kubernetes.core.k8s_exec module – Execute command in Pod

Note

This module is part of the kubernetes.core collection (version 2.3.2).

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.

To use it in a playbook, specify: kubernetes.core.k8s_exec.

New in version 0.10.0: of kubernetes.core

Synopsis

  • Use the Kubernetes Python client to execute command on K8s pods.

Note

This module has a corresponding action plugin.

Requirements

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

  • python >= 3.6

  • kubernetes >= 12.0.0

  • 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.

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.

command

string / required

The command to execute.

container

string

The name of the container in the pod to connect to.

Defaults to only container if there is only one container in the pod.

If not specified, will choose the first container from the given pod as kubectl cmdline does.

context

string

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

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 2.3.0 of kubernetes.core

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 2.3.0 of kubernetes.core

Username to impersonate for the operation.

Can also be specified via K8S_AUTH_IMPERSONATE_USER environment.

kubeconfig

raw

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.

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.

namespace

string / required

The pod namespace name.

no_proxy

string

added in 2.3.0 of kubernetes.core

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:

  • no

  • yes

pod

string / required

The pod name.

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 (for example, HTTP_PROXY).

proxy_headers

dictionary

added in 2.0.0 of kubernetes.core

The Header used for the HTTP proxy.

Documentation can be found here https://urllib3.readthedocs.io/en/latest/reference/urllib3.util.html?highlight%3Dproxy_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.

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:

  • no

  • yes

Notes

Note

  • Return code rc for the command executed is added in output in version 2.2.0, and deprecates return code return_code.

  • Return code return_code for the command executed is added in output in version 1.0.0.

  • The authenticated user must have at least read access to the pods resource and write access to the pods/exec resource.

  • 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: Execute a command
  kubernetes.core.k8s_exec:
    namespace: myproject
    pod: zuul-scheduler
    command: zuul-scheduler full-reconfigure

- name: Check RC status of command executed
  kubernetes.core.k8s_exec:
    namespace: myproject
    pod: busybox-test
    command: cmd_with_non_zero_exit_code
  register: command_status
  ignore_errors: True

- name: Check last command status
  debug:
    msg: "cmd failed"
  when: command_status.rc != 0

- name: Specify a container name to execute the command on
  kubernetes.core.k8s_exec:
    namespace: myproject
    pod: busybox-test
    container: manager
    command: echo "hello"

Return Values

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

Key

Description

result

complex

The command object

Returned: success

rc

integer

added in 2.2.0 of kubernetes.core

The command status code

Returned: success

return_code

integer

The command status code. This attribute is deprecated and will be removed in a future release. Please use rc instead.

Returned: success

stderr

string

The command stderr

Returned: success

stderr_lines

string

The command stderr

Returned: success

stdout

string

The command stdout

Returned: success

stdout_lines

string

The command stdout

Returned: success

Authors

  • Tristan de Cacqueray (@tristanC)