kubernetes.core.k8s_scale module – Set a new size for a Deployment, ReplicaSet, Replication Controller, or Job.

Note

This module is part of the kubernetes.core collection (version 3.2.0).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install kubernetes.core. You need further requirements to be able to use this module, see Requirements for details.

To use it in a playbook, specify: kubernetes.core.k8s_scale.

Synopsis

  • Similar to the kubectl scale command. Use to set the number of replicas for a Deployment, ReplicaSet, or Replication Controller, or the parallelism attribute of a Job. Supports check mode.

  • wait parameter is not supported for Jobs.

Note

This module has a corresponding action plugin.

Requirements

The below requirements are needed on the host that executes this module.

  • python >= 3.9

  • kubernetes >= 24.2.0

  • PyYAML >= 3.11

Parameters

Parameter

Comments

api_key

string

Token used to authenticate with the API. Can also be specified via K8S_AUTH_API_KEY environment variable.

api_version

aliases: api, version

string

Use to specify the API version.

Use to create, delete, or discover an object without providing a full resource definition.

Use in conjunction with kind, name, and namespace to identify a specific object.

If resource definition is provided, the apiVersion value from the resource_definition will override this option.

Default: "v1"

ca_cert

aliases: ssl_ca_cert

path

Path to a CA certificate used to authenticate with the API. The full certificate chain must be provided to avoid certificate validation errors. Can also be specified via K8S_AUTH_SSL_CA_CERT environment variable.

client_cert

aliases: cert_file

path

Path to a certificate used to authenticate with the API. Can also be specified via K8S_AUTH_CERT_FILE environment variable.

client_key

aliases: key_file

path

Path to a key file used to authenticate with the API. Can also be specified via K8S_AUTH_KEY_FILE environment variable.

context

string

The name of a context found in the config file. Can also be specified via K8S_AUTH_CONTEXT environment variable.

continue_on_error

boolean

added in kubernetes.core 2.0.0

Whether to continue on errors when multiple resources are defined.

Choices:

  • false ← (default)

  • true

current_replicas

integer

For Deployment, ReplicaSet, Replication Controller, only scale, if the number of existing replicas matches. In the case of a Job, update parallelism only if the current parallelism value matches.

host

string

Provide a URL for accessing the API. Can also be specified via K8S_AUTH_HOST environment variable.

impersonate_groups

list / elements=string

added in kubernetes.core 2.3.0

Group(s) to impersonate for the operation.

Can also be specified via K8S_AUTH_IMPERSONATE_GROUPS environment. Example: Group1,Group2

impersonate_user

string

added in kubernetes.core 2.3.0

Username to impersonate for the operation.

Can also be specified via K8S_AUTH_IMPERSONATE_USER environment.

kind

string

Use to specify an object model.

Use to create, delete, or discover an object without providing a full resource definition.

Use in conjunction with api_version, name, and namespace to identify a specific object.

If resource definition is provided, the kind value from the resource_definition will override this option.

kubeconfig

any

Path to an existing Kubernetes config file. If not provided, and no other connection options are provided, the Kubernetes client will attempt to load the default configuration file from ~/.kube/config. Can also be specified via K8S_AUTH_KUBECONFIG environment variable.

Multiple Kubernetes config file can be provided using separator ‘;’ for Windows platform or ‘:’ for others platforms.

The kubernetes configuration can be provided as dictionary. This feature requires a python kubernetes client version >= 17.17.0. Added in version 2.2.0.

label_selectors

list / elements=string

added in kubernetes.core 2.0.0

List of label selectors to use to filter results.

Default: []

name

string

Use to specify an object name.

Use to create, delete, or discover an object without providing a full resource definition.

Use in conjunction with api_version, kind and namespace to identify a specific object.

If resource definition is provided, the metadata.name value from the resource_definition will override this option.

namespace

string

Use to specify an object namespace.

Useful when creating, deleting, or discovering an object without providing a full resource definition.

Use in conjunction with api_version, kind, and name to identify a specific object.

If resource definition is provided, the metadata.namespace value from the resource_definition will override this option.

no_proxy

string

added in kubernetes.core 2.3.0

The comma separated list of hosts/domains/IP/CIDR that shouldn’t go through proxy. Can also be specified via K8S_AUTH_NO_PROXY environment variable.

Please note that this module does not pick up typical proxy settings from the environment (e.g. NO_PROXY).

This feature requires kubernetes>=19.15.0. When kubernetes library is less than 19.15.0, it fails even no_proxy set in correct.

example value is “localhost,.local,.example.com,127.0.0.1,127.0.0.0/8,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16”

password

string

Provide a password for authenticating with the API. Can also be specified via K8S_AUTH_PASSWORD environment variable.

Please read the description of the username option for a discussion of when this option is applicable.

persist_config

boolean

Whether or not to save the kube config refresh tokens. Can also be specified via K8S_AUTH_PERSIST_CONFIG environment variable.

When the k8s context is using a user credentials with refresh tokens (like oidc or gke/gcloud auth), the token is refreshed by the k8s python client library but not saved by default. So the old refresh token can expire and the next auth might fail. Setting this flag to true will tell the k8s python client to save the new refresh token to the kube config file.

Default to false.

Please note that the current version of the k8s python client library does not support setting this flag to True yet.

The fix for this k8s python library is here: https://github.com/kubernetes-client/python-base/pull/169

Choices:

  • false

  • true

proxy

string

The URL of an HTTP proxy to use for the connection. Can also be specified via K8S_AUTH_PROXY environment variable.

Please note that this module does not pick up typical proxy settings from the environment (e.g. HTTP_PROXY).

proxy_headers

dictionary

added in kubernetes.core 2.0.0

The Header used for the HTTP proxy.

Documentation can be found here https://urllib3.readthedocs.io/en/latest/reference/urllib3.util.html?highlight=proxy_headers#urllib3.util.make_headers.

basic_auth

string

Colon-separated username:password for basic authentication header.

Can also be specified via K8S_AUTH_PROXY_HEADERS_BASIC_AUTH environment.

proxy_basic_auth

string

Colon-separated username:password for proxy basic authentication header.

Can also be specified via K8S_AUTH_PROXY_HEADERS_PROXY_BASIC_AUTH environment.

user_agent

string

String representing the user-agent you want, such as foo/1.0.

Can also be specified via K8S_AUTH_PROXY_HEADERS_USER_AGENT environment.

replicas

integer / required

The desired number of replicas.

resource_definition

aliases: definition, inline

string

Provide a valid YAML definition (either as a string, list, or dict) for an object when creating or updating.

NOTE: kind, api_version, name, and namespace will be overwritten by corresponding values found in the provided resource_definition.

resource_version

string

Only attempt to scale, if the current object version matches.

src

path

Provide a path to a file containing a valid YAML definition of an object or objects to be created or updated. Mutually exclusive with resource_definition. NOTE: kind, api_version, name, and namespace will be overwritten by corresponding values found in the configuration read in from the src file.

Reads from the local file system. To read from the Ansible controller’s file system, including vaulted files, use the file lookup plugin or template lookup plugin, combined with the from_yaml filter, and pass the result to resource_definition. See Examples below.

The URL to manifest files that can be used to create the resource. Added in version 2.4.0.

Mutually exclusive with template in case of kubernetes.core.k8s module.

username

string

Provide a username for authenticating with the API. Can also be specified via K8S_AUTH_USERNAME environment variable.

Please note that this only works with clusters configured to use HTTP Basic Auth. If your cluster has a different form of authentication (e.g. OAuth2 in OpenShift), this option will not work as expected and you should look into the community.okd.k8s_auth module, as that might do what you need.

validate_certs

aliases: verify_ssl

boolean

Whether or not to verify the API server’s SSL certificates. Can also be specified via K8S_AUTH_VERIFY_SSL environment variable.

Choices:

  • false

  • true

wait

boolean

For Deployment, ReplicaSet, Replication Controller, wait for the status value of ready_replicas to change to the number of replicas. In the case of a Job, this option is ignored.

Choices:

  • false

  • true ← (default)

wait_sleep

integer

added in kubernetes.core 2.0.0

Number of seconds to sleep between checks.

Default: 5

wait_timeout

integer

When wait is True, the number of seconds to wait for the ready_replicas status to equal replicas. If the status is not reached within the allotted time, an error will result. In the case of a Job, this option is ignored.

Default: 20

Notes

Note

  • To avoid SSL certificate validation errors when validate_certs is True, the full certificate chain for the API server must be provided via ca_cert or in the kubeconfig file.

Examples

- name: Scale deployment up, and extend timeout
  kubernetes.core.k8s_scale:
    api_version: v1
    kind: Deployment
    name: elastic
    namespace: myproject
    replicas: 3
    wait_timeout: 60

- name: Scale deployment down when current replicas match
  kubernetes.core.k8s_scale:
    api_version: v1
    kind: Deployment
    name: elastic
    namespace: myproject
    current_replicas: 3
    replicas: 2

- name: Increase job parallelism
  kubernetes.core.k8s_scale:
    api_version: batch/v1
    kind: job
    name: pi-with-timeout
    namespace: testing
    replicas: 2

# Match object using local file or inline definition

- name: Scale deployment based on a file from the local filesystem
  kubernetes.core.k8s_scale:
    src: /myproject/elastic_deployment.yml
    replicas: 3
    wait: no

- name: Scale deployment based on a template output
  kubernetes.core.k8s_scale:
    resource_definition: "{{ lookup('template', '/myproject/elastic_deployment.yml') | from_yaml }}"
    replicas: 3
    wait: no

- name: Scale deployment based on a file from the Ansible controller filesystem
  kubernetes.core.k8s_scale:
    resource_definition: "{{ lookup('file', '/myproject/elastic_deployment.yml') | from_yaml }}"
    replicas: 3
    wait: no

- name: Scale deployment using label selectors (continue operation in case error occured on one resource)
  kubernetes.core.k8s_scale:
    replicas: 3
    kind: Deployment
    namespace: test
    label_selectors:
      - app=test
    continue_on_error: true

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

result

complex

If a change was made, will return the patched object, otherwise returns the existing object.

Returned: success

api_version

string

The versioned schema of this representation of an object.

Returned: success

duration

integer

elapsed time of task in seconds

Returned: when wait is true

Sample: 48

kind

string

Represents the REST resource this object represents.

Returned: success

metadata

complex

Standard object metadata. Includes name, namespace, annotations, labels, etc.

Returned: success

spec

complex

Specific attributes of the object. Will vary based on the api_version and kind.

Returned: success

status

complex

Current status details for the object.

Returned: success

Authors

  • Chris Houseknecht (@chouseknecht)

  • Fabian von Feilitzsch (@fabianvf)