Doc: add example of using kubectl connection plugin (#741)

Doc: add example of using kubectl connection plugin

SUMMARY
Currently documentation for collection don't include any examples of using kubenrenes.core.kubectl connection plugin and it's hard to start using that plugin.
ISSUE TYPE

Docs Pull Request

COMPONENT NAME
kubenrenes.core.kubectl connection plugin
ADDITIONAL INFORMATION
This PR was inspired by #288 and based on feedback on that PR and my own experience. Thanks @tpo for his try and @geerlingguy for his Ansible for DevOps book

Reviewed-by: Bikouo Aubin
Reviewed-by: Sandra McCann <samccann@redhat.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: Yuriy Novostavskiy
Reviewed-by: purdzan

.ansible-lint-ignore

@@ -0,0 +1,2 @@
+# no-changed-when is not requried for examples
+plugins/connection/kubectl.py no-changed-when

changelogs/fragments/20240601-doc-example-of-using-kubectl.yaml

@@ -0,0 +1,3 @@
+---
+minor_changes:
+  - connection/kubectl.py - Added an example of using the kubectl connection plugin to the documentation (https://github.com/ansible-collections/kubernetes.core/pull/741).

docs/kubernetes.core.kubectl_connection.rst

@@ -365,6 +365,82 @@ Parameters
 
 
 
+Examples
+--------
+
+.. code-block:: yaml
+
+    - name: Run a command in a pod using local kubectl with kubeconfig file ~/.kube/config
+      hosts: localhost
+      gather_facts: no
+      vars:
+        ansible_connection: kubernetes.core.kubectl
+        ansible_kubectl_namespace: my-namespace
+        ansible_kubectl_pod: my-pod
+        ansible_kubectl_container: my-container
+      tasks:
+        # be aware that the command is executed as the user that started the container
+        # and requires python to be installed in the image
+        - name: Run a command in a pod
+          ansible.builtin.command: echo "Hello, World!"
+
+    - name: Run a command in a pod using local kubectl with inventory variables
+      # Example inventory:
+      # k8s:
+      #   hosts:
+      #     foo.example.com:
+      #       ansible_connection: kubernetes.core.kubectl
+      #       ansible_kubectl_kubeconfig: /root/.kube/foo.example.com.config
+      #       ansible_kubectl_pod: my-foo-pod
+      #       ansible_kubectl_container: my-foo-container
+      #       ansible_kubectl_namespace: my-foo-namespace
+      #     bar.example.com:
+      #       ansible_connection: kubernetes.core.kubectl
+      #       ansible_kubectl_kubeconfig: /root/.kube/bar.example.com.config
+      #       ansible_kubectl_pod: my-bar-pod
+      #       ansible_kubectl_container: my-bar-container
+      #       ansible_kubectl_namespace: my-bar-namespace
+      hosts: k8s
+      gather_facts: no
+      tasks:
+        # be aware that the command is executed as the user that started the container
+        # and requires python to be installed in the image
+        - name: Run a command in a pod
+          ansible.builtin.command: echo "Hello, World!"
+
+    - name: Run a command in a pod using dynamic inventory
+      hosts: localhost
+      gather_facts: no
+      vars:
+        kubeconfig: /root/.kube/config
+        namespace: my-namespace
+        my_app: my-app
+      tasks:
+        - name: Get My App pod info based on label
+          kubernetes.core.k8s_info:
+            kubeconfig: "{{ kubeconfig }}"
+            namespace: "{{ namespace }}"
+            kind: Pod
+            label_selectors: app.kubernetes.io/name = "{{ my_app }}"
+          register: my_app_pod
+
+        - name: Get My App pod name
+          ansible.builtin.set_fact:
+            my_app_pod_name: "{{ my_app_pod.resources[0].metadata.name }}"
+
+        - name: Add My App pod to inventory
+          ansible.builtin.add_host:
+            name: "{{ my_app_pod_name }}"
+            ansible_connection: kubernetes.core.kubectl
+            ansible_kubectl_kubeconfig: "{{ kubeconfig }}"
+            ansible_kubectl_pod: "{{ my_app_pod_name }}"
+            ansible_kubectl_namespace: "{{ namespace }}"
+
+        - name: Run a command in My App pod
+          # be aware that the command is executed as the user that started the container
+          # and requires python to be installed in the image
+          ansible.builtin.command: echo "Hello, World!"
+          delegate_to: "{{ my_app_pod_name }}"
 
 
 

plugins/connection/kubectl.py

@@ -181,6 +181,81 @@
         aliases: [ kubectl_verify_ssl ]
 """
 
+EXAMPLES = r"""
+
+- name: Run a command in a pod using local kubectl with kubeconfig file ~/.kube/config
+  hosts: localhost
+  gather_facts: no
+  vars:
+    ansible_connection: kubernetes.core.kubectl
+    ansible_kubectl_namespace: my-namespace
+    ansible_kubectl_pod: my-pod
+    ansible_kubectl_container: my-container
+  tasks:
+    # be aware that the command is executed as the user that started the container
+    # and requires python to be installed in the image
+    - name: Run a command in a pod
+      ansible.builtin.command: echo "Hello, World!"
+
+- name: Run a command in a pod using local kubectl with inventory variables
+  # Example inventory:
+  # k8s:
+  #   hosts:
+  #     foo.example.com:
+  #       ansible_connection: kubernetes.core.kubectl
+  #       ansible_kubectl_kubeconfig: /root/.kube/foo.example.com.config
+  #       ansible_kubectl_pod: my-foo-pod
+  #       ansible_kubectl_container: my-foo-container
+  #       ansible_kubectl_namespace: my-foo-namespace
+  #     bar.example.com:
+  #       ansible_connection: kubernetes.core.kubectl
+  #       ansible_kubectl_kubeconfig: /root/.kube/bar.example.com.config
+  #       ansible_kubectl_pod: my-bar-pod
+  #       ansible_kubectl_container: my-bar-container
+  #       ansible_kubectl_namespace: my-bar-namespace
+  hosts: k8s
+  gather_facts: no
+  tasks:
+    # be aware that the command is executed as the user that started the container
+    # and requires python to be installed in the image
+    - name: Run a command in a pod
+      ansible.builtin.command: echo "Hello, World!"
+
+- name: Run a command in a pod using dynamic inventory
+  hosts: localhost
+  gather_facts: no
+  vars:
+    kubeconfig: /root/.kube/config
+    namespace: my-namespace
+    my_app: my-app
+  tasks:
+    - name: Get My App pod info based on label
+      kubernetes.core.k8s_info:
+        kubeconfig: "{{ kubeconfig }}"
+        namespace: "{{ namespace }}"
+        kind: Pod
+        label_selectors: app.kubernetes.io/name = "{{ my_app }}"
+      register: my_app_pod
+
+    - name: Get My App pod name
+      ansible.builtin.set_fact:
+        my_app_pod_name: "{{ my_app_pod.resources[0].metadata.name }}"
+
+    - name: Add My App pod to inventory
+      ansible.builtin.add_host:
+        name: "{{ my_app_pod_name }}"
+        ansible_connection: kubernetes.core.kubectl
+        ansible_kubectl_kubeconfig: "{{ kubeconfig }}"
+        ansible_kubectl_pod: "{{ my_app_pod_name }}"
+        ansible_kubectl_namespace: "{{ namespace }}"
+
+    - name: Run a command in My App pod
+      # be aware that the command is executed as the user that started the container
+      # and requires python to be installed in the image
+      ansible.builtin.command: echo "Hello, World!"
+      delegate_to: "{{ my_app_pod_name }}"
+"""
+
 import json
 import os
 import os.path