kubernetes.core.k8s_log module – Fetch logs from Kubernetes resources

Note

This module is part of the kubernetes.core collection (version 2.4.0).

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_log.

New in kubernetes.core 0.10.0

Synopsis

  • Use the Kubernetes Python client to perform read operations on K8s log endpoints.

  • Authenticate using either a config file, certificates, password or token.

  • Supports check mode.

  • Analogous to `kubectl logs` or `oc logs`

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

all_containers

boolean

added in kubernetes.core 2.4.0

If set to true, retrieve all containers’ logs in the pod(s).

mutually exclusive with container.

Choices:

  • false

  • true

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.

container

string

Use to specify the container within a pod to grab the log from.

If there is only one container, this will default to that container.

If there is more than one container, this option is required or set all_containers to true.

mutually exclusive with all_containers.

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

If using label_selectors, cannot be overridden.

Default: "Pod"

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

List of label selectors to use to filter results

Only one of name or label_selectors may be provided.

name

string

Use to specify an object name.

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

Only one of name or label_selectors may be provided.

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

previous

boolean

added in kubernetes.core 2.4.0

If true, print the logs for the previous instance of the container in a pod if it exists.

Choices:

  • false ← (default)

  • 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.

since_seconds

string

added in kubernetes.core 2.2.0

A relative time in seconds before the current time from which to show logs.

tail_lines

integer

added in kubernetes.core 2.4.0

A number of lines from the end of the logs to retrieve.

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

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: Get a log from a Pod
  kubernetes.core.k8s_log:
    name: example-1
    namespace: testing
  register: log

# This will get the log from the first Pod found matching the selector
- name: Log a Pod matching a label selector
  kubernetes.core.k8s_log:
    namespace: testing
    label_selectors:
    - app=example
  register: log

# This will get the log from a single Pod managed by this Deployment
- name: Get a log from a Deployment
  kubernetes.core.k8s_log:
    api_version: apps/v1
    kind: Deployment
    namespace: testing
    name: example
    since_seconds: "4000"
  register: log

# This will get the log from a single Pod managed by this DeploymentConfig
- name: Get a log from a DeploymentConfig
  kubernetes.core.k8s_log:
    api_version: apps.openshift.io/v1
    kind: DeploymentConfig
    namespace: testing
    name: example
    tail_lines: 100
  register: log

# This will get the logs from all containers in Pod
- name: Get the logs from all containers in pod
  kubernetes.core.k8s_log:
    namespace: testing
    name: some-pod
    all_containers: true

Return Values

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

Key

Description

log

string

The text log of the object

Returned: success

log_lines

list / elements=string

The log of the object, split on newlines

Returned: success

Authors

  • Fabian von Feilitzsch (@fabianvf)