cgroup driver
for more details.
KubeletPodResources: Enable the kubelet's pod resources gRPC endpoint. See
Support Device Monitoring
for more details.
KubeletPodResourcesGet: Enable the Get gRPC endpoint on kubelet's for Pod resources.
This API augments the resource allocation reporting.
KubeletPodResourcesGetAllocatable: Enable the kubelet's pod resources
GetAllocatableResources functionality. This API augments the
resource allocation reporting.
KubeletPodResourcesDynamicResources: Extend the kubelet's pod resources gRPC endpoint
to include resources allocated in ResourceClaims via DynamicResourceAllocation API.
See resource allocation reporting
for more details. with informations about the allocatable resources, enabling clients to properly
track the free compute resources on a node.
KubeletTracing: Add support for distributed tracing in the kubelet.
When enabled, kubelet CRI interface and authenticated http servers are instrumented to generate
OpenTelemetry trace spans.
See Traces for Kubernetes System Components
for more details.
LegacyServiceAccountTokenNoAutoGeneration: Stop auto-generation of Secret-based
service account tokens.
LegacyServiceAccountTokenCleanUp: Enable cleaning up Secret-based
service account tokens
when they are not used in a specified time (default to be one year).
LocalStorageCapacityIsolationFSQuotaMonitoring: When LocalStorageCapacityIsolation
is enabled for
local ephemeral storage
and the backing filesystem for emptyDir volumes
supports project quotas and they are enabled, use project quotas to monitor
emptyDir volume storage consumption rather than
filesystem walk for better performance and accuracy.
LogarithmicScaleDown: Enable semi-random selection of pods to evict on controller scaledown
based on logarithmic bucketing of pod timestamps.
LoggingAlphaOptions: Allow fine-tuing of experimental, alpha-quality logging options.
LoggingBetaOptions: Allow fine-tuing of experimental, beta-quality logging options.
MaxUnavailableStatefulSet: Enables setting the maxUnavailable field for the
rolling update strategy
of a StatefulSet. The field specifies the maximum number of Pods
that can be unavailable during the update.
MemoryManager: Allows setting memory affinity for a container based on
NUMA topology.
MemoryQoS: Enable memory protection and usage throttle on pod / container using
cgroup v2 memory controller.
MinimizeIPTablesRestore: Enables new performance improvement logics
in the kube-proxy iptables mode.
MultiCIDRRangeAllocator: Enables the MultiCIDR range allocator.
MultiCIDRServiceAllocator: Track IP address allocations for Service cluster IPs using IPAddress objects.
NewVolumeManagerReconstruction: Enables improved discovery of mounted volumes during kubelet
startup. Since this code has been significantly refactored, we allow to opt-out in case kubelet
gets stuck at the startup or is not unmounting volumes from terminated Pods. Note that this
refactoring was behind SELinuxMountReadWriteOncePod alpha feature gate in Kubernetes 1.25.
Before Kubernetes v1.25, the kubelet used different default behavior for discovering mounted
volumes during the kubelet startup. If you disable this feature gate (it's enabled by default), you select
the legacy discovery behavior.
In Kubernetes v1.25 and v1.26, this behavior toggle was part of the SELinuxMountReadWriteOncePod
feature gate.
NodeInclusionPolicyInPodTopologySpread: Enable using nodeAffinityPolicy and nodeTaintsPolicy in
Pod topology spread constraints
when calculating pod topology spread skew.
NodeLogQuery: Enables querying logs of node services using the /logs endpoint.
NodeOutOfServiceVolumeDetach: When a Node is marked out-of-service using the
node.kubernetes.io/out-of-service taint, Pods on the node will be forcefully deleted
if they can not tolerate this taint, and the volume detach operations for Pods terminating
on the node will happen immediately. The deleted Pods can recover quickly on different nodes.
NodeSwap: Enable the kubelet to allocate swap memory for Kubernetes workloads on a node.
Must be used with KubeletConfiguration.failSwapOn set to false.
For more details, please see swap memory.
OpenAPIEnums: Enables populating "enum" fields of OpenAPI schemas in the
spec returned from the API server.
OpenAPIV3: Enables the API server to publish OpenAPI v3.
PDBUnhealthyPodEvictionPolicy: Enables the unhealthyPodEvictionPolicy field of a PodDisruptionBudget.
This specifies when unhealthy pods should be considered for eviction. Please see
Unhealthy Pod Eviction Policy
for more details.
PersistentVolumeLastPhaseTransitionTime: Adds a new field to PersistentVolume
which holds a timestamp of when the volume last transitioned its phase.
PodAndContainerStatsFromCRI: Configure the kubelet to gather container and pod stats from the
CRI container runtime rather than gathering them from cAdvisor. As of 1.26, this also includes
gathering metrics from CRI and emitting them over /metrics/cadvisor (rather than having cAdvisor emit them directly).
PodDeletionCost: Enable the Pod Deletion Cost
feature which allows users to influence ReplicaSet downscaling order.
PodDisruptionConditions: Enables support for appending a dedicated pod condition indicating that
the pod is being deleted due to a disruption.
PodHostIPs: Enable the status.hostIPs field for pods and the downward API.
The field lets you expose host IP addresses to workloads.
PodReadyToStartContainersCondition: Enable the kubelet to mark the PodReadyToStartContainers
condition on pods. This was previously (1.25-1.27) known as PodHasNetworkCondition.
PodSchedulingReadiness: Enable setting schedulingGates field to control a Pod's
scheduling readiness.
ProcMountType: Enables control over the type proc mounts for containers
by setting the procMount field of a SecurityContext.
ProxyTerminatingEndpoints: Enable the kube-proxy to handle terminating
endpoints when ExternalTrafficPolicy=Local.
QOSReserved: Allows resource reservations at the QoS level preventing pods
at lower QoS levels from bursting into resources requested at higher QoS levels
(memory only for now).
ReadWriteOncePod: Enables the usage of ReadWriteOncePod PersistentVolume
access mode.
RecoverVolumeExpansionFailure: Enables users to edit their PVCs to smaller
sizes so as they can recover from previously issued volume expansion failures.
See Recovering from Failure when Expanding Volumes
for more details.
RemainingItemCount: Allow the API servers to show a count of remaining
items in the response to a
chunking list request.
RemoveSelfLink: Sets the .metadata.selfLink field to blank (empty string) for all
objects and collections. This field has been deprecated since the Kubernetes v1.16
release. When this feature is enabled, the .metadata.selfLink field remains part of
the Kubernetes API, but is always unset.
RetroactiveDefaultStorageClass: Allow assigning StorageClass to unbound PVCs retroactively.
RotateKubeletServerCertificate: Enable the rotation of the server TLS certificate on the kubelet.
See kubelet configuration
for more details.
SELinuxMountReadWriteOncePod: Speeds up container startup by allowing kubelet to mount volumes
for a Pod directly with the correct SELinux label instead of changing each file on the volumes
recursively. The initial implementation focused on ReadWriteOncePod volumes.
SchedulerQueueingHints: Enables the scheduler's queueing hints enhancement,
which benefits to reduce the useless requeueing.
The scheduler retries scheduling pods if something changes in the cluster that could make the pod scheduled.
Queueing hints are internal signals that allow the scheduler to filter the changes in the cluster
that are relevant to the unscheduled pod, based on previous scheduling attempts.
SeccompDefault: Enables the use of RuntimeDefault as the default seccomp profile
for all workloads.
The seccomp profile is specified in the securityContext of a Pod and/or a Container.
SecurityContextDeny: This gate signals that the SecurityContextDeny admission controller is deprecated.
ServerSideFieldValidation: Enables server-side field validation. This means the validation
of resource schema is performed at the API server side rather than the client side
(for example, the kubectl create or kubectl apply command line).
ServiceNodePortStaticSubrange: Enables the use of different port allocation
strategies for NodePort Services. For more details, see
reserve NodePort ranges to avoid collisions.
SidecarContainers: Allow setting the restartPolicy of an init container to
Always so that the container becomes a sidecar container (restartable init containers).
See Sidecar containers and restartPolicy
for more details.
SizeMemoryBackedVolumes: Enable kubelets to determine the size limit for
memory-backed volumes (mainly emptyDir volumes).
SkipReadOnlyValidationGCE: Skip validation for GCE, will enable in the
next version.
StableLoadBalancerNodeSet: Enables less load balancer re-configurations by
the service controller (KCCM) as an effect of changing node state.
StatefulSetStartOrdinal: Allow configuration of the start ordinal in a
StatefulSet. See
Start ordinal
for more details.
StorageVersionHash: Allow API servers to expose the storage version hash in the
discovery.
TopologyAwareHints: Enables topology aware routing based on topology hints
in EndpointSlices. See Topology Aware Hints
for more details.
TopologyManager: Enable a mechanism to coordinate fine-grained hardware resource
assignments for different components in Kubernetes. See
Control Topology Management Policies on a node.
TopologyManagerPolicyAlphaOptions: Allow fine-tuning of topology manager policies,
experimental, Alpha-quality options.
This feature gate guards a group of topology manager options whose quality level is alpha.
This feature gate will never graduate to beta or stable.
TopologyManagerPolicyBetaOptions: Allow fine-tuning of topology manager policies,
experimental, Beta-quality options.
This feature gate guards a group of topology manager options whose quality level is beta.
This feature gate will never graduate to stable.
TopologyManagerPolicyOptions: Allow fine-tuning of topology manager policies,
UnknownVersionInteroperabilityProxy: Proxy resource requests to the correct peer kube-apiserver when
multiple kube-apiservers exist at varied versions.
See Mixed version proxy for more information.
UserNamespacesSupport: Enable user namespace support for Pods.
Before Kubernetes v1.28, this feature gate was named UserNamespacesStatelessPodsSupport.
ValidatingAdmissionPolicy: Enable ValidatingAdmissionPolicy
support for CEL validations be used in Admission Control.
VolumeCapacityPriority: Enable support for prioritizing nodes in different
topologies based on available PV capacity.
WatchBookmark: Enable support for watch bookmark events.
WinDSR: Allows kube-proxy to create DSR loadbalancers for Windows.
WinOverlay: Allows kube-proxy to run in overlay mode for Windows.
WindowsHostNetwork: Enables support for joining Windows containers to a hosts' network namespace.
What's next
The deprecation policy for Kubernetes explains
the project's approach to removing features and components.
Since Kubernetes 1.24, new beta APIs are not enabled by default. When enabling a beta
feature, you will also need to enable any associated API resources.
For example, to enable a particular resource like
storage.k8s.io/v1beta1/csistoragecapacities, set --runtime-config=storage.k8s.io/v1beta1/csistoragecapacities.
See API Versioning for more details on the command line flags.
12.2 - Feature Gates (removed)
This page contains list of feature gates that have been removed. The information on this page is for reference.
A removed feature gate is different from a GA'ed or deprecated one in that a removed one is
no longer recognized as a valid feature gate.
However, a GA'ed or a deprecated feature gate is still recognized by the corresponding Kubernetes
components although they are unable to cause any behavior differences in a cluster.
The "From" column contains the Kubernetes release when a feature is introduced
or its release stage is changed.
The "To" column, if not empty, contains the last Kubernetes release in which
you can still use a feature gate. If the feature stage is either "Deprecated"
or "GA", the "To" column is the Kubernetes release when the feature is removed.
Feature Gates Removed
Feature
Default
Stage
From
To
Accelerators
false
Alpha
1.6
1.10
Accelerators
-
Deprecated
1.11
1.11
AdvancedAuditing
false
Alpha
1.7
1.7
AdvancedAuditing
true
Beta
1.8
1.11
AdvancedAuditing
true
GA
1.12
1.27
AffinityInAnnotations
false
Alpha
1.6
1.7
AffinityInAnnotations
-
Deprecated
1.8
1.8
AllowExtTrafficLocalEndpoints
false
Beta
1.4
1.6
AllowExtTrafficLocalEndpoints
true
GA
1.7
1.9
AllowInsecureBackendProxy
true
Beta
1.17
1.20
AllowInsecureBackendProxy
true
GA
1.21
1.25
AttachVolumeLimit
false
Alpha
1.11
1.11
AttachVolumeLimit
true
Beta
1.12
1.16
AttachVolumeLimit
true
GA
1.17
1.21
BalanceAttachedNodeVolumes
false
Alpha
1.11
1.21
BalanceAttachedNodeVolumes
false
Deprecated
1.22
1.22
BlockVolume
false
Alpha
1.9
1.12
BlockVolume
true
Beta
1.13
1.17
BlockVolume
true
GA
1.18
1.21
BoundServiceAccountTokenVolume
false
Alpha
1.13
1.20
BoundServiceAccountTokenVolume
true
Beta
1.21
1.21
BoundServiceAccountTokenVolume
true
GA
1.22
1.23
CRIContainerLogRotation
false
Alpha
1.10
1.10
CRIContainerLogRotation
true
Beta
1.11
1.20
CRIContainerLogRotation
true
GA
1.21
1.22
CSIBlockVolume
false
Alpha
1.11
1.13
CSIBlockVolume
true
Beta
1.14
1.17
CSIBlockVolume
true
GA
1.18
1.21
CSIDriverRegistry
false
Alpha
1.12
1.13
CSIDriverRegistry
true
Beta
1.14
1.17
CSIDriverRegistry
true
GA
1.18
1.21
CSIInlineVolume
false
Alpha
1.15
1.15
CSIInlineVolume
true
Beta
1.16
1.24
CSIInlineVolume
true
GA
1.25
1.26
CSIMigration
false
Alpha
1.14
1.16
CSIMigration
true
Beta
1.17
1.24
CSIMigration
true
GA
1.25
1.26
CSIMigrationAWS
false
Alpha
1.14
1.16
CSIMigrationAWS
false
Beta
1.17
1.22
CSIMigrationAWS
true
Beta
1.23
1.24
CSIMigrationAWS
true
GA
1.25
1.26
CSIMigrationAWSComplete
false
Alpha
1.17
1.20
CSIMigrationAWSComplete
-
Deprecated
1.21
1.21
CSIMigrationAzureDisk
false
Alpha
1.15
1.18
CSIMigrationAzureDisk
false
Beta
1.19
1.22
CSIMigrationAzureDisk
true
Beta
1.23
1.23
CSIMigrationAzureDisk
true
GA
1.24
1.26
CSIMigrationAzureDiskComplete
false
Alpha
1.17
1.20
CSIMigrationAzureDiskComplete
-
Deprecated
1.21
1.21
CSIMigrationAzureFileComplete
false
Alpha
1.17
1.20
CSIMigrationAzureFileComplete
-
Deprecated
1.21
1.21
CSIMigrationGCE
false
Alpha
1.14
1.16
CSIMigrationGCE
false
Beta
1.17
1.22
CSIMigrationGCE
true
Beta
1.23
1.24
CSIMigrationGCE
true
GA
1.25
1.27
CSIMigrationGCEComplete
false
Alpha
1.17
1.20
CSIMigrationGCEComplete
-
Deprecated
1.21
1.21
CSIMigrationOpenStack
false
Alpha
1.14
1.17
CSIMigrationOpenStack
true
Beta
1.18
1.23
CSIMigrationOpenStack
true
GA
1.24
1.25
CSIMigrationOpenStackComplete
false
Alpha
1.17
1.20
CSIMigrationOpenStackComplete
-
Deprecated
1.21
1.21
CSIMigrationvSphereComplete
false
Beta
1.19
1.21
CSIMigrationvSphereComplete
-
Deprecated
1.22
1.22
CSINodeInfo
false
Alpha
1.12
1.13
CSINodeInfo
true
Beta
1.14
1.16
CSINodeInfo
true
GA
1.17
1.22
CSIPersistentVolume
false
Alpha
1.9
1.9
CSIPersistentVolume
true
Beta
1.10
1.12
CSIPersistentVolume
true
GA
1.13
1.16
CSIServiceAccountToken
false
Alpha
1.20
1.20
CSIServiceAccountToken
true
Beta
1.21
1.21
CSIServiceAccountToken
true
GA
1.22
1.24
CSIStorageCapacity
false
Alpha
1.19
1.20
CSIStorageCapacity
true
Beta
1.21
1.23
CSIStorageCapacity
true
GA
1.24
1.27
CSIVolumeFSGroupPolicy
false
Alpha
1.19
1.19
CSIVolumeFSGroupPolicy
true
Beta
1.20
1.22
CSIVolumeFSGroupPolicy
true
GA
1.23
1.25
CSRDuration
true
Beta
1.22
1.23
CSRDuration
true
GA
1.24
1.25
ConfigurableFSGroupPolicy
false
Alpha
1.18
1.19
ConfigurableFSGroupPolicy
true
Beta
1.20
1.22
ConfigurableFSGroupPolicy
true
GA
1.23
1.25
ControllerManagerLeaderMigration
false
Alpha
1.21
1.21
ControllerManagerLeaderMigration
true
Beta
1.22
1.23
ControllerManagerLeaderMigration
true
GA
1.24
1.26
CronJobControllerV2
false
Alpha
1.20
1.20
CronJobControllerV2
true
Beta
1.21
1.21
CronJobControllerV2
true
GA
1.22
1.23
CustomPodDNS
false
Alpha
1.9
1.9
CustomPodDNS
true
Beta
1.10
1.13
CustomPodDNS
true
GA
1.14
1.16
CustomResourceDefaulting
false
Alpha
1.15
1.15
CustomResourceDefaulting
true
Beta
1.16
1.16
CustomResourceDefaulting
true
GA
1.17
1.18
CustomResourcePublishOpenAPI
false
Alpha
1.14
1.14
CustomResourcePublishOpenAPI
true
Beta
1.15
1.15
CustomResourcePublishOpenAPI
true
GA
1.16
1.18
CustomResourceSubresources
false
Alpha
1.10
1.10
CustomResourceSubresources
true
Beta
1.11
1.15
CustomResourceSubresources
true
GA
1.16
1.18
CustomResourceValidation
false
Alpha
1.8
1.8
CustomResourceValidation
true
Beta
1.9
1.15
CustomResourceValidation
true
GA
1.16
1.18
CustomResourceWebhookConversion
false
Alpha
1.13
1.14
CustomResourceWebhookConversion
true
Beta
1.15
1.15
CustomResourceWebhookConversion
true
GA
1.16
1.18
DaemonSetUpdateSurge
false
Alpha
1.21
1.21
DaemonSetUpdateSurge
true
Beta
1.22
1.24
DaemonSetUpdateSurge
true
GA
1.25
1.26
DefaultPodTopologySpread
false
Alpha
1.19
1.19
DefaultPodTopologySpread
true
Beta
1.20
1.23
DefaultPodTopologySpread
true
GA
1.24
1.25
DelegateFSGroupToCSIDriver
false
Alpha
1.22
1.22
DelegateFSGroupToCSIDriver
true
Beta
1.23
1.25
DelegateFSGroupToCSIDriver
true
GA
1.26
1.27
DevicePlugins
false
Alpha
1.8
1.9
DevicePlugins
true
Beta
1.10
1.25
DevicePlugins
true
GA
1.26
1.27
DisableAcceleratorUsageMetrics
false
Alpha
1.19
1.19
DisableAcceleratorUsageMetrics
true
Beta
1.20
1.24
DisableAcceleratorUsageMetrics
true
GA
1.25
1.27
DryRun
false
Alpha
1.12
1.12
DryRun
true
Beta
1.13
1.18
DryRun
true
GA
1.19
1.27
DynamicAuditing
false
Alpha
1.13
1.18
DynamicAuditing
-
Deprecated
1.19
1.19
DynamicKubeletConfig
false
Alpha
1.4
1.10
DynamicKubeletConfig
true
Beta
1.11
1.21
DynamicKubeletConfig
false
Deprecated
1.22
1.25
DynamicProvisioningScheduling
false
Alpha
1.11
1.11
DynamicProvisioningScheduling
-
Deprecated
1.12
-
DynamicVolumeProvisioning
true
Alpha
1.3
1.7
DynamicVolumeProvisioning
true
GA
1.8
1.12
EnableAggregatedDiscoveryTimeout
true
Deprecated
1.16
1.17
EnableEquivalenceClassCache
false
Alpha
1.8
1.12
EnableEquivalenceClassCache
-
Deprecated
1.13
1.23
EndpointSlice
false
Alpha
1.16
1.16
EndpointSlice
false
Beta
1.17
1.17
EndpointSlice
true
Beta
1.18
1.20
EndpointSlice
true
GA
1.21
1.24
EndpointSliceNodeName
false
Alpha
1.20
1.20
EndpointSliceNodeName
true
GA
1.21
1.24
EndpointSliceProxying
false
Alpha
1.18
1.18
EndpointSliceProxying
true
Beta
1.19
1.21
EndpointSliceProxying
true
GA
1.22
1.24
EndpointSliceTerminatingCondition
false
Alpha
1.20
1.21
EndpointSliceTerminatingCondition
true
Beta
1.22
1.25
EndpointSliceTerminatingCondition
true
GA
1.26
1.27
EphemeralContainers
false
Alpha
1.16
1.22
EphemeralContainers
true
Beta
1.23
1.24
EphemeralContainers
true
GA
1.25
1.26
EvenPodsSpread
false
Alpha
1.16
1.17
EvenPodsSpread
true
Beta
1.18
1.18
EvenPodsSpread
true
GA
1.19
1.21
ExpandCSIVolumes
false
Alpha
1.14
1.15
ExpandCSIVolumes
true
Beta
1.16
1.23
ExpandCSIVolumes
true
GA
1.24
1.26
ExpandInUsePersistentVolumes
false
Alpha
1.11
1.14
ExpandInUsePersistentVolumes
true
Beta
1.15
1.23
ExpandInUsePersistentVolumes
true
GA
1.24
1.26
ExpandPersistentVolumes
false
Alpha
1.8
1.10
ExpandPersistentVolumes
true
Beta
1.11
1.23
ExpandPersistentVolumes
true
GA
1.24
1.26
ExperimentalCriticalPodAnnotation
false
Alpha
1.5
1.12
ExperimentalCriticalPodAnnotation
false
Deprecated
1.13
1.16
ExternalPolicyForExternalIP
true
GA
1.18
1.22
GCERegionalPersistentDisk
true
Beta
1.10
1.12
GCERegionalPersistentDisk
true
GA
1.13
1.16
GenericEphemeralVolume
false
Alpha
1.19
1.20
GenericEphemeralVolume
true
Beta
1.21
1.22
GenericEphemeralVolume
true
GA
1.23
1.24
HugePageStorageMediumSize
false
Alpha
1.18
1.18
HugePageStorageMediumSize
true
Beta
1.19
1.21
HugePageStorageMediumSize
true
GA
1.22
1.24
HugePages
false
Alpha
1.8
1.9
HugePages
true
Beta
1.10
1.13
HugePages
true
GA
1.14
1.16
HyperVContainer
false
Alpha
1.10
1.19
HyperVContainer
false
Deprecated
1.20
1.20
IPv6DualStack
false
Alpha
1.15
1.20
IPv6DualStack
true
Beta
1.21
1.22
IPv6DualStack
true
GA
1.23
1.24
IdentifyPodOS
false
Alpha
1.23
1.23
IdentifyPodOS
true
Beta
1.24
1.24
IdentifyPodOS
true
GA
1.25
1.26
ImmutableEphemeralVolumes
false
Alpha
1.18
1.18
ImmutableEphemeralVolumes
true
Beta
1.19
1.20
ImmutableEphemeralVolumes
true
GA
1.21
1.24
IndexedJob
false
Alpha
1.21
1.21
IndexedJob
true
Beta
1.22
1.23
IndexedJob
true
GA
1.24
1.25
IngressClassNamespacedParams
false
Alpha
1.21
1.21
IngressClassNamespacedParams
true
Beta
1.22
1.22
IngressClassNamespacedParams
true
GA
1.23
1.24
Initializers
false
Alpha
1.7
1.13
Initializers
-
Deprecated
1.14
1.14
KMSv1
true
Deprecated
1.28
KubeletConfigFile
false
Alpha
1.8
1.9
KubeletConfigFile
-
Deprecated
1.10
1.10
KubeletCredentialProviders
false
Alpha
1.20
1.23
KubeletCredentialProviders
true
Beta
1.24
1.25
KubeletCredentialProviders
true
GA
1.26
1.28
KubeletPluginsWatcher
false
Alpha
1.11
1.11
KubeletPluginsWatcher
true
Beta
1.12
1.12
KubeletPluginsWatcher
true
GA
1.13
1.16
LegacyNodeRoleBehavior
false
Alpha
1.16
1.18
LegacyNodeRoleBehavior
true
Beta
1.19
1.20
LegacyNodeRoleBehavior
false
GA
1.21
1.22
LocalStorageCapacityIsolation
false
Alpha
1.7
1.9
LocalStorageCapacityIsolation
true
Beta
1.10
1.24
LocalStorageCapacityIsolation
true
GA
1.25
1.26
MixedProtocolLBService
false
Alpha
1.20
1.23
MixedProtocolLBService
true
Beta
1.24
1.25
MixedProtocolLBService
true
GA
1.26
1.27
MountContainers
false
Alpha
1.9
1.16
MountContainers
false
Deprecated
1.17
1.17
MountPropagation
false
Alpha
1.8
1.9
MountPropagation
true
Beta
1.10
1.11
MountPropagation
true
GA
1.12
1.14
NamespaceDefaultLabelName
true
Beta
1.21
1.21
NamespaceDefaultLabelName
true
GA
1.22
1.23
NetworkPolicyEndPort
false
Alpha
1.21
1.21
NetworkPolicyEndPort
true
Beta
1.22
1.24
NetworkPolicyEndPort
true
GA
1.25
1.26
NetworkPolicyStatus
false
Alpha
1.24
1.27
NodeDisruptionExclusion
false
Alpha
1.16
1.18
NodeDisruptionExclusion
true
Beta
1.19
1.20
NodeDisruptionExclusion
true
GA
1.21
1.22
NodeLease
false
Alpha
1.12
1.13
NodeLease
true
Beta
1.14
1.16
NodeLease
true
GA
1.17
1.23
NonPreemptingPriority
false
Alpha
1.15
1.18
NonPreemptingPriority
true
Beta
1.19
1.23
NonPreemptingPriority
true
GA
1.24
1.25
PVCProtection
false
Alpha
1.9
1.9
PVCProtection
-
Deprecated
1.10
1.10
PersistentLocalVolumes
false
Alpha
1.7
1.9
PersistentLocalVolumes
true
Beta
1.10
1.13
PersistentLocalVolumes
true
GA
1.14
1.16
PodAffinityNamespaceSelector
false
Alpha
1.21
1.21
PodAffinityNamespaceSelector
true
Beta
1.22
1.23
PodAffinityNamespaceSelector
true
GA
1.24
1.25
PodDisruptionBudget
false
Alpha
1.3
1.4
PodDisruptionBudget
true
Beta
1.5
1.20
PodDisruptionBudget
true
GA
1.21
1.25
PodHasNetworkCondition
false
Alpha
1.25
1.27
PodOverhead
false
Alpha
1.16
1.17
PodOverhead
true
Beta
1.18
1.23
PodOverhead
true
GA
1.24
1.25
PodPriority
false
Alpha
1.8
1.10
PodPriority
true
Beta
1.11
1.13
PodPriority
true
GA
1.14
1.18
PodReadinessGates
false
Alpha
1.11
1.11
PodReadinessGates
true
Beta
1.12
1.13
PodReadinessGates
true
GA
1.14
1.16
PodSecurity
false
Alpha
1.22
1.22
PodSecurity
true
Beta
1.23
1.24
PodSecurity
true
GA
1.25
1.27
PodShareProcessNamespace
false
Alpha
1.10
1.11
PodShareProcessNamespace
true
Beta
1.12
1.16
PodShareProcessNamespace
true
GA
1.17
1.19
PreferNominatedNode
false
Alpha
1.21
1.21
PreferNominatedNode
true
Beta
1.22
1.23
PreferNominatedNode
true
GA
1.24
1.25
RequestManagement
false
Alpha
1.15
1.16
RequestManagement
-
Deprecated
1.17
1.17
ResourceLimitsPriorityFunction
false
Alpha
1.9
1.18
ResourceLimitsPriorityFunction
-
Deprecated
1.19
1.19
ResourceQuotaScopeSelectors
false
Alpha
1.11
1.11
ResourceQuotaScopeSelectors
true
Beta
1.12
1.16
ResourceQuotaScopeSelectors
true
GA
1.17
1.18
RootCAConfigMap
false
Alpha
1.13
1.19
RootCAConfigMap
true
Beta
1.20
1.20
RootCAConfigMap
true
GA
1.21
1.22
RotateKubeletClientCertificate
true
Beta
1.8
1.18
RotateKubeletClientCertificate
true
GA
1.19
1.21
RunAsGroup
true
Beta
1.14
1.20
RunAsGroup
true
GA
1.21
1.22
RuntimeClass
false
Alpha
1.12
1.13
RuntimeClass
true
Beta
1.14
1.19
RuntimeClass
true
GA
1.20
1.24
SCTPSupport
false
Alpha
1.12
1.18
SCTPSupport
true
Beta
1.19
1.19
SCTPSupport
true
GA
1.20
1.22
ScheduleDaemonSetPods
false
Alpha
1.11
1.11
ScheduleDaemonSetPods
true
Beta
1.12
1.16
ScheduleDaemonSetPods
true
GA
1.17
1.18
SelectorIndex
false
Alpha
1.18
1.18
SelectorIndex
true
Beta
1.19
1.19
SelectorIndex
true
GA
1.20
1.25
ServiceAccountIssuerDiscovery
false
Alpha
1.18
1.19
ServiceAccountIssuerDiscovery
true
Beta
1.20
1.20
ServiceAccountIssuerDiscovery
true
GA
1.21
1.23
ServiceAppProtocol
false
Alpha
1.18
1.18
ServiceAppProtocol
true
Beta
1.19
1.19
ServiceAppProtocol
true
GA
1.20
1.22
ServiceIPStaticSubrange
false
Alpha
1.24
1.24
ServiceIPStaticSubrange
true
Beta
1.25
1.25
ServiceIPStaticSubrange
true
GA
1.26
1.27
ServiceInternalTrafficPolicy
false
Alpha
1.21
1.21
ServiceInternalTrafficPolicy
true
Beta
1.22
1.25
ServiceInternalTrafficPolicy
true
GA
1.26
1.27
ServiceLBNodePortControl
false
Alpha
1.20
1.21
ServiceLBNodePortControl
true
Beta
1.22
1.23
ServiceLBNodePortControl
true
GA
1.24
1.25
ServiceLoadBalancerClass
false
Alpha
1.21
1.21
ServiceLoadBalancerClass
true
Beta
1.22
1.23
ServiceLoadBalancerClass
true
GA
1.24
1.25
ServiceLoadBalancerFinalizer
false
Alpha
1.15
1.15
ServiceLoadBalancerFinalizer
true
Beta
1.16
1.16
ServiceLoadBalancerFinalizer
true
GA
1.17
1.20
ServiceNodeExclusion
false
Alpha
1.8
1.18
ServiceNodeExclusion
true
Beta
1.19
1.20
ServiceNodeExclusion
true
GA
1.21
1.22
ServiceTopology
false
Alpha
1.17
1.19
ServiceTopology
false
Deprecated
1.20
1.22
SetHostnameAsFQDN
false
Alpha
1.19
1.19
SetHostnameAsFQDN
true
Beta
1.20
1.21
SetHostnameAsFQDN
true
GA
1.22
1,24
StartupProbe
false
Alpha
1.16
1.17
StartupProbe
true
Beta
1.18
1.19
StartupProbe
true
GA
1.20
1.23
StatefulSetMinReadySeconds
false
Alpha
1.22
1.22
StatefulSetMinReadySeconds
true
Beta
1.23
1.24
StatefulSetMinReadySeconds
true
GA
1.25
1.26
StorageObjectInUseProtection
true
Beta
1.10
1.10
StorageObjectInUseProtection
true
GA
1.11
1.24
StreamingProxyRedirects
false
Beta
1.5
1.5
StreamingProxyRedirects
true
Beta
1.6
1.17
StreamingProxyRedirects
true
Deprecated
1.18
1.21
StreamingProxyRedirects
false
Deprecated
1.22
1.24
SupportIPVSProxyMode
false
Alpha
1.8
1.8
SupportIPVSProxyMode
false
Beta
1.9
1.9
SupportIPVSProxyMode
true
Beta
1.10
1.10
SupportIPVSProxyMode
true
GA
1.11
1.20
SupportNodePidsLimit
false
Alpha
1.14
1.14
SupportNodePidsLimit
true
Beta
1.15
1.19
SupportNodePidsLimit
true
GA
1.20
1.23
SupportPodPidsLimit
false
Alpha
1.10
1.13
SupportPodPidsLimit
true
Beta
1.14
1.19
SupportPodPidsLimit
true
GA
1.20
1.23
SuspendJob
false
Alpha
1.21
1.21
SuspendJob
true
Beta
1.22
1.23
SuspendJob
true
GA
1.24
1.25
Sysctls
true
Beta
1.11
1.20
Sysctls
true
GA
1.21
1.22
TTLAfterFinished
false
Alpha
1.12
1.20
TTLAfterFinished
true
Beta
1.21
1.22
TTLAfterFinished
true
GA
1.23
1.24
TaintBasedEvictions
false
Alpha
1.6
1.12
TaintBasedEvictions
true
Beta
1.13
1.17
TaintBasedEvictions
true
GA
1.18
1.20
TaintNodesByCondition
false
Alpha
1.8
1.11
TaintNodesByCondition
true
Beta
1.12
1.16
TaintNodesByCondition
true
GA
1.17
1.18
TokenRequest
false
Alpha
1.10
1.11
TokenRequest
true
Beta
1.12
1.19
TokenRequest
true
GA
1.20
1.21
TokenRequestProjection
false
Alpha
1.11
1.11
TokenRequestProjection
true
Beta
1.12
1.19
TokenRequestProjection
true
GA
1.20
1.21
UserNamespacesStatelessPodsSupport
false
Alpha
1.25
1.27
ValidateProxyRedirects
false
Alpha
1.12
1.13
ValidateProxyRedirects
true
Beta
1.14
1.21
ValidateProxyRedirects
true
Deprecated
1.22
1.24
VolumePVCDataSource
false
Alpha
1.15
1.15
VolumePVCDataSource
true
Beta
1.16
1.17
VolumePVCDataSource
true
GA
1.18
1.21
VolumeScheduling
false
Alpha
1.9
1.9
VolumeScheduling
true
Beta
1.10
1.12
VolumeScheduling
true
GA
1.13
1.16
VolumeSnapshotDataSource
false
Alpha
1.12
1.16
VolumeSnapshotDataSource
true
Beta
1.17
1.19
VolumeSnapshotDataSource
true
GA
1.20
1.22
VolumeSubpath
true
GA
1.10
1.24
VolumeSubpathEnvExpansion
false
Alpha
1.14
1.14
VolumeSubpathEnvExpansion
true
Beta
1.15
1.16
VolumeSubpathEnvExpansion
true
GA
1.17
1.24
WarningHeaders
true
Beta
1.19
1.21
WarningHeaders
true
GA
1.22
1.24
WindowsEndpointSliceProxying
false
Alpha
1.19
1.20
WindowsEndpointSliceProxying
true
Beta
1.21
1.21
WindowsEndpointSliceProxying
true
GA
1.22
1.24
WindowsGMSA
false
Alpha
1.14
1.15
WindowsGMSA
true
Beta
1.16
1.17
WindowsGMSA
true
GA
1.18
1.20
WindowsHostProcessContainers
false
Alpha
1.22
1.22
WindowsHostProcessContainers
true
Beta
1.23
1.25
WindowsHostProcessContainers
true
GA
1.26
1.27
WindowsRunAsUserName
false
Alpha
1.16
1.16
WindowsRunAsUserName
true
Beta
1.17
1.17
WindowsRunAsUserName
true
GA
1.18
1.20
Descriptions for removed feature gates
Accelerators: Provided an early form of plugin to enable Nvidia GPU support when using
Docker Engine; no longer available. See
Device Plugins for
an alternative.
AllowExtTrafficLocalEndpoints: Enable a service to route external requests to node local endpoints.
AllowInsecureBackendProxy: Enable the users to skip TLS verification of
kubelets on Pod log requests.
AttachVolumeLimit: Enable volume plugins to report limits on number of volumes
that can be attached to a node.
See dynamic volume limits
for more details.
BalanceAttachedNodeVolumes: Include volume count on node to be considered for
balanced resource allocation while scheduling. A node which has closer CPU,
memory utilization, and volume count is favored by the scheduler while making decisions.
BlockVolume: Enable the definition and consumption of raw block devices in Pods.
See Raw Block Volume Support
for more details.
BoundServiceAccountTokenVolume: Migrate ServiceAccount volumes to use a projected volume
consisting of a ServiceAccountTokenVolumeProjection. Cluster admins can use metric
serviceaccount_stale_tokens_total to monitor workloads that are depending on the extended
tokens. If there are no such workloads, turn off extended tokens by starting kube-apiserver with
flag --service-account-extend-token-expiration=false.
Check Bound Service Account Tokens
for more details.
CRIContainerLogRotation: Enable container log rotation for CRI container runtime.
The default max size of a log file is 10MB and the default max number of
log files allowed for a container is 5.
These values can be configured in the kubelet config.
See logging at node level
for more details.
CSIBlockVolume: Enable external CSI volume drivers to support block storage.
See csi raw block volume support
for more details.
CSIDriverRegistry: Enable all logic related to the CSIDriver API object in
csi.storage.k8s.io.
CSIInlineVolume: Enable CSI Inline volumes support for pods.
CSIMigration: Enables shims and translation logic to route volume
operations from in-tree plugins to corresponding pre-installed CSI plugins
CSIMigrationAWS: Enables shims and translation logic to route volume
operations from the AWS-EBS in-tree plugin to EBS CSI plugin. Supports
falling back to in-tree EBS plugin for mount operations to nodes that have
the feature disabled or that do not have EBS CSI plugin installed and
configured. Does not support falling back for provision operations, for those
the CSI plugin must be installed and configured.
CSIMigrationAWSComplete: Stops registering the EBS in-tree plugin in
kubelet and volume controllers and enables shims and translation logic to
route volume operations from the AWS-EBS in-tree plugin to EBS CSI plugin.
Requires CSIMigration and CSIMigrationAWS feature flags enabled and EBS CSI
plugin installed and configured on all nodes in the cluster. This flag has
been deprecated in favor of the InTreePluginAWSUnregister feature flag
which prevents the registration of in-tree EBS plugin.
CSIMigrationAzureDisk: Enables shims and translation logic to route volume
operations from the Azure-Disk in-tree plugin to AzureDisk CSI plugin.
Supports falling back to in-tree AzureDisk plugin for mount operations to
nodes that have the feature disabled or that do not have AzureDisk CSI plugin
installed and configured. Does not support falling back for provision
operations, for those the CSI plugin must be installed and configured.
Requires CSIMigration feature flag enabled.
CSIMigrationAzureDiskComplete: Stops registering the Azure-Disk in-tree
plugin in kubelet and volume controllers and enables shims and translation
logic to route volume operations from the Azure-Disk in-tree plugin to
AzureDisk CSI plugin. Requires CSIMigration and CSIMigrationAzureDisk feature
flags enabled and AzureDisk CSI plugin installed and configured on all nodes
in the cluster. This flag has been deprecated in favor of the
InTreePluginAzureDiskUnregister feature flag which prevents the registration
of in-tree AzureDisk plugin.
CSIMigrationAzureFileComplete: Stops registering the Azure-File in-tree
plugin in kubelet and volume controllers and enables shims and translation
logic to route volume operations from the Azure-File in-tree plugin to
AzureFile CSI plugin. Requires CSIMigration and CSIMigrationAzureFile feature
flags enabled and AzureFile CSI plugin installed and configured on all nodes
in the cluster. This flag has been deprecated in favor of the
InTreePluginAzureFileUnregister feature flag which prevents the registration
of in-tree AzureFile plugin.
CSIMigrationGCE: Enables shims and translation logic to route volume
operations from the GCE-PD in-tree plugin to PD CSI plugin. Supports falling
back to in-tree GCE plugin for mount operations to nodes that have the
feature disabled or that do not have PD CSI plugin installed and configured.
Does not support falling back for provision operations, for those the CSI
plugin must be installed and configured. Requires CSIMigration feature flag
enabled.
CSIMigrationGCEComplete: Stops registering the GCE-PD in-tree plugin in
kubelet and volume controllers and enables shims and translation logic to
route volume operations from the GCE-PD in-tree plugin to PD CSI plugin.
Requires CSIMigration and CSIMigrationGCE feature flags enabled and PD CSI
plugin installed and configured on all nodes in the cluster. This flag has
been deprecated in favor of the InTreePluginGCEUnregister feature flag which
prevents the registration of in-tree GCE PD plugin.
CSIMigrationOpenStack: Enables shims and translation logic to route volume
operations from the Cinder in-tree plugin to Cinder CSI plugin. Supports
falling back to in-tree Cinder plugin for mount operations to nodes that have
the feature disabled or that do not have Cinder CSI plugin installed and
configured. Does not support falling back for provision operations, for those
the CSI plugin must be installed and configured. Requires CSIMigration
feature flag enabled.
CSIMigrationOpenStackComplete: Stops registering the Cinder in-tree plugin in
kubelet and volume controllers and enables shims and translation logic to route
volume operations from the Cinder in-tree plugin to Cinder CSI plugin.
Requires CSIMigration and CSIMigrationOpenStack feature flags enabled and Cinder
CSI plugin installed and configured on all nodes in the cluster. This flag has
been deprecated in favor of the InTreePluginOpenStackUnregister feature flag
which prevents the registration of in-tree openstack cinder plugin.
CSIMigrationvSphereComplete: Stops registering the vSphere in-tree plugin in kubelet
and volume controllers and enables shims and translation logic to route volume operations
from the vSphere in-tree plugin to vSphere CSI plugin. Requires CSIMigration and
CSIMigrationvSphere feature flags enabled and vSphere CSI plugin installed and
configured on all nodes in the cluster. This flag has been deprecated in favor
of the InTreePluginvSphereUnregister feature flag which prevents the
registration of in-tree vsphere plugin.
CSINodeInfo: Enable all logic related to the CSINodeInfo API object in csi.storage.k8s.io.
CSIPersistentVolume: Enable discovering and mounting volumes provisioned through a
CSI (Container Storage Interface)
compatible volume plugin.
CSIServiceAccountToken: Enable CSI drivers to receive the pods' service account token
that they mount volumes for. See
Token Requests.
CSIStorageCapacity: Enables CSI drivers to publish storage capacity information
and the Kubernetes scheduler to use that information when scheduling pods. See
Storage Capacity.
Check the csi volume type documentation for more details.
CSIVolumeFSGroupPolicy: Allows CSIDrivers to use the fsGroupPolicy field.
This field controls whether volumes created by a CSIDriver support volume ownership
and permission modifications when these volumes are mounted.
CSRDuration: Allows clients to request a duration for certificates issued
via the Kubernetes CSR API.
CronJobControllerV2: Use an alternative implementation of the
CronJob controller. Otherwise,
version 1 of the same controller is selected.
ControllerManagerLeaderMigration: Enables Leader Migration for
kube-controller-manager and
cloud-controller-manager
which allows a cluster operator to live migrate
controllers from the kube-controller-manager into an external controller-manager
(e.g. the cloud-controller-manager) in an HA cluster without downtime.
CustomPodDNS: Enable customizing the DNS settings for a Pod using its dnsConfig property.
Check Pod's DNS Config
for more details.
CustomResourceDefaulting: Enable CRD support for default values in OpenAPI v3 validation schemas.
CustomResourcePublishOpenAPI: Enables publishing of CRD OpenAPI specs.
CustomResourceSubresources: Enable /status and /scale subresources
on resources created from CustomResourceDefinition.
CustomResourceValidation: Enable schema based validation on resources created from
CustomResourceDefinition.
CustomResourceWebhookConversion: Enable webhook-based conversion
on resources created from CustomResourceDefinition.
DefaultPodTopologySpread: Enables the use of PodTopologySpread scheduling plugin to do
default spreading.
DelegateFSGroupToCSIDriver: If supported by the CSI driver, delegates the
role of applying fsGroup from a Pod's securityContext to the driver by
passing fsGroup through the NodeStageVolume and NodePublishVolume CSI calls.
DevicePlugins: Enable the device-plugins
based resource provisioning on nodes.
DryRun: Enable server-side dry run requests
so that validation, merging, and mutation can be tested without committing.
DynamicAuditing: Used to enable dynamic auditing before v1.19.
DynamicKubeletConfig: Enable the dynamic configuration of kubelet. The
feature is no longer supported outside of supported skew policy. The feature
gate was removed from kubelet in 1.24.
DynamicProvisioningScheduling: Extend the default scheduler to be aware of
volume topology and handle PV provisioning.
This feature was superseded by the VolumeScheduling feature in v1.12.
DynamicVolumeProvisioning: Enable the
dynamic provisioning of persistent volumes to Pods.
EnableAggregatedDiscoveryTimeout: Enable the five second
timeout on aggregated discovery calls.
EnableEquivalenceClassCache: Enable the scheduler to cache equivalence of
nodes when scheduling Pods.
EndpointSlice: Enables EndpointSlices for more scalable and extensible
network endpoints. See Enabling EndpointSlices.
EndpointSliceProxying: When enabled, kube-proxy running
on Linux will use EndpointSlices as the primary data source instead of
Endpoints, enabling scalability and performance improvements. See
Enabling Endpoint Slices.
EndpointSliceTerminatingCondition: Enables EndpointSlice terminating and serving
condition fields.
EphemeralContainers: Enable the ability to add
ephemeral containers
to running Pods.
ExperimentalCriticalPodAnnotation: Enable annotating specific pods as critical
so that their scheduling is guaranteed.
This feature is deprecated by Pod Priority and Preemption as of v1.13.
ExternalPolicyForExternalIP: Fix a bug where ExternalTrafficPolicy is not
applied to Service ExternalIPs.
GCERegionalPersistentDisk: Enable the regional PD feature on GCE.
GenericEphemeralVolume: Enables ephemeral, inline volumes that support all features
of normal volumes (can be provided by third-party storage vendors, storage capacity tracking,
restore from snapshot, etc.).
See Ephemeral Volumes.
HugePageStorageMediumSize: Enable support for multiple sizes pre-allocated
huge pages.
HugePages: Enable the allocation and consumption of pre-allocated
huge pages.
IPv6DualStack: Enable dual stack
support for IPv6.
IdentifyPodOS: Allows the Pod OS field to be specified. This helps in identifying
the OS of the pod authoritatively during the API server admission time.
In Kubernetes 1.28, the allowed values for the pod.spec.os.name
are windows and linux.
ImmutableEphemeralVolumes: Allows for marking individual Secrets and ConfigMaps as
immutable for better safety and performance.
IndexedJob: Allows the Job
controller to manage Pod completions per completion index.
IngressClassNamespacedParams: Allow namespace-scoped parameters reference in
IngressClass resource. This feature adds two fields - Scope and Namespace
to IngressClass.spec.parameters.
Initializers: Allow asynchronous coordination of object creation using the
Initializers admission plugin.
KubeletCredentialProviders: Enable kubelet exec credential providers for
image pull credentials.
KubeletPluginsWatcher: Enable probe-based plugin watcher utility to enable kubelet
to discover plugins such as CSI volume drivers.
LegacyNodeRoleBehavior: When disabled, legacy behavior in service load balancers and
node disruption will ignore the node-role.kubernetes.io/master label in favor of the
feature-specific labels provided by NodeDisruptionExclusion and ServiceNodeExclusion.
MixedProtocolLBService: Enable using different protocols in the same LoadBalancer type
Service instance.
MountContainers: Enable using utility containers on host as the volume mounter.
MountPropagation: Enable sharing volume mounted by one container to other containers or pods.
For more details, please see mount propagation.
NamespaceDefaultLabelName: Configure the API Server to set an immutable
labelkubernetes.io/metadata.name
on all namespaces, containing the namespace name.
NetworkPolicyStatus: Enable the status subresource for NetworkPolicy objects.
NodeDisruptionExclusion: Enable use of the Node label node.kubernetes.io/exclude-disruption
which prevents nodes from being evacuated during zone failures.
NodeLease: Enable the new Lease API to report node heartbeats, which could be used as a node health signal.
NonPreemptingPriority: Enable preemptionPolicy field for PriorityClass and Pod.
PVCProtection: Enable the prevention of a PersistentVolumeClaim (PVC) from
being deleted when it is still used by any Pod.
PersistentLocalVolumes: Enable the usage of local volume type in Pods.
Pod affinity has to be specified if requesting a local volume.
PodHasNetworkCondition: Enable the kubelet to mark the PodHasNetwork
condition on pods. This was renamed to PodReadyToStartContainersCondition in 1.28.
PodOverhead: Enable the PodOverhead
feature to account for pod overheads.
PodPriority: Enable the descheduling and preemption of Pods based on their
priorities.
PodReadinessGates: Enable the setting of PodReadinessGate field for extending
Pod readiness evaluation. See Pod readiness gate
for more details.
PodSecurity: Enables the PodSecurity admission plugin.
PodShareProcessNamespace: Enable the setting of shareProcessNamespace in a Pod for sharing
a single process namespace between containers running in a pod. More details can be found in
Share Process Namespace between Containers in a Pod.
PreferNominatedNode: This flag tells the scheduler whether the nominated
nodes will be checked first before looping through all the other nodes in
the cluster.
RequestManagement: Enables managing request concurrency with prioritization and fairness
at each API server. Deprecated by APIPriorityAndFairness since 1.17.
ResourceLimitsPriorityFunction: Enable a scheduler priority function that
assigns a lowest possible score of 1 to a node that satisfies at least one of
the input Pod's cpu and memory limits. The intent is to break ties between
nodes with same scores.
RootCAConfigMap: Configure the kube-controller-manager to publish a
ConfigMap named kube-root-ca.crt
to every namespace. This ConfigMap contains a CA bundle used for verifying connections
to the kube-apiserver. See
Bound Service Account Tokens
for more details.
RotateKubeletClientCertificate: Enable the rotation of the client TLS certificate on the kubelet.
See kubelet configuration
for more details.
RunAsGroup: Enable control over the primary group ID set on the init processes of containers.
RuntimeClass: Enable the RuntimeClass feature for
selecting container runtime configurations.
SCTPSupport: Enables the SCTPprotocol value in Pod, Service, Endpoints, EndpointSlice,
and NetworkPolicy definitions.
ScheduleDaemonSetPods: Enable DaemonSet Pods to be scheduled by the default scheduler instead
of the DaemonSet controller.
SelectorIndex: Allows label and field based indexes in API server watch cache to accelerate
list operations.
ServiceAccountIssuerDiscovery: Enable OIDC discovery endpoints (issuer and JWKS URLs) for the
service account issuer in the API server. See
Configure Service Accounts for Pods
for more details.
ServiceAppProtocol: Enables the appProtocol field on Services and Endpoints.
ServiceIPStaticSubrange: Enables a strategy for Services ClusterIP allocations, whereby the
ClusterIP range is subdivided. Dynamic allocated ClusterIP addresses will be allocated preferently
from the upper range allowing users to assign static ClusterIPs from the lower range with a low
risk of collision. See
Avoiding collisions
for more details.
ServiceInternalTrafficPolicy: Enables the internalTrafficPolicy field on Services.
ServiceLoadBalancerFinalizer: Enable finalizer protection for Service load balancers.
ServiceLBNodePortControl: Enables the allocateLoadBalancerNodePorts field on Services.
ServiceNodeExclusion: Enable the exclusion of nodes from load balancers created by a cloud provider.
A node is eligible for exclusion if labelled with "node.kubernetes.io/exclude-from-external-load-balancers".
ServiceTopology: Enable service to route traffic based upon the Node topology of the cluster.
SetHostnameAsFQDN: Enable the ability of setting Fully Qualified Domain Name(FQDN) as the
hostname of a pod. See
Pod's setHostnameAsFQDN field.
StartupProbe: Enable the startup
probe in the kubelet.
StatefulSetMinReadySeconds: Allows minReadySeconds to be respected by
the StatefulSet controller.
StorageObjectInUseProtection: Postpone the deletion of PersistentVolume or
PersistentVolumeClaim objects if they are still being used.
StreamingProxyRedirects: Instructs the API server to intercept (and follow) redirects from the
backend (kubelet) for streaming requests. Examples of streaming requests include the exec,
attach and port-forward requests.
SupportIPVSProxyMode: Enable providing in-cluster service load balancing using IPVS.
See service proxies for more details.
SupportNodePidsLimit: Enable the support to limiting PIDs on the Node. The parameter
pid=<number> in the --system-reserved and --kube-reserved options can be specified to
ensure that the specified number of process IDs will be reserved for the system as a whole and for
Kubernetes system daemons respectively.
SupportPodPidsLimit: Enable the support to limiting PIDs in Pods.
SuspendJob: Enable support to suspend and resume Jobs. For more details, see
the Jobs docs.
Sysctls: Enable support for namespaced kernel parameters (sysctls) that can be set for each
pod. See sysctls for more details.
TTLAfterFinished: Allow a TTL controller
to clean up resources after they finish execution.
TaintBasedEvictions: Enable evicting pods from nodes based on taints on Nodes and tolerations
on Pods. See taints and tolerations
for more details.
TaintNodesByCondition: Enable automatic tainting nodes based on
node conditions.
TokenRequest: Enable the TokenRequest endpoint on service account resources.
TokenRequestProjection: Enable the injection of service account tokens into a Pod through a
projected volume.
UserNamespacesStatelessPodsSupport: Enable user namespace support for stateless Pods. This flag was renamed on newer releases to UserNamespacesSupport.
ValidateProxyRedirects: This flag controls whether the API server should validate that redirects
are only followed to the same host. Only used if the StreamingProxyRedirects flag is enabled.
VolumePVCDataSource: Enable support for specifying an existing PVC as a DataSource.
VolumeScheduling: Enable volume topology aware scheduling and make the PersistentVolumeClaim
(PVC) binding aware of scheduling decisions. It also enables the usage of
local volume type when used together with the
PersistentLocalVolumes feature gate.
VolumeSnapshotDataSource: Enable volume snapshot data source support.
VolumeSubpath: Allow mounting a subpath of a volume in a container.
VolumeSubpathEnvExpansion: Enable subPathExpr field for expanding environment
variables into a subPath.
WarningHeaders: Allow sending warning headers in API responses.
WindowsEndpointSliceProxying: When enabled, kube-proxy running on Windows will use
EndpointSlices as the primary data source instead of Endpoints, enabling scalability and
performance improvements. See
Enabling Endpoint Slices.
WindowsGMSA: Enables passing of GMSA credential specs from pods to container runtimes.
WindowsHostProcessContainers: Enables support for Windows HostProcess containers.
WindowsRunAsUserName : Enable support for running applications in Windows containers with as a
non-default user. See Configuring RunAsUserName
for more details.
12.3 - kubelet
Synopsis
The kubelet is the primary "node agent" that runs on each node. It can
register the node with the apiserver using one of: the hostname; a flag to
override the hostname; or specific logic for a cloud provider.
The kubelet works in terms of a PodSpec. A PodSpec is a YAML or JSON object
that describes a pod. The kubelet takes a set of PodSpecs that are provided
through various mechanisms (primarily through the apiserver) and ensures that
the containers described in those PodSpecs are running and healthy. The
kubelet doesn't manage containers which were not created by Kubernetes.
Other than from a PodSpec from the apiserver, there are two ways that a
container manifest can be provided to the kubelet.
File: Path passed as a flag on the command line. Files under this path will be
monitored periodically for updates. The monitoring period is 20s by default
and is configurable via a flag.
HTTP endpoint: HTTP endpoint passed as a parameter on the command line. This
endpoint is checked every 20 seconds (also configurable with a flag).
kubelet [flags]
Options
--address string Default: 0.0.0.0
The IP address for the kubelet to serve on (set to 0.0.0.0 or :: for listening on all interfaces and IP address families) (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--allowed-unsafe-sysctls strings
Comma-separated whitelist of unsafe sysctls or unsafe sysctl patterns (ending in *). Use these at your own risk. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--anonymous-auth Default: true
Enables anonymous requests to the kubelet server. Requests that are not rejected by another authentication method are treated as anonymous requests. Anonymous requests have a username of system:anonymous, and a group name of system:unauthenticated. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--authentication-token-webhook
Use the TokenReview API to determine authentication for bearer tokens. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
The duration to cache responses from the webhook token authenticator. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--authorization-mode string Default: AlwaysAllow
Authorization mode for kubelet server. Valid options are "AlwaysAllow" or "Webhook". Webhook mode uses the SubjectAccessReview API to determine authorization. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
The duration to cache 'authorized' responses from the webhook authorizer. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
The duration to cache 'unauthorized' responses from the webhook authorizer. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--bootstrap-kubeconfig string
Path to a kubeconfig file that will be used to get client certificate for kubelet. If the file specified by --kubeconfig does not exist, the bootstrap kubeconfig is used to request a client certificate from the API server. On success, a kubeconfig file referencing the generated client certificate and key is written to the path specified by --kubeconfig. The client certificate and key file will be stored in the directory pointed by --cert-dir.
--cert-dir string Default: /var/lib/kubelet/pki
The directory where the TLS certs are located. If --tls-cert-file and --tls-private-key-file are provided, this flag will be ignored.
--cgroup-driver string Default: cgroupfs
Driver that the kubelet uses to manipulate cgroups on the host. Possible values: "cgroupfs", "systemd". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cgroup-root string Default: ''
Optional root cgroup to use for pods. This is handled by the container runtime on a best effort basis. Default: '', which means use the container runtime default. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cgroups-per-qos Default: true
Enable creation of QoS cgroup hierarchy, if true, top level QoS and pod cgroups are created. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--client-ca-file string
If set, any request presenting a client certificate signed by one of the authorities in the client-ca-file is authenticated with an identity corresponding to the CommonName of the client certificate. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cloud-config string
The path to the cloud provider configuration file. Empty string for no configuration file. (DEPRECATED: will be removed in 1.24 or later, in favor of removing cloud providers code from kubelet.)
--cloud-provider string
The provider for cloud services. Set to empty string for running with no cloud provider. If set, the cloud provider determines the name of the node (consult cloud provider documentation to determine if and how the hostname is used). (DEPRECATED: will be removed in 1.24 or later, in favor of removing cloud provider code from kubelet.)
--cluster-dns strings
Comma-separated list of DNS server IP address. This value is used for containers DNS server in case of Pods with "dnsPolicy: ClusterFirst". Note: all DNS servers appearing in the list MUST serve the same set of records otherwise name resolution within the cluster may not work correctly. There is no guarantee as to which DNS server may be contacted for name resolution. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cluster-domain string
Domain for this cluster. If set, kubelet will configure all containers to search this domain in addition to the host's search domains. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--config string
The kubelet will load its initial configuration from this file. The path may be absolute or relative; relative paths start at the kubelet's current working directory. Omit this flag to use the built-in default configuration values. Command-line flags override configuration from this file.
--config-dir string Default: ''
Path to a directory to specify drop-ins, allows the user to optionally specify additional configs to overwrite what is provided by default and in the `--config` flag. Note: Set the 'KUBELET_CONFIG_DROPIN_DIR_ALPHA' environment variable to specify the directory.
--container-log-max-files int32 Default: 5
<Warning: Beta feature> Set the maximum number of container log files that can be present for a container. The number must be >= 2. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--container-log-max-size string Default: 10Mi
<Warning: Beta feature> Set the maximum size (e.g. 10Mi) of container log file before it is rotated. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--container-runtime-endpoint string
The endpoint of remote runtime service. UNIX domain sockets are supported on Linux, while 'npipe' and 'tcp' endpoints are supported on windows. Examples: unix:///path/to/runtime.sock, npipe:////./pipe/runtime.
--contention-profiling
Enable block profiling, if profiling is enabled. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cpu-cfs-quota Default: true
Enable CPU CFS quota enforcement for containers that specify CPU limits. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cpu-cfs-quota-period duration Default: 100ms
Sets CPU CFS quota period value, cpu.cfs_period_us, defaults to Linux Kernel default. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cpu-manager-policy string Default: none
The CPU manager policy to use. Possible values: "none", "static". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--cpu-manager-policy-options string
A set of 'key=value' CPU manager policy options to use, to fine tune their behaviour. If not supplied, keep the default behaviour. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
<Warning: Alpha feature> CPU manager reconciliation period. Examples: "10s", or "1m". If not supplied, defaults to node status update frequency. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--enable-controller-attach-detach Default: true
Enables the Attach/Detach controller to manage attachment/detachment of volumes scheduled to this node, and disables kubelet from executing any attach/detach operations. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--enable-debugging-handlers Default: true
Enables server endpoints for log collection and local running of containers and commands. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--enable-server Default: true
Enable the kubelet's server. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--enforce-node-allocatable strings Default: pods
A comma separated list of levels of node allocatable enforcement to be enforced by kubelet. Acceptable options are "none", "pods", "system-reserved", and "kube-reserved". If the latter two options are specified, --system-reserved-cgroup and --kube-reserved-cgroup must also be set, respectively. If "none" is specified, no additional options should be set. See official documentation for more details. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--event-burst int32 Default: 100
Maximum size of a bursty event records, temporarily allows event records to burst to this number, while still not exceeding --event-qps. The number must be >= 0. If 0 will use default burst (100). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--event-qps int32 Default: 50
QPS to limit event creations. The number must be >= 0. If 0 will use default QPS (50). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
A set of eviction thresholds (e.g. "memory.available<1Gi") that if met would trigger a pod eviction. On a Linux node, the default value also includes "nodefs.inodesFree<5%". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--eviction-max-pod-grace-period int32
Maximum allowed grace period (in seconds) to use when terminating pods in response to a soft eviction threshold being met. If negative, defer to pod specified value. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--eviction-minimum-reclaim string
A set of minimum reclaims (e.g. "imagefs.available=2Gi") that describes the minimum amount of resource the kubelet will reclaim when performing a pod eviction if that resource is under pressure. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Duration for which the kubelet has to wait before transitioning out of an eviction pressure condition. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--eviction-soft string
A set of eviction thresholds (e.g. "memory.available<1.5Gi") that if met over a corresponding grace period would trigger a pod eviction. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--eviction-soft-grace-period string
A set of eviction grace periods (e.g. "memory.available=1m30s") that correspond to how long a soft eviction threshold must hold before triggering a pod eviction. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--exit-on-lock-contention
Whether kubelet should exit upon lock-file contention.
When set to true, hard eviction thresholds will be ignored while calculating node allocatable. See here for more details. (DEPRECATED: will be removed in 1.24 or later)
--experimental-mounter-path string Default: mount
[Experimental] Path of mounter binary. Leave empty to use the default mount. (DEPRECATED: will be removed in 1.24 or later, in favor of using CSI.)
--fail-swap-on Default: true
Makes the kubelet fail to start if swap is enabled on the node. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--feature-gates <A list of 'key=true/false' pairs>
Duration between checking config files for new data. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--hairpin-mode string Default: promiscuous-bridge
How should the kubelet setup hairpin NAT. This allows endpoints of a Service to load balance back to themselves if they should try to access their own Service. Valid values are "promiscuous-bridge", "hairpin-veth" and "none". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--healthz-bind-address string Default: 127.0.0.1
The IP address for the healthz server to serve on (set to "0.0.0.0" or "::" for listening in all interfaces and IP families). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--healthz-port int32 Default: 10248
The port of the localhost healthz endpoint (set to 0 to disable). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
-h, --help
help for kubelet
--hostname-override string
If non-empty, will use this string as identification instead of the actual hostname. If --cloud-provider is set, the cloud provider determines the name of the node (consult cloud provider documentation to determine if and how the hostname is used).
--http-check-frequency duration Default: 20s
Duration between checking HTTP for new data. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--image-credential-provider-bin-dir string
The path to the directory where credential provider plugin binaries are located.
--image-credential-provider-config string
The path to the credential provider plugin config file.
--image-gc-high-threshold int32 Default: 85
The percent of disk usage after which image garbage collection is always run. Values must be within the range [0, 100], To disable image garbage collection, set to 100. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--image-gc-low-threshold int32 Default: 80
The percent of disk usage before which image garbage collection is never run. Lowest disk usage to garbage collect to. Values must be within the range [0, 100] and should not be larger than that of --image-gc-high-threshold. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--image-service-endpoint string
The endpoint of remote image service. If not specified, it will be the same with --container-runtime-endpoint by default. UNIX domain socket are supported on Linux, while `npipe` and `tcp` endpoints are supported on Windows. Examples: unix:///var/run/dockershim.sock, npipe:////./pipe/dockershim
--keep-terminated-pod-volumes
Keep terminated pod volumes mounted to the node after the pod terminates. Can be useful for debugging volume related issues. (DEPRECATED: will be removed in a future version)
--kernel-memcg-notification
If enabled, the kubelet will integrate with the kernel memcg notification to determine if memory eviction thresholds are crossed rather than polling. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--kube-api-burst int32 Default: 100
Burst to use while talking with kubernetes API server. The number must be >= 0. If 0 will use default burst (100). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Content type of requests sent to apiserver. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--kube-api-qps int32 Default: 50
QPS to use while talking with kubernetes API server. The number must be >= 0. If 0 will use default QPS (50). Doesn't cover events and node heartbeat apis which rate limiting is controlled by a different set of flags. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--kube-reserved string Default: <None>
A set of <resource name>=<resource quantity> (e.g. "cpu=200m,memory=500Mi,ephemeral-storage=1Gi,pid='100'&auot;) pairs that describe resources reserved for kubernetes system components. Currently cpu, memory and local ephemeral-storage for root file system are supported. See here for more detail. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--kube-reserved-cgroup string Default: ''
Absolute name of the top level cgroup that is used to manage kubernetes components for which compute resources were reserved via --kube-reserved flag. Ex. "/kube-reserved". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--kubeconfig string
Path to a kubeconfig file, specifying how to connect to the API server. Providing --kubeconfig enables API server mode, omitting --kubeconfig enables standalone mode.
--kubelet-cgroups string
Optional absolute name of cgroups to create and run the kubelet in. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--local-storage-capacity-isolation> Default: true
If true, local ephemeral storage isolation is enabled. Otherwise, local storage isolation feature will be disabled. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--lock-file string
<Warning: Alpha feature> The path to file for kubelet to use as a lock file.
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes.
--log-json-info-buffer-size string Default: '0'
[Alpha] In JSON format with split output streams, the info messages can be buffered for a while to increase performance. The default value of zero bytes disables buffering. The size can be specified as number of bytes (512), multiples of 1000 (1K), multiples of 1024 (2Ki), or powers of those (3M, 4G, 5Mi, 6Gi). Enable the LoggingAlphaOptions feature gate to use this. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--log-json-split-stream
[Alpha] In JSON format, write error messages to stderr and info messages to stdout. The default is to write a single stream to stdout. Enable the LoggingAlphaOptions feature gate to use this. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--logging-format string Default: text
Sets the log format. Permitted formats: "json" (gated by LoggingBetaOptions, "text"). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--make-iptables-util-chains Default: true
If true, kubelet will ensure iptables utility rules are present on host. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--manifest-url string
URL for accessing additional Pod specifications to run. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--manifest-url-header string
Comma-separated list of HTTP headers to use when accessing the URL provided to --manifest-url. Multiple headers with the same name will be added in the same order provided. This flag can be repeatedly invoked. For example: --manifest-url-header 'a:hello,b:again,c:world' --manifest-url-header 'b:beautiful' (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--max-open-files int Default: 1000000
Number of files that can be opened by kubelet process. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--max-pods int32 Default: 110
Number of Pods that can run on this kubelet. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--maximum-dead-containers int32 Default: -1
Maximum number of old instances of containers to retain globally. Each container takes up some disk space. To disable, set to a negative number. (DEPRECATED: Use --eviction-hard or --eviction-soft instead. Will be removed in a future version.)
Maximum number of old instances to retain per container. Each container takes up some disk space. (DEPRECATED: Use --eviction-hard or --eviction-soft instead. Will be removed in a future version.)
--memory-manager-policy string Default: None
Memory Manager policy to use. Possible values: "None", "Static". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--minimum-container-ttl-duration duration
Minimum age for a finished container before it is garbage collected. Examples: "300ms", "10s" or "2h45m". (DEPRECATED: Use --eviction-hard or --eviction-soft instead. Will be removed in a future version.)
Minimum age for an unused image before it is garbage collected. Examples: "300ms", "10s" or "2h45m". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--node-ip string
IP address (or comma-separated dual-stack IP addresses) of the node. If unset, kubelet will use the node's default IPv4 address, if any, or its default IPv6 address if it has no IPv4 addresses. You can pass "::" to make it prefer the default IPv6 address rather than the default IPv4 address.
--node-labels <key=value pairs>
<Warning: Alpha feature>Labels to add when registering the node in the cluster. Labels must be key=value pairs separated by ','. Labels in the 'kubernetes.io' namespace must begin with an allowed prefix ('kubelet.kubernetes.io', 'node.kubernetes.io') or be in the specifically allowed set ('beta.kubernetes.io/arch', 'beta.kubernetes.io/instance-type', 'beta.kubernetes.io/os', 'failure-domain.beta.kubernetes.io/region', 'failure-domain.beta.kubernetes.io/zone', 'kubernetes.io/arch', 'kubernetes.io/hostname', 'kubernetes.io/os', 'node.kubernetes.io/instance-type', 'topology.kubernetes.io/region', 'topology.kubernetes.io/zone')
--node-status-max-images int32 Default: 50
The maximum number of images to report in node.status.images. If -1 is specified, no cap will be applied. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Specifies how often kubelet posts node status to master. Note: be cautious when changing the constant, it must work with nodeMonitorGracePeriod in Node controller. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--oom-score-adj int32 Default: -999
The oom-score-adj value for kubelet process. Values must be within the range [-1000, 1000]. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--pod-cidr string
The CIDR to use for pod IP addresses, only used in standalone mode. In cluster mode, this is obtained from the master. For IPv6, the maximum number of IP's allocated is 65536 (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Specified image will not be pruned by the image garbage collector. CRI implementations have their own configuration to set this image. (DEPRECATED: will be removed in 1.27. Image garbage collector will get sandbox image information from CRI.)
--pod-manifest-path string
Path to the directory containing static pod files to run, or the path to a single static pod file. Files starting with dots will be ignored. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--pod-max-pids int Default: -1
Set the maximum number of processes per pod. If -1, the kubelet defaults to the node allocatable PID capacity. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--pods-per-core int32
Number of Pods per core that can run on this kubelet. The total number of pods on this kubelet cannot exceed --max-pods, so --max-pods will be used if this calculation results in a larger number of pods allowed on the kubelet. A value of 0 disables this limit. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--port int32 Default: 10250
The port for the kubelet to serve on. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--protect-kernel-defaults
Default kubelet behaviour for kernel tuning. If set, kubelet errors if any of kernel tunables is different than kubelet defaults. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--provider-id string
Unique identifier for identifying the node in a machine database, i.e cloud provider. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--qos-reserved string
<Warning: Alpha feature> A set of <resource name>=<percentage> (e.g. "memory=50%") pairs that describe how pod resource requests are reserved at the QoS level. Currently only memory is supported. Requires the QOSReserved feature gate to be enabled. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--read-only-port int32 Default: 10255
The read-only port for the kubelet to serve on with no authentication/authorization (set to 0 to disable). (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--register-node Default: true
Register the node with the API server. If --kubeconfig is not provided, this flag is irrelevant, as the kubelet won't have an API server to register with. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--register-schedulable Default: true
Register the node as schedulable. Won't have any effect if --register-node is false. (DEPRECATED: will be removed in a future version)
--register-with-taints string
Register the node with the given list of taints (comma separated <key>=<value>:<effect>). No-op if --register-node is false. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--registry-burst int32 Default: 10
Maximum size of a bursty pulls, temporarily allows pulls to burst to this number, while still not exceeding --registry-qps. Only used if --registry-qps is greater than 0. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--registry-qps int32 Default: 5
If > 0, limit registry pull QPS to this value. If 0, unlimited. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--reserved-cpus string
A comma-separated list of CPUs or CPU ranges that are reserved for system and kubernetes usage. This specific list will supersede cpu counts in --system-reserved and --kube-reserved. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--reserved-memory string
A comma-separated list of memory reservations for NUMA nodes. (e.g. "--reserved-memory 0:memory=1Gi,hugepages-1M=2Gi --reserved-memory 1:memory=2Gi"). The total sum for each memory type should be equal to the sum of --kube-reserved, --system-reserved and --eviction-threshold. See here for more details. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--resolv-conf string Default: /etc/resolv.conf
Resolver configuration file used as the basis for the container DNS resolution configuration. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--root-dir string Default: /var/lib/kubelet
Directory path for managing kubelet files (volume mounts, etc).
--rotate-certificates
Auto rotate the kubelet client certificates by requesting new certificates from the kube-apiserver when the certificate expiration approaches. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--rotate-server-certificates
Auto-request and rotate the kubelet serving certificates by requesting new certificates from the kube-apiserver when the certificate expiration approaches. Requires the RotateKubeletServerCertificate feature gate to be enabled, and approval of the submitted CertificateSigningRequest objects. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--runonce
If true, exit after spawning pods from local manifests or remote urls. Exclusive with --enable-server (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--runtime-cgroups string
Optional absolute name of cgroups to create and run the runtime in.
--runtime-request-timeout duration Default: 2m0s
Timeout of all runtime requests except long running request - pull, logs, exec and attach. When timeout exceeded, kubelet will cancel the request, throw out an error and retry later. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--seccomp-default Default: false
Enable the use of RuntimeDefault as the default seccomp profile for all workloads.
--serialize-image-pulls Default: true
Pull images one at a time. We recommend *not* changing the default value on nodes that run docker daemon with version < 1.9 or an aufs storage backend. Issue #10959 has more details. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Maximum time a streaming connection can be idle before the connection is automatically closed. 0 indicates no timeout. Example: 5m. Note: All connections to the kubelet server have a maximum duration of 4 hours. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--sync-frequency duration Default: 1m0s
Max period between synchronizing running containers and config. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--system-cgroups string
Optional absolute name of cgroups in which to place all non-kernel processes that are not already inside a cgroup under '/'. Empty for no container. Rolling back the flag requires a reboot. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--system-reserved string Default: <none>
A set of <resource name>=<resource quantity> (e.g. "cpu=200m,memory=500Mi,ephemeral-storage=1Gi,pid='100'") pairs that describe resources reserved for non-kubernetes components. Currently only cpu and memory and local ephemeral storage for root file system are supported. See here for more detail. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--system-reserved-cgroup string Default: ''
Absolute name of the top level cgroup that is used to manage non-kubernetes components for which compute resources were reserved via --system-reserved flag. Ex. /system-reserved. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--tls-cert-file string
File containing x509 certificate used for serving HTTPS (with intermediate certs, if any, concatenated after server cert). If --tls-cert-file and --tls-private-key-file are not provided, a self-signed certificate and key are generated for the public address and saved to the directory passed to --cert-dir. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--tls-cipher-suites string
Comma-separated list of cipher suites for the server. If omitted, the default Go cipher suites will be used.
Preferred values:
TLS_AES_128_GCM_SHA256, TLS_AES_256_GCM_SHA384, TLS_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, TLS_RSA_WITH_AES_256_GCM_SHA384
Insecure values:
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_RC4_128_SHA.
(DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--tls-min-version string
Minimum TLS version supported. Possible values: "VersionTLS10", "VersionTLS11", "VersionTLS12", "VersionTLS13". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--tls-private-key-file string
File containing x509 private key matching --tls-cert-file. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--topology-manager-policy string Default: 'none'
Topology Manager policy to use. Possible values: "none", "best-effort", "restricted", "single-numa-node". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--topology-manager-policy-options string
A set of <key>=<value> topology manager policy options to use, to fine tune their behaviour. If not supplied, keep the default behaviour. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
Scope to which topology hints are applied. Topology manager collects hints from hint providers and applies them to the defined scope to ensure the pod admission. Possible values: "container", "pod". (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
-v, --v Level
Number for the log level verbosity
--version version[=true]
Print version information and quit; --version=vX.Y.Z... sets the reported version.
--vmodule <A list of 'pattern=N' strings>
Comma-separated list of pattern=N settings for file-filtered logging (only works for text log format).
The full path of the directory in which to search for additional third party volume plugins. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
--volume-stats-agg-period duration Default: 1m0s
Specifies interval for kubelet to calculate and cache the volume disk usage for all pods and volumes. To disable volume calculations, set to 0. (DEPRECATED: This parameter should be set via the config file specified by the kubelet's --config flag. See kubelet-config-file for more information.)
12.4 - kube-apiserver
Synopsis
The Kubernetes API server validates and configures data
for the api objects which include pods, services, replicationcontrollers, and
others. The API Server services REST operations and provides the frontend to the
cluster's shared state through which all other components interact.
kube-apiserver [flags]
Options
--admission-control-config-file string
File with admission control configuration.
--advertise-address string
The IP address on which to advertise the apiserver to members of the cluster. This address must be reachable by the rest of the cluster. If blank, the --bind-address will be used. If --bind-address is unspecified, the host's default interface will be used.
Aggregator reject forwarding redirect response back to client.
--allow-metric-labels stringToString Default: []
The map from metric-label to value allow-list of this label. The key's format is <MetricName>,<LabelName>. The value's format is <allowed_value>,<allowed_value>...e.g. metric1,label1='v1,v2,v3', metric1,label2='v1,v2,v3' metric2,label1='v1,v2,v3'.
--allow-privileged
If true, allow privileged containers. [default=false]
--anonymous-auth Default: true
Enables anonymous requests to the secure port of the API server. Requests that are not rejected by another authentication method are treated as anonymous requests. Anonymous requests have a username of system:anonymous, and a group name of system:unauthenticated.
--api-audiences strings
Identifiers of the API. The service account token authenticator will validate that tokens used against the API are bound to at least one of these audiences. If the --service-account-issuer flag is configured and this flag is not, this field defaults to a single element list containing the issuer URL.
--audit-log-batch-buffer-size int Default: 10000
The size of the buffer to store events before batching and writing. Only used in batch mode.
--audit-log-batch-max-size int Default: 1
The maximum size of a batch. Only used in batch mode.
--audit-log-batch-max-wait duration
The amount of time to wait before force writing the batch that hadn't reached the max size. Only used in batch mode.
--audit-log-batch-throttle-burst int
Maximum number of requests sent at the same moment if ThrottleQPS was not utilized before. Only used in batch mode.
--audit-log-batch-throttle-enable
Whether batching throttling is enabled. Only used in batch mode.
--audit-log-batch-throttle-qps float
Maximum average number of batches per second. Only used in batch mode.
--audit-log-compress
If set, the rotated log files will be compressed using gzip.
--audit-log-format string Default: "json"
Format of saved audits. "legacy" indicates 1-line text format for each event. "json" indicates structured json format. Known formats are legacy,json.
--audit-log-maxage int
The maximum number of days to retain old audit log files based on the timestamp encoded in their filename.
--audit-log-maxbackup int
The maximum number of old audit log files to retain. Setting a value of 0 will mean there's no restriction on the number of files.
--audit-log-maxsize int
The maximum size in megabytes of the audit log file before it gets rotated.
--audit-log-mode string Default: "blocking"
Strategy for sending audit events. Blocking indicates sending events should block server responses. Batch causes the backend to buffer and write events asynchronously. Known modes are batch,blocking,blocking-strict.
--audit-log-path string
If set, all requests coming to the apiserver will be logged to this file. '-' means standard out.
--audit-log-truncate-enabled
Whether event and batch truncating is enabled.
--audit-log-truncate-max-batch-size int Default: 10485760
Maximum size of the batch sent to the underlying backend. Actual serialized size can be several hundreds of bytes greater. If a batch exceeds this limit, it is split into several batches of smaller size.
--audit-log-truncate-max-event-size int Default: 102400
Maximum size of the audit event sent to the underlying backend. If the size of an event is greater than this number, first request and response are removed, and if this doesn't reduce the size enough, event is discarded.
The amount of time to wait before retrying the first failed request.
--audit-webhook-mode string Default: "batch"
Strategy for sending audit events. Blocking indicates sending events should block server responses. Batch causes the backend to buffer and write events asynchronously. Known modes are batch,blocking,blocking-strict.
--audit-webhook-truncate-enabled
Whether event and batch truncating is enabled.
--audit-webhook-truncate-max-batch-size int Default: 10485760
Maximum size of the batch sent to the underlying backend. Actual serialized size can be several hundreds of bytes greater. If a batch exceeds this limit, it is split into several batches of smaller size.
--audit-webhook-truncate-max-event-size int Default: 102400
Maximum size of the audit event sent to the underlying backend. If the size of an event is greater than this number, first request and response are removed, and if this doesn't reduce the size enough, event is discarded.
The duration to cache responses from the webhook token authenticator.
--authentication-token-webhook-config-file string
File with webhook configuration for token authentication in kubeconfig format. The API server will query the remote service to determine authentication for bearer tokens.
The duration to cache 'unauthorized' responses from the webhook authorizer.
--authorization-webhook-config-file string
File with webhook configuration in kubeconfig format, used with --authorization-mode=Webhook. The API server will query the remote service to determine access on the API server's secure port.
The API version of the authorization.k8s.io SubjectAccessReview to send to and expect from the webhook.
--azure-container-registry-config string
Path to the file containing Azure container registry configuration information.
--bind-address string Default: 0.0.0.0
The IP address on which to listen for the --secure-port port. The associated interface(s) must be reachable by the rest of the cluster, and by CLI/web clients. If blank or an unspecified address (0.0.0.0 or ::), all interfaces and IP address families will be used.
--cert-dir string Default: "/var/run/kubernetes"
The directory where the TLS certs are located. If --tls-cert-file and --tls-private-key-file are provided, this flag will be ignored.
--client-ca-file string
If set, any request presenting a client certificate signed by one of the authorities in the client-ca-file is authenticated with an identity corresponding to the CommonName of the client certificate.
--cloud-config string
The path to the cloud provider configuration file. Empty string for no configuration file.
--cloud-provider string
The provider for cloud services. Empty string for no provider.
CIDRs opened in GCE firewall for L7 LB traffic proxy & health checks
--contention-profiling
Enable block profiling, if profiling is enabled
--cors-allowed-origins strings
List of allowed origins for CORS, comma separated. An allowed origin can be a regular expression to support subdomain matching. If this list is empty CORS will not be enabled. Please ensure each expression matches the entire hostname by anchoring to the start with '^' or including the '//' prefix, and by anchoring to the end with '$' or including the ':' port separator suffix. Examples of valid expressions are '//example.com(:|$)' and '^https://example.com(:|$)'
--debug-socket-path string
Use an unprotected (no authn/authz) unix-domain socket for profiling with the given path
--default-not-ready-toleration-seconds int Default: 300
Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.
--default-unreachable-toleration-seconds int Default: 300
Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.
--delete-collection-workers int Default: 1
Number of workers spawned for DeleteCollection call. These are used to speed up namespace cleanup.
--disable-admission-plugins strings
admission plugins that should be disabled although they are in the default enabled plugins list (NamespaceLifecycle, LimitRanger, ServiceAccount, TaintNodesByCondition, PodSecurity, Priority, DefaultTolerationSeconds, DefaultStorageClass, StorageObjectInUseProtection, PersistentVolumeClaimResize, RuntimeClass, CertificateApproval, CertificateSigning, ClusterTrustBundleAttest, CertificateSubjectRestriction, DefaultIngressClass, MutatingAdmissionWebhook, ValidatingAdmissionPolicy, ValidatingAdmissionWebhook, ResourceQuota). Comma-delimited list of admission plugins: AlwaysAdmit, AlwaysDeny, AlwaysPullImages, CertificateApproval, CertificateSigning, CertificateSubjectRestriction, ClusterTrustBundleAttest, DefaultIngressClass, DefaultStorageClass, DefaultTolerationSeconds, DenyServiceExternalIPs, EventRateLimit, ExtendedResourceToleration, ImagePolicyWebhook, LimitPodHardAntiAffinityTopology, LimitRanger, MutatingAdmissionWebhook, NamespaceAutoProvision, NamespaceExists, NamespaceLifecycle, NodeRestriction, OwnerReferencesPermissionEnforcement, PersistentVolumeClaimResize, PersistentVolumeLabel, PodNodeSelector, PodSecurity, PodTolerationRestriction, Priority, ResourceQuota, RuntimeClass, SecurityContextDeny, ServiceAccount, StorageObjectInUseProtection, TaintNodesByCondition, ValidatingAdmissionPolicy, ValidatingAdmissionWebhook. The order of plugins in this flag does not matter.
--disabled-metrics strings
This flag provides an escape hatch for misbehaving metrics. You must provide the fully qualified metric name in order to disable it. Disclaimer: disabling metrics is higher in precedence than showing hidden metrics.
--egress-selector-config-file string
File with apiserver egress selector configuration.
--enable-admission-plugins strings
admission plugins that should be enabled in addition to default enabled ones (NamespaceLifecycle, LimitRanger, ServiceAccount, TaintNodesByCondition, PodSecurity, Priority, DefaultTolerationSeconds, DefaultStorageClass, StorageObjectInUseProtection, PersistentVolumeClaimResize, RuntimeClass, CertificateApproval, CertificateSigning, ClusterTrustBundleAttest, CertificateSubjectRestriction, DefaultIngressClass, MutatingAdmissionWebhook, ValidatingAdmissionPolicy, ValidatingAdmissionWebhook, ResourceQuota). Comma-delimited list of admission plugins: AlwaysAdmit, AlwaysDeny, AlwaysPullImages, CertificateApproval, CertificateSigning, CertificateSubjectRestriction, ClusterTrustBundleAttest, DefaultIngressClass, DefaultStorageClass, DefaultTolerationSeconds, DenyServiceExternalIPs, EventRateLimit, ExtendedResourceToleration, ImagePolicyWebhook, LimitPodHardAntiAffinityTopology, LimitRanger, MutatingAdmissionWebhook, NamespaceAutoProvision, NamespaceExists, NamespaceLifecycle, NodeRestriction, OwnerReferencesPermissionEnforcement, PersistentVolumeClaimResize, PersistentVolumeLabel, PodNodeSelector, PodSecurity, PodTolerationRestriction, Priority, ResourceQuota, RuntimeClass, SecurityContextDeny, ServiceAccount, StorageObjectInUseProtection, TaintNodesByCondition, ValidatingAdmissionPolicy, ValidatingAdmissionWebhook. The order of plugins in this flag does not matter.
--enable-aggregator-routing
Turns on aggregator routing requests to endpoints IP rather than cluster IP.
--enable-bootstrap-token-auth
Enable to allow secrets of type 'bootstrap.kubernetes.io/token' in the 'kube-system' namespace to be used for TLS bootstrapping authentication.
--enable-garbage-collector Default: true
Enables the generic garbage collector. MUST be synced with the corresponding flag of the kube-controller-manager.
--enable-priority-and-fairness Default: true
If true and the APIPriorityAndFairness feature gate is enabled, replace the max-in-flight handler with an enhanced one that queues and dispatches with priority and fairness
--encryption-provider-config string
The file containing configuration for encryption providers to be used for storing secrets in etcd
--encryption-provider-config-automatic-reload
Determines if the file set by --encryption-provider-config should be automatically reloaded if the disk contents change. Setting this to true disables the ability to uniquely identify distinct KMS plugins via the API server healthz endpoints.
The interval of requests to poll etcd and update metric. 0 disables the metric collection
--etcd-healthcheck-timeout duration Default: 2s
The timeout to use when checking etcd health.
--etcd-keyfile string
SSL key file used to secure etcd communication.
--etcd-prefix string Default: "/registry"
The prefix to prepend to all resource paths in etcd.
--etcd-readycheck-timeout duration Default: 2s
The timeout to use when checking etcd readiness
--etcd-servers strings
List of etcd servers to connect with (scheme://ip:port), comma separated.
--etcd-servers-overrides strings
Per-resource etcd servers overrides, comma separated. The individual override format: group/resource#servers, where servers are URLs, semicolon separated. Note that this applies only to resources compiled into this server binary.
--event-ttl duration Default: 1h0m0s
Amount of time to retain events.
--external-hostname string
The hostname to use when generating externalized URLs for this master (e.g. Swagger API Docs or OpenID Discovery).
To prevent HTTP/2 clients from getting stuck on a single apiserver, randomly close a connection (GOAWAY). The client's other in-flight requests won't be affected, and the client will reconnect, likely landing on a different apiserver after going through the load balancer again. This argument sets the fraction of requests that will be sent a GOAWAY. Clusters with single apiservers, or which don't use a load balancer, should NOT enable this. Min is 0 (off), Max is .02 (1/50 requests); .001 (1/1000) is a recommended starting point.
-h, --help
help for kube-apiserver
--http2-max-streams-per-connection int
The limit that the server gives to clients for the maximum number of streams in an HTTP/2 connection. Zero means to use golang's default.
--kubelet-certificate-authority string
Path to a cert file for the certificate authority.
List of the preferred NodeAddressTypes to use for kubelet connections.
--kubelet-timeout duration Default: 5s
Timeout for kubelet operations.
--kubernetes-service-node-port int
If non-zero, the Kubernetes master service (which apiserver creates/maintains) will be of type NodePort, using this as the value of the port. If zero, the Kubernetes master service will be of type ClusterIP.
--lease-reuse-duration-seconds int Default: 60
The time in seconds that each lease is reused. A lower value could avoid large number of objects reusing the same lease. Notice that a too small value may cause performance problems at storage layer.
--livez-grace-period duration
This option represents the maximum amount of time it should take for apiserver to complete its startup sequence and become live. From apiserver's start time to when this amount of time has elapsed, /livez will assume that unfinished post-start hooks will complete successfully and therefore return true.
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes
--logging-format string Default: "text"
Sets the log format. Permitted formats: "text".
--max-connection-bytes-per-sec int
If non-zero, throttle each user connection to this number of bytes/sec. Currently only applies to long-running requests.
--max-mutating-requests-inflight int Default: 200
This and --max-requests-inflight are summed to determine the server's total concurrency limit (which must be positive) if --enable-priority-and-fairness is true. Otherwise, this flag limits the maximum number of mutating requests in flight, or a zero value disables the limit completely.
--max-requests-inflight int Default: 400
This and --max-mutating-requests-inflight are summed to determine the server's total concurrency limit (which must be positive) if --enable-priority-and-fairness is true. Otherwise, this flag limits the maximum number of non-mutating requests in flight, or a zero value disables the limit completely.
--min-request-timeout int Default: 1800
An optional field indicating the minimum number of seconds a handler must keep a request open before timing it out. Currently only honored by the watch request handler, which picks a randomized value above this number as the connection timeout, to spread out load.
--oidc-ca-file string
If set, the OpenID server's certificate will be verified by one of the authorities in the oidc-ca-file, otherwise the host's root CA set will be used.
--oidc-client-id string
The client ID for the OpenID Connect client, must be set if oidc-issuer-url is set.
--oidc-groups-claim string
If provided, the name of a custom OpenID Connect claim for specifying user groups. The claim value is expected to be a string or array of strings. This flag is experimental, please see the authentication documentation for further details.
--oidc-groups-prefix string
If provided, all groups will be prefixed with this value to prevent conflicts with other authentication strategies.
--oidc-issuer-url string
The URL of the OpenID issuer, only HTTPS scheme will be accepted. If set, it will be used to verify the OIDC JSON Web Token (JWT).
A key=value pair that describes a required claim in the ID Token. If set, the claim is verified to be present in the ID Token with a matching value. Repeat this flag to specify multiple claims.
--oidc-signing-algs strings Default: "RS256"
Comma-separated list of allowed JOSE asymmetric signing algorithms. JWTs with a supported 'alg' header values are: RS256, RS384, RS512, ES256, ES384, ES512, PS256, PS384, PS512. Values are defined by RFC 7518 https://tools.ietf.org/html/rfc7518#section-3.1.
--oidc-username-claim string Default: "sub"
The OpenID claim to use as the user name. Note that claims other than the default ('sub') is not guaranteed to be unique and immutable. This flag is experimental, please see the authentication documentation for further details.
--oidc-username-prefix string
If provided, all usernames will be prefixed with this value. If not provided, username claims other than 'email' are prefixed by the issuer URL to avoid clashes. To skip any prefixing, provide the value '-'.
--peer-advertise-ip string
If set and the UnknownVersionInteroperabilityProxy feature gate is enabled, this IP will be used by peer kube-apiservers to proxy requests to this kube-apiserver when the request cannot be handled by the peer due to version skew between the kube-apiservers. This flag is only used in clusters configured with multiple kube-apiservers for high availability.
--peer-advertise-port string
If set and the UnknownVersionInteroperabilityProxy feature gate is enabled, this port will be used by peer kube-apiservers to proxy requests to this kube-apiserver when the request cannot be handled by the peer due to version skew between the kube-apiservers. This flag is only used in clusters configured with multiple kube-apiservers for high availability.
--peer-ca-file string
If set and the UnknownVersionInteroperabilityProxy feature gate is enabled, this file will be used to verify serving certificates of peer kube-apiservers. This flag is only used in clusters configured with multiple kube-apiservers for high availability.
--permit-address-sharing
If true, SO_REUSEADDR will be used when binding the port. This allows binding to wildcard IPs like 0.0.0.0 and specific IPs in parallel, and it avoids waiting for the kernel to release sockets in TIME_WAIT state. [default=false]
--permit-port-sharing
If true, SO_REUSEPORT will be used when binding the port, which allows more than one instance to bind on the same address and port. [default=false]
--profiling Default: true
Enable profiling via web interface host:port/debug/pprof/
--proxy-client-cert-file string
Client certificate used to prove the identity of the aggregator or kube-apiserver when it must call out during a request. This includes proxying requests to a user api-server and calling out to webhook admission plugins. It is expected that this cert includes a signature from the CA in the --requestheader-client-ca-file flag. That CA is published in the 'extension-apiserver-authentication' configmap in the kube-system namespace. Components receiving calls from kube-aggregator should use that CA to perform their half of the mutual TLS verification.
--proxy-client-key-file string
Private key for the client certificate used to prove the identity of the aggregator or kube-apiserver when it must call out during a request. This includes proxying requests to a user api-server and calling out to webhook admission plugins.
--request-timeout duration Default: 1m0s
An optional field indicating the duration a handler must keep a request open before timing it out. This is the default request timeout for requests but may be overridden by flags such as --min-request-timeout for specific types of requests.
--requestheader-allowed-names strings
List of client certificate common names to allow to provide usernames in headers specified by --requestheader-username-headers. If empty, any client certificate validated by the authorities in --requestheader-client-ca-file is allowed.
--requestheader-client-ca-file string
Root certificate bundle to use to verify client certificates on incoming requests before trusting usernames in headers specified by --requestheader-username-headers. WARNING: generally do not depend on authorization being already done for incoming requests.
--requestheader-extra-headers-prefix strings
List of request header prefixes to inspect. X-Remote-Extra- is suggested.
--requestheader-group-headers strings
List of request headers to inspect for groups. X-Remote-Group is suggested.
--requestheader-username-headers strings
List of request headers to inspect for usernames. X-Remote-User is common.
A set of key=value pairs that enable or disable built-in APIs. Supported options are: v1=true|false for the core API group <group>/<version>=true|false for a specific API group and version (e.g. apps/v1=true) api/all=true|false controls all API versions api/ga=true|false controls all API versions of the form v[0-9]+ api/beta=true|false controls all API versions of the form v[0-9]+beta[0-9]+ api/alpha=true|false controls all API versions of the form v[0-9]+alpha[0-9]+ api/legacy is deprecated, and will be removed in a future version
--secure-port int Default: 6443
The port on which to serve HTTPS with authentication and authorization. It cannot be switched off with 0.
Turns on projected service account expiration extension during token generation, which helps safe transition from legacy token to bound service account token feature. If this flag is enabled, admission injected tokens would be extended up to 1 year to prevent unexpected failure during transition, ignoring value of service-account-max-token-expiration.
--service-account-issuer strings
Identifier of the service account token issuer. The issuer will assert this identifier in "iss" claim of issued tokens. This value is a string or URI. If this option is not a valid URI per the OpenID Discovery 1.0 spec, the ServiceAccountIssuerDiscovery feature will remain disabled, even if the feature gate is set to true. It is highly recommended that this value comply with the OpenID spec: https://openid.net/specs/openid-connect-discovery-1_0.html. In practice, this means that service-account-issuer must be an https URL. It is also highly recommended that this URL be capable of serving OpenID discovery documents at {service-account-issuer}/.well-known/openid-configuration. When this flag is specified multiple times, the first is used to generate tokens and all are used to determine which issuers are accepted.
--service-account-jwks-uri string
Overrides the URI for the JSON Web Key Set in the discovery doc served at /.well-known/openid-configuration. This flag is useful if the discovery docand key set are served to relying parties from a URL other than the API server's external (as auto-detected or overridden with external-hostname).
--service-account-key-file strings
File containing PEM-encoded x509 RSA or ECDSA private or public keys, used to verify ServiceAccount tokens. The specified file can contain multiple keys, and the flag can be specified multiple times with different files. If unspecified, --tls-private-key-file is used. Must be specified when --service-account-signing-key-file is provided
--service-account-lookup Default: true
If true, validate ServiceAccount tokens exist in etcd as part of authentication.
--service-account-max-token-expiration duration
The maximum validity duration of a token created by the service account token issuer. If an otherwise valid TokenRequest with a validity duration larger than this value is requested, a token will be issued with a validity duration of this value.
--service-account-signing-key-file string
Path to the file that contains the current private key of the service account token issuer. The issuer will sign issued ID tokens with this private key.
--service-cluster-ip-range string
A CIDR notation IP range from which to assign service cluster IPs. This must not overlap with any IP ranges assigned to nodes or pods. Max of two dual-stack CIDRs is allowed.
--service-node-port-range <a string in the form 'N1-N2'> Default: 30000-32767
A port range to reserve for services with NodePort visibility. This must not overlap with the ephemeral port range on nodes. Example: '30000-32767'. Inclusive at both ends of the range.
--show-hidden-metrics-for-version string
The previous version for which you want to show hidden metrics. Only the previous minor version is meaningful, other values will not be allowed. The format is <major>.<minor>, e.g.: '1.16'. The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, rather than being surprised when they are permanently removed in the release after that.
--shutdown-delay-duration duration
Time to delay the termination. During that time the server keeps serving requests normally. The endpoints /healthz and /livez will return success, but /readyz immediately returns failure. Graceful termination starts after this delay has elapsed. This can be used to allow load balancer to stop sending traffic to this server.
--shutdown-send-retry-after
If true the HTTP Server will continue listening until all non long running request(s) in flight have been drained, during this window all incoming requests will be rejected with a status code 429 and a 'Retry-After' response header, in addition 'Connection: close' response header is set in order to tear down the TCP connection when idle.
This option, if set, represents the maximum amount of grace period the apiserver will wait for active watch request(s) to drain during the graceful server shutdown window.
--storage-backend string
The storage backend for persistence. Options: 'etcd3' (default).
The media type to use to store objects in storage. Some resources or storage backends may only support a specific media type and will ignore this setting. Supported media types: [application/json, application/yaml, application/vnd.kubernetes.protobuf]
--strict-transport-security-directives strings
List of directives for HSTS, comma separated. If this list is empty, then HSTS directives will not be added. Example: 'max-age=31536000,includeSubDomains,preload'
--tls-cert-file string
File containing the default x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert). If HTTPS serving is enabled, and --tls-cert-file and --tls-private-key-file are not provided, a self-signed certificate and key are generated for the public address and saved to the directory specified by --cert-dir.
--tls-cipher-suites strings
Comma-separated list of cipher suites for the server. If omitted, the default Go cipher suites will be used. Preferred values: TLS_AES_128_GCM_SHA256, TLS_AES_256_GCM_SHA384, TLS_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, TLS_RSA_WITH_AES_256_GCM_SHA384. Insecure values: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_RC4_128_SHA.
--tls-min-version string
Minimum TLS version supported. Possible values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13
--tls-private-key-file string
File containing the default x509 private key matching --tls-cert-file.
--tls-sni-cert-key string
A pair of x509 certificate and private key file paths, optionally suffixed with a list of domain patterns which are fully qualified domain names, possibly with prefixed wildcard segments. The domain patterns also allow IP addresses, but IPs should only be used if the apiserver has visibility to the IP address requested by a client. If no domain patterns are provided, the names of the certificate are extracted. Non-wildcard matches trump over wildcard matches, explicit domain patterns trump over extracted names. For multiple key/certificate pairs, use the --tls-sni-cert-key multiple times. Examples: "example.crt,example.key" or "foo.crt,foo.key:*.foo.com,foo.com".
--token-auth-file string
If set, the file that will be used to secure the secure port of the API server via token authentication.
--tracing-config-file string
File with apiserver tracing configuration.
-v, --v int
number for the log level verbosity
--version version[=true]
--version, --version=raw prints version information and quits; --version=vX.Y.Z... sets the reported version
--vmodule pattern=N,...
comma-separated list of pattern=N settings for file-filtered logging (only works for text log format)
--watch-cache Default: true
Enable watch caching in the apiserver
--watch-cache-sizes strings
Watch cache size settings for some resources (pods, nodes, etc.), comma separated. The individual setting format: resource[.group]#size, where resource is lowercase plural (no version), group is omitted for resources of apiVersion v1 (the legacy core API) and included for others, and size is a number. This option is only meaningful for resources built into the apiserver, not ones defined by CRDs or aggregated from external servers, and is only consulted if the watch-cache is enabled. The only meaningful size setting to supply here is zero, which means to disable watch caching for the associated resource; all non-zero values are equivalent and mean to not disable watch caching for that resource
12.5 - kube-controller-manager
Synopsis
The Kubernetes controller manager is a daemon that embeds
the core control loops shipped with Kubernetes. In applications of robotics and
automation, a control loop is a non-terminating loop that regulates the state of
the system. In Kubernetes, a controller is a control loop that watches the shared
state of the cluster through the apiserver and makes changes attempting to move the
current state towards the desired state. Examples of controllers that ship with
Kubernetes today are the replication controller, endpoints controller, namespace
controller, and serviceaccounts controller.
kube-controller-manager [flags]
Options
--allocate-node-cidrs
Should CIDRs for Pods be allocated and set on the cloud provider.
--allow-metric-labels stringToString Default: []
The map from metric-label to value allow-list of this label. The key's format is <MetricName>,<LabelName>. The value's format is <allowed_value>,<allowed_value>...e.g. metric1,label1='v1,v2,v3', metric1,label2='v1,v2,v3' metric2,label1='v1,v2,v3'.
The reconciler sync wait time between volume attach detach. This duration must be larger than one second, and increasing this value from the default may allow for volumes to be mismatched with pods.
--authentication-kubeconfig string
kubeconfig file pointing at the 'core' kubernetes server with enough rights to create tokenreviews.authentication.k8s.io. This is optional. If empty, all token requests are considered to be anonymous and no client CA is looked up in the cluster.
--authentication-skip-lookup
If false, the authentication-kubeconfig will be used to lookup missing authentication configuration from the cluster.
The duration to cache responses from the webhook token authenticator.
--authentication-tolerate-lookup-failure
If true, failures to look up missing authentication configuration from the cluster are not considered fatal. Note that this can result in authentication that treats all requests as anonymous.
A list of HTTP paths to skip during authorization, i.e. these are authorized without contacting the 'core' kubernetes server.
--authorization-kubeconfig string
kubeconfig file pointing at the 'core' kubernetes server with enough rights to create subjectaccessreviews.authorization.k8s.io. This is optional. If empty, all requests not skipped by authorization are forbidden.
The duration to cache 'unauthorized' responses from the webhook authorizer.
--azure-container-registry-config string
Path to the file containing Azure container registry configuration information.
--bind-address string Default: 0.0.0.0
The IP address on which to listen for the --secure-port port. The associated interface(s) must be reachable by the rest of the cluster, and by CLI/web clients. If blank or an unspecified address (0.0.0.0 or ::), all interfaces and IP address families will be used.
--cert-dir string
The directory where the TLS certs are located. If --tls-cert-file and --tls-private-key-file are provided, this flag will be ignored.
If set, any request presenting a client certificate signed by one of the authorities in the client-ca-file is authenticated with an identity corresponding to the CommonName of the client certificate.
--cloud-config string
The path to the cloud provider configuration file. Empty string for no configuration file.
--cloud-provider string
The provider for cloud services. Empty string for no provider.
--cluster-cidr string
CIDR Range for Pods in cluster. Requires --allocate-node-cidrs to be true
--cluster-name string Default: "kubernetes"
The instance prefix for the cluster.
--cluster-signing-cert-file string
Filename containing a PEM-encoded X509 CA certificate used to issue cluster-scoped certificates. If specified, no more specific --cluster-signing-* flag may be specified.
The max length of duration signed certificates will be given. Individual CSRs may request shorter certs by setting spec.expirationSeconds.
--cluster-signing-key-file string
Filename containing a PEM-encoded RSA or ECDSA private key used to sign cluster-scoped certificates. If specified, no more specific --cluster-signing-* flag may be specified.
Filename containing a PEM-encoded X509 CA certificate used to issue certificates for the kubernetes.io/kube-apiserver-client signer. If specified, --cluster-signing-{cert,key}-file must not be set.
Filename containing a PEM-encoded RSA or ECDSA private key used to sign certificates for the kubernetes.io/kube-apiserver-client signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--cluster-signing-kubelet-client-cert-file string
Filename containing a PEM-encoded X509 CA certificate used to issue certificates for the kubernetes.io/kube-apiserver-client-kubelet signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--cluster-signing-kubelet-client-key-file string
Filename containing a PEM-encoded RSA or ECDSA private key used to sign certificates for the kubernetes.io/kube-apiserver-client-kubelet signer. If specified, --cluster-signing-{cert,key}-file must not be set.
Filename containing a PEM-encoded X509 CA certificate used to issue certificates for the kubernetes.io/kubelet-serving signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--cluster-signing-kubelet-serving-key-file string
Filename containing a PEM-encoded RSA or ECDSA private key used to sign certificates for the kubernetes.io/kubelet-serving signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--cluster-signing-legacy-unknown-cert-file string
Filename containing a PEM-encoded X509 CA certificate used to issue certificates for the kubernetes.io/legacy-unknown signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--cluster-signing-legacy-unknown-key-file string
Filename containing a PEM-encoded RSA or ECDSA private key used to sign certificates for the kubernetes.io/legacy-unknown signer. If specified, --cluster-signing-{cert,key}-file must not be set.
--concurrent-cron-job-syncs int32 Default: 5
The number of cron job objects that are allowed to sync concurrently. Larger number = more responsive jobs, but more CPU (and network) load
--concurrent-deployment-syncs int32 Default: 5
The number of deployment objects that are allowed to sync concurrently. Larger number = more responsive deployments, but more CPU (and network) load
--concurrent-endpoint-syncs int32 Default: 5
The number of endpoint syncing operations that will be done concurrently. Larger number = faster endpoint updating, but more CPU (and network) load
The number of ephemeral volume syncing operations that will be done concurrently. Larger number = faster ephemeral volume updating, but more CPU (and network) load
--concurrent-gc-syncs int32 Default: 20
The number of garbage collector workers that are allowed to sync concurrently.
The number of horizontal pod autoscaler objects that are allowed to sync concurrently. Larger number = more responsive horizontal pod autoscaler objects processing, but more CPU (and network) load.
--concurrent-job-syncs int32 Default: 5
The number of job objects that are allowed to sync concurrently. Larger number = more responsive jobs, but more CPU (and network) load
--concurrent-namespace-syncs int32 Default: 10
The number of namespace objects that are allowed to sync concurrently. Larger number = more responsive namespace termination, but more CPU (and network) load
--concurrent-rc-syncs int32 Default: 5
The number of replication controllers that are allowed to sync concurrently. Larger number = more responsive replica management, but more CPU (and network) load
--concurrent-replicaset-syncs int32 Default: 5
The number of replica sets that are allowed to sync concurrently. Larger number = more responsive replica management, but more CPU (and network) load
The number of service endpoint syncing operations that will be done concurrently. Larger number = faster endpoint slice updating, but more CPU (and network) load. Defaults to 5.
--concurrent-service-syncs int32 Default: 1
The number of services that are allowed to sync concurrently. Larger number = more responsive service management, but more CPU (and network) load
The number of service account token objects that are allowed to sync concurrently. Larger number = more responsive token generation, but more CPU (and network) load
--concurrent-statefulset-syncs int32 Default: 5
The number of statefulset objects that are allowed to sync concurrently. Larger number = more responsive statefulsets, but more CPU (and network) load
The number of ValidatingAdmissionPolicyStatusController workers that are allowed to sync concurrently.
--configure-cloud-routes Default: true
Should CIDRs allocated by allocate-node-cidrs be configured on the cloud provider.
--contention-profiling
Enable block profiling, if profiling is enabled
--controller-start-interval duration
Interval between starting controller managers.
--controllers strings Default: "*"
A list of controllers to enable. '*' enables all on-by-default controllers, 'foo' enables the controller named 'foo', '-foo' disables the controller named 'foo'. All controllers: bootstrap-signer-controller, certificatesigningrequest-approving-controller, certificatesigningrequest-cleaner-controller, certificatesigningrequest-signing-controller, cloud-node-lifecycle-controller, clusterrole-aggregation-controller, cronjob-controller, daemonset-controller, deployment-controller, disruption-controller, endpoints-controller, endpointslice-controller, endpointslice-mirroring-controller, ephemeral-volume-controller, garbage-collector-controller, horizontal-pod-autoscaler-controller, job-controller, namespace-controller, node-ipam-controller, node-lifecycle-controller, node-route-controller, persistentvolume-attach-detach-controller, persistentvolume-binder-controller, persistentvolume-expander-controller, persistentvolume-protection-controller, persistentvolumeclaim-protection-controller, pod-garbage-collector-controller, replicaset-controller, replicationcontroller-controller, resourcequota-controller, root-ca-certificate-publisher-controller, service-lb-controller, serviceaccount-controller, serviceaccount-token-controller, statefulset-controller, token-cleaner-controller, ttl-after-finished-controller, ttl-controller Disabled-by-default controllers: bootstrap-signer-controller, token-cleaner-controller
--disable-attach-detach-reconcile-sync
Disable volume attach detach reconciler sync. Disabling this may cause volumes to be mismatched with pods. Use wisely.
--disabled-metrics strings
This flag provides an escape hatch for misbehaving metrics. You must provide the fully qualified metric name in order to disable it. Disclaimer: disabling metrics is higher in precedence than showing hidden metrics.
--enable-dynamic-provisioning Default: true
Enable dynamic provisioning for environments that support it.
--enable-garbage-collector Default: true
Enables the generic garbage collector. MUST be synced with the corresponding flag of the kube-apiserver.
--enable-hostpath-provisioner
Enable HostPath PV provisioning when running without a cloud provider. This allows testing and development of provisioning features. HostPath provisioning is not supported in any way, won't work in a multi-node cluster, and should not be used for anything other than testing or development.
--enable-leader-migration
Whether to enable controller leader migration.
--endpoint-updates-batch-period duration
The length of endpoint updates batching period. Processing of pod changes will be delayed by this duration to join them with potential upcoming updates and reduce the overall number of endpoints updates. Larger number = higher endpoint programming latency, but lower number of endpoints revision generated
--endpointslice-updates-batch-period duration
The length of endpoint slice updates batching period. Processing of pod changes will be delayed by this duration to join them with potential upcoming updates and reduce the overall number of endpoints updates. Larger number = higher endpoint programming latency, but lower number of endpoints revision generated
--external-cloud-volume-plugin string
The plugin to use when cloud provider is set to external. Can be empty, should only be set when cloud-provider is external. Currently used to allow node-ipam-controller, persistentvolume-binder-controller, persistentvolume-expander-controller and attach-detach-controller to work for in tree cloud providers.
QPS to use while talking with kubernetes apiserver.
--kubeconfig string
Path to kubeconfig file with authorization and master location information (the master location can be overridden by the master flag).
--large-cluster-size-threshold int32 Default: 50
Number of nodes from which node-lifecycle-controller treats the cluster as large for the eviction logic purposes. --secondary-node-eviction-rate is implicitly overridden to 0 for clusters this size or smaller.
--leader-elect Default: true
Start a leader election client and gain leadership before executing the main loop. Enable this when running replicated components for high availability.
The duration that non-leader candidates will wait after observing a leadership renewal until attempting to acquire leadership of a led but unrenewed leader slot. This is effectively the maximum duration that a leader can be stopped before it is replaced by another candidate. This is only applicable if leader election is enabled.
The interval between attempts by the acting master to renew a leadership slot before it stops leading. This must be less than the lease duration. This is only applicable if leader election is enabled.
The namespace of resource object that is used for locking during leader election.
--leader-elect-retry-period duration Default: 2s
The duration the clients should wait between attempting acquisition and renewal of a leadership. This is only applicable if leader election is enabled.
--leader-migration-config string
Path to the config file for controller leader migration, or empty to use the value that reflects default configuration of the controller manager. The config file should be of type LeaderMigrationConfiguration, group controllermanager.config.k8s.io, version v1alpha1.
The period of time since the last usage of an legacy service account token before it can be deleted.
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes
--logging-format string Default: "text"
Sets the log format. Permitted formats: "text".
--master string
The address of the Kubernetes API server (overrides any value in kubeconfig).
--max-endpoints-per-slice int32 Default: 100
The maximum number of endpoints that will be added to an EndpointSlice. More endpoints per slice will result in less endpoint slices, but larger resources. Defaults to 100.
--min-resync-period duration Default: 12h0m0s
The resync period in reflectors will be random between MinResyncPeriod and 2*MinResyncPeriod.
The number of service endpoint syncing operations that will be done concurrently by the endpointslice-mirroring-controller. Larger number = faster endpoint slice updating, but more CPU (and network) load. Defaults to 5.
The length of EndpointSlice updates batching period for endpointslice-mirroring-controller. Processing of EndpointSlice changes will be delayed by this duration to join them with potential upcoming updates and reduce the overall number of EndpointSlice updates. Larger number = higher endpoint programming latency, but lower number of endpoints revision generated
The maximum number of endpoints that will be added to an EndpointSlice by the endpointslice-mirroring-controller. More endpoints per slice will result in less endpoint slices, but larger resources. Defaults to 100.
--namespace-sync-period duration Default: 5m0s
The period for syncing namespace life-cycle updates
--node-cidr-mask-size int32
Mask size for node cidr in cluster. Default is 24 for IPv4 and 64 for IPv6.
--node-cidr-mask-size-ipv4 int32
Mask size for IPv4 node cidr in dual-stack cluster. Default is 24.
--node-cidr-mask-size-ipv6 int32
Mask size for IPv6 node cidr in dual-stack cluster. Default is 64.
--node-eviction-rate float Default: 0.1
Number of nodes per second on which pods are deleted in case of node failure when a zone is healthy (see --unhealthy-zone-threshold for definition of healthy/unhealthy). Zone refers to entire cluster in non-multizone clusters.
--node-monitor-grace-period duration Default: 40s
Amount of time which we allow running Node to be unresponsive before marking it unhealthy. Must be N times more than kubelet's nodeStatusUpdateFrequency, where N means number of retries allowed for kubelet to post node status.
--node-monitor-period duration Default: 5s
The period for syncing NodeStatus in cloud-node-lifecycle-controller.
Amount of time which we allow starting Node to be unresponsive before marking it unhealthy.
--permit-address-sharing
If true, SO_REUSEADDR will be used when binding the port. This allows binding to wildcard IPs like 0.0.0.0 and specific IPs in parallel, and it avoids waiting for the kernel to release sockets in TIME_WAIT state. [default=false]
--permit-port-sharing
If true, SO_REUSEPORT will be used when binding the port, which allows more than one instance to bind on the same address and port. [default=false]
--profiling Default: true
Enable profiling via web interface host:port/debug/pprof/
The minimum ActiveDeadlineSeconds to use for a HostPath Recycler pod. This is for development and testing only and will not work in a multi-node cluster.
The file path to a pod definition used as a template for HostPath persistent volume recycling. This is for development and testing only and will not work in a multi-node cluster.
--pv-recycler-pod-template-filepath-nfs string
The file path to a pod definition used as a template for NFS persistent volume recycling
the increment of time added per Gi to ActiveDeadlineSeconds for a HostPath scrubber pod. This is for development and testing only and will not work in a multi-node cluster.
--pvclaimbinder-sync-period duration Default: 15s
The period for syncing persistent volumes and persistent volume claims
--requestheader-allowed-names strings
List of client certificate common names to allow to provide usernames in headers specified by --requestheader-username-headers. If empty, any client certificate validated by the authorities in --requestheader-client-ca-file is allowed.
--requestheader-client-ca-file string
Root certificate bundle to use to verify client certificates on incoming requests before trusting usernames in headers specified by --requestheader-username-headers. WARNING: generally do not depend on authorization being already done for incoming requests.
Number of nodes per second on which pods are deleted in case of node failure when a zone is unhealthy (see --unhealthy-zone-threshold for definition of healthy/unhealthy). Zone refers to entire cluster in non-multizone clusters. This value is implicitly overridden to 0 if the cluster size is smaller than --large-cluster-size-threshold.
--secure-port int Default: 10257
The port on which to serve HTTPS with authentication and authorization. If 0, don't serve HTTPS at all.
--service-account-private-key-file string
Filename containing a PEM-encoded private RSA or ECDSA key used to sign service account tokens.
--service-cluster-ip-range string
CIDR Range for Services in cluster. Requires --allocate-node-cidrs to be true
--show-hidden-metrics-for-version string
The previous version for which you want to show hidden metrics. Only the previous minor version is meaningful, other values will not be allowed. The format is <major>.<minor>, e.g.: '1.16'. The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, rather than being surprised when they are permanently removed in the release after that.
Number of terminated pods that can exist before the terminated pod garbage collector starts deleting terminated pods. If <= 0, the terminated pod garbage collector is disabled.
--tls-cert-file string
File containing the default x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert). If HTTPS serving is enabled, and --tls-cert-file and --tls-private-key-file are not provided, a self-signed certificate and key are generated for the public address and saved to the directory specified by --cert-dir.
--tls-cipher-suites strings
Comma-separated list of cipher suites for the server. If omitted, the default Go cipher suites will be used. Preferred values: TLS_AES_128_GCM_SHA256, TLS_AES_256_GCM_SHA384, TLS_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, TLS_RSA_WITH_AES_256_GCM_SHA384. Insecure values: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_RC4_128_SHA.
--tls-min-version string
Minimum TLS version supported. Possible values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13
--tls-private-key-file string
File containing the default x509 private key matching --tls-cert-file.
--tls-sni-cert-key string
A pair of x509 certificate and private key file paths, optionally suffixed with a list of domain patterns which are fully qualified domain names, possibly with prefixed wildcard segments. The domain patterns also allow IP addresses, but IPs should only be used if the apiserver has visibility to the IP address requested by a client. If no domain patterns are provided, the names of the certificate are extracted. Non-wildcard matches trump over wildcard matches, explicit domain patterns trump over extracted names. For multiple key/certificate pairs, use the --tls-sni-cert-key multiple times. Examples: "example.crt,example.key" or "foo.crt,foo.key:*.foo.com,foo.com".
--unhealthy-zone-threshold float Default: 0.55
Fraction of Nodes in a zone which needs to be not Ready (minimum 3) for zone to be treated as unhealthy.
--use-service-account-credentials
If true, use individual service account credentials for each controller.
-v, --v int
number for the log level verbosity
--version version[=true]
--version, --version=raw prints version information and quits; --version=vX.Y.Z... sets the reported version
--vmodule pattern=N,...
comma-separated list of pattern=N settings for file-filtered logging (only works for text log format)
12.6 - kube-proxy
Synopsis
The Kubernetes network proxy runs on each node. This
reflects services as defined in the Kubernetes API on each node and can do simple
TCP, UDP, and SCTP stream forwarding or round robin TCP, UDP, and SCTP forwarding across a set of backends.
Service cluster IPs and ports are currently found through Docker-links-compatible
environment variables specifying ports opened by the service proxy. There is an optional
addon that provides cluster DNS for these cluster IPs. The user must create a service
with the apiserver API to configure the proxy.
kube-proxy [flags]
Options
--add_dir_header
If true, adds the file directory to the header of the log messages
--alsologtostderr
log to standard error as well as files (no effect when -logtostderr=true)
--bind-address string Default: 0.0.0.0
The IP address for the proxy server to serve on (set to '0.0.0.0' for all IPv4 interfaces and '::' for all IPv6 interfaces). This parameter is ignored if a config file is specified by --config.
--bind-address-hard-fail
If true kube-proxy will treat failure to bind to a port as fatal and exit
Comma-separated list of files to check for boot-id. Use the first one that exists.
--cleanup
If true cleanup iptables and ipvs rules and exit.
--cluster-cidr string
The CIDR range of pods in the cluster. When configured, traffic sent to a Service cluster IP from outside this range will be masqueraded and traffic sent from pods to an external LoadBalancer IP will be directed to the respective cluster IP instead. For dual-stack clusters, a comma-separated list is accepted with at least one CIDR per IP family (IPv4 and IPv6). This parameter is ignored if a config file is specified by --config.
--config string
The path to the configuration file.
--config-sync-period duration Default: 15m0s
How often configuration from the apiserver is refreshed. Must be greater than 0.
--conntrack-max-per-core int32 Default: 32768
Maximum number of NAT connections to track per CPU core (0 to leave the limit as-is and ignore conntrack-min).
--conntrack-min int32 Default: 131072
Minimum number of conntrack entries to allocate, regardless of conntrack-max-per-core (set conntrack-max-per-core=0 to leave the limit as-is).
The IP address with port for the health check server to serve on (set to '0.0.0.0:10256' for all IPv4 interfaces and '[::]:10256' for all IPv6 interfaces). Set empty to disable. This parameter is ignored if a config file is specified by --config.
-h, --help
help for kube-proxy
--hostname-override string
If non-empty, will use this string as identification instead of the actual hostname.
--iptables-localhost-nodeports Default: true
If false Kube-proxy will disable the legacy behavior of allowing NodePort services to be accessed via localhost, This only applies to iptables mode and ipv4.
--iptables-masquerade-bit int32 Default: 14
If using the pure iptables proxy, the bit of the fwmark space to mark packets requiring SNAT with. Must be within the range [0, 31].
--iptables-min-sync-period duration Default: 1s
The minimum interval of how often the iptables rules can be refreshed as endpoints and services change (e.g. '5s', '1m', '2h22m').
--iptables-sync-period duration Default: 30s
The maximum interval of how often iptables rules are refreshed (e.g. '5s', '1m', '2h22m'). Must be greater than 0.
--ipvs-exclude-cidrs strings
A comma-separated list of CIDR's which the ipvs proxier should not touch when cleaning up IPVS rules.
--ipvs-min-sync-period duration
The minimum interval of how often the ipvs rules can be refreshed as endpoints and services change (e.g. '5s', '1m', '2h22m').
--ipvs-scheduler string
The ipvs scheduler type when proxy mode is ipvs
--ipvs-strict-arp
Enable strict ARP by setting arp_ignore to 1 and arp_announce to 2
--ipvs-sync-period duration Default: 30s
The maximum interval of how often ipvs rules are refreshed (e.g. '5s', '1m', '2h22m'). Must be greater than 0.
--ipvs-tcp-timeout duration
The timeout for idle IPVS TCP connections, 0 to leave as-is. (e.g. '5s', '1m', '2h22m').
--ipvs-tcpfin-timeout duration
The timeout for IPVS TCP connections after receiving a FIN packet, 0 to leave as-is. (e.g. '5s', '1m', '2h22m').
--ipvs-udp-timeout duration
The timeout for IPVS UDP packets, 0 to leave as-is. (e.g. '5s', '1m', '2h22m').
--kube-api-burst int32 Default: 10
Burst to use while talking with kubernetes apiserver
QPS to use while talking with kubernetes apiserver
--kubeconfig string
Path to kubeconfig file with authorization information (the master location can be overridden by the master flag).
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes
--log_backtrace_at <a string in the form 'file:N'> Default: :0
when logging hits line file:N, emit a stack trace
--log_dir string
If non-empty, write log files in this directory (no effect when -logtostderr=true)
--log_file string
If non-empty, use this log file (no effect when -logtostderr=true)
--log_file_max_size uint Default: 1800
Defines the maximum size a log file can grow to (no effect when -logtostderr=true). Unit is megabytes. If the value is 0, the maximum file size is unlimited.
The IP address with port for the metrics server to serve on (set to '0.0.0.0:10249' for all IPv4 interfaces and '[::]:10249' for all IPv6 interfaces). Set empty to disable. This parameter is ignored if a config file is specified by --config.
--nodeport-addresses strings
A string slice of values which specify the addresses to use for NodePorts. Values may be valid IP blocks (e.g. 1.2.3.0/24, 1.2.3.4/32). The default empty string slice ([]) means to use all local addresses. This parameter is ignored if a config file is specified by --config.
--one_output
If true, only write logs to their native severity level (vs also writing to each lower severity level; no effect when -logtostderr=true)
--oom-score-adj int32 Default: -999
The oom-score-adj value for kube-proxy process. Values must be within the range [-1000, 1000]. This parameter is ignored if a config file is specified by --config.
--pod-bridge-interface string
A bridge interface name in the cluster. Kube-proxy considers traffic as local if originating from an interface which matches the value. This argument should be set if DetectLocalMode is set to BridgeInterface.
--pod-interface-name-prefix string
An interface prefix in the cluster. Kube-proxy considers traffic as local if originating from interfaces that match the given prefix. This argument should be set if DetectLocalMode is set to InterfaceNamePrefix.
--profiling
If true enables profiling via web interface on /debug/pprof handler. This parameter is ignored if a config file is specified by --config.
--proxy-mode ProxyMode
Which proxy mode to use: on Linux this can be 'iptables' (default) or 'ipvs'. On Windows the only supported value is 'kernelspace'.This parameter is ignored if a config file is specified by --config.
--proxy-port-range port-range
Range of host ports (beginPort-endPort, single port or beginPort+offset, inclusive) that may be consumed in order to proxy service traffic. If (unspecified, 0, or 0-0) then ports will be randomly chosen.
--show-hidden-metrics-for-version string
The previous version for which you want to show hidden metrics. Only the previous minor version is meaningful, other values will not be allowed. The format is <major>.<minor>, e.g.: '1.16'. The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, rather than being surprised when they are permanently removed in the release after that. This parameter is ignored if a config file is specified by --config.
--skip_headers
If true, avoid header prefixes in the log messages
--skip_log_headers
If true, avoid headers when opening log files (no effect when -logtostderr=true)
--stderrthreshold int Default: 2
logs at or above this threshold go to stderr when writing to files and stderr (no effect when -logtostderr=true or -alsologtostderr=false)
-v, --v int
number for the log level verbosity
--version version[=true]
--version, --version=raw prints version information and quits; --version=vX.Y.Z... sets the reported version
--vmodule pattern=N,...
comma-separated list of pattern=N settings for file-filtered logging (only works for text log format)
--write-config-to string
If set, write the default configuration values to this file and exit.
12.7 - kube-scheduler
Synopsis
The Kubernetes scheduler is a control plane process which assigns
Pods to Nodes. The scheduler determines which Nodes are valid placements for
each Pod in the scheduling queue according to constraints and available
resources. The scheduler then ranks each valid Node and binds the Pod to a
suitable Node. Multiple different schedulers may be used within a cluster;
kube-scheduler is the reference implementation.
See scheduling
for more information about scheduling and the kube-scheduler component.
kube-scheduler [flags]
Options
--allow-metric-labels stringToString Default: []
The map from metric-label to value allow-list of this label. The key's format is <MetricName>,<LabelName>. The value's format is <allowed_value>,<allowed_value>...e.g. metric1,label1='v1,v2,v3', metric1,label2='v1,v2,v3' metric2,label1='v1,v2,v3'.
--authentication-kubeconfig string
kubeconfig file pointing at the 'core' kubernetes server with enough rights to create tokenreviews.authentication.k8s.io. This is optional. If empty, all token requests are considered to be anonymous and no client CA is looked up in the cluster.
--authentication-skip-lookup
If false, the authentication-kubeconfig will be used to lookup missing authentication configuration from the cluster.
If true, failures to look up missing authentication configuration from the cluster are not considered fatal. Note that this can result in authentication that treats all requests as anonymous.
A list of HTTP paths to skip during authorization, i.e. these are authorized without contacting the 'core' kubernetes server.
--authorization-kubeconfig string
kubeconfig file pointing at the 'core' kubernetes server with enough rights to create subjectaccessreviews.authorization.k8s.io. This is optional. If empty, all requests not skipped by authorization are forbidden.
The duration to cache 'unauthorized' responses from the webhook authorizer.
--azure-container-registry-config string
Path to the file containing Azure container registry configuration information.
--bind-address string Default: 0.0.0.0
The IP address on which to listen for the --secure-port port. The associated interface(s) must be reachable by the rest of the cluster, and by CLI/web clients. If blank or an unspecified address (0.0.0.0 or ::), all interfaces and IP address families will be used.
--cert-dir string
The directory where the TLS certs are located. If --tls-cert-file and --tls-private-key-file are provided, this flag will be ignored.
--client-ca-file string
If set, any request presenting a client certificate signed by one of the authorities in the client-ca-file is authenticated with an identity corresponding to the CommonName of the client certificate.
--config string
The path to the configuration file.
--contention-profiling Default: true
DEPRECATED: enable block profiling, if profiling is enabled. This parameter is ignored if a config file is specified in --config.
--disabled-metrics strings
This flag provides an escape hatch for misbehaving metrics. You must provide the fully qualified metric name in order to disable it. Disclaimer: disabling metrics is higher in precedence than showing hidden metrics.
DEPRECATED: content type of requests sent to apiserver. This parameter is ignored if a config file is specified in --config.
--kube-api-qps float Default: 50
DEPRECATED: QPS to use while talking with kubernetes apiserver. This parameter is ignored if a config file is specified in --config.
--kubeconfig string
DEPRECATED: path to kubeconfig file with authorization and master location information. This parameter is ignored if a config file is specified in --config.
--leader-elect Default: true
Start a leader election client and gain leadership before executing the main loop. Enable this when running replicated components for high availability.
The duration that non-leader candidates will wait after observing a leadership renewal until attempting to acquire leadership of a led but unrenewed leader slot. This is effectively the maximum duration that a leader can be stopped before it is replaced by another candidate. This is only applicable if leader election is enabled.
The interval between attempts by the acting master to renew a leadership slot before it stops leading. This must be less than the lease duration. This is only applicable if leader election is enabled.
The namespace of resource object that is used for locking during leader election.
--leader-elect-retry-period duration Default: 2s
The duration the clients should wait between attempting acquisition and renewal of a leadership. This is only applicable if leader election is enabled.
--log-flush-frequency duration Default: 5s
Maximum number of seconds between log flushes
--logging-format string Default: "text"
Sets the log format. Permitted formats: "text".
--master string
The address of the Kubernetes API server (overrides any value in kubeconfig)
--permit-address-sharing
If true, SO_REUSEADDR will be used when binding the port. This allows binding to wildcard IPs like 0.0.0.0 and specific IPs in parallel, and it avoids waiting for the kernel to release sockets in TIME_WAIT state. [default=false]
--permit-port-sharing
If true, SO_REUSEPORT will be used when binding the port, which allows more than one instance to bind on the same address and port. [default=false]
DEPRECATED: the maximum time a pod can stay in unschedulablePods. If a pod stays in unschedulablePods for longer than this value, the pod will be moved from unschedulablePods to backoffQ or activeQ. This flag is deprecated and will be removed in 1.26
--profiling Default: true
DEPRECATED: enable profiling via web interface host:port/debug/pprof/. This parameter is ignored if a config file is specified in --config.
--requestheader-allowed-names strings
List of client certificate common names to allow to provide usernames in headers specified by --requestheader-username-headers. If empty, any client certificate validated by the authorities in --requestheader-client-ca-file is allowed.
--requestheader-client-ca-file string
Root certificate bundle to use to verify client certificates on incoming requests before trusting usernames in headers specified by --requestheader-username-headers. WARNING: generally do not depend on authorization being already done for incoming requests.
List of request headers to inspect for usernames. X-Remote-User is common.
--secure-port int Default: 10259
The port on which to serve HTTPS with authentication and authorization. If 0, don't serve HTTPS at all.
--show-hidden-metrics-for-version string
The previous version for which you want to show hidden metrics. Only the previous minor version is meaningful, other values will not be allowed. The format is <major>.<minor>, e.g.: '1.16'. The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, rather than being surprised when they are permanently removed in the release after that.
--tls-cert-file string
File containing the default x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert). If HTTPS serving is enabled, and --tls-cert-file and --tls-private-key-file are not provided, a self-signed certificate and key are generated for the public address and saved to the directory specified by --cert-dir.
--tls-cipher-suites strings
Comma-separated list of cipher suites for the server. If omitted, the default Go cipher suites will be used. Preferred values: TLS_AES_128_GCM_SHA256, TLS_AES_256_GCM_SHA384, TLS_CHACHA20_POLY1305_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_256_CBC_SHA, TLS_RSA_WITH_AES_256_GCM_SHA384. Insecure values: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_RC4_128_SHA, TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_RC4_128_SHA.
--tls-min-version string
Minimum TLS version supported. Possible values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13
--tls-private-key-file string
File containing the default x509 private key matching --tls-cert-file.
--tls-sni-cert-key string
A pair of x509 certificate and private key file paths, optionally suffixed with a list of domain patterns which are fully qualified domain names, possibly with prefixed wildcard segments. The domain patterns also allow IP addresses, but IPs should only be used if the apiserver has visibility to the IP address requested by a client. If no domain patterns are provided, the names of the certificate are extracted. Non-wildcard matches trump over wildcard matches, explicit domain patterns trump over extracted names. For multiple key/certificate pairs, use the --tls-sni-cert-key multiple times. Examples: "example.crt,example.key" or "foo.crt,foo.key:*.foo.com,foo.com".
-v, --v int
number for the log level verbosity
--version version[=true]
--version, --version=raw prints version information and quits; --version=vX.Y.Z... sets the reported version
--vmodule pattern=N,...
comma-separated list of pattern=N settings for file-filtered logging (only works for text log format)
--write-config-to string
If set, write the configuration values to this file and exit.
13 - Debug cluster
13.1 - Flow control
API Priority and Fairness controls the behavior of the Kubernetes API server in
an overload situation. You can find more information about it in the
API Priority and Fairness
documentation.
Diagnostics
Every HTTP response from an API server with the priority and fairness feature
enabled has two extra headers: X-Kubernetes-PF-FlowSchema-UID and
X-Kubernetes-PF-PriorityLevel-UID, noting the flow schema that matched the request
and the priority level to which it was assigned, respectively. The API objects'
names are not included in these headers (to avoid revealing details in case the
requesting user does not have permission to view them). When debugging, you
can use a command such as:
kubectl get flowschemas -o custom-columns="uid:{metadata.uid},name:{metadata.name}"kubectl get prioritylevelconfigurations -o custom-columns="uid:{metadata.uid},name:{metadata.name}"
to get a mapping of UIDs to names for both FlowSchemas and
PriorityLevelConfigurations.
Debug endpoints
With the APIPriorityAndFairness feature enabled, the kube-apiserver
serves the following additional paths at its HTTP(S) ports.
You need to ensure you have permissions to access these endpoints.
You don't have to do anything if you are using admin.
Permissions can be granted if needed following the RBAC doc
to access /debug/api_priority_and_fairness/ by specifying nonResourceURLs.
/debug/api_priority_and_fairness/dump_priority_levels - a listing of
all the priority levels and the current state of each. You can fetch like this:
kubectl get --raw /debug/api_priority_and_fairness/dump_priority_levels
NextDispatchR: The R progress meter reading, in units of seat-seconds, at
which the next request will be dispatched.
InitialSeatsSum: The sum of InitialSeats associated with all requests in
a given queue.
MaxSeatsSum: The sum of MaxSeats associated with all requests in a given
queue.
TotalWorkSum: The sum of total work, in units of seat-seconds, of all
waiting requests in a given queue.
Note: seat-second (abbreviate as ss) is a measure of work, in units of
seat-seconds, in the APF world.
/debug/api_priority_and_fairness/dump_requests - a listing of all the requests
including requests waiting in a queue and requests being executing.
You can fetch like this:
kubectl get --raw /debug/api_priority_and_fairness/dump_requests
QueueIndex: The index of the queue. It will be -1 for priority levels
without queues.
RequestIndexInQueue: The index in the queue for a given request. It will
be -1 for executing requests.
InitialSeats: The number of seats will be occupied during the initial
(normal) stage of execution of the request.
FinalSeats: The number of seats will be occupied during the final stage
of request execution, accounting for the associated WATCH notifications.
AdditionalLatency: The extra time taken during the final stage of request
execution. FinalSeats will be occupied during this time period. It does not
mean any latency that a user will observe.
StartTime: The time a request starts to execute. It will be
0001-01-01T00:00:00Z for queued requests.
Debug logging
At -v=3 or more verbosity, the API server outputs an httplog line for every
request in the API server log, and it includes the following attributes.
apf_fs: the name of the flow schema to which the request was classified.
apf_pl: the name of the priority level for that flow schema.
apf_iseats: the number of seats determined for the initial
(normal) stage of execution of the request.
apf_fseats: the number of seats determined for the final stage of
execution (accounting for the associated watch notifications) of the
request.
apf_additionalLatency: the duration of the final stage of
execution of the request.
At higher levels of verbosity there will be log lines exposing details
of how APF handled the request, primarily for debugging purposes.
Response headers
APF adds the following two headers to each HTTP response message.
They won't appear in the audit log. They can be viewed from the client side.
For client using klog, use verbosity -v=8 or higher to view these headers.
X-Kubernetes-PF-FlowSchema-UID holds the UID of the FlowSchema
object to which the corresponding request was classified.
X-Kubernetes-PF-PriorityLevel-UID holds the UID of the
PriorityLevelConfiguration object associated with that FlowSchema.
What's next
For background information on design details for API priority and fairness, see
the enhancement proposal.
Cluster contains information to allow an exec plugin to communicate
with the kubernetes cluster being authenticated to.
To ensure that this struct contains everything someone would need to communicate
with a kubernetes cluster (just like they would via a kubeconfig), the fields
should shadow "k8s.io/client-go/tools/clientcmd/api/v1".Cluster, with the exception
of CertificateAuthority, since CA data will always be passed to the plugin as bytes.
Field
Description
server[Required] string
Server is the address of the kubernetes cluster (https://hostname:port).
tls-server-name string
TLSServerName is passed to the server for SNI and is used in the client to
check server certificates against. If ServerName is empty, the hostname
used to contact the server is used.
insecure-skip-tls-verify bool
InsecureSkipTLSVerify skips the validity check for the server's certificate.
This will make your HTTPS connections insecure.
certificate-authority-data []byte
CAData contains PEM-encoded certificate authority certificates.
If empty, system roots should be used.
proxy-url string
ProxyURL is the URL to the proxy to be used for all requests to this
cluster.
disable-compression bool
DisableCompression allows client to opt-out of response compression for all requests to the server. This is useful
to speed up requests (specifically lists) when client-server network bandwidth is ample, by saving time on
compression (server-side) and decompression (client-side): https://github.com/kubernetes/kubernetes/issues/112296.
Config holds additional config data that is specific to the exec
plugin with regards to the cluster being authenticated to.
This data is sourced from the clientcmd Cluster object's
extensions[client.authentication.k8s.io/exec] field:
clusters:
name: my-cluster
cluster:
...
extensions:
name: client.authentication.k8s.io/exec # reserved extension name for per cluster exec config
extension:
audience: 06e3fbd18de8 # arbitrary config
In some environments, the user config may be exactly the same across many clusters
(i.e. call this exec plugin) minus some details that are specific to each cluster
such as the audience. This field allows the per cluster config to be directly
specified with the cluster info. Using this field to store secret data is not
recommended as one of the prime benefits of exec plugins is that no secrets need
to be stored directly in the kubeconfig.
Cluster contains information to allow an exec plugin to communicate with the
kubernetes cluster being authenticated to. Note that Cluster is non-nil only
when provideClusterInfo is set to true in the exec provider config (i.e.,
ExecConfig.ProvideClusterInfo).
interactive[Required] bool
Interactive declares whether stdin has been passed to this exec plugin.
ExecCredentialStatus holds credentials for the transport to use.
Token and ClientKeyData are sensitive fields. This data should only be
transmitted in-memory between client and exec plugin process. Exec plugin
itself should at least be protected via file permissions.
Cluster contains information to allow an exec plugin to communicate
with the kubernetes cluster being authenticated to.
To ensure that this struct contains everything someone would need to communicate
with a kubernetes cluster (just like they would via a kubeconfig), the fields
should shadow "k8s.io/client-go/tools/clientcmd/api/v1".Cluster, with the exception
of CertificateAuthority, since CA data will always be passed to the plugin as bytes.
Field
Description
server[Required] string
Server is the address of the kubernetes cluster (https://hostname:port).
tls-server-name string
TLSServerName is passed to the server for SNI and is used in the client to
check server certificates against. If ServerName is empty, the hostname
used to contact the server is used.
insecure-skip-tls-verify bool
InsecureSkipTLSVerify skips the validity check for the server's certificate.
This will make your HTTPS connections insecure.
certificate-authority-data []byte
CAData contains PEM-encoded certificate authority certificates.
If empty, system roots should be used.
proxy-url string
ProxyURL is the URL to the proxy to be used for all requests to this
cluster.
disable-compression bool
DisableCompression allows client to opt-out of response compression for all requests to the server. This is useful
to speed up requests (specifically lists) when client-server network bandwidth is ample, by saving time on
compression (server-side) and decompression (client-side): https://github.com/kubernetes/kubernetes/issues/112296.
Config holds additional config data that is specific to the exec
plugin with regards to the cluster being authenticated to.
This data is sourced from the clientcmd Cluster object's
extensions[client.authentication.k8s.io/exec] field:
clusters:
name: my-cluster
cluster:
...
extensions:
name: client.authentication.k8s.io/exec # reserved extension name for per cluster exec config
extension:
audience: 06e3fbd18de8 # arbitrary config
In some environments, the user config may be exactly the same across many clusters
(i.e. call this exec plugin) minus some details that are specific to each cluster
such as the audience. This field allows the per cluster config to be directly
specified with the cluster info. Using this field to store secret data is not
recommended as one of the prime benefits of exec plugins is that no secrets need
to be stored directly in the kubeconfig.
Cluster contains information to allow an exec plugin to communicate with the
kubernetes cluster being authenticated to. Note that Cluster is non-nil only
when provideClusterInfo is set to true in the exec provider config (i.e.,
ExecConfig.ProvideClusterInfo).
interactive[Required] bool
Interactive declares whether stdin has been passed to this exec plugin.
ExecCredentialStatus holds credentials for the transport to use.
Token and ClientKeyData are sensitive fields. This data should only be
transmitted in-memory between client and exec plugin process. Exec plugin
itself should at least be protected via file permissions.
limits are the limits to place on event queries received.
Limits can be placed on events received server-wide, per namespace,
per user, and per source+object.
At least one limit is required.
type is the type of limit to which this configuration applies
qps[Required] int32
qps is the number of event queries per second that are allowed for this
type of limit. The qps and burst fields are used together to determine if
a particular event query is accepted. The qps determines how many queries
are accepted once the burst amount of queries has been exhausted.
burst[Required] int32
burst is the burst number of event queries that are allowed for this type
of limit. The qps and burst fields are used together to determine if a
particular event query is accepted. The burst determines the maximum size
of the allowance granted for a particular bucket. For example, if the burst
is 10 and the qps is 3, then the admission control will accept 10 queries
before blocking any queries. Every second, 3 more queries will be allowed.
If some of that allowance is not used, then it will roll over to the next
second, until the maximum allowance of 10 is reached.
cacheSize int32
cacheSize is the size of the LRU cache for this type of limit. If a bucket
is evicted from the cache, then the allowance for that bucket is reset. If
more queries are later received for an evicted bucket, then that bucket
will re-enter the cache with a clean slate, giving that bucket a full
allowance of burst queries.
The default cache size is 4096.
If limitType is 'server', then cacheSize is ignored.
Containers is a list of a subset of the information in each container of the Pod being created.
annotations map[string]string
Annotations is a list of key-value pairs extracted from the Pod's annotations.
It only includes keys which match the pattern *.image-policy.k8s.io/*.
It is up to each webhook backend to determine how to interpret these annotations, if at all.
namespace string
Namespace is the namespace the pod is being created in.
ImageReviewStatus is the result of the review for the pod creation request.
Field
Description
allowed[Required] bool
Allowed indicates that all images were allowed to be run.
reason string
Reason should be empty unless Allowed is false in which case it
may contain a short description of what is wrong. Kubernetes
may truncate excessively long errors when displaying to the user.
auditAnnotations map[string]string
AuditAnnotations will be added to the attributes object of the
admission controller request using 'AddAnnotation'. The keys should
be prefix-less (i.e., the admission controller will add an
appropriate prefix).
UID is an identifier for the individual request/response. It allows us to distinguish instances of requests which are
otherwise identical (parallel requests, requests when earlier requests did not modify etc)
The UID is meant to track the round trip (request/response) between the KAS and the WebHook, not the user request.
It is suitable for correlating log entries between the webhook and apiserver, for either auditing or debugging.
RequestKind is the fully-qualified type of the original API request (for example, v1.Pod or autoscaling.v1.Scale).
If this is specified and differs from the value in "kind", an equivalent match and conversion was performed.
For example, if deployments can be modified via apps/v1 and apps/v1beta1, and a webhook registered a rule of
apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"] and matchPolicy: Equivalent,
an API request to apps/v1beta1 deployments would be converted and sent to the webhook
with kind: {group:"apps", version:"v1", kind:"Deployment"} (matching the rule the webhook registered for),
and requestKind: {group:"apps", version:"v1beta1", kind:"Deployment"} (indicating the kind of the original API request).
See documentation for the "matchPolicy" field in the webhook configuration type for more details.
RequestResource is the fully-qualified resource of the original API request (for example, v1.pods).
If this is specified and differs from the value in "resource", an equivalent match and conversion was performed.
For example, if deployments can be modified via apps/v1 and apps/v1beta1, and a webhook registered a rule of
apiGroups:["apps"], apiVersions:["v1"], resources: ["deployments"] and matchPolicy: Equivalent,
an API request to apps/v1beta1 deployments would be converted and sent to the webhook
with resource: {group:"apps", version:"v1", resource:"deployments"} (matching the resource the webhook registered for),
and requestResource: {group:"apps", version:"v1beta1", resource:"deployments"} (indicating the resource of the original API request).
See documentation for the "matchPolicy" field in the webhook configuration type.
requestSubResource string
RequestSubResource is the name of the subresource of the original API request, if any (for example, "status" or "scale")
If this is specified and differs from the value in "subResource", an equivalent match and conversion was performed.
See documentation for the "matchPolicy" field in the webhook configuration type.
name string
Name is the name of the object as presented in the request. On a CREATE operation, the client may omit name and
rely on the server to generate the name. If that is the case, this field will contain an empty string.
namespace string
Namespace is the namespace associated with the request (if any).
Operation is the operation being performed. This may be different than the operation
requested. e.g. a patch can result in either a CREATE or UPDATE Operation.
Options is the operation option structure of the operation being performed.
e.g. meta.k8s.io/v1.DeleteOptions or meta.k8s.io/v1.CreateOptions. This may be
different than the options the caller provided. e.g. for a patch request the performed
Operation might be a CREATE, in which case the Options will a
meta.k8s.io/v1.CreateOptions even though the caller provided meta.k8s.io/v1.PatchOptions.
The type of Patch. Currently we only allow "JSONPatch".
auditAnnotations map[string]string
AuditAnnotations is an unstructured key value map set by remote admission controller (e.g. error=image-blacklisted).
MutatingAdmissionWebhook and ValidatingAdmissionWebhook admission controller will prefix the keys with
admission webhook name (e.g. imagepolicy.example.com/error=image-blacklisted). AuditAnnotations will be provided by
the admission webhook to add additional context to the audit log for this request.
warnings []string
warnings is a list of warning messages to return to the requesting API client.
Warning messages describe a problem the client making the API request should correct or be aware of.
Limit warnings to 120 characters if possible.
Warnings over 256 characters and large numbers of warnings may be truncated.
Source IPs, from where the request originated and intermediate proxies.
The source IPs are listed from (in order):
X-Forwarded-For request header IPs
X-Real-Ip header, if not present in the X-Forwarded-For list
The remote address for the connection, if it doesn't match the last
IP in the list up to here (X-Forwarded-For or X-Real-Ip).
Note: All but the last IP can be arbitrarily set by the client.
userAgent string
UserAgent records the user agent string reported by the client.
Note that the UserAgent is provided by the client, and must not be trusted.
The response status, populated even when the ResponseObject is not a Status type.
For successful responses, this will only include the Code and StatusSuccess.
For non-status type error responses, this will be auto-populated with the error Message.
API object from the request, in JSON format. The RequestObject is recorded as-is in the request
(possibly re-encoded as JSON), prior to version conversion, defaulting, admission or
merging. It is an external versioned object type, and may not be a valid object on its own.
Omitted for non-resource requests. Only logged at Request Level and higher.
API object returned in the response, in JSON. The ResponseObject is recorded after conversion
to the external type, and serialized as JSON. Omitted for non-resource requests. Only logged
at Response Level.
Annotations is an unstructured key value map stored with an audit event that may be set by
plugins invoked in the request serving chain, including authentication, authorization and
admission plugins. Note that these annotations are for the audit event, and do not correspond
to the metadata.annotations of the submitted object. Keys should uniquely identify the informing
component to avoid name collisions (e.g. podsecuritypolicy.admission.k8s.io/policy). Values
should be short. Annotations are included in the Metadata level.
Rules specify the audit Level a request should be recorded at.
A request may match multiple rules, in which case the FIRST matching rule is used.
The default audit level is None, but can be overridden by a catch-all rule at the end of the list.
PolicyRules are strictly ordered.
OmitStages is a list of stages for which no events are created. Note that this can also
be specified per rule in which case the union of both are omitted.
omitManagedFields bool
OmitManagedFields indicates whether to omit the managed fields of the request
and response bodies from being written to the API audit log.
This is used as a global default - a value of 'true' will omit the managed fileds,
otherwise the managed fields will be included in the API audit log.
Note that this can also be specified per rule in which case the value specified
in a rule will override the global default.
GroupResources represents resource kinds in an API group.
Field
Description
group string
Group is the name of the API group that contains the resources.
The empty string represents the core API group.
resources []string
Resources is a list of resources this rule applies to.
For example:
'pods' matches pods.
'pods/log' matches the log subresource of pods.
'*' matches all resources and their subresources.
'pods/*' matches all subresources of pods.
'*/scale' matches all scale subresources.
If wildcard is present, the validation rule will ensure resources do not
overlap with each other.
An empty list implies all resources and subresources in this API groups apply.
resourceNames []string
ResourceNames is a list of resource instance names that the policy matches.
Using this field requires Resources to be specified.
An empty list implies that every instance of the resource is matched.
The Level that requests matching this rule are recorded at.
users []string
The users (by authenticated user name) this rule applies to.
An empty list implies every user.
userGroups []string
The user groups this rule applies to. A user is considered matching
if it is a member of any of the UserGroups.
An empty list implies every user group.
verbs []string
The verbs that match this rule.
An empty list implies every verb.
Resources that this rule matches. An empty list implies all kinds in all API groups.
namespaces []string
Namespaces that this rule matches.
The empty string "" matches non-namespaced resources.
An empty list implies every namespace.
nonResourceURLs []string
NonResourceURLs is a set of URL paths that should be audited.
*s are allowed, but only as the full, final step in the path.
Examples:
"/metrics" - Log requests for apiserver metrics
"/healthz*" - Log all health checks
OmitStages is a list of stages for which no events are created. Note that this can also
be specified policy wide in which case the union of both are omitted.
An empty list means no restrictions will apply.
omitManagedFields bool
OmitManagedFields indicates whether to omit the managed fields of the request
and response bodies from being written to the API audit log.
a value of 'true' will drop the managed fields from the API audit log
a value of 'false' indicates that the managed fileds should be included
in the API audit log
Note that the value, if specified, in this rule will override the global default
If a value is not specified then the global default specified in
Policy.OmitManagedFields will stand.
Configuration is an embedded configuration object to be used as the plugin's
configuration. If present, it will be used instead of the path to the configuration file.
14.8 - kube-apiserver Configuration (v1alpha1)
Package v1alpha1 is the v1alpha1 version of the API.
TracingConfiguration provides versioned configuration for OpenTelemetry tracing clients.
Field
Description
endpoint string
Endpoint of the collector this component will report traces to.
The connection is insecure, and does not currently support TLS.
Recommended is unset, and endpoint is the otlp grpc default, localhost:4317.
samplingRatePerMillion int32
SamplingRatePerMillion is the number of samples to collect per million spans.
Recommended is unset. If unset, sampler respects its parent span's sampling
rate, but otherwise never samples.
AdmissionConfiguration
AdmissionConfiguration provides versioned configuration for admission controllers.
Configuration is an embedded configuration object to be used as the plugin's
configuration. If present, it will be used instead of the path to the configuration file.
EgressSelection provides the configuration for a single egress selection client.
Field
Description
name[Required] string
name is the name of the egress selection.
Currently supported values are "controlplane", "master", "etcd" and "cluster"
The "master" egress selector is deprecated in favor of "controlplane"
TLSConfig provides the authentication information to connect to konnectivity server
Only used with TCPTransport
Field
Description
caBundle string
caBundle is the file location of the CA to be used to determine trust with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
If absent while TCPTransport.URL is prefixed with https://, default to system trust roots.
clientKey string
clientKey is the file location of the client key to be used in mtls handshakes with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
Must be configured if TCPTransport.URL is prefixed with https://
clientCert string
clientCert is the file location of the client certificate to be used in mtls handshakes with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
Must be configured if TCPTransport.URL is prefixed with https://
TCP is the TCP configuration for communicating with the konnectivity server via TCP
ProxyProtocol of GRPC is not supported with TCP transport at the moment
Requires at least one of TCP or UDS to be set
UDSTransport provides the information to connect to konnectivity server via UDS
Field
Description
udsName[Required] string
UDSName is the name of the unix domain socket to connect to konnectivity server
This does not use a unix:// prefix. (Eg: /etc/srv/kubernetes/konnectivity-server/konnectivity-server.socket)
14.9 - kube-apiserver Configuration (v1beta1)
Package v1beta1 is the v1beta1 version of the API.
TracingConfiguration provides versioned configuration for OpenTelemetry tracing clients.
Field
Description
endpoint string
Endpoint of the collector this component will report traces to.
The connection is insecure, and does not currently support TLS.
Recommended is unset, and endpoint is the otlp grpc default, localhost:4317.
samplingRatePerMillion int32
SamplingRatePerMillion is the number of samples to collect per million spans.
Recommended is unset. If unset, sampler respects its parent span's sampling
rate, but otherwise never samples.
EgressSelectorConfiguration
EgressSelectorConfiguration provides versioned configuration for egress selector clients.
EgressSelection provides the configuration for a single egress selection client.
Field
Description
name[Required] string
name is the name of the egress selection.
Currently supported values are "controlplane", "master", "etcd" and "cluster"
The "master" egress selector is deprecated in favor of "controlplane"
TLSConfig provides the authentication information to connect to konnectivity server
Only used with TCPTransport
Field
Description
caBundle string
caBundle is the file location of the CA to be used to determine trust with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
If absent while TCPTransport.URL is prefixed with https://, default to system trust roots.
clientKey string
clientKey is the file location of the client key to be used in mtls handshakes with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
Must be configured if TCPTransport.URL is prefixed with https://
clientCert string
clientCert is the file location of the client certificate to be used in mtls handshakes with the konnectivity server.
Must be absent/empty if TCPTransport.URL is prefixed with http://
Must be configured if TCPTransport.URL is prefixed with https://
TCP is the TCP configuration for communicating with the konnectivity server via TCP
ProxyProtocol of GRPC is not supported with TCP transport at the moment
Requires at least one of TCP or UDS to be set
UDSTransport provides the information to connect to konnectivity server via UDS
Field
Description
udsName[Required] string
UDSName is the name of the unix domain socket to connect to konnectivity server
This does not use a unix:// prefix. (Eg: /etc/srv/kubernetes/konnectivity-server/konnectivity-server.socket)
EncryptionConfiguration stores the complete configuration for encryption providers.
It also allows the use of wildcards to specify the resources that should be encrypted.
Use '*<group>o encrypt all resources within a group or '*.*' to encrypt all resources.
'*.' can be used to encrypt all resource in the core group. '*.*' will encrypt all
resources, even custom resources that are added after API server start.
Use of wildcards that overlap within the same resource list or across multiple
entries are not allowed since part of the configuration would be ineffective.
Resource lists are processed in order, with earlier lists taking precedence.
KMSConfiguration contains the name, cache size and path to configuration file for a KMS based envelope transformer.
Field
Description
apiVersion string
apiVersion of KeyManagementService
name[Required] string
name is the name of the KMS plugin to be used.
cachesize int32
cachesize is the maximum number of secrets which are cached in memory. The default value is 1000.
Set to a negative value to disable caching. This field is only allowed for KMS v1 providers.
endpoint[Required] string
endpoint is the gRPC server listening address, for example "unix:///var/run/kms-provider.sock".
ResourceConfiguration stores per resource configuration.
Field
Description
resources[Required] []string
resources is a list of kubernetes resources which have to be encrypted. The resource names are derived from resource or resource.group of the group/version/resource.
eg: pandas.awesome.bears.example is a custom resource with 'group': awesome.bears.example, 'resource': pandas.
Use '*.*' to encrypt all resources and '*.<group>' to encrypt all resources in a specific group.
eg: '*.awesome.bears.example' will encrypt all resources in the group 'awesome.bears.example'.
eg: '*.' will encrypt all resources in the core group (such as pods, configmaps, etc).
ServiceControllerConfiguration contains elements describing ServiceController.
Field
Description
ConcurrentServiceSyncs[Required] int32
concurrentServiceSyncs is the number of services that are
allowed to sync concurrently. Larger number = more responsive service
management, but more CPU (and network) load.
CloudControllerManagerConfiguration
CloudControllerManagerConfiguration contains elements describing cloud-controller manager.
CloudProviderConfiguration holds configuration for CloudProvider related features.
ExternalCloudVolumePlugin[Required] string
externalCloudVolumePlugin specifies the plugin to use when cloudProvider is "external".
It is currently used by the in repo cloud providers to handle node and volume control in the KCM.
UseServiceAccountCredentials[Required] bool
useServiceAccountCredentials indicates whether controllers should be run with
individual service account credentials.
nodeSyncPeriod is the period for syncing nodes from cloudprovider. Longer
periods will result in fewer calls to cloud provider, but may delay addition
of new nodes to cluster.
WebhookConfiguration contains configuration related to
cloud-controller-manager hosted webhooks
Field
Description
Webhooks[Required] []string
Webhooks is the list of webhooks to enable or disable
'*' means "all enabled by default webhooks"
'foo' means "enable 'foo'"
'-foo' means "disable 'foo'"
first item for a particular name wins
ControllerLeaderConfiguration provides the configuration for a migrating leader lock.
Field
Description
name[Required] string
Name is the name of the controller being migrated
E.g. service-controller, route-controller, cloud-node-controller, etc
component[Required] string
Component is the name of the component in which the controller should be running.
E.g. kube-controller-manager, cloud-controller-manager, etc
Or '*' meaning the controller can be run under any component that participates in the migration
leaderElection defines the configuration of leader election client.
Controllers[Required] []string
Controllers is the list of controllers to enable or disable
'*' means "all enabled by default controllers"
'foo' means "enable 'foo'"
'-foo' means "disable 'foo'"
first item for a particular name wins
AttachDetachControllerConfiguration contains elements describing AttachDetachController.
Field
Description
DisableAttachDetachReconcilerSync[Required] bool
Reconciler runs a periodic loop to reconcile the desired state of the with
the actual state of the world by triggering attach detach operations.
This flag enables or disables reconcile. Is false by default, and thus enabled.
clusterSigningDuration is the max length of duration signed certificates will be given.
Individual CSRs may request shorter certs by setting spec.expirationSeconds.
CronJobControllerConfiguration contains elements describing CrongJob2Controller.
Field
Description
ConcurrentCronJobSyncs[Required] int32
concurrentCronJobSyncs is the number of job objects that are
allowed to sync concurrently. Larger number = more responsive jobs,
but more CPU (and network) load.
DaemonSetControllerConfiguration contains elements describing DaemonSetController.
Field
Description
ConcurrentDaemonSetSyncs[Required] int32
concurrentDaemonSetSyncs is the number of daemonset objects that are
allowed to sync concurrently. Larger number = more responsive daemonset,
but more CPU (and network) load.
DeploymentControllerConfiguration contains elements describing DeploymentController.
Field
Description
ConcurrentDeploymentSyncs[Required] int32
concurrentDeploymentSyncs is the number of deployment objects that are
allowed to sync concurrently. Larger number = more responsive deployments,
but more CPU (and network) load.
EndpointControllerConfiguration contains elements describing EndpointController.
Field
Description
ConcurrentEndpointSyncs[Required] int32
concurrentEndpointSyncs is the number of endpoint syncing operations
that will be done concurrently. Larger number = faster endpoint updating,
but more CPU (and network) load.
EndpointUpdatesBatchPeriod describes the length of endpoint updates batching period.
Processing of pod changes will be delayed by this duration to join them with potential
upcoming updates and reduce the overall number of endpoints updates.
EndpointSliceControllerConfiguration contains elements describing
EndpointSliceController.
Field
Description
ConcurrentServiceEndpointSyncs[Required] int32
concurrentServiceEndpointSyncs is the number of service endpoint syncing
operations that will be done concurrently. Larger number = faster
endpoint slice updating, but more CPU (and network) load.
MaxEndpointsPerSlice[Required] int32
maxEndpointsPerSlice is the maximum number of endpoints that will be
added to an EndpointSlice. More endpoints per slice will result in fewer
and larger endpoint slices, but larger resources.
EndpointUpdatesBatchPeriod describes the length of endpoint updates batching period.
Processing of pod changes will be delayed by this duration to join them with potential
upcoming updates and reduce the overall number of endpoints updates.
mirroringConcurrentServiceEndpointSyncs is the number of service endpoint
syncing operations that will be done concurrently. Larger number = faster
endpoint slice updating, but more CPU (and network) load.
MirroringMaxEndpointsPerSubset[Required] int32
mirroringMaxEndpointsPerSubset is the maximum number of endpoints that
will be mirrored to an EndpointSlice for an EndpointSubset.
mirroringEndpointUpdatesBatchPeriod can be used to batch EndpointSlice
updates. All updates triggered by EndpointSlice changes will be delayed
by up to 'mirroringEndpointUpdatesBatchPeriod'. If other addresses in the
same Endpoints resource change in that period, they will be batched to a
single EndpointSlice update. Default 0 value means that each Endpoints
update triggers an EndpointSlice update.
EphemeralVolumeControllerConfiguration contains elements describing EphemeralVolumeController.
Field
Description
ConcurrentEphemeralVolumeSyncs[Required] int32
ConcurrentEphemeralVolumeSyncseSyncs is the number of ephemeral volume syncing operations
that will be done concurrently. Larger number = faster ephemeral volume updating,
but more CPU (and network) load.
GarbageCollectorControllerConfiguration contains elements describing GarbageCollectorController.
Field
Description
EnableGarbageCollector[Required] bool
enables the generic garbage collector. MUST be synced with the
corresponding flag of the kube-apiserver. WARNING: the generic garbage
collector is an alpha feature.
ConcurrentGCSyncs[Required] int32
concurrentGCSyncs is the number of garbage collector workers that are
allowed to sync concurrently.
ConcurrentHorizontalPodAutoscalerSyncs is the number of HPA objects that are allowed to sync concurrently.
Larger number = more responsive HPA processing, but more CPU (and network) load.
HorizontalPodAutoscalerDowncaleStabilizationWindow is a period for which autoscaler will look
backwards and not scale down below any recommendation it made during that period.
HorizontalPodAutoscalerInitialReadinessDelay is period after pod start during which readiness
changes are treated as readiness being set for the first time. The only effect of this is that
HPA will disregard CPU samples from unready pods that had last readiness change during that
period.
JobControllerConfiguration contains elements describing JobController.
Field
Description
ConcurrentJobSyncs[Required] int32
concurrentJobSyncs is the number of job objects that are
allowed to sync concurrently. Larger number = more responsive jobs,
but more CPU (and network) load.
NodeIPAMControllerConfiguration contains elements describing NodeIpamController.
Field
Description
ServiceCIDR[Required] string
serviceCIDR is CIDR Range for Services in cluster.
SecondaryServiceCIDR[Required] string
secondaryServiceCIDR is CIDR Range for Services in cluster. This is used in dual stack clusters. SecondaryServiceCIDR must be of different IP family than ServiceCIDR
NodeCIDRMaskSize[Required] int32
NodeCIDRMaskSize is the mask size for node cidr in cluster.
NodeCIDRMaskSizeIPv4[Required] int32
NodeCIDRMaskSizeIPv4 is the mask size for node cidr in dual-stack cluster.
NodeCIDRMaskSizeIPv6[Required] int32
NodeCIDRMaskSizeIPv6 is the mask size for node cidr in dual-stack cluster.
nodeMontiorGracePeriod is the amount of time which we allow a running node to be
unresponsive before marking it unhealthy. Must be N times more than kubelet's
nodeStatusUpdateFrequency, where N means number of retries allowed for kubelet
to post node status.
podEvictionTimeout is the grace period for deleting pods on failed nodes.
LargeClusterSizeThreshold[Required] int32
secondaryNodeEvictionRate is implicitly overridden to 0 for clusters smaller than or equal to largeClusterSizeThreshold
UnhealthyZoneThreshold[Required] float32
Zone is treated as unhealthy in nodeEvictionRate and secondaryNodeEvictionRate when at least
unhealthyZoneThreshold (no less than 3) of Nodes in the zone are NotReady
PersistentVolumeRecyclerConfiguration contains elements describing persistent volume plugins.
Field
Description
MaximumRetry[Required] int32
maximumRetry is number of retries the PV recycler will execute on failure to recycle
PV.
MinimumTimeoutNFS[Required] int32
minimumTimeoutNFS is the minimum ActiveDeadlineSeconds to use for an NFS Recycler
pod.
PodTemplateFilePathNFS[Required] string
podTemplateFilePathNFS is the file path to a pod definition used as a template for
NFS persistent volume recycling
IncrementTimeoutNFS[Required] int32
incrementTimeoutNFS is the increment of time added per Gi to ActiveDeadlineSeconds
for an NFS scrubber pod.
PodTemplateFilePathHostPath[Required] string
podTemplateFilePathHostPath is the file path to a pod definition used as a template for
HostPath persistent volume recycling. This is for development and testing only and
will not work in a multi-node cluster.
MinimumTimeoutHostPath[Required] int32
minimumTimeoutHostPath is the minimum ActiveDeadlineSeconds to use for a HostPath
Recycler pod. This is for development and testing only and will not work in a multi-node
cluster.
IncrementTimeoutHostPath[Required] int32
incrementTimeoutHostPath is the increment of time added per Gi to ActiveDeadlineSeconds
for a HostPath scrubber pod. This is for development and testing only and will not work
in a multi-node cluster.
PodGCControllerConfiguration contains elements describing PodGCController.
Field
Description
TerminatedPodGCThreshold[Required] int32
terminatedPodGCThreshold is the number of terminated pods that can exist
before the terminated pod garbage collector starts deleting terminated pods.
If <= 0, the terminated pod garbage collector is disabled.
ReplicaSetControllerConfiguration contains elements describing ReplicaSetController.
Field
Description
ConcurrentRSSyncs[Required] int32
concurrentRSSyncs is the number of replica sets that are allowed to sync
concurrently. Larger number = more responsive replica management, but more
CPU (and network) load.
ReplicationControllerConfiguration contains elements describing ReplicationController.
Field
Description
ConcurrentRCSyncs[Required] int32
concurrentRCSyncs is the number of replication controllers that are
allowed to sync concurrently. Larger number = more responsive replica
management, but more CPU (and network) load.
resourceQuotaSyncPeriod is the period for syncing quota usage status
in the system.
ConcurrentResourceQuotaSyncs[Required] int32
concurrentResourceQuotaSyncs is the number of resource quotas that are
allowed to sync concurrently. Larger number = more responsive quota
management, but more CPU (and network) load.
StatefulSetControllerConfiguration contains elements describing StatefulSetController.
Field
Description
ConcurrentStatefulSetSyncs[Required] int32
concurrentStatefulSetSyncs is the number of statefulset objects that are
allowed to sync concurrently. Larger number = more responsive statefulsets,
but more CPU (and network) load.
ValidatingAdmissionPolicyStatusControllerConfiguration contains elements describing ValidatingAdmissionPolicyStatusController.
Field
Description
ConcurrentPolicySyncs[Required] int32
ConcurrentPolicySyncs is the number of policy objects that are
allowed to sync concurrently. Larger number = quicker type checking,
but more CPU (and network) load.
The default value is 5.
VolumeConfiguration contains all enumerated flags meant to configure all volume
plugins. From this config, the controller-manager binary will create many instances of
volume.VolumeConfig, each containing only the configuration needed for that plugin which
are then passed to the appropriate plugin. The ControllerManager binary is the only part
of the code which knows what plugins are supported and which flags correspond to each plugin.
Field
Description
EnableHostPathProvisioning[Required] bool
enableHostPathProvisioning enables HostPath PV provisioning when running without a
cloud provider. This allows testing and development of provisioning features. HostPath
provisioning is not supported in any way, won't work in a multi-node cluster, and
should not be used for anything other than testing or development.
EnableDynamicProvisioning[Required] bool
enableDynamicProvisioning enables the provisioning of volumes when running within an environment
that supports dynamic provisioning. Defaults to true.
ClientConnectionConfiguration contains details for constructing a client.
Field
Description
kubeconfig[Required] string
kubeconfig is the path to a KubeConfig file.
acceptContentTypes[Required] string
acceptContentTypes defines the Accept header sent by clients when connecting to a server, overriding the
default value of 'application/json'. This field will control all connections to the server used by a particular
client.
contentType[Required] string
contentType is the content type used when sending data to the server from this client.
qps[Required] float32
qps controls the number of queries per second allowed for this connection.
burst[Required] int32
burst allows extra queries to accumulate when a client is exceeding its rate.
LeaderElectionConfiguration defines the configuration of leader election
clients for components that can run with leader election enabled.
Field
Description
leaderElect[Required] bool
leaderElect enables a leader election client to gain leadership
before executing the main loop. Enable this when running replicated
components for high availability.
leaseDuration is the duration that non-leader candidates will wait
after observing a leadership renewal until attempting to acquire
leadership of a led but unrenewed leader slot. This is effectively the
maximum duration that a leader can be stopped before it is replaced
by another candidate. This is only applicable if leader election is
enabled.
renewDeadline is the interval between attempts by the acting master to
renew a leadership slot before it stops leading. This must be less
than or equal to the lease duration. This is only applicable if leader
election is enabled.
retryPeriod is the duration the clients should wait between attempting
acquisition and renewal of a leadership. This is only applicable if
leader election is enabled.
resourceLock[Required] string
resourceLock indicates the resource object type that will be used to lock
during leader election cycles.
resourceName[Required] string
resourceName indicates the name of resource object that will be used to lock
during leader election cycles.
resourceNamespace[Required] string
resourceName indicates the namespace of resource object that will be used to lock
during leader election cycles.
KubeProxyConfiguration
KubeProxyConfiguration contains everything necessary to configure the
Kubernetes proxy server.
Field
Description
apiVersion string
kubeproxy.config.k8s.io/v1alpha1
kind string
KubeProxyConfiguration
featureGates[Required] map[string]bool
featureGates is a map of feature names to bools that enable or disable alpha/experimental features.
bindAddress[Required] string
bindAddress is the IP address for the proxy server to serve on (set to 0.0.0.0
for all interfaces)
healthzBindAddress[Required] string
healthzBindAddress is the IP address and port for the health check server to serve on,
defaulting to 0.0.0.0:10256
metricsBindAddress[Required] string
metricsBindAddress is the IP address and port for the metrics server to serve on,
defaulting to 127.0.0.1:10249 (set to 0.0.0.0 for all interfaces)
bindAddressHardFail[Required] bool
bindAddressHardFail, if true, kube-proxy will treat failure to bind to a port as fatal and exit
enableProfiling[Required] bool
enableProfiling enables profiling via web interface on /debug/pprof handler.
Profiling handlers will be handled by metrics server.
clusterCIDR[Required] string
clusterCIDR is the CIDR range of the pods in the cluster. It is used to
bridge traffic coming from outside of the cluster. If not provided,
no off-cluster bridging will be performed.
hostnameOverride[Required] string
hostnameOverride, if non-empty, will be used as the identity instead of the actual hostname.
portRange is the range of host ports (beginPort-endPort, inclusive) that may be consumed
in order to proxy service traffic. If unspecified (0-0) then ports will be randomly chosen.
configSyncPeriod is how often configuration from the apiserver is refreshed. Must be greater
than 0.
nodePortAddresses[Required] []string
nodePortAddresses is the --nodeport-addresses value for kube-proxy process. Values must be valid
IP blocks. These values are as a parameter to select the interfaces where nodeport works.
In case someone would like to expose a service on localhost for local visit and some other interfaces for
particular purpose, a list of IP blocks would do that.
If set it to "127.0.0.0/8", kube-proxy will only select the loopback interface for NodePort.
If set it to a non-zero IP block, kube-proxy will filter that down to just the IPs that applied to the node.
An empty string slice is meant to select all network interfaces.
DetectLocalConfiguration contains optional settings related to DetectLocalMode option
Field
Description
bridgeInterface[Required] string
BridgeInterface is a string argument which represents a single bridge interface name.
Kube-proxy considers traffic as local if originating from this given bridge.
This argument should be set if DetectLocalMode is set to LocalModeBridgeInterface.
interfaceNamePrefix[Required] string
InterfaceNamePrefix is a string argument which represents a single interface prefix name.
Kube-proxy considers traffic as local if originating from one or more interfaces which match
the given prefix. This argument should be set if DetectLocalMode is set to LocalModeInterfaceNamePrefix.
tcpCloseWaitTimeout is how long an idle conntrack entry
in CLOSE_WAIT state will remain in the conntrack
table. (e.g. '60s'). Must be greater than 0 to set.
tcpFinTimeout is the timeout value used for IPVS TCP sessions after receiving a FIN.
The default value is 0, which preserves the current timeout value on the system.
ProxyMode represents modes used by the Kubernetes proxy server.
Currently, two modes of proxy are available on Linux platforms: 'iptables' and 'ipvs'.
One mode of proxy is available on Windows platforms: 'kernelspace'.
If the proxy mode is unspecified, the best-available proxy mode will be used (currently this
is iptables on Linux and kernelspace on Windows). If the selected proxy mode cannot be
used (due to lack of kernel support, missing userspace components, etc) then kube-proxy
will exit with an error.
ClientConnectionConfiguration contains details for constructing a client.
Field
Description
kubeconfig[Required] string
kubeconfig is the path to a KubeConfig file.
acceptContentTypes[Required] string
acceptContentTypes defines the Accept header sent by clients when connecting to a server, overriding the
default value of 'application/json'. This field will control all connections to the server used by a particular
client.
contentType[Required] string
contentType is the content type used when sending data to the server from this client.
qps[Required] float32
qps controls the number of queries per second allowed for this connection.
burst[Required] int32
burst allows extra queries to accumulate when a client is exceeding its rate.
LeaderElectionConfiguration defines the configuration of leader election
clients for components that can run with leader election enabled.
Field
Description
leaderElect[Required] bool
leaderElect enables a leader election client to gain leadership
before executing the main loop. Enable this when running replicated
components for high availability.
leaseDuration is the duration that non-leader candidates will wait
after observing a leadership renewal until attempting to acquire
leadership of a led but unrenewed leader slot. This is effectively the
maximum duration that a leader can be stopped before it is replaced
by another candidate. This is only applicable if leader election is
enabled.
renewDeadline is the interval between attempts by the acting master to
renew a leadership slot before it stops leading. This must be less
than or equal to the lease duration. This is only applicable if leader
election is enabled.
retryPeriod is the duration the clients should wait between attempting
acquisition and renewal of a leadership. This is only applicable if
leader election is enabled.
resourceLock[Required] string
resourceLock indicates the resource object type that will be used to lock
during leader election cycles.
resourceName[Required] string
resourceName indicates the name of resource object that will be used to lock
during leader election cycles.
resourceNamespace[Required] string
resourceName indicates the namespace of resource object that will be used to lock
during leader election cycles.
DefaultPreemptionArgs
DefaultPreemptionArgs holds arguments used to configure the
DefaultPreemption plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1
kind string
DefaultPreemptionArgs
minCandidateNodesPercentage[Required] int32
MinCandidateNodesPercentage is the minimum number of candidates to
shortlist when dry running preemption as a percentage of number of nodes.
Must be in the range [0, 100]. Defaults to 10% of the cluster size if
unspecified.
minCandidateNodesAbsolute[Required] int32
MinCandidateNodesAbsolute is the absolute minimum number of candidates to
shortlist. The likely number of candidates enumerated for dry running
preemption is given by the formula:
numCandidates = max(numNodes * minCandidateNodesPercentage, minCandidateNodesAbsolute)
We say "likely" because there are other factors such as PDB violations
that play a role in the number of candidates shortlisted. Must be at least
0 nodes. Defaults to 100 nodes if unspecified.
InterPodAffinityArgs
InterPodAffinityArgs holds arguments used to configure the InterPodAffinity plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1
kind string
InterPodAffinityArgs
hardPodAffinityWeight[Required] int32
HardPodAffinityWeight is the scoring weight for existing pods with a
matching hard affinity to the incoming pod.
ignorePreferredTermsOfExistingPods[Required] bool
IgnorePreferredTermsOfExistingPods configures the scheduler to ignore existing pods' preferred affinity
rules when scoring candidate nodes, unless the incoming pod has inter-pod affinities.
KubeSchedulerConfiguration
KubeSchedulerConfiguration configures a scheduler
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1
kind string
KubeSchedulerConfiguration
parallelism[Required] int32
Parallelism defines the amount of parallelism in algorithms for scheduling a Pods. Must be greater than 0. Defaults to 16
(Members of DebuggingConfiguration are embedded into this type.)
DebuggingConfiguration holds configuration for Debugging related features
TODO: We might wanna make this a substruct like Debugging componentbaseconfigv1alpha1.DebuggingConfiguration
percentageOfNodesToScore[Required] int32
PercentageOfNodesToScore is the percentage of all nodes that once found feasible
for running a pod, the scheduler stops its search for more feasible nodes in
the cluster. This helps improve scheduler's performance. Scheduler always tries to find
at least "minFeasibleNodesToFind" feasible nodes no matter what the value of this flag is.
Example: if the cluster size is 500 nodes and the value of this flag is 30,
then scheduler stops finding further feasible nodes once it finds 150 feasible ones.
When the value is 0, default percentage (5%--50% based on the size of the cluster) of the
nodes will be scored. It is overridden by profile level PercentageofNodesToScore.
podInitialBackoffSeconds[Required] int64
PodInitialBackoffSeconds is the initial backoff for unschedulable pods.
If specified, it must be greater than 0. If this value is null, the default value (1s)
will be used.
podMaxBackoffSeconds[Required] int64
PodMaxBackoffSeconds is the max backoff for unschedulable pods.
If specified, it must be greater than podInitialBackoffSeconds. If this value is null,
the default value (10s) will be used.
Profiles are scheduling profiles that kube-scheduler supports. Pods can
choose to be scheduled under a particular profile by setting its associated
scheduler name. Pods that don't specify any scheduler name are scheduled
with the "default-scheduler" profile, if present here.
Extenders are the list of scheduler extenders, each holding the values of how to communicate
with the extender. These extenders are shared by all scheduler profiles.
delayCacheUntilActive[Required] bool
DelayCacheUntilActive specifies when to start caching. If this is true and leader election is enabled,
the scheduler will wait to fill informer caches until it is the leader. Doing so will have slower
failover with the benefit of lower memory overhead while waiting to become leader.
Defaults to false.
NodeAffinityArgs
NodeAffinityArgs holds arguments to configure the NodeAffinity plugin.
AddedAffinity is applied to all Pods additionally to the NodeAffinity
specified in the PodSpec. That is, Nodes need to satisfy AddedAffinity
AND .spec.NodeAffinity. AddedAffinity is empty by default (all Nodes
match).
When AddedAffinity is used, some Pods with affinity requirements that match
a specific Node (such as Daemonset Pods) might remain unschedulable.
NodeResourcesBalancedAllocationArgs
NodeResourcesBalancedAllocationArgs holds arguments used to configure NodeResourcesBalancedAllocation plugin.
Resources to be managed, the default is "cpu" and "memory" if not specified.
NodeResourcesFitArgs
NodeResourcesFitArgs holds arguments used to configure the NodeResourcesFit plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1
kind string
NodeResourcesFitArgs
ignoredResources[Required] []string
IgnoredResources is the list of resources that NodeResources fit filter
should ignore. This doesn't apply to scoring.
ignoredResourceGroups[Required] []string
IgnoredResourceGroups defines the list of resource groups that NodeResources fit filter should ignore.
e.g. if group is ["example.com"], it will ignore all resource names that begin
with "example.com", such as "example.com/aaa" and "example.com/bbb".
A resource group name can't contain '/'. This doesn't apply to scoring.
DefaultConstraints defines topology spread constraints to be applied to
Pods that don't define any in pod.spec.topologySpreadConstraints.
.defaultConstraints[*].labelSelectors must be empty, as they are
deduced from the Pod's membership to Services, ReplicationControllers,
ReplicaSets or StatefulSets.
When not empty, .defaultingType must be "List".
DefaultingType determines how .defaultConstraints are deduced. Can be one
of "System" or "List".
"System": Use kubernetes defined constraints that spread Pods among
Nodes and Zones.
"List": Use constraints defined in .defaultConstraints.
Defaults to "System".
VolumeBindingArgs
VolumeBindingArgs holds arguments used to configure the VolumeBinding plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1
kind string
VolumeBindingArgs
bindTimeoutSeconds[Required] int64
BindTimeoutSeconds is the timeout in seconds in volume binding operation.
Value must be non-negative integer. The value zero indicates no waiting.
If this value is nil, the default value (600) will be used.
Shape specifies the points defining the score function shape, which is
used to score nodes based on the utilization of statically provisioned
PVs. The utilization is calculated by dividing the total requested
storage of the pod by the total capacity of feasible PVs on each node.
Each point contains utilization (ranges from 0 to 100) and its
associated score (ranges from 0 to 10). You can turn the priority by
specifying different scores for different utilization numbers.
The default shape points are:
0 for 0 utilization
10 for 100 utilization
All points must be sorted in increasing order by utilization.
Extender holds the parameters used to communicate with the extender. If a verb is unspecified/empty,
it is assumed that the extender chose not to provide that extension.
Field
Description
urlPrefix[Required] string
URLPrefix at which the extender is available
filterVerb[Required] string
Verb for the filter call, empty if not supported. This verb is appended to the URLPrefix when issuing the filter call to extender.
preemptVerb[Required] string
Verb for the preempt call, empty if not supported. This verb is appended to the URLPrefix when issuing the preempt call to extender.
prioritizeVerb[Required] string
Verb for the prioritize call, empty if not supported. This verb is appended to the URLPrefix when issuing the prioritize call to extender.
weight[Required] int64
The numeric multiplier for the node scores that the prioritize call generates.
The weight should be a positive integer
bindVerb[Required] string
Verb for the bind call, empty if not supported. This verb is appended to the URLPrefix when issuing the bind call to extender.
If this method is implemented by the extender, it is the extender's responsibility to bind the pod to apiserver. Only one extender
can implement this function.
enableHTTPS[Required] bool
EnableHTTPS specifies whether https should be used to communicate with the extender
HTTPTimeout specifies the timeout duration for a call to the extender. Filter timeout fails the scheduling of the pod. Prioritize
timeout is ignored, k8s/other extenders priorities are used to select the node.
nodeCacheCapable[Required] bool
NodeCacheCapable specifies that the extender is capable of caching node information,
so the scheduler should only send minimal information about the eligible nodes
assuming that the extender already cached full details of all nodes in the cluster
ManagedResources is a list of extended resources that are managed by
this extender.
A pod will be sent to the extender on the Filter, Prioritize and Bind
(if the extender is the binder) phases iff the pod requests at least
one of the extended resources in this list. If empty or unspecified,
all pods will be sent to this extender.
If IgnoredByScheduler is set to true for a resource, kube-scheduler
will skip checking the resource in predicates.
ignorable[Required] bool
Ignorable specifies if the extender is ignorable, i.e. scheduling should not
fail when the extender returns an error or is not reachable.
ExtenderTLSConfig contains settings to enable TLS with extender
Field
Description
insecure[Required] bool
Server should be accessed without verifying the TLS certificate. For testing only.
serverName[Required] string
ServerName is passed to the server for SNI and is used in the client to check server
certificates against. If ServerName is empty, the hostname used to contact the
server is used.
certFile[Required] string
Server requires TLS client certificate authentication
keyFile[Required] string
Server requires TLS client certificate authentication
caFile[Required] string
Trusted root certificates for server
certData[Required] []byte
CertData holds PEM-encoded bytes (typically read from a client certificate file).
CertData takes precedence over CertFile
keyData[Required] []byte
KeyData holds PEM-encoded bytes (typically read from a client certificate key file).
KeyData takes precedence over KeyFile
caData[Required] []byte
CAData holds PEM-encoded bytes (typically read from a root certificates bundle).
CAData takes precedence over CAFile
SchedulerName is the name of the scheduler associated to this profile.
If SchedulerName matches with the pod's "spec.schedulerName", then the pod
is scheduled with this profile.
percentageOfNodesToScore[Required] int32
PercentageOfNodesToScore is the percentage of all nodes that once found feasible
for running a pod, the scheduler stops its search for more feasible nodes in
the cluster. This helps improve scheduler's performance. Scheduler always tries to find
at least "minFeasibleNodesToFind" feasible nodes no matter what the value of this flag is.
Example: if the cluster size is 500 nodes and the value of this flag is 30,
then scheduler stops finding further feasible nodes once it finds 150 feasible ones.
When the value is 0, default percentage (5%--50% based on the size of the cluster) of the
nodes will be scored. It will override global PercentageOfNodesToScore. If it is empty,
global PercentageOfNodesToScore will be used.
Plugins specify the set of plugins that should be enabled or disabled.
Enabled plugins are the ones that should be enabled in addition to the
default plugins. Disabled plugins are any of the default plugins that
should be disabled.
When no enabled or disabled plugin is specified for an extension point,
default plugins for that extension point will be used if there is any.
If a QueueSort plugin is specified, the same QueueSort Plugin and
PluginConfig must be specified for all profiles.
PluginConfig is an optional set of custom plugin arguments for each plugin.
Omitting config args for a plugin is equivalent to using the default config
for that plugin.
PluginConfig specifies arguments that should be passed to a plugin at the time of initialization.
A plugin that is invoked at multiple extension points is initialized once. Args can have arbitrary structure.
It is up to the plugin to process these Args.
PluginSet specifies enabled and disabled plugins for an extension point.
If an array is empty, missing, or nil, default plugins at that extension point will be used.
Enabled specifies plugins that should be enabled in addition to default plugins.
If the default plugin is also configured in the scheduler config file, the weight of plugin will
be overridden accordingly.
These are called after default plugins and in the same order specified here.
Disabled specifies default plugins that should be disabled.
When all default plugins need to be disabled, an array containing only one "*" should be provided.
Plugins include multiple extension points. When specified, the list of plugins for
a particular extension point are the only ones enabled. If an extension point is
omitted from the config, then the default set of plugins is used for that extension point.
Enabled plugins are called in the order specified here, after default plugins. If they need to
be invoked before default plugins, default plugins must be disabled and re-enabled here in desired order.
Bind is a list of plugins that should be invoked at "Bind" extension point of the scheduling framework.
The scheduler call these plugins in order. Scheduler skips the rest of these plugins as soon as one returns success.
MultiPoint is a simplified config section to enable plugins for all valid extension points.
Plugins enabled through MultiPoint will automatically register for every individual extension
point the plugin has implemented. Disabling a plugin through MultiPoint disables that behavior.
The same is true for disabling "*" through MultiPoint (no default plugins will be automatically registered).
Plugins can still be disabled through their individual extension points.
In terms of precedence, plugin config follows this basic hierarchy
Specific extension points
Explicitly configured MultiPoint plugins
The set of default plugins, as MultiPoint plugins
This implies that a higher precedence plugin will run first and overwrite any settings within MultiPoint.
Explicitly user-configured plugins also take a higher precedence over default plugins.
Within this hierarchy, an Enabled setting takes precedence over Disabled. For example, if a plugin is
set in both multiPoint.Enabled and multiPoint.Disabled, the plugin will be enabled. Similarly,
including multiPoint.Disabled = '*' and multiPoint.Enabled = pluginA will still register that specific
plugin through MultiPoint. This follows the same behavior as all other extension point configurations.
Resources to consider when scoring.
The default resource set includes "cpu" and "memory" with an equal weight.
Allowed weights go from 1 to 100.
Weight defaults to 1 if not specified or explicitly set to 0.
ClientConnectionConfiguration contains details for constructing a client.
Field
Description
kubeconfig[Required] string
kubeconfig is the path to a KubeConfig file.
acceptContentTypes[Required] string
acceptContentTypes defines the Accept header sent by clients when connecting to a server, overriding the
default value of 'application/json'. This field will control all connections to the server used by a particular
client.
contentType[Required] string
contentType is the content type used when sending data to the server from this client.
qps[Required] float32
qps controls the number of queries per second allowed for this connection.
burst[Required] int32
burst allows extra queries to accumulate when a client is exceeding its rate.
LeaderElectionConfiguration defines the configuration of leader election
clients for components that can run with leader election enabled.
Field
Description
leaderElect[Required] bool
leaderElect enables a leader election client to gain leadership
before executing the main loop. Enable this when running replicated
components for high availability.
leaseDuration is the duration that non-leader candidates will wait
after observing a leadership renewal until attempting to acquire
leadership of a led but unrenewed leader slot. This is effectively the
maximum duration that a leader can be stopped before it is replaced
by another candidate. This is only applicable if leader election is
enabled.
renewDeadline is the interval between attempts by the acting master to
renew a leadership slot before it stops leading. This must be less
than or equal to the lease duration. This is only applicable if leader
election is enabled.
retryPeriod is the duration the clients should wait between attempting
acquisition and renewal of a leadership. This is only applicable if
leader election is enabled.
resourceLock[Required] string
resourceLock indicates the resource object type that will be used to lock
during leader election cycles.
resourceName[Required] string
resourceName indicates the name of resource object that will be used to lock
during leader election cycles.
resourceNamespace[Required] string
resourceName indicates the namespace of resource object that will be used to lock
during leader election cycles.
DefaultPreemptionArgs
DefaultPreemptionArgs holds arguments used to configure the
DefaultPreemption plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1beta3
kind string
DefaultPreemptionArgs
minCandidateNodesPercentage[Required] int32
MinCandidateNodesPercentage is the minimum number of candidates to
shortlist when dry running preemption as a percentage of number of nodes.
Must be in the range [0, 100]. Defaults to 10% of the cluster size if
unspecified.
minCandidateNodesAbsolute[Required] int32
MinCandidateNodesAbsolute is the absolute minimum number of candidates to
shortlist. The likely number of candidates enumerated for dry running
preemption is given by the formula:
numCandidates = max(numNodes * minCandidateNodesPercentage, minCandidateNodesAbsolute)
We say "likely" because there are other factors such as PDB violations
that play a role in the number of candidates shortlisted. Must be at least
0 nodes. Defaults to 100 nodes if unspecified.
InterPodAffinityArgs
InterPodAffinityArgs holds arguments used to configure the InterPodAffinity plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1beta3
kind string
InterPodAffinityArgs
hardPodAffinityWeight[Required] int32
HardPodAffinityWeight is the scoring weight for existing pods with a
matching hard affinity to the incoming pod.
ignorePreferredTermsOfExistingPods[Required] bool
IgnorePreferredTermsOfExistingPods configures the scheduler to ignore existing pods' preferred affinity
rules when scoring candidate nodes, unless the incoming pod has inter-pod affinities.
KubeSchedulerConfiguration
KubeSchedulerConfiguration configures a scheduler
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1beta3
kind string
KubeSchedulerConfiguration
parallelism[Required] int32
Parallelism defines the amount of parallelism in algorithms for scheduling a Pods. Must be greater than 0. Defaults to 16
(Members of DebuggingConfiguration are embedded into this type.)
DebuggingConfiguration holds configuration for Debugging related features
TODO: We might wanna make this a substruct like Debugging componentbaseconfigv1alpha1.DebuggingConfiguration
percentageOfNodesToScore[Required] int32
PercentageOfNodesToScore is the percentage of all nodes that once found feasible
for running a pod, the scheduler stops its search for more feasible nodes in
the cluster. This helps improve scheduler's performance. Scheduler always tries to find
at least "minFeasibleNodesToFind" feasible nodes no matter what the value of this flag is.
Example: if the cluster size is 500 nodes and the value of this flag is 30,
then scheduler stops finding further feasible nodes once it finds 150 feasible ones.
When the value is 0, default percentage (5%--50% based on the size of the cluster) of the
nodes will be scored.
podInitialBackoffSeconds[Required] int64
PodInitialBackoffSeconds is the initial backoff for unschedulable pods.
If specified, it must be greater than 0. If this value is null, the default value (1s)
will be used.
podMaxBackoffSeconds[Required] int64
PodMaxBackoffSeconds is the max backoff for unschedulable pods.
If specified, it must be greater than podInitialBackoffSeconds. If this value is null,
the default value (10s) will be used.
Profiles are scheduling profiles that kube-scheduler supports. Pods can
choose to be scheduled under a particular profile by setting its associated
scheduler name. Pods that don't specify any scheduler name are scheduled
with the "default-scheduler" profile, if present here.
Extenders are the list of scheduler extenders, each holding the values of how to communicate
with the extender. These extenders are shared by all scheduler profiles.
NodeAffinityArgs
NodeAffinityArgs holds arguments to configure the NodeAffinity plugin.
AddedAffinity is applied to all Pods additionally to the NodeAffinity
specified in the PodSpec. That is, Nodes need to satisfy AddedAffinity
AND .spec.NodeAffinity. AddedAffinity is empty by default (all Nodes
match).
When AddedAffinity is used, some Pods with affinity requirements that match
a specific Node (such as Daemonset Pods) might remain unschedulable.
NodeResourcesBalancedAllocationArgs
NodeResourcesBalancedAllocationArgs holds arguments used to configure NodeResourcesBalancedAllocation plugin.
Resources to be managed, the default is "cpu" and "memory" if not specified.
NodeResourcesFitArgs
NodeResourcesFitArgs holds arguments used to configure the NodeResourcesFit plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1beta3
kind string
NodeResourcesFitArgs
ignoredResources[Required] []string
IgnoredResources is the list of resources that NodeResources fit filter
should ignore. This doesn't apply to scoring.
ignoredResourceGroups[Required] []string
IgnoredResourceGroups defines the list of resource groups that NodeResources fit filter should ignore.
e.g. if group is ["example.com"], it will ignore all resource names that begin
with "example.com", such as "example.com/aaa" and "example.com/bbb".
A resource group name can't contain '/'. This doesn't apply to scoring.
DefaultConstraints defines topology spread constraints to be applied to
Pods that don't define any in pod.spec.topologySpreadConstraints.
.defaultConstraints[*].labelSelectors must be empty, as they are
deduced from the Pod's membership to Services, ReplicationControllers,
ReplicaSets or StatefulSets.
When not empty, .defaultingType must be "List".
DefaultingType determines how .defaultConstraints are deduced. Can be one
of "System" or "List".
"System": Use kubernetes defined constraints that spread Pods among
Nodes and Zones.
"List": Use constraints defined in .defaultConstraints.
Defaults to "System".
VolumeBindingArgs
VolumeBindingArgs holds arguments used to configure the VolumeBinding plugin.
Field
Description
apiVersion string
kubescheduler.config.k8s.io/v1beta3
kind string
VolumeBindingArgs
bindTimeoutSeconds[Required] int64
BindTimeoutSeconds is the timeout in seconds in volume binding operation.
Value must be non-negative integer. The value zero indicates no waiting.
If this value is nil, the default value (600) will be used.
Shape specifies the points defining the score function shape, which is
used to score nodes based on the utilization of statically provisioned
PVs. The utilization is calculated by dividing the total requested
storage of the pod by the total capacity of feasible PVs on each node.
Each point contains utilization (ranges from 0 to 100) and its
associated score (ranges from 0 to 10). You can turn the priority by
specifying different scores for different utilization numbers.
The default shape points are:
0 for 0 utilization
10 for 100 utilization
All points must be sorted in increasing order by utilization.
Extender holds the parameters used to communicate with the extender. If a verb is unspecified/empty,
it is assumed that the extender chose not to provide that extension.
Field
Description
urlPrefix[Required] string
URLPrefix at which the extender is available
filterVerb[Required] string
Verb for the filter call, empty if not supported. This verb is appended to the URLPrefix when issuing the filter call to extender.
preemptVerb[Required] string
Verb for the preempt call, empty if not supported. This verb is appended to the URLPrefix when issuing the preempt call to extender.
prioritizeVerb[Required] string
Verb for the prioritize call, empty if not supported. This verb is appended to the URLPrefix when issuing the prioritize call to extender.
weight[Required] int64
The numeric multiplier for the node scores that the prioritize call generates.
The weight should be a positive integer
bindVerb[Required] string
Verb for the bind call, empty if not supported. This verb is appended to the URLPrefix when issuing the bind call to extender.
If this method is implemented by the extender, it is the extender's responsibility to bind the pod to apiserver. Only one extender
can implement this function.
enableHTTPS[Required] bool
EnableHTTPS specifies whether https should be used to communicate with the extender
HTTPTimeout specifies the timeout duration for a call to the extender. Filter timeout fails the scheduling of the pod. Prioritize
timeout is ignored, k8s/other extenders priorities are used to select the node.
nodeCacheCapable[Required] bool
NodeCacheCapable specifies that the extender is capable of caching node information,
so the scheduler should only send minimal information about the eligible nodes
assuming that the extender already cached full details of all nodes in the cluster
ManagedResources is a list of extended resources that are managed by
this extender.
A pod will be sent to the extender on the Filter, Prioritize and Bind
(if the extender is the binder) phases iff the pod requests at least
one of the extended resources in this list. If empty or unspecified,
all pods will be sent to this extender.
If IgnoredByScheduler is set to true for a resource, kube-scheduler
will skip checking the resource in predicates.
ignorable[Required] bool
Ignorable specifies if the extender is ignorable, i.e. scheduling should not
fail when the extender returns an error or is not reachable.
ExtenderTLSConfig contains settings to enable TLS with extender
Field
Description
insecure[Required] bool
Server should be accessed without verifying the TLS certificate. For testing only.
serverName[Required] string
ServerName is passed to the server for SNI and is used in the client to check server
certificates against. If ServerName is empty, the hostname used to contact the
server is used.
certFile[Required] string
Server requires TLS client certificate authentication
keyFile[Required] string
Server requires TLS client certificate authentication
caFile[Required] string
Trusted root certificates for server
certData[Required] []byte
CertData holds PEM-encoded bytes (typically read from a client certificate file).
CertData takes precedence over CertFile
keyData[Required] []byte
KeyData holds PEM-encoded bytes (typically read from a client certificate key file).
KeyData takes precedence over KeyFile
caData[Required] []byte
CAData holds PEM-encoded bytes (typically read from a root certificates bundle).
CAData takes precedence over CAFile
SchedulerName is the name of the scheduler associated to this profile.
If SchedulerName matches with the pod's "spec.schedulerName", then the pod
is scheduled with this profile.
Plugins specify the set of plugins that should be enabled or disabled.
Enabled plugins are the ones that should be enabled in addition to the
default plugins. Disabled plugins are any of the default plugins that
should be disabled.
When no enabled or disabled plugin is specified for an extension point,
default plugins for that extension point will be used if there is any.
If a QueueSort plugin is specified, the same QueueSort Plugin and
PluginConfig must be specified for all profiles.
PluginConfig is an optional set of custom plugin arguments for each plugin.
Omitting config args for a plugin is equivalent to using the default config
for that plugin.
PluginConfig specifies arguments that should be passed to a plugin at the time of initialization.
A plugin that is invoked at multiple extension points is initialized once. Args can have arbitrary structure.
It is up to the plugin to process these Args.
PluginSet specifies enabled and disabled plugins for an extension point.
If an array is empty, missing, or nil, default plugins at that extension point will be used.
Enabled specifies plugins that should be enabled in addition to default plugins.
If the default plugin is also configured in the scheduler config file, the weight of plugin will
be overridden accordingly.
These are called after default plugins and in the same order specified here.
Disabled specifies default plugins that should be disabled.
When all default plugins need to be disabled, an array containing only one "*" should be provided.
Plugins include multiple extension points. When specified, the list of plugins for
a particular extension point are the only ones enabled. If an extension point is
omitted from the config, then the default set of plugins is used for that extension point.
Enabled plugins are called in the order specified here, after default plugins. If they need to
be invoked before default plugins, default plugins must be disabled and re-enabled here in desired order.
Bind is a list of plugins that should be invoked at "Bind" extension point of the scheduling framework.
The scheduler call these plugins in order. Scheduler skips the rest of these plugins as soon as one returns success.
MultiPoint is a simplified config section to enable plugins for all valid extension points.
Plugins enabled through MultiPoint will automatically register for every individual extension
point the plugin has implemented. Disabling a plugin through MultiPoint disables that behavior.
The same is true for disabling "*" through MultiPoint (no default plugins will be automatically registered).
Plugins can still be disabled through their individual extension points.
In terms of precedence, plugin config follows this basic hierarchy
Specific extension points
Explicitly configured MultiPoint plugins
The set of default plugins, as MultiPoint plugins
This implies that a higher precedence plugin will run first and overwrite any settings within MultiPoint.
Explicitly user-configured plugins also take a higher precedence over default plugins.
Within this hierarchy, an Enabled setting takes precedence over Disabled. For example, if a plugin is
set in both multiPoint.Enabled and multiPoint.Disabled, the plugin will be enabled. Similarly,
including multiPoint.Disabled = '*' and multiPoint.Enabled = pluginA will still register that specific
plugin through MultiPoint. This follows the same behavior as all other extension point configurations.
Resources to consider when scoring.
The default resource set includes "cpu" and "memory" with an equal weight.
Allowed weights go from 1 to 100.
Weight defaults to 1 if not specified or explicitly set to 0.
UtilizationShapePoint represents single point of priority function shape.
Field
Description
utilization[Required] int32
Utilization (x axis). Valid values are 0 to 100. Fully utilized node maps to 100.
score[Required] int32
Score assigned to given utilization (y axis). Valid values are 0 to 10.
14.15 - kubeadm Configuration (v1beta3)
Overview
Package v1beta3 defines the v1beta3 version of the kubeadm configuration file format.
This version improves on the v1beta2 format by fixing some minor issues and adding a few new fields.
A list of changes since v1beta2:
The deprecated "ClusterConfiguration.useHyperKubeImage" field has been removed.
Kubeadm no longer supports the hyperkube image.
The "ClusterConfiguration.DNS.Type" field has been removed since CoreDNS is the only supported
DNS server type by kubeadm.
Include "datapolicy" tags on the fields that hold secrets.
This would result in the field values to be omitted when API structures are printed with klog.
Add "InitConfiguration.SkipPhases", "JoinConfiguration.SkipPhases" to allow skipping
a list of phases during kubeadm init/join command execution.
Add "InitConfiguration.NodeRegistration.ImagePullPolicy" and "JoinConfiguration.NodeRegistration.ImagePullPolicy"
to allow specifying the images pull policy during kubeadm "init" and "join".
The value must be one of "Always", "Never" or "IfNotPresent".
"IfNotPresent" is the default, which has been the existing behavior prior to this addition.
Add "InitConfiguration.Patches.Directory", "JoinConfiguration.Patches.Directory" to allow
the user to configure a directory from which to take patches for components deployed by kubeadm.
Move the BootstrapToken* API and related utilities out of the "kubeadm" API group to a new group
"bootstraptoken". The kubeadm API version v1beta3 no longer contains the BootstrapToken* structures.
Migration from old kubeadm config versions
kubeadm v1.15.x and newer can be used to migrate from v1beta1 to v1beta2.
kubeadm v1.22.x and newer no longer support v1beta1 and older APIs, but can be used to migrate v1beta2 to v1beta3.
kubeadm v1.27.x and newer no longer support v1beta2 and older APIs,
Basics
The preferred way to configure kubeadm is to pass an YAML configuration file with the --config option. Some of the
configuration options defined in the kubeadm config file are also available as command line flags, but only
the most common/simple use case are supported with this approach.
A kubeadm config file could contain multiple configuration types separated using three dashes (---).
kubeadm supports the following configuration types:
The list of configuration types that must be included in a configuration file depends by the action you are
performing (init or join) and by the configuration options you are going to use (defaults or advanced
customization).
If some configuration types are not provided, or provided only partially, kubeadm will use default values; defaults
provided by kubeadm includes also enforcing consistency of values across components when required (e.g.
--cluster-cidr flag on controller manager and clusterCIDR on kube-proxy).
Users are always allowed to override default values, with the only exception of a small subset of setting with
relevance for security (e.g. enforce authorization-mode Node and RBAC on api server).
If the user provides a configuration types that is not expected for the action you are performing, kubeadm will
ignore those types and print a warning.
Kubeadm init configuration types
When executing kubeadm init with the --config option, the following configuration types could be used:
InitConfiguration, ClusterConfiguration, KubeProxyConfiguration, KubeletConfiguration, but only one
between InitConfiguration and ClusterConfiguration is mandatory.
The InitConfiguration type should be used to configure runtime settings, that in case of kubeadm init
are the configuration of the bootstrap token and all the setting which are specific to the node where
kubeadm is executed, including:
NodeRegistration, that holds fields that relate to registering the new node to the cluster;
use it to customize the node name, the CRI socket to use or any other settings that should apply to this
node only (e.g. the node ip).
LocalAPIEndpoint, that represents the endpoint of the instance of the API server to be deployed on this node;
use it e.g. to customize the API server advertise address.
The ClusterConfiguration type should be used to configure cluster-wide settings,
including settings for:
networking that holds configuration for the networking topology of the cluster; use it e.g. to customize
Pod subnet or services subnet.
etcd: use it e.g. to customize the local etcd or to configure the API server
for using an external etcd cluster.
kube-apiserver, kube-scheduler, kube-controller-manager configurations; use it to customize control-plane
components by adding customized setting or overriding kubeadm default settings.
The KubeProxyConfiguration type should be used to change the configuration passed to kube-proxy instances
deployed in the cluster. If this object is not provided or provided only partially, kubeadm applies defaults.
See https://kubernetes.io/docs/reference/command-line-tools-reference/kube-proxy/ or
https://pkg.go.dev/k8s.io/kube-proxy/config/v1alpha1#KubeProxyConfiguration
for kube-proxy official documentation.
The KubeletConfiguration type should be used to change the configurations that will be passed to all kubelet instances
deployed in the cluster. If this object is not provided or provided only partially, kubeadm applies defaults.
See https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/ or
https://pkg.go.dev/k8s.io/kubelet/config/v1beta1#KubeletConfiguration
for kubelet official documentation.
Here is a fully populated example of a single YAML file containing multiple
configuration types to be used during a kubeadm init run.
apiVersion:kubeadm.k8s.io/v1beta3kind:InitConfigurationbootstrapTokens:- token:"9a08jv.c0izixklcxtmnze7"description:"kubeadm bootstrap token"ttl:"24h"- token:"783bde.3f89s0fje9f38fhf"description:"another bootstrap token"usages:- authentication- signinggroups:- system:bootstrappers:kubeadm:default-node-tokennodeRegistration:name:"ec2-10-100-0-1"criSocket:"/var/run/dockershim.sock"taints:- key:"kubeadmNode"value:"someValue"effect:"NoSchedule"kubeletExtraArgs:v:4ignorePreflightErrors:- IsPrivilegedUserimagePullPolicy:"IfNotPresent"localAPIEndpoint:advertiseAddress:"10.100.0.1"bindPort:6443certificateKey:"e6a2eb8581237ab72a4f494f30285ec12a9694d750b9785706a83bfcbbbd2204"skipPhases:- addon/kube-proxy---apiVersion:kubeadm.k8s.io/v1beta3kind:ClusterConfigurationetcd:# one of local or externallocal:imageRepository:"registry.k8s.io"imageTag:"3.2.24"dataDir:"/var/lib/etcd"extraArgs:listen-client-urls:"http://10.100.0.1:2379"serverCertSANs:- "ec2-10-100-0-1.compute-1.amazonaws.com"peerCertSANs:- "10.100.0.1"# external:# endpoints:# - "10.100.0.1:2379"# - "10.100.0.2:2379"# caFile: "/etcd/kubernetes/pki/etcd/etcd-ca.crt"# certFile: "/etcd/kubernetes/pki/etcd/etcd.crt"# keyFile: "/etcd/kubernetes/pki/etcd/etcd.key"networking:serviceSubnet:"10.96.0.0/16"podSubnet:"10.244.0.0/24"dnsDomain:"cluster.local"kubernetesVersion:"v1.21.0"controlPlaneEndpoint:"10.100.0.1:6443"apiServer:extraArgs:authorization-mode:"Node,RBAC"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:FilecertSANs:- "10.100.1.1"- "ec2-10-100-0-1.compute-1.amazonaws.com"timeoutForControlPlane:4m0scontrollerManager:extraArgs:"node-cidr-mask-size": "20"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:Filescheduler:extraArgs:bind-address:"10.100.0.1"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:FilecertificatesDir:"/etc/kubernetes/pki"imageRepository:"registry.k8s.io"clusterName:"example-cluster"---apiVersion:kubelet.config.k8s.io/v1beta1kind:KubeletConfiguration# kubelet specific options here---apiVersion:kubeproxy.config.k8s.io/v1alpha1kind:KubeProxyConfiguration# kube-proxy specific options here
Kubeadm join configuration types
When executing kubeadm join with the --config option, the JoinConfiguration type should be provided.
The JoinConfiguration type should be used to configure runtime settings, that in case of kubeadm join
are the discovery method used for accessing the cluster info and all the setting which are specific
to the node where kubeadm is executed, including:
nodeRegistration, that holds fields that relate to registering the new node to the cluster;
use it to customize the node name, the CRI socket to use or any other settings that should apply to this
node only (e.g. the node ip).
apiEndpoint, that represents the endpoint of the instance of the API server to be eventually deployed on this node.
expires specifies the timestamp when this token expires. Defaults to being set
dynamically at runtime based on the ttl. expires and ttl are mutually exclusive.
usages []string
usages describes the ways in which this token can be used. Can by default be used
for establishing bidirectional trust, but that can be changed here.
groups []string
groups specifies the extra groups that this token will authenticate as when/if
used for authentication
BootstrapTokenString is a token of the format abcdef.abcdef0123456789 that is used
for both validation of the practically of the API server from a joining node's point
of view and as an authentication method for the node in the bootstrap phase of
"kubeadm join". This token is and should be short-lived.
Field
Description
-[Required] string
No description provided.
-[Required] string
No description provided.
ClusterConfiguration
ClusterConfiguration contains cluster-wide configuration for a kubeadm cluster
networking holds configuration for the networking topology of the cluster.
kubernetesVersion string
kubernetesVersion is the target version of the control plane.
controlPlaneEndpoint string
controlPlaneEndpoint sets a stable IP address or DNS name for the control plane.
It can be a valid IP address or a RFC-1123 DNS subdomain, both with optional TCP port.
In case the controlPlaneEndpoint is not specified, the advertiseAddress + bindPort
are used; in case the controlPlaneEndpoint is specified but without a TCP port,
the bindPort is used.
Possible usages are:
In a cluster with more than one control plane instances, this field should be
assigned the address of the external load balancer in front of the
control plane instances.
In environments with enforced node recycling, the controlPlaneEndpoint could
be used for assigning a stable DNS to the control plane.
dns defines the options for the DNS add-on installed in the cluster.
certificatesDir string
certificatesDir specifies where to store or look for all required certificates.
imageRepository string
imageRepository sets the container registry to pull images from.
If empty, registry.k8s.io will be used by default.
In case of kubernetes version is a CI build (kubernetes version starts with ci/)
gcr.io/k8s-staging-ci-images will be used as a default for control plane components
and for kube-proxy, while registry.k8s.io will be used for all the other images.
featureGates map[string]bool
featureGates contains the feature gates enabled by the user.
clusterName string
The cluster name.
InitConfiguration
InitConfiguration contains a list of elements that is specific "kubeadm init"-only runtime
information.
kubeadm init-only information. These fields are solely used the first time kubeadm init runs.
After that, the information in the fields IS NOT uploaded to the kubeadm-config ConfigMap
that is used by kubeadm upgrade for instance. These fields must be omitempty.
bootstrapTokens is respected at kubeadm init time and describes a set of Bootstrap Tokens to create.
This information IS NOT uploaded to the kubeadm cluster configmap, partly because of its sensitive nature
localAPIEndpoint represents the endpoint of the API server instance that's deployed on this
control plane node. In HA setups, this differs from ClusterConfiguration.controlPlaneEndpoint
in the sense that controlPlaneEndpoint is the global endpoint for the cluster, which then
load-balances the requests to each individual API server.
This configuration object lets you customize what IP/DNS name and port the local API server
advertises it's accessible on. By default, kubeadm tries to auto-detect the IP of the default
interface and use that, but in case that process fails you may set the desired value here.
certificateKey string
certificateKey sets the key with which certificates and keys are encrypted prior to being
uploaded in a Secret in the cluster during the uploadcerts init phase.
skipPhases []string
skipPhases is a list of phases to skip during command execution.
The list of phases can be obtained with the kubeadm init --help command.
The flag "--skip-phases" takes precedence over this field.
nodeRegistration holds fields that relate to registering the new
control-plane node to the cluster.
caCertPath string
caCertPath is the path to the SSL certificate authority used to secure
comunications between a node and the control-plane.
Defaults to "/etc/kubernetes/pki/ca.crt".
controlPlane defines the additional control plane instance to be deployed
on the joining node. If nil, no additional control plane instance will be deployed.
skipPhases []string
skipPhases is a list of phases to skip during command execution.
The list of phases can be obtained with the kubeadm join --help command.
The flag --skip-phases takes precedence over this field.
BootstrapTokenDiscovery is used to set the options for bootstrap token based discovery
Field
Description
token[Required] string
token is a token used to validate cluster information fetched from the
control-plane.
apiServerEndpoint string
apiServerEndpoint is an IP or domain name to the API server from which
information will be fetched.
caCertHashes []string
caCertHashes specifies a set of public key pins to verify when token-based discovery
is used. The root CA found during discovery must match one of these values.
Specifying an empty set disables root CA pinning, which can be unsafe.
Each hash is specified as <type>:<value>, where the only currently supported type is
"sha256". This is a hex-encoded SHA-256 hash of the Subject Public Key Info (SPKI)
object in DER-encoded ASN.1. These hashes can be calculated using, for example, OpenSSL.
unsafeSkipCAVerification bool
unsafeSkipCAVerification allows token-based discovery without CA verification
via caCertHashes. This can weaken the security of kubeadm since other nodes can
impersonate the control-plane.
ControlPlaneComponent holds settings common to control plane component of the cluster
Field
Description
extraArgs map[string]string
extraArgs is an extra set of flags to pass to the control plane component.
A key in this map is the flag name as it appears on the command line except
without leading dash(es).
file is used to specify a file or URL to a kubeconfig file from which to load
cluster information.
bootstrapToken and file are mutually exclusive.
tlsBootstrapToken string
tlsBootstrapToken is a token used for TLS bootstrapping.
If bootstrapToken is set, this field is defaulted to .bootstrapToken.token, but
can be overridden. If file is set, this field must be set in case the KubeConfigFile
does not contain any other authentication information
ImageMeta allows to customize the image used for components that are not
originated from the Kubernetes/Kubernetes release process
Field
Description
imageRepository string
imageRepository sets the container registry to pull images from.
If not set, the imageRepository defined in ClusterConfiguration will be used instead.
imageTag string
imageTag allows to specify a tag for the image.
In case this value is set, kubeadm does not change automatically the version of
the above components during upgrades.
localAPIEndpoint represents the endpoint of the API server instance to be
deployed on this node.
certificateKey string
certificateKey is the key that is used for decryption of certificates after
they are downloaded from the secret upon joining a new control plane node.
The corresponding encryption key is in the InitConfiguration.
(Members of ImageMeta are embedded into this type.)
ImageMeta allows to customize the container used for etcd.
dataDir[Required] string
dataDir is the directory etcd will place its data.
Defaults to "/var/lib/etcd".
extraArgs map[string]string
extraArgs are extra arguments provided to the etcd binary when run
inside a static Pod. A key in this map is the flag name as it appears on the
command line except without leading dash(es).
serverCertSANs []string
serverCertSANs sets extra Subject Alternative Names (SANs) for the etcd
server signing certificate.
peerCertSANs []string
peerCertSANs sets extra Subject Alternative Names (SANs) for the etcd peer
signing certificate.
NodeRegistrationOptions holds fields that relate to registering a new control-plane or
node to the cluster, either via "kubeadm init" or "kubeadm join"
Field
Description
name string
name is the .metadata.name field of the Node API object that will be created in this
kubeadm init or kubeadm join operation.
This field is also used in the CommonName field of the kubelet's client certificate to
the API server.
Defaults to the hostname of the node if not provided.
criSocket string
criSocket is used to retrieve container runtime info.
This information will be annotated to the Node API object, for later re-use.
taints specifies the taints the Node API object should be registered with.
If this field is unset, i.e. nil, it will be defaulted with a control-plane taint for control-plane nodes.
If you don't want to taint your control-plane node, set this field to an empty list,
i.e. taints: [] in the YAML file. This field is solely used for Node registration.
kubeletExtraArgs map[string]string
kubeletExtraArgs passes through extra arguments to the kubelet.
The arguments here are passed to the kubelet command line via the environment file
kubeadm writes at runtime for the kubelet to source.
This overrides the generic base-level configuration in the kubelet-config ConfigMap.
Flags have higher priority when parsing. These values are local and specific to the node
kubeadm is executing on. A key in this map is the flag name as it appears on the
command line except without leading dash(es).
ignorePreflightErrors []string
ignorePreflightErrors provides a list of pre-flight errors to be ignored when
the current node is registered, e.g. IsPrevilegedUser,Swap.
Value all ignores errors from all checks.
imagePullPolicy specifies the policy for image pulling during kubeadm "init" and
"join" operations.
The value of this field must be one of "Always", "IfNotPresent" or "Never".
If this field is not set, kubeadm will default it to "IfNotPresent", or pull the required
images if not present on the host.
Patches contains options related to applying patches to components deployed by kubeadm.
Field
Description
directory string
directory is a path to a directory that contains files named
"target[suffix][+patchtype].extension".
For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of
"kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd". "patchtype" can
be one of "strategic" "merge" or "json" and they match the patch formats supported by
kubectl.
The default "patchtype" is "strategic". "extension" must be either "json" or "yaml".
"suffix" is an optional string that can be used to determine which patches are applied
first alpha-numerically.
14.16 - kubeadm Configuration (v1beta4)
Overview
Package v1beta4 defines the v1beta4 version of the kubeadm configuration file format.
This version improves on the v1beta3 format by fixing some minor issues and adding a few new fields.
A list of changes since v1beta3:
TODO https://github.com/kubernetes/kubeadm/issues/2890
Support custom environment variables in control plane components under
ClusterConfiguration.
Use APIServer.ExtraEnvs, ControllerManager.ExtraEnvs, Scheduler.ExtraEnvs,
Etcd.Local.ExtraEnvs.
The ResetConfiguration API type is now supported in v1beta4.
Users are able to reset a node by passing a --config file to kubeadm reset.
Migration from old kubeadm config versions
kubeadm v1.15.x and newer can be used to migrate from v1beta1 to v1beta2.
kubeadm v1.22.x and newer no longer support v1beta1 and older APIs, but can be used to migrate v1beta2 to v1beta3.
kubeadm v1.27.x and newer no longer support v1beta2 and older APIs.
TODO: https://github.com/kubernetes/kubeadm/issues/2890
add version that can be used to convert to v1beta4
Basics
The preferred way to configure kubeadm is to pass an YAML configuration file with
the `--config“ option. Some of the configuration options defined in the kubeadm
config file are also available as command line flags, but only the most
common/simple use case are supported with this approach.
A kubeadm config file could contain multiple configuration types separated using three dashes (---).
kubeadm supports the following configuration types:
The list of configuration types that must be included in a configuration file depends by the action you are
performing (init or join`) and by the configuration options you are going to use (defaults or advanced customization).
If some configuration types are not provided, or provided only partially, kubeadm will use default values; defaults
provided by kubeadm includes also enforcing consistency of values across components when required (e.g.
--cluster-cidr flag on controller manager and clusterCIDR on kube-proxy).
Users are always allowed to override default values, with the only exception of a small subset of setting with
relevance for security (e.g. enforce authorization-mode Node and RBAC on api server).
If the user provides a configuration types that is not expected for the action you are performing, kubeadm will
ignore those types and print a warning.
Kubeadm init configuration types
When executing kubeadm init with the `--config“ option, the following configuration types could be used:
InitConfiguration, ClusterConfiguration, KubeProxyConfiguration, KubeletConfiguration, but only one
between InitConfiguration and ClusterConfiguration is mandatory.
The InitConfiguration type should be used to configure runtime settings, that in case of kubeadm init
are the configuration of the bootstrap token and all the setting which are specific to the node where kubeadm
is executed, including:
NodeRegistration, that holds fields that relate to registering the new node to the cluster;
use it to customize the node name, the CRI socket to use or any other settings that should apply to this
node only (e.g. the node ip).
LocalAPIEndpoint, that represents the endpoint of the instance of the API server to be deployed on this node;
use it e.g. to customize the API server advertise address.
The ClusterConfiguration type should be used to configure cluster-wide settings,
including settings for:
networking that holds configuration for the networking topology of the cluster; use it e.g. to customize
Pod subnet or services subnet.
etcd: use it e.g. to customize the local etcd or to configure the API server
for using an external etcd cluster.
kube-apiserver, kube-scheduler, kube-controller-manager configurations; use it to customize control-plane
components by adding customized setting or overriding kubeadm default settings.
The KubeProxyConfiguration type should be used to change the configuration passed to kube-proxy instances deployed
in the cluster. If this object is not provided or provided only partially, kubeadm applies defaults.
See https://kubernetes.io/docs/reference/command-line-tools-reference/kube-proxy/ or
https://pkg.go.dev/k8s.io/kube-proxy/config/v1alpha1#KubeProxyConfiguration
for kube-proxy official documentation.
The KubeletConfiguration type should be used to change the configurations that will be passed to all kubelet instances
deployed in the cluster. If this object is not provided or provided only partially, kubeadm applies defaults.
See https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/ or
https://pkg.go.dev/k8s.io/kubelet/config/v1beta1#KubeletConfiguration
for kubelet official documentation.
Here is a fully populated example of a single YAML file containing multiple
configuration types to be used during a kubeadm init run.
apiVersion:kubeadm.k8s.io/v1beta4kind:InitConfigurationbootstrapTokens:- token:"9a08jv.c0izixklcxtmnze7"description:"kubeadm bootstrap token"ttl:"24h"- token:"783bde.3f89s0fje9f38fhf"description:"another bootstrap token"usages:- authentication- signinggroups:- system:bootstrappers:kubeadm:default-node-tokennodeRegistration:name:"ec2-10-100-0-1"criSocket:"unix:///var/run/containerd/containerd.sock"taints:- key:"kubeadmNode"value:"someValue"effect:"NoSchedule"kubeletExtraArgs:v:4ignorePreflightErrors:- IsPrivilegedUserimagePullPolicy:"IfNotPresent"localAPIEndpoint:advertiseAddress:"10.100.0.1"bindPort:6443certificateKey:"e6a2eb8581237ab72a4f494f30285ec12a9694d750b9785706a83bfcbbbd2204"skipPhases:- addon/kube-proxy---apiVersion:kubeadm.k8s.io/v1beta4kind:ClusterConfigurationetcd:# one of local or externallocal:imageRepository:"registry.k8s.io"imageTag:"3.2.24"dataDir:"/var/lib/etcd"extraArgs:listen-client-urls:"http://10.100.0.1:2379"serverCertSANs:- "ec2-10-100-0-1.compute-1.amazonaws.com"peerCertSANs:- "10.100.0.1"# external:# endpoints:# - "10.100.0.1:2379"# - "10.100.0.2:2379"# caFile: "/etcd/kubernetes/pki/etcd/etcd-ca.crt"# certFile: "/etcd/kubernetes/pki/etcd/etcd.crt"# keyFile: "/etcd/kubernetes/pki/etcd/etcd.key"networking:serviceSubnet:"10.96.0.0/16"podSubnet:"10.244.0.0/24"dnsDomain:"cluster.local"kubernetesVersion:"v1.21.0"controlPlaneEndpoint:"10.100.0.1:6443"apiServer:extraArgs:authorization-mode:"Node,RBAC"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:FilecertSANs:- "10.100.1.1"- "ec2-10-100-0-1.compute-1.amazonaws.com"timeoutForControlPlane:4m0scontrollerManager:extraArgs:"node-cidr-mask-size": "20"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:Filescheduler:extraArgs:address:"10.100.0.1"extraVolumes:- name:"some-volume"hostPath:"/etc/some-path"mountPath:"/etc/some-pod-path"readOnly:falsepathType:FilecertificatesDir:"/etc/kubernetes/pki"imageRepository:"registry.k8s.io"clusterName:"example-cluster"---apiVersion:kubelet.config.k8s.io/v1beta1kind:KubeletConfiguration# kubelet specific options here---apiVersion:kubeproxy.config.k8s.io/v1alpha1kind:KubeProxyConfiguration# kube-proxy specific options here
Kubeadm join configuration types
When executing kubeadm join with the --config option, the JoinConfiguration type should be provided.
The JoinConfiguration type should be used to configure runtime settings, that in case of kubeadm join
are the discovery method used for accessing the cluster info and all the setting which are specific
to the node where kubeadm is executed, including:
nodeRegistration, that holds fields that relate to registering the new node to the cluster;
use it to customize the node name, the CRI socket to use or any other settings that should apply to this
node only (e.g. the node ip).
`apiEndpoint“, that represents the endpoint of the instance of the API server to be eventually deployed on this node.
expires specifies the timestamp when this token expires. Defaults to being set
dynamically at runtime based on the ttl. expires and ttl are mutually exclusive.
usages []string
usages describes the ways in which this token can be used. Can by default be used
for establishing bidirectional trust, but that can be changed here.
groups []string
groups specifies the extra groups that this token will authenticate as when/if
used for authentication
BootstrapTokenString is a token of the format abcdef.abcdef0123456789 that is used
for both validation of the practically of the API server from a joining node's point
of view and as an authentication method for the node in the bootstrap phase of
"kubeadm join". This token is and should be short-lived.
Field
Description
-[Required] string
No description provided.
-[Required] string
No description provided.
ClusterConfiguration
ClusterConfiguration contains cluster-wide configuration for a kubeadm cluster
Networking holds configuration for the networking topology of the cluster.
kubernetesVersion string
KubernetesVersion is the target version of the control plane.
controlPlaneEndpoint string
ControlPlaneEndpoint sets a stable IP address or DNS name for the control plane; it
can be a valid IP address or a RFC-1123 DNS subdomain, both with optional TCP port.
In case the ControlPlaneEndpoint is not specified, the AdvertiseAddress + BindPort
are used; in case the ControlPlaneEndpoint is specified but without a TCP port,
the BindPort is used.
Possible usages are:
e.g. In a cluster with more than one control plane instances, this field should be
assigned the address of the external load balancer in front of the
control plane instances.
e.g. in environments with enforced node recycling, the ControlPlaneEndpoint
could be used for assigning a stable DNS to the control plane.
DNS defines the options for the DNS add-on installed in the cluster.
certificatesDir string
CertificatesDir specifies where to store or look for all required certificates.
imageRepository string
ImageRepository sets the container registry to pull images from.
If empty, registry.k8s.io will be used by default; in case of kubernetes version is a CI build (kubernetes version starts with ci/)
gcr.io/k8s-staging-ci-images will be used as a default for control plane components and for kube-proxy, while registry.k8s.io
will be used for all the other images.
featureGates map[string]bool
FeatureGates enabled by the user.
clusterName string
The cluster name
InitConfiguration
InitConfiguration contains a list of elements that is specific "kubeadm init"-only runtime
information.
BootstrapTokens is respected at kubeadm init time and describes a set of Bootstrap Tokens to create.
This information IS NOT uploaded to the kubeadm cluster configmap, partly because of its sensitive nature
LocalAPIEndpoint represents the endpoint of the API server instance that's deployed on this control plane node
In HA setups, this differs from ClusterConfiguration.ControlPlaneEndpoint in the sense that ControlPlaneEndpoint
is the global endpoint for the cluster, which then loadbalances the requests to each individual API server. This
configuration object lets you customize what IP/DNS name and port the local API server advertises it's accessible
on. By default, kubeadm tries to auto-detect the IP of the default interface and use that, but in case that process
fails you may set the desired value here.
certificateKey string
CertificateKey sets the key with which certificates and keys are encrypted prior to being uploaded in
a secret in the cluster during the uploadcerts init phase.
skipPhases []string
SkipPhases is a list of phases to skip during command execution.
The list of phases can be obtained with the "kubeadm init --help" command.
The flag "--skip-phases" takes precedence over this field.
NodeRegistration holds fields that relate to registering the new control-plane node to the cluster
caCertPath string
CACertPath is the path to the SSL certificate authority used to
secure comunications between node and control-plane.
Defaults to "/etc/kubernetes/pki/ca.crt".
ControlPlane defines the additional control plane instance to be deployed on the joining node.
If nil, no additional control plane instance will be deployed.
skipPhases []string
SkipPhases is a list of phases to skip during command execution.
The list of phases can be obtained with the "kubeadm join --help" command.
The flag "--skip-phases" takes precedence over this field.
Patches contains options related to applying patches to components deployed by kubeadm during
"kubeadm join".
ResetConfiguration
ResetConfiguration contains a list of fields that are specifically "kubeadm reset"-only runtime information.
Field
Description
apiVersion string
kubeadm.k8s.io/v1beta4
kind string
ResetConfiguration
cleanupTmpDir bool
CleanupTmpDir specifies whether the "/etc/kubernetes/tmp" directory should be cleaned during the reset process.
certificatesDir string
CertificatesDir specifies the directory where the certificates are stored. If specified, it will be cleaned during the reset process.
criSocket string
CRISocket is used to retrieve container runtime info and used for the removal of the containers.
If CRISocket is not specified by flag or config file, kubeadm will try to detect one valid CRISocket instead.
dryRun bool
DryRun tells if the dry run mode is enabled, don't apply any change if it is and just output what would be done.
force bool
Force flag instructs kubeadm to reset the node without prompting for confirmation.
ignorePreflightErrors []string
IgnorePreflightErrors provides a slice of pre-flight errors to be ignored during the reset process, e.g. 'IsPrivilegedUser,Swap'.
Value 'all' ignores errors from all checks.
skipPhases []string
SkipPhases is a list of phases to skip during command execution.
The list of phases can be obtained with the "kubeadm reset phase --help" command.
BootstrapTokenDiscovery is used to set the options for bootstrap token based discovery
Field
Description
token[Required] string
Token is a token used to validate cluster information
fetched from the control-plane.
apiServerEndpoint string
APIServerEndpoint is an IP or domain name to the API server from which info will be fetched.
caCertHashes []string
CACertHashes specifies a set of public key pins to verify
when token-based discovery is used. The root CA found during discovery
must match one of these values. Specifying an empty set disables root CA
pinning, which can be unsafe. Each hash is specified as ":",
where the only currently supported type is "sha256". This is a hex-encoded
SHA-256 hash of the Subject Public Key Info (SPKI) object in DER-encoded
ASN.1. These hashes can be calculated using, for example, OpenSSL.
unsafeSkipCAVerification bool
UnsafeSkipCAVerification allows token-based discovery
without CA verification via CACertHashes. This can weaken
the security of kubeadm since other nodes can impersonate the control-plane.
ControlPlaneComponent holds settings common to control plane component of the cluster
Field
Description
extraArgs map[string]string
ExtraArgs is an extra set of flags to pass to the control plane component.
A key in this map is the flag name as it appears on the
command line except without leading dash(es).
TODO: This is temporary and ideally we would like to switch all components to
use ComponentConfig + ConfigMaps.
ExtraEnvs is an extra set of environment variables to pass to the control plane component.
Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
File is used to specify a file or URL to a kubeconfig file from which to load cluster information
BootstrapToken and File are mutually exclusive
tlsBootstrapToken string
TLSBootstrapToken is a token used for TLS bootstrapping.
If .BootstrapToken is set, this field is defaulted to .BootstrapToken.Token, but can be overridden.
If .File is set, this field must be set in case the KubeConfigFile does not contain any other authentication information
ImageMeta allows to customize the image used for components that are not
originated from the Kubernetes/Kubernetes release process
Field
Description
imageRepository string
ImageRepository sets the container registry to pull images from.
if not set, the ImageRepository defined in ClusterConfiguration will be used instead.
imageTag string
ImageTag allows to specify a tag for the image.
In case this value is set, kubeadm does not change automatically the version of the above components during upgrades.
LocalAPIEndpoint represents the endpoint of the API server instance to be deployed on this node.
certificateKey string
CertificateKey is the key that is used for decryption of certificates after they are downloaded from the secret
upon joining a new control plane node. The corresponding encryption key is in the InitConfiguration.
(Members of ImageMeta are embedded into this type.)
ImageMeta allows to customize the container used for etcd
dataDir[Required] string
DataDir is the directory etcd will place its data.
Defaults to "/var/lib/etcd".
extraArgs map[string]string
ExtraArgs are extra arguments provided to the etcd binary
when run inside a static pod.
A key in this map is the flag name as it appears on the
command line except without leading dash(es).
ExtraEnvs is an extra set of environment variables to pass to the control plane component.
Environment variables passed using ExtraEnvs will override any existing environment variables, or *_proxy environment variables that kubeadm adds by default.
serverCertSANs []string
ServerCertSANs sets extra Subject Alternative Names for the etcd server signing cert.
peerCertSANs []string
PeerCertSANs sets extra Subject Alternative Names for the etcd peer signing cert.
NodeRegistrationOptions holds fields that relate to registering a new control-plane or node to the cluster, either via "kubeadm init" or "kubeadm join"
Field
Description
name string
Name is the .Metadata.Name field of the Node API object that will be created in this kubeadm init or kubeadm join operation.
This field is also used in the CommonName field of the kubelet's client certificate to the API server.
Defaults to the hostname of the node if not provided.
criSocket string
CRISocket is used to retrieve container runtime info. This information will be annotated to the Node API object, for later re-use
Taints specifies the taints the Node API object should be registered with. If this field is unset, i.e. nil,
it will be defaulted with a control-plane taint for control-plane nodes. If you don't want to taint your control-plane
node, set this field to an empty slice, i.e. taints: [] in the YAML file. This field is solely used for Node registration.
kubeletExtraArgs map[string]string
KubeletExtraArgs passes through extra arguments to the kubelet. The arguments here are passed to the kubelet command line via the environment file
kubeadm writes at runtime for the kubelet to source. This overrides the generic base-level configuration in the kubelet-config ConfigMap
Flags have higher priority when parsing. These values are local and specific to the node kubeadm is executing on.
A key in this map is the flag name as it appears on the
command line except without leading dash(es).
ignorePreflightErrors []string
IgnorePreflightErrors provides a slice of pre-flight errors to be ignored when the current node is registered, e.g. 'IsPrivilegedUser,Swap'.
Value 'all' ignores errors from all checks.
ImagePullPolicy specifies the policy for image pulling during kubeadm "init" and "join" operations.
The value of this field must be one of "Always", "IfNotPresent" or "Never".
If this field is unset kubeadm will default it to "IfNotPresent", or pull the required images if not present on the host.
Patches contains options related to applying patches to components deployed by kubeadm.
Field
Description
directory string
Directory is a path to a directory that contains files named "target[suffix][+patchtype].extension".
For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of
"kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration".
"patchtype" can be one of "strategic" "merge" or "json" and they match the patch formats supported by kubectl.
The default "patchtype" is "strategic". "extension" must be either "json" or "yaml".
"suffix" is an optional string that can be used to determine which patches are applied
first alpha-numerically.
ProxyURL is the URL to the proxy to be used for all requests made by this
client. URLs with "http", "https", and "socks5" schemes are supported. If
this configuration is not provided or the empty string, the client
attempts to construct a proxy configuration from http_proxy and
https_proxy environment variables. If these environment variables are not
set, the client does not attempt to proxy requests.
socks5 proxying does not currently support spdy streaming endpoints (exec,
attach, port forward).
disable-compression bool
DisableCompression allows client to opt-out of response compression for all requests to the server. This is useful
to speed up requests (specifically lists) when client-server network bandwidth is ample, by saving time on
compression (server-side) and decompression (client-side): https://github.com/kubernetes/kubernetes/issues/112296.
Context is a tuple of references to a cluster (how do I communicate with a kubernetes cluster), a user (how do I identify myself), and a namespace (what subset of resources do I want to work with)
Field
Description
cluster[Required] string
Cluster is the name of the cluster for this context
user[Required] string
AuthInfo is the name of the authInfo for this context
namespace string
Namespace is the default namespace to use on unspecified requests
Env defines additional environment variables to expose to the process. These
are unioned with the host's environment, as well as variables client-go uses
to pass argument to the plugin.
apiVersion[Required] string
Preferred input version of the ExecInfo. The returned ExecCredentials MUST use
the same encoding version as the input.
installHint[Required] string
This text is shown to the user when the executable doesn't seem to be
present. For example, brew install foo-cli might be a good InstallHint for
foo-cli on Mac OS systems.
provideClusterInfo[Required] bool
ProvideClusterInfo determines whether or not to provide cluster information,
which could potentially contain very large CA data, to this exec plugin as a
part of the KUBERNETES_EXEC_INFO environment variable. By default, it is set
to false. Package k8s.io/client-go/tools/auth/exec provides helper methods for
reading this environment variable.
InteractiveMode determines this plugin's relationship with standard input. Valid
values are "Never" (this exec plugin never uses standard input), "IfAvailable" (this
exec plugin wants to use standard input if it is available), or "Always" (this exec
plugin requires standard input to function). See ExecInteractiveMode values for more
details.
If APIVersion is client.authentication.k8s.io/v1alpha1 or
client.authentication.k8s.io/v1beta1, then this field is optional and defaults
to "IfAvailable" when unset. Otherwise, this field is required.
CredentialProviderConfig is the configuration containing information about
each exec credential provider. Kubelet reads this configuration from disk and enables
each provider as specified by the CredentialProvider type.
providers is a list of credential provider plugins that will be enabled by the kubelet.
Multiple providers may match against a single image, in which case credentials
from all providers will be returned to the kubelet. If multiple providers are called
for a single image, the results are combined. If providers return overlapping
auth keys, the value from the provider earlier in this list is used.
CredentialProvider represents an exec plugin to be invoked by the kubelet. The plugin is only
invoked when an image being pulled matches the images handled by the plugin (see matchImages).
Field
Description
name[Required] string
name is the required name of the credential provider. It must match the name of the
provider executable as seen by the kubelet. The executable must be in the kubelet's
bin directory (set by the --image-credential-provider-bin-dir flag).
matchImages[Required] []string
matchImages is a required list of strings used to match against images in order to
determine if this provider should be invoked. If one of the strings matches the
requested image from the kubelet, the plugin will be invoked and given a chance
to provide credentials. Images are expected to contain the registry domain
and URL path.
Each entry in matchImages is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like '*.k8s.io' or 'k8s.*.io', and top-level-domains such as 'k8s.*'.
Matching partial subdomains like 'app.k8s.io' is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
A match exists between an image and a matchImage when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
defaultCacheDuration is the default duration the plugin will cache credentials in-memory
if a cache duration is not provided in the plugin response. This field is required.
apiVersion[Required] string
Required input version of the exec CredentialProviderRequest. The returned CredentialProviderResponse
MUST use the same encoding version as the input. Current supported values are:
credentialprovider.kubelet.k8s.io/v1
args []string
Arguments to pass to the command when executing it.
Env defines additional environment variables to expose to the process. These
are unioned with the host's environment, as well as variables client-go uses
to pass argument to the plugin.
CredentialProviderConfig is the configuration containing information about
each exec credential provider. Kubelet reads this configuration from disk and enables
each provider as specified by the CredentialProvider type.
providers is a list of credential provider plugins that will be enabled by the kubelet.
Multiple providers may match against a single image, in which case credentials
from all providers will be returned to the kubelet. If multiple providers are called
for a single image, the results are combined. If providers return overlapping
auth keys, the value from the provider earlier in this list is used.
CredentialProvider represents an exec plugin to be invoked by the kubelet. The plugin is only
invoked when an image being pulled matches the images handled by the plugin (see matchImages).
Field
Description
name[Required] string
name is the required name of the credential provider. It must match the name of the
provider executable as seen by the kubelet. The executable must be in the kubelet's
bin directory (set by the --image-credential-provider-bin-dir flag).
matchImages[Required] []string
matchImages is a required list of strings used to match against images in order to
determine if this provider should be invoked. If one of the strings matches the
requested image from the kubelet, the plugin will be invoked and given a chance
to provide credentials. Images are expected to contain the registry domain
and URL path.
Each entry in matchImages is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like *.k8s.io or k8s.*.io, and top-level-domains such as k8s.*.
Matching partial subdomains like app*.k8s.io is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
A match exists between an image and a matchImage when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
defaultCacheDuration is the default duration the plugin will cache credentials in-memory
if a cache duration is not provided in the plugin response. This field is required.
apiVersion[Required] string
Required input version of the exec CredentialProviderRequest. The returned CredentialProviderResponse
MUST use the same encoding version as the input. Current supported values are:
credentialprovider.kubelet.k8s.io/v1alpha1
args []string
Arguments to pass to the command when executing it.
Env defines additional environment variables to expose to the process. These
are unioned with the host's environment, as well as variables client-go uses
to pass argument to the plugin.
JSONOptions contains options for logging format "json".
Field
Description
splitStream[Required] bool
[Alpha] SplitStream redirects error messages to stderr while
info messages go to stdout, with buffering. The default is to write
both to stdout, without buffering. Only available when
the LoggingAlphaOptions feature gate is enabled.
[Alpha] InfoBufferSize sets the size of the info stream when
using split streams. The default is zero, which disables buffering.
Only available when the LoggingAlphaOptions feature gate is enabled.
LogFormatFactory
LogFormatFactory provides support for a certain additional,
non-default log format.
Maximum time between log flushes.
If a string, parsed as a duration (i.e. "1s")
If an int, the maximum number of nanoseconds (i.e. 1s = 1000000000).
Ignored if the selected logging backend writes log messages without buffering.
Verbosity is the threshold that determines which log messages are
logged. Default is zero which logs only the most important
messages. Higher values enable additional messages. Error messages
are always logged.
[Alpha] Options holds additional parameters that are specific
to the different logging formats. Only the options for the selected
format get used, but all of them get validated.
Only available when the LoggingAlphaOptions feature gate is enabled.
LoggingOptions
LoggingOptions can be used with ValidateAndApplyWithOptions to override
certain global defaults.
TracingConfiguration provides versioned configuration for OpenTelemetry tracing clients.
Field
Description
endpoint string
Endpoint of the collector this component will report traces to.
The connection is insecure, and does not currently support TLS.
Recommended is unset, and endpoint is the otlp grpc default, localhost:4317.
samplingRatePerMillion int32
SamplingRatePerMillion is the number of samples to collect per million spans.
Recommended is unset. If unset, sampler respects its parent span's sampling
rate, but otherwise never samples.
VModuleConfiguration
(Alias of []k8s.io/component-base/logs/api/v1.VModuleItem)
VerbosityLevel represents a klog or logr verbosity threshold.
CredentialProviderConfig
CredentialProviderConfig is the configuration containing information about
each exec credential provider. Kubelet reads this configuration from disk and enables
each provider as specified by the CredentialProvider type.
providers is a list of credential provider plugins that will be enabled by the kubelet.
Multiple providers may match against a single image, in which case credentials
from all providers will be returned to the kubelet. If multiple providers are called
for a single image, the results are combined. If providers return overlapping
auth keys, the value from the provider earlier in this list is used.
KubeletConfiguration
KubeletConfiguration contains the configuration for the Kubelet
Field
Description
apiVersion string
kubelet.config.k8s.io/v1beta1
kind string
KubeletConfiguration
enableServer[Required] bool
enableServer enables Kubelet's secured server.
Note: Kubelet's insecure port is controlled by the readOnlyPort option.
Default: true
staticPodPath string
staticPodPath is the path to the directory containing local (static) pods to
run, or the path to a single static pod file.
Default: ""
httpCheckFrequency is the duration between checking http for new data.
Default: "20s"
staticPodURL string
staticPodURL is the URL for accessing static pods to run.
Default: ""
staticPodURLHeader map[string][]string
staticPodURLHeader is a map of slices with HTTP headers to use when accessing the podURL.
Default: nil
address string
address is the IP address for the Kubelet to serve on (set to 0.0.0.0
for all interfaces).
Default: "0.0.0.0"
port int32
port is the port for the Kubelet to serve on.
The port number must be between 1 and 65535, inclusive.
Default: 10250
readOnlyPort int32
readOnlyPort is the read-only port for the Kubelet to serve on with
no authentication/authorization.
The port number must be between 1 and 65535, inclusive.
Setting this field to 0 disables the read-only service.
Default: 0 (disabled)
tlsCertFile string
tlsCertFile is the file containing x509 Certificate for HTTPS. (CA cert,
if any, concatenated after server cert). If tlsCertFile and
tlsPrivateKeyFile are not provided, a self-signed certificate
and key are generated for the public address and saved to the directory
passed to the Kubelet's --cert-dir flag.
Default: ""
tlsPrivateKeyFile string
tlsPrivateKeyFile is the file containing x509 private key matching tlsCertFile.
Default: ""
tlsCipherSuites []string
tlsCipherSuites is the list of allowed cipher suites for the server.
Note that TLS 1.3 ciphersuites are not configurable.
Values are from tls package constants (https://golang.org/pkg/crypto/tls/#pkg-constants).
Default: nil
tlsMinVersion string
tlsMinVersion is the minimum TLS version supported.
Values are from tls package constants (https://golang.org/pkg/crypto/tls/#pkg-constants).
Default: ""
rotateCertificates bool
rotateCertificates enables client certificate rotation. The Kubelet will request a
new certificate from the certificates.k8s.io API. This requires an approver to approve the
certificate signing requests.
Default: false
serverTLSBootstrap bool
serverTLSBootstrap enables server certificate bootstrap. Instead of self
signing a serving certificate, the Kubelet will request a certificate from
the 'certificates.k8s.io' API. This requires an approver to approve the
certificate signing requests (CSR). The RotateKubeletServerCertificate feature
must be enabled when setting this field.
Default: false
authentication specifies how requests to the Kubelet's server are authenticated.
Defaults:
anonymous:
enabled: false
webhook:
enabled: true
cacheTTL: "2m"
authorization specifies how requests to the Kubelet's server are authorized.
Defaults:
mode: Webhook
webhook:
cacheAuthorizedTTL: "5m"
cacheUnauthorizedTTL: "30s"
registryPullQPS int32
registryPullQPS is the limit of registry pulls per second.
The value must not be a negative number.
Setting it to 0 means no limit.
Default: 5
registryBurst int32
registryBurst is the maximum size of bursty pulls, temporarily allows
pulls to burst to this number, while still not exceeding registryPullQPS.
The value must not be a negative number.
Only used if registryPullQPS is greater than 0.
Default: 10
eventRecordQPS int32
eventRecordQPS is the maximum event creations per second. If 0, there
is no limit enforced. The value cannot be a negative number.
Default: 50
eventBurst int32
eventBurst is the maximum size of a burst of event creations, temporarily
allows event creations to burst to this number, while still not exceeding
eventRecordQPS. This field canot be a negative number and it is only used
when eventRecordQPS > 0.
Default: 100
enableDebuggingHandlers bool
enableDebuggingHandlers enables server endpoints for log access
and local running of containers and commands, including the exec,
attach, logs, and portforward features.
Default: true
enableContentionProfiling bool
enableContentionProfiling enables block profiling, if enableDebuggingHandlers is true.
Default: false
healthzPort int32
healthzPort is the port of the localhost healthz endpoint (set to 0 to disable).
A valid number is between 1 and 65535.
Default: 10248
healthzBindAddress string
healthzBindAddress is the IP address for the healthz server to serve on.
Default: "127.0.0.1"
oomScoreAdj int32
oomScoreAdj is The oom-score-adj value for kubelet process. Values
must be within the range [-1000, 1000].
Default: -999
clusterDomain string
clusterDomain is the DNS domain for this cluster. If set, kubelet will
configure all containers to search this domain in addition to the
host's search domains.
Default: ""
clusterDNS []string
clusterDNS is a list of IP addresses for the cluster DNS server. If set,
kubelet will configure all containers to use this for DNS resolution
instead of the host's DNS servers.
Default: nil
nodeStatusUpdateFrequency is the frequency that kubelet computes node
status. If node lease feature is not enabled, it is also the frequency that
kubelet posts node status to master.
Note: When node lease feature is not enabled, be cautious when changing the
constant, it must work with nodeMonitorGracePeriod in nodecontroller.
Default: "10s"
nodeStatusReportFrequency is the frequency that kubelet posts node
status to master if node status does not change. Kubelet will ignore this
frequency and post node status immediately if any change is detected. It is
only used when node lease feature is enabled. nodeStatusReportFrequency's
default value is 5m. But if nodeStatusUpdateFrequency is set explicitly,
nodeStatusReportFrequency's default value will be set to
nodeStatusUpdateFrequency for backward compatibility.
Default: "5m"
nodeLeaseDurationSeconds int32
nodeLeaseDurationSeconds is the duration the Kubelet will set on its corresponding Lease.
NodeLease provides an indicator of node health by having the Kubelet create and
periodically renew a lease, named after the node, in the kube-node-lease namespace.
If the lease expires, the node can be considered unhealthy.
The lease is currently renewed every 10s, per KEP-0009. In the future, the lease renewal
interval may be set based on the lease duration.
The field value must be greater than 0.
Default: 40
imageMinimumGCAge is the minimum age for an unused image before it is
garbage collected.
Default: "2m"
imageGCHighThresholdPercent int32
imageGCHighThresholdPercent is the percent of disk usage after which
image garbage collection is always run. The percent is calculated by
dividing this field value by 100, so this field must be between 0 and
100, inclusive. When specified, the value must be greater than
imageGCLowThresholdPercent.
Default: 85
imageGCLowThresholdPercent int32
imageGCLowThresholdPercent is the percent of disk usage before which
image garbage collection is never run. Lowest disk usage to garbage
collect to. The percent is calculated by dividing this field value by 100,
so the field value must be between 0 and 100, inclusive. When specified, the
value must be less than imageGCHighThresholdPercent.
Default: 80
volumeStatsAggPeriod is the frequency for calculating and caching volume
disk usage for all pods.
Default: "1m"
kubeletCgroups string
kubeletCgroups is the absolute name of cgroups to isolate the kubelet in
Default: ""
systemCgroups string
systemCgroups is absolute name of cgroups in which to place
all non-kernel processes that are not already in a container. Empty
for no container. Rolling back the flag requires a reboot.
The cgroupRoot must be specified if this field is not empty.
Default: ""
cgroupRoot string
cgroupRoot is the root cgroup to use for pods. This is handled by the
container runtime on a best effort basis.
cgroupsPerQOS bool
cgroupsPerQOS enable QoS based CGroup hierarchy: top level CGroups for QoS classes
and all Burstable and BestEffort Pods are brought up under their specific top level
QoS CGroup.
Default: true
cgroupDriver string
cgroupDriver is the driver kubelet uses to manipulate CGroups on the host (cgroupfs
or systemd).
Default: "cgroupfs"
cpuManagerPolicy string
cpuManagerPolicy is the name of the policy to use.
Requires the CPUManager feature gate to be enabled.
Default: "None"
cpuManagerPolicyOptions map[string]string
cpuManagerPolicyOptions is a set of key=value which allows to set extra options
to fine tune the behaviour of the cpu manager policies.
Requires both the "CPUManager" and "CPUManagerPolicyOptions" feature gates to be enabled.
Default: nil
cpuManagerReconcilePeriod is the reconciliation period for the CPU Manager.
Requires the CPUManager feature gate to be enabled.
Default: "10s"
memoryManagerPolicy string
memoryManagerPolicy is the name of the policy to use by memory manager.
Requires the MemoryManager feature gate to be enabled.
Default: "none"
topologyManagerPolicy string
topologyManagerPolicy is the name of the topology manager policy to use.
Valid values include:
restricted: kubelet only allows pods with optimal NUMA node alignment for
requested resources;
best-effort: kubelet will favor pods with NUMA alignment of CPU and device
resources;
none: kubelet has no knowledge of NUMA alignment of a pod's CPU and device resources.
single-numa-node: kubelet only allows pods with a single NUMA alignment
of CPU and device resources.
Default: "none"
topologyManagerScope string
topologyManagerScope represents the scope of topology hint generation
that topology manager requests and hint providers generate. Valid values include:
container: topology policy is applied on a per-container basis.
pod: topology policy is applied on a per-pod basis.
Default: "container"
topologyManagerPolicyOptions map[string]string
TopologyManagerPolicyOptions is a set of key=value which allows to set extra options
to fine tune the behaviour of the topology manager policies.
Requires both the "TopologyManager" and "TopologyManagerPolicyOptions" feature gates to be enabled.
Default: nil
qosReserved map[string]string
qosReserved is a set of resource name to percentage pairs that specify
the minimum percentage of a resource reserved for exclusive use by the
guaranteed QoS tier.
Currently supported resources: "memory"
Requires the QOSReserved feature gate to be enabled.
Default: nil
runtimeRequestTimeout is the timeout for all runtime requests except long running
requests - pull, logs, exec and attach.
Default: "2m"
hairpinMode string
hairpinMode specifies how the Kubelet should configure the container
bridge for hairpin packets.
Setting this flag allows endpoints in a Service to loadbalance back to
themselves if they should try to access their own Service. Values:
"promiscuous-bridge": make the container bridge promiscuous.
"hairpin-veth": set the hairpin flag on container veth interfaces.
"none": do nothing.
Generally, one must set --hairpin-mode=hairpin-veth to achieve hairpin NAT,
because promiscuous-bridge assumes the existence of a container bridge named cbr0.
Default: "promiscuous-bridge"
maxPods int32
maxPods is the maximum number of Pods that can run on this Kubelet.
The value must be a non-negative integer.
Default: 110
podCIDR string
podCIDR is the CIDR to use for pod IP addresses, only used in standalone mode.
In cluster mode, this is obtained from the control plane.
Default: ""
podPidsLimit int64
podPidsLimit is the maximum number of PIDs in any pod.
Default: -1
resolvConf string
resolvConf is the resolver configuration file used as the basis
for the container DNS resolution configuration.
If set to the empty string, will override the default and effectively disable DNS lookups.
Default: "/etc/resolv.conf"
runOnce bool
runOnce causes the Kubelet to check the API server once for pods,
run those in addition to the pods specified by static pod files, and exit.
Default: false
cpuCFSQuota bool
cpuCFSQuota enables CPU CFS quota enforcement for containers that
specify CPU limits.
Default: true
cpuCFSQuotaPeriod is the CPU CFS quota period value, cpu.cfs_period_us.
The value must be between 1 ms and 1 second, inclusive.
Requires the CustomCPUCFSQuotaPeriod feature gate to be enabled.
Default: "100ms"
nodeStatusMaxImages int32
nodeStatusMaxImages caps the number of images reported in Node.status.images.
The value must be greater than -2.
Note: If -1 is specified, no cap will be applied. If 0 is specified, no image is returned.
Default: 50
maxOpenFiles int64
maxOpenFiles is Number of files that can be opened by Kubelet process.
The value must be a non-negative number.
Default: 1000000
contentType string
contentType is contentType of requests sent to apiserver.
Default: "application/vnd.kubernetes.protobuf"
kubeAPIQPS int32
kubeAPIQPS is the QPS to use while talking with kubernetes apiserver.
Default: 50
kubeAPIBurst int32
kubeAPIBurst is the burst to allow while talking with kubernetes API server.
This field cannot be a negative number.
Default: 100
serializeImagePulls bool
serializeImagePulls when enabled, tells the Kubelet to pull images one
at a time. We recommend not changing the default value on nodes that
run docker daemon with version < 1.9 or an Aufs storage backend.
Issue #10959 has more details.
Default: true
maxParallelImagePulls int32
MaxParallelImagePulls sets the maximum number of image pulls in parallel.
This field cannot be set if SerializeImagePulls is true.
Setting it to nil means no limit.
Default: nil
evictionHard map[string]string
evictionHard is a map of signal names to quantities that defines hard eviction
thresholds. For example: {"memory.available": "300Mi"}.
To explicitly disable, pass a 0% or 100% threshold on an arbitrary resource.
Default:
memory.available: "100Mi"
nodefs.available: "10%"
nodefs.inodesFree: "5%"
imagefs.available: "15%"
evictionSoft map[string]string
evictionSoft is a map of signal names to quantities that defines soft eviction thresholds.
For example: {"memory.available": "300Mi"}.
Default: nil
evictionSoftGracePeriod map[string]string
evictionSoftGracePeriod is a map of signal names to quantities that defines grace
periods for each soft eviction signal. For example: {"memory.available": "30s"}.
Default: nil
evictionPressureTransitionPeriod is the duration for which the kubelet has to wait
before transitioning out of an eviction pressure condition.
Default: "5m"
evictionMaxPodGracePeriod int32
evictionMaxPodGracePeriod is the maximum allowed grace period (in seconds) to use
when terminating pods in response to a soft eviction threshold being met. This value
effectively caps the Pod's terminationGracePeriodSeconds value during soft evictions.
Note: Due to issue #64530, the behavior has a bug where this value currently just
overrides the grace period during soft eviction, which can increase the grace
period from what is set on the Pod. This bug will be fixed in a future release.
Default: 0
evictionMinimumReclaim map[string]string
evictionMinimumReclaim is a map of signal names to quantities that defines minimum reclaims,
which describe the minimum amount of a given resource the kubelet will reclaim when
performing a pod eviction while that resource is under pressure.
For example: {"imagefs.available": "2Gi"}.
Default: nil
podsPerCore int32
podsPerCore is the maximum number of pods per core. Cannot exceed maxPods.
The value must be a non-negative integer.
If 0, there is no limit on the number of Pods.
Default: 0
enableControllerAttachDetach bool
enableControllerAttachDetach enables the Attach/Detach controller to
manage attachment/detachment of volumes scheduled to this node, and
disables kubelet from executing any attach/detach operations.
Note: attaching/detaching CSI volumes is not supported by the kubelet,
so this option needs to be true for that use case.
Default: true
protectKernelDefaults bool
protectKernelDefaults, if true, causes the Kubelet to error if kernel
flags are not as it expects. Otherwise the Kubelet will attempt to modify
kernel flags to match its expectation.
Default: false
makeIPTablesUtilChains bool
makeIPTablesUtilChains, if true, causes the Kubelet to create the
KUBE-IPTABLES-HINT chain in iptables as a hint to other components about the
configuration of iptables on the system.
Default: true
iptablesMasqueradeBit int32
iptablesMasqueradeBit formerly controlled the creation of the KUBE-MARK-MASQ
chain.
Deprecated: no longer has any effect.
Default: 14
iptablesDropBit int32
iptablesDropBit formerly controlled the creation of the KUBE-MARK-DROP chain.
Deprecated: no longer has any effect.
Default: 15
featureGates map[string]bool
featureGates is a map of feature names to bools that enable or disable experimental
features. This field modifies piecemeal the built-in default values from
"k8s.io/kubernetes/pkg/features/kube_features.go".
Default: nil
failSwapOn bool
failSwapOn tells the Kubelet to fail to start if swap is enabled on the node.
Default: true
memorySwap configures swap memory available to container workloads.
containerLogMaxSize string
containerLogMaxSize is a quantity defining the maximum size of the container log
file before it is rotated. For example: "5Mi" or "256Ki".
Default: "10Mi"
containerLogMaxFiles int32
containerLogMaxFiles specifies the maximum number of container log files that can
be present for a container.
Default: 5
configMapAndSecretChangeDetectionStrategy is a mode in which ConfigMap and Secret
managers are running. Valid values include:
Get: kubelet fetches necessary objects directly from the API server;
Cache: kubelet uses TTL cache for object fetched from the API server;
Watch: kubelet uses watches to observe changes to objects that are in its interest.
Default: "Watch"
systemReserved map[string]string
systemReserved is a set of ResourceName=ResourceQuantity (e.g. cpu=200m,memory=150G)
pairs that describe resources reserved for non-kubernetes components.
Currently only cpu and memory are supported.
See http://kubernetes.io/docs/user-guide/compute-resources for more detail.
Default: nil
kubeReserved map[string]string
kubeReserved is a set of ResourceName=ResourceQuantity (e.g. cpu=200m,memory=150G) pairs
that describe resources reserved for kubernetes system components.
Currently cpu, memory and local storage for root file system are supported.
See https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/
for more details.
Default: nil
reservedSystemCPUs[Required] string
The reservedSystemCPUs option specifies the CPU list reserved for the host
level system threads and kubernetes related threads. This provide a "static"
CPU list rather than the "dynamic" list by systemReserved and kubeReserved.
This option does not support systemReservedCgroup or kubeReservedCgroup.
showHiddenMetricsForVersion string
showHiddenMetricsForVersion is the previous version for which you want to show
hidden metrics.
Only the previous minor version is meaningful, other values will not be allowed.
The format is <major>.<minor>, e.g.: 1.16.
The purpose of this format is make sure you have the opportunity to notice
if the next release hides additional metrics, rather than being surprised
when they are permanently removed in the release after that.
Default: ""
systemReservedCgroup string
systemReservedCgroup helps the kubelet identify absolute name of top level CGroup used
to enforce systemReserved compute resource reservation for OS system daemons.
Refer to Node Allocatable
doc for more information.
Default: ""
kubeReservedCgroup string
kubeReservedCgroup helps the kubelet identify absolute name of top level CGroup used
to enforce KubeReserved compute resource reservation for Kubernetes node system daemons.
Refer to Node Allocatable
doc for more information.
Default: ""
enforceNodeAllocatable []string
This flag specifies the various Node Allocatable enforcements that Kubelet needs to perform.
This flag accepts a list of options. Acceptable options are none, pods,
system-reserved and kube-reserved.
If none is specified, no other options may be specified.
When system-reserved is in the list, systemReservedCgroup must be specified.
When kube-reserved is in the list, kubeReservedCgroup must be specified.
This field is supported only when cgroupsPerQOS is set to true.
Refer to Node Allocatable
for more information.
Default: ["pods"]
allowedUnsafeSysctls []string
A comma separated whitelist of unsafe sysctls or sysctl patterns (ending in *).
Unsafe sysctl groups are kernel.shm*, kernel.msg*, kernel.sem, fs.mqueue.*,
and net.*. For example: "kernel.msg*,net.ipv4.route.min_pmtu"
Default: []
volumePluginDir string
volumePluginDir is the full path of the directory in which to search
for additional third party volume plugins.
Default: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec/"
providerID string
providerID, if set, sets the unique ID of the instance that an external
provider (i.e. cloudprovider) can use to identify a specific node.
Default: ""
kernelMemcgNotification bool
kernelMemcgNotification, if set, instructs the kubelet to integrate with the
kernel memcg notification for determining if memory eviction thresholds are
exceeded rather than polling.
Default: false
logging specifies the options of logging.
Refer to Logs Options
for more information.
Default:
Format: text
enableSystemLogHandler bool
enableSystemLogHandler enables system logs via web interface host:port/logs/
Default: true
enableSystemLogQuery bool
enableSystemLogQuery enables the node log query feature on the /logs endpoint.
EnableSystemLogHandler has to be enabled in addition for this feature to work.
Default: false
shutdownGracePeriod specifies the total duration that the node should delay the
shutdown and total grace period for pod termination during a node shutdown.
Default: "0s"
shutdownGracePeriodCriticalPods specifies the duration used to terminate critical
pods during a node shutdown. This should be less than shutdownGracePeriod.
For example, if shutdownGracePeriod=30s, and shutdownGracePeriodCriticalPods=10s,
during a node shutdown the first 20 seconds would be reserved for gracefully
terminating normal pods, and the last 10 seconds would be reserved for terminating
critical pods.
Default: "0s"
shutdownGracePeriodByPodPriority specifies the shutdown grace period for Pods based
on their associated priority class value.
When a shutdown request is received, the Kubelet will initiate shutdown on all pods
running on the node with a grace period that depends on the priority of the pod,
and then wait for all pods to exit.
Each entry in the array represents the graceful shutdown time a pod with a priority
class value that lies in the range of that value and the next higher entry in the
list when the node is shutting down.
For example, to allow critical pods 10s to shutdown, priority>=10000 pods 20s to
shutdown, and all remaining pods 30s to shutdown.
The time the Kubelet will wait before exiting will at most be the maximum of all
shutdownGracePeriodSeconds for each priority class range represented on the node.
When all pods have exited or reached their grace periods, the Kubelet will release
the shutdown inhibit lock.
Requires the GracefulNodeShutdown feature gate to be enabled.
This configuration must be empty if either ShutdownGracePeriod or ShutdownGracePeriodCriticalPods is set.
Default: nil
reservedMemory specifies a comma-separated list of memory reservations for NUMA nodes.
The parameter makes sense only in the context of the memory manager feature.
The memory manager will not allocate reserved memory for container workloads.
For example, if you have a NUMA0 with 10Gi of memory and the reservedMemory was
specified to reserve 1Gi of memory at NUMA0, the memory manager will assume that
only 9Gi is available for allocation.
You can specify a different amount of NUMA node and memory types.
You can omit this parameter at all, but you should be aware that the amount of
reserved memory from all NUMA nodes should be equal to the amount of memory specified
by the node allocatable.
If at least one node allocatable parameter has a non-zero value, you will need
to specify at least one NUMA node.
Also, avoid specifying:
Duplicates, the same NUMA node, and memory type, but with a different value.
zero limits for any memory type.
NUMAs nodes IDs that do not exist under the machine.
memory types except for memory and hugepages-
Default: nil
enableProfilingHandler bool
enableProfilingHandler enables profiling via web interface host:port/debug/pprof/
Default: true
enableDebugFlagsHandler bool
enableDebugFlagsHandler enables flags endpoint via web interface host:port/debug/flags/v
Default: true
seccompDefault bool
SeccompDefault enables the use of RuntimeDefault as the default seccomp profile for all workloads.
Default: false
memoryThrottlingFactor float64
MemoryThrottlingFactor specifies the factor multiplied by the memory limit or node allocatable memory
when setting the cgroupv2 memory.high value to enforce MemoryQoS.
Decreasing this factor will set lower high limit for container cgroups and put heavier reclaim pressure
while increasing will put less reclaim pressure.
See https://kep.k8s.io/2570 for more details.
Default: 0.9
registerWithTaints are an array of taints to add to a node object when
the kubelet registers itself. This only takes effect when registerNode
is true and upon the initial registration of the node.
Default: nil
registerNode bool
registerNode enables automatic registration with the apiserver.
Default: true
Tracing specifies the versioned configuration for OpenTelemetry tracing clients.
See https://kep.k8s.io/2832 for more details.
Default: nil
localStorageCapacityIsolation bool
LocalStorageCapacityIsolation enables local ephemeral storage isolation feature. The default setting is true.
This feature allows users to set request/limit for container's ephemeral storage and manage it in a similar way
as cpu and memory. It also allows setting sizeLimit for emptyDir volume, which will trigger pod eviction if disk
usage from the volume exceeds the limit.
This feature depends on the capability of detecting correct root file system disk usage. For certain systems,
such as kind rootless, if this capability cannot be supported, the feature LocalStorageCapacityIsolation should be
disabled. Once disabled, user should not set request/limit for container's ephemeral storage, or sizeLimit for emptyDir.
Default: true
containerRuntimeEndpoint[Required] string
ContainerRuntimeEndpoint is the endpoint of container runtime.
Unix Domain Sockets are supported on Linux, while npipe and tcp endpoints are supported on Windows.
Examples:'unix:///path/to/runtime.sock', 'npipe:////./pipe/runtime'
imageServiceEndpoint string
ImageServiceEndpoint is the endpoint of container image service.
Unix Domain Socket are supported on Linux, while npipe and tcp endpoints are supported on Windows.
Examples:'unix:///path/to/runtime.sock', 'npipe:////./pipe/runtime'.
If not specified, the value in containerRuntimeEndpoint is used.
SerializedNodeConfigSource
SerializedNodeConfigSource allows us to serialize v1.NodeConfigSource.
This type is used internally by the Kubelet for tracking checkpointed dynamic configs.
It exists in the kubeletconfig API group because it is classified as a versioned input to the Kubelet.
CredentialProvider represents an exec plugin to be invoked by the kubelet. The plugin is only
invoked when an image being pulled matches the images handled by the plugin (see matchImages).
Field
Description
name[Required] string
name is the required name of the credential provider. It must match the name of the
provider executable as seen by the kubelet. The executable must be in the kubelet's
bin directory (set by the --image-credential-provider-bin-dir flag).
matchImages[Required] []string
matchImages is a required list of strings used to match against images in order to
determine if this provider should be invoked. If one of the strings matches the
requested image from the kubelet, the plugin will be invoked and given a chance
to provide credentials. Images are expected to contain the registry domain
and URL path.
Each entry in matchImages is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like '*.k8s.io' or 'k8s.*.io', and top-level-domains such as 'k8s.*'.
Matching partial subdomains like 'app*.k8s.io' is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
A match exists between an image and a matchImage when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
defaultCacheDuration is the default duration the plugin will cache credentials in-memory
if a cache duration is not provided in the plugin response. This field is required.
apiVersion[Required] string
Required input version of the exec CredentialProviderRequest. The returned CredentialProviderResponse
MUST use the same encoding version as the input. Current supported values are:
credentialprovider.kubelet.k8s.io/v1beta1
args []string
Arguments to pass to the command when executing it.
Env defines additional environment variables to expose to the process. These
are unioned with the host's environment, as well as variables client-go uses
to pass argument to the plugin.
enabled allows anonymous requests to the kubelet server.
Requests that are not rejected by another authentication method are treated as
anonymous requests.
Anonymous requests have a username of system:anonymous, and a group name of
system:unauthenticated.
mode is the authorization mode to apply to requests to the kubelet server.
Valid values are AlwaysAllow and Webhook.
Webhook mode uses the SubjectAccessReview API to determine authorization.
clientCAFile is the path to a PEM-encoded certificate bundle. If set, any request
presenting a client certificate signed by one of the authorities in the bundle
is authenticated with a username corresponding to the CommonName,
and groups corresponding to the Organization in the client certificate.
swapBehavior configures swap memory available to container workloads. May be one of
"", "LimitedSwap": workload combined memory and swap usage cannot exceed pod memory limit
"UnlimitedSwap": workloads can use unlimited swap, up to the allocatable limit.
CredentialProviderRequest includes the image that the kubelet requires authentication for.
Kubelet will pass this request object to the plugin via stdin. In general, plugins should
prefer responding with the same apiVersion they were sent.
Field
Description
apiVersion string
credentialprovider.kubelet.k8s.io/v1
kind string
CredentialProviderRequest
image[Required] string
image is the container image that is being pulled as part of the
credential provider plugin request. Plugins may optionally parse the image
to extract any information required to fetch credentials.
CredentialProviderResponse
CredentialProviderResponse holds credentials that the kubelet should use for the specified
image provided in the original request. Kubelet will read the response from the plugin via stdout.
This response should be set to the same apiVersion as CredentialProviderRequest.
cacheKeyType indiciates the type of caching key to use based on the image provided
in the request. There are three valid values for the cache key type: Image, Registry, and
Global. If an invalid value is specified, the response will NOT be used by the kubelet.
cacheDuration indicates the duration the provided credentials should be cached for.
The kubelet will use this field to set the in-memory cache duration for credentials
in the AuthConfig. If null, the kubelet will use defaultCacheDuration provided in
CredentialProviderConfig. If set to 0, the kubelet will not cache the provided AuthConfig.
auth is a map containing authentication information passed into the kubelet.
Each key is a match image string (more on this below). The corresponding authConfig value
should be valid for all images that match against this key. A plugin should set
this field to null if no valid credentials can be returned for the requested image.
Each key in the map is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like '*.k8s.io' or 'k8s.*.io', and top-level-domains such as 'k8s.*'.
Matching partial subdomains like 'app*.k8s.io' is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
The kubelet will match images against the key when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
When multiple keys are returned, the kubelet will traverse all keys in reverse order so that:
longer keys come before shorter keys with the same prefix
non-wildcard keys come before wildcard keys with the same prefix.
For any given match, the kubelet will attempt an image pull with the provided credentials,
stopping after the first successfully authenticated pull.
AuthConfig contains authentication information for a container registry.
Only username/password based authentication is supported today, but more authentication
mechanisms may be added in the future.
Field
Description
username[Required] string
username is the username used for authenticating to the container registry
An empty username is valid.
password[Required] string
password is the password used for authenticating to the container registry
An empty password is valid.
CredentialProviderRequest includes the image that the kubelet requires authentication for.
Kubelet will pass this request object to the plugin via stdin. In general, plugins should
prefer responding with the same apiVersion they were sent.
Field
Description
apiVersion string
credentialprovider.kubelet.k8s.io/v1alpha1
kind string
CredentialProviderRequest
image[Required] string
image is the container image that is being pulled as part of the
credential provider plugin request. Plugins may optionally parse the image
to extract any information required to fetch credentials.
CredentialProviderResponse
CredentialProviderResponse holds credentials that the kubelet should use for the specified
image provided in the original request. Kubelet will read the response from the plugin via stdout.
This response should be set to the same apiVersion as CredentialProviderRequest.
cacheKeyType indiciates the type of caching key to use based on the image provided
in the request. There are three valid values for the cache key type: Image, Registry, and
Global. If an invalid value is specified, the response will NOT be used by the kubelet.
cacheDuration indicates the duration the provided credentials should be cached for.
The kubelet will use this field to set the in-memory cache duration for credentials
in the AuthConfig. If null, the kubelet will use defaultCacheDuration provided in
CredentialProviderConfig. If set to 0, the kubelet will not cache the provided AuthConfig.
auth is a map containing authentication information passed into the kubelet.
Each key is a match image string (more on this below). The corresponding authConfig value
should be valid for all images that match against this key. A plugin should set
this field to null if no valid credentials can be returned for the requested image.
Each key in the map is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like '*.k8s.io' or 'k8s.*.io', and top-level-domains such as 'k8s.*'.
Matching partial subdomains like 'app*.k8s.io' is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
The kubelet will match images against the key when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
When multiple keys are returned, the kubelet will traverse all keys in reverse order so that:
longer keys come before shorter keys with the same prefix
non-wildcard keys come before wildcard keys with the same prefix.
For any given match, the kubelet will attempt an image pull with the provided credentials,
stopping after the first successfully authenticated pull.
AuthConfig contains authentication information for a container registry.
Only username/password based authentication is supported today, but more authentication
mechanisms may be added in the future.
Field
Description
username[Required] string
username is the username used for authenticating to the container registry
An empty username is valid.
password[Required] string
password is the password used for authenticating to the container registry
An empty password is valid.
CredentialProviderRequest includes the image that the kubelet requires authentication for.
Kubelet will pass this request object to the plugin via stdin. In general, plugins should
prefer responding with the same apiVersion they were sent.
Field
Description
apiVersion string
credentialprovider.kubelet.k8s.io/v1beta1
kind string
CredentialProviderRequest
image[Required] string
image is the container image that is being pulled as part of the
credential provider plugin request. Plugins may optionally parse the image
to extract any information required to fetch credentials.
CredentialProviderResponse
CredentialProviderResponse holds credentials that the kubelet should use for the specified
image provided in the original request. Kubelet will read the response from the plugin via stdout.
This response should be set to the same apiVersion as CredentialProviderRequest.
cacheKeyType indiciates the type of caching key to use based on the image provided
in the request. There are three valid values for the cache key type: Image, Registry, and
Global. If an invalid value is specified, the response will NOT be used by the kubelet.
cacheDuration indicates the duration the provided credentials should be cached for.
The kubelet will use this field to set the in-memory cache duration for credentials
in the AuthConfig. If null, the kubelet will use defaultCacheDuration provided in
CredentialProviderConfig. If set to 0, the kubelet will not cache the provided AuthConfig.
auth is a map containing authentication information passed into the kubelet.
Each key is a match image string (more on this below). The corresponding authConfig value
should be valid for all images that match against this key. A plugin should set
this field to null if no valid credentials can be returned for the requested image.
Each key in the map is a pattern which can optionally contain a port and a path.
Globs can be used in the domain, but not in the port or the path. Globs are supported
as subdomains like '*.k8s.io' or 'k8s.*.io', and top-level-domains such as 'k8s.*'.
Matching partial subdomains like 'app*.k8s.io' is also supported. Each glob can only match
a single subdomain segment, so *.io does not match *.k8s.io.
The kubelet will match images against the key when all of the below are true:
Both contain the same number of domain parts and each part matches.
The URL path of an imageMatch must be a prefix of the target image URL path.
If the imageMatch contains a port, then the port must match in the image as well.
When multiple keys are returned, the kubelet will traverse all keys in reverse order so that:
longer keys come before shorter keys with the same prefix
non-wildcard keys come before wildcard keys with the same prefix.
For any given match, the kubelet will attempt an image pull with the provided credentials,
stopping after the first successfully authenticated pull.
AuthConfig contains authentication information for a container registry.
Only username/password based authentication is supported today, but more authentication
mechanisms may be added in the future.
Field
Description
username[Required] string
username is the username used for authenticating to the container registry
An empty username is valid.
password[Required] string
password is the password used for authenticating to the container registry
An empty password is valid.
indicates the time at which the metrics were produced
windowSeconds[Required] int64
indicates the window ([Timestamp-Window, Timestamp]) from
which these metrics were calculated, when returning rate
metrics calculated from cumulative metrics (or zero for
non-calculated instantaneous metrics).
selector represents the label selector that could be used to select
this metric, and will generally just be the selector passed in to
the query used to fetch this metric.
When left blank, only the metric's Name will be used to gather metrics.
15.2 - Kubernetes External Metrics (v1beta1)
Package v1beta1 is the v1beta1 version of the external metrics API.
ExternalMetricValue is a metric value for external metric
A single metric value is identified by metric name and a set of string labels.
For one metric there can be multiple values with different sets of labels.
Field
Description
apiVersion string
external.metrics.k8s.io/v1beta1
kind string
ExternalMetricValue
metricName[Required] string
the name of the metric
metricLabels[Required] map[string]string
a set of labels that identify a single time series for the metric
indicates the time at which the metrics were produced
window[Required] int64
indicates the window ([Timestamp-Window, Timestamp]) from
which these metrics were calculated, when returning rate
metrics calculated from cumulative metrics (or zero for
non-calculated instantaneous metrics).
You can customize the behavior of the kube-scheduler by writing a configuration
file and passing its path as a command line argument.
A scheduling Profile allows you to configure the different stages of scheduling
in the kube-scheduler.
Each stage is exposed in an extension point. Plugins provide scheduling behaviors
by implementing one or more of these extension points.
You can specify scheduling profiles by running kube-scheduler --config <filename>,
using the
KubeSchedulerConfiguration v1
struct.
Note: KubeSchedulerConfiguration v1beta3
is deprecated in v1.26 and will be removed in v1.29.
Please migrate KubeSchedulerConfiguration to v1.
Profiles
A scheduling Profile allows you to configure the different stages of scheduling
in the kube-scheduler.
Each stage is exposed in an extension point.
Plugins provide scheduling behaviors by implementing one
or more of these extension points.
You can configure a single instance of kube-scheduler to run
multiple profiles.
Extension points
Scheduling happens in a series of stages that are exposed through the following
extension points:
queueSort: These plugins provide an ordering function that is used to
sort pending Pods in the scheduling queue. Exactly one queue sort plugin
may be enabled at a time.
preFilter: These plugins are used to pre-process or check information
about a Pod or the cluster before filtering. They can mark a pod as
unschedulable.
filter: These plugins are the equivalent of Predicates in a scheduling
Policy and are used to filter out nodes that can not run the Pod. Filters
are called in the configured order. A pod is marked as unschedulable if no
nodes pass all the filters.
postFilter: These plugins are called in their configured order when no
feasible nodes were found for the pod. If any postFilter plugin marks the
Pod schedulable, the remaining plugins are not called.
preScore: This is an informational extension point that can be used
for doing pre-scoring work.
score: These plugins provide a score to each node that has passed the
filtering phase. The scheduler will then select the node with the highest
weighted scores sum.
reserve: This is an informational extension point that notifies plugins
when resources have been reserved for a given Pod. Plugins also implement an
Unreserve call that gets called in the case of failure during or after
Reserve.
permit: These plugins can prevent or delay the binding of a Pod.
preBind: These plugins perform any work required before a Pod is bound.
bind: The plugins bind a Pod to a Node. bind plugins are called in order
and once one has done the binding, the remaining plugins are skipped. At
least one bind plugin is required.
postBind: This is an informational extension point that is called after
a Pod has been bound.
multiPoint: This is a config-only field that allows plugins to be enabled
or disabled for all of their applicable extension points simultaneously.
For each extension point, you could disable specific default plugins
or enable your own. For example:
You can use * as name in the disabled array to disable all default plugins
for that extension point. This can also be used to rearrange plugins order, if
desired.
Scheduling plugins
The following plugins, enabled by default, implement one or more of these
extension points:
ImageLocality: Favors nodes that already have the container images that the
Pod runs.
Extension points: score.
NodeUnschedulable: Filters out nodes that have .spec.unschedulable set to
true.
Extension points: filter.
NodeResourcesFit: Checks if the node has all the resources that the Pod is
requesting. The score can use one of three strategies: LeastAllocated
(default), MostAllocated and RequestedToCapacityRatio.
Extension points: preFilter, filter, score.
NodeResourcesBalancedAllocation: Favors nodes that would obtain a more
balanced resource usage if the Pod is scheduled there.
Extension points: score.
VolumeBinding: Checks if the node has or if it can bind the requested
volumes.
Extension points: preFilter, filter, reserve, preBind, score.
Note:score extension point is enabled when VolumeCapacityPriority feature is
enabled. It prioritizes the smallest PVs that can fit the requested volume
size.
VolumeRestrictions: Checks that volumes mounted in the node satisfy
restrictions that are specific to the volume provider.
Extension points: filter.
VolumeZone: Checks that volumes requested satisfy any zone requirements they
might have.
Extension points: filter.
NodeVolumeLimits: Checks that CSI volume limits can be satisfied for the
node.
Extension points: filter.
EBSLimits: Checks that AWS EBS volume limits can be satisfied for the node.
Extension points: filter.
GCEPDLimits: Checks that GCP-PD volume limits can be satisfied for the node.
Extension points: filter.
AzureDiskLimits: Checks that Azure disk volume limits can be satisfied for
the node.
Extension points: filter.
PrioritySort: Provides the default priority based sorting.
Extension points: queueSort.
DefaultBinder: Provides the default binding mechanism.
Extension points: bind.
DefaultPreemption: Provides the default preemption mechanism.
Extension points: postFilter.
You can also enable the following plugins, through the component config APIs,
that are not enabled by default:
CinderLimits: Checks that OpenStack Cinder
volume limits can be satisfied for the node.
Extension points: filter.
Multiple profiles
You can configure kube-scheduler to run more than one profile.
Each profile has an associated scheduler name and can have a different set of
plugins configured in its extension points.
With the following sample configuration, the scheduler will run with two
profiles: one with the default plugins and one with all scoring plugins
disabled.
Pods that want to be scheduled according to a specific profile can include
the corresponding scheduler name in its .spec.schedulerName.
By default, one profile with the scheduler name default-scheduler is created.
This profile includes the default plugins described above. When declaring more
than one profile, a unique scheduler name for each of them is required.
If a Pod doesn't specify a scheduler name, kube-apiserver will set it to
default-scheduler. Therefore, a profile with this scheduler name should exist
to get those pods scheduled.
Note: Pod's scheduling events have .spec.schedulerName as the ReportingController.
Events for leader election use the scheduler name of the first profile in the
list.
Note: All profiles must use the same plugin in the queueSort extension point and have
the same configuration parameters (if applicable). This is because the scheduler
only has one pending pods queue.
Plugins that apply to multiple extension points
Starting from kubescheduler.config.k8s.io/v1beta3, there is an additional field in the
profile config, multiPoint, which allows for easily enabling or disabling a plugin
across several extension points. The intent of multiPoint config is to simplify the
configuration needed for users and administrators when using custom profiles.
Consider a plugin, MyPlugin, which implements the preScore, score, preFilter,
and filter extension points. To enable MyPlugin for all its available extension
points, the profile config looks like:
One benefit of using multiPoint here is that if MyPlugin implements another
extension point in the future, the multiPoint config will automatically enable it
for the new extension.
Specific extension points can be excluded from MultiPoint expansion using
the disabled field for that extension point. This works with disabling default
plugins, non-default plugins, or with the wildcard ('*') to disable all plugins.
An example of this, disabling Score and PreScore, would be:
Starting from kubescheduler.config.k8s.io/v1beta3, all default plugins
are enabled internally through MultiPoint.
However, individual extension points are still available to allow flexible
reconfiguration of the default values (such as ordering and Score weights). For
example, consider two Score plugins DefaultScore1 and DefaultScore2, each with
a weight of 1. They can be reordered with different weights like so:
In this example, it's unnecessary to specify the plugins in MultiPoint explicitly
because they are default plugins. And the only plugin specified in Score is DefaultScore2.
This is because plugins set through specific extension points will always take precedence
over MultiPoint plugins. So, this snippet essentially re-orders the two plugins
without needing to specify both of them.
The general hierarchy for precedence when configuring MultiPoint plugins is as follows:
Specific extension points run first, and their settings override whatever is set elsewhere
Plugins manually configured through MultiPoint and their settings
Default plugins and their default settings
To demonstrate the above hierarchy, the following example is based on these plugins:
Plugin
Extension Points
DefaultQueueSort
QueueSort
CustomQueueSort
QueueSort
DefaultPlugin1
Score, Filter
DefaultPlugin2
Score
CustomPlugin1
Score, Filter
CustomPlugin2
Score, Filter
A valid sample configuration for these plugins would be:
Note that there is no error for re-declaring a MultiPoint plugin in a specific
extension point. The re-declaration is ignored (and logged), as specific extension points
take precedence.
Besides keeping most of the config in one spot, this sample does a few things:
Enables the custom queueSort plugin and disables the default one
Enables CustomPlugin1 and CustomPlugin2, which will run first for all of their extension points
Disables DefaultPlugin1, but only for filter
Reorders DefaultPlugin2 to run first in score (even before the custom plugins)
In versions of the config before v1beta3, without multiPoint, the above snippet would equate to this:
While this is a complicated example, it demonstrates the flexibility of MultiPoint config
as well as its seamless integration with the existing methods for configuring extension points.
With the v1beta2 configuration version, you can use a new score extension for the
NodeResourcesFit plugin.
The new extension combines the functionalities of the NodeResourcesLeastAllocated,
NodeResourcesMostAllocated and RequestedToCapacityRatio plugins.
For example, if you previously used the NodeResourcesMostAllocated plugin, you
would instead use NodeResourcesFit (enabled by default) and add a pluginConfig
with a scoreStrategy that is similar to:
In Kubernetes versions before v1.23, a scheduling policy can be used to specify the predicates and priorities process. For example, you can set a scheduling policy by
running kube-scheduler --policy-config-file <filename> or kube-scheduler --policy-configmap <ConfigMap>.
This scheduling policy is not supported since Kubernetes v1.23. Associated flags policy-config-file, policy-configmap, policy-configmap-namespace and use-legacy-policy-config are also not supported. Instead, use the Scheduler Configuration to achieve similar behavior.
Kubernetes contains several tools to help you work with the Kubernetes system.
crictl
crictl is a command-line
interface for inspecting and debugging CRI-compatible
container runtimes.
Dashboard
Dashboard, the web-based user interface of Kubernetes, allows you to deploy containerized applications
to a Kubernetes cluster, troubleshoot them, and manage the cluster and its
resources itself.
Helm
🛇 This item links to a third party project or product that is not part of Kubernetes itself. More information
Helm is a tool for managing packages of pre-configured
Kubernetes resources. These packages are known as Helm charts.
Use Helm to:
Find and use popular software packaged as Kubernetes charts
Share your own applications as Kubernetes charts
Create reproducible builds of your Kubernetes applications
Intelligently manage your Kubernetes manifest files
Manage releases of Helm packages
Kompose
Kompose is a tool to help Docker Compose users move to Kubernetes.
Use Kompose to:
Translate a Docker Compose file into Kubernetes objects
Go from local Docker development to managing your application via Kubernetes
Kui is a GUI tool that takes your normal
kubectl command line requests and responds with graphics.
Kui takes the normal kubectl command line requests and responds with graphics. Instead
of ASCII tables, Kui provides a GUI rendering with tables that you can sort.
Kui lets you:
Directly click on long, auto-generated resource names instead of copying and pasting
Type in kubectl commands and see them execute, even sometimes faster than kubectl itself
Query a Job and see its execution rendered
as a waterfall diagram
Click through resources in your cluster using a tabbed UI
Minikube
minikube is a tool that
runs a single-node Kubernetes cluster locally on your workstation for
development and testing purposes.
17.1 - Mapping from dockercli to crictl
Note:
This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.
crictl is a command-line interface for CRI-compatible container runtimes.
You can use it to inspect and debug container runtimes and applications on a
Kubernetes node. crictl and its source are hosted in the
cri-tools repository.
This page provides a reference for mapping common commands for the docker
command-line tool into the equivalent commands for crictl.
Mapping from docker CLI to crictl
The exact versions for the mapping table are for docker CLI v1.40 and crictl
v1.19.0. This list is not exhaustive. For example, it doesn't include
experimental docker CLI commands.
Note: The output format of crictl is similar to docker CLI, despite some missing
columns for some CLI. Make sure to check output for the specific command if your
command output is being parsed programmatically.
Retrieve debugging information
mapping from docker cli to crictl - retrieve debugging information
docker cli
crictl
Description
Unsupported Features
attach
attach
Attach to a running container
--detach-keys, --sig-proxy
exec
exec
Run a command in a running container
--privileged, --user, --detach-keys
images
images
List images
info
info
Display system-wide information
inspect
inspect, inspecti
Return low-level information on a container, image or task
logs
logs
Fetch the logs of a container
--details
ps
ps
List containers
stats
stats
Display a live stream of container(s) resource usage statistics
Column: NET/BLOCK I/O, PIDs
version
version
Show the runtime (Docker, ContainerD, or others) version information
Perform Changes
mapping from docker cli to crictl - perform changes
docker cli
crictl
Description
Unsupported Features
create
create
Create a new container
kill
stop (timeout = 0)
Kill one or more running container
--signal
pull
pull
Pull an image or a repository from a registry
--all-tags, --disable-content-trust
rm
rm
Remove one or more containers
rmi
rmi
Remove one or more images
run
run
Run a command in a new container
start
start
Start one or more stopped containers
--detach-keys
stop
stop
Stop one or more running containers
update
update
Update configuration of one or more containers
--restart, --blkio-weight and some other resource limit not supported by CRI.
Supported only in crictl
mapping from docker cli to crictl - supported only in crictl
Kubeadm is a tool built to provide