Added support for copying files to init Containers. (#971)

SUMMARY
Was going trough the list with issues and found 958; which seemed a quick fix.
What I fixed with with this PR:

Added support for copying files to init containers.
Fixed the format message when an exec is failing for a pod (the order was wrong).
Added a check if the container that you try to run copy for is started.

ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
copy.py module
ADDITIONAL INFORMATION
Some testing.
Verify that the pod does not exist:
kubectl -n default get pod/yorick
Output:
Error from server (NotFound): pods "yorick" not found

Run the playbook to create the file, create the deployment, wait for the init container to be ready, copy the created file to the init container, cat the copied file (using kubernetes.core.k8s_exec) that is now in the init container and try to copy the created file to the (not started) container (which fails - to see the new error message for it):
cat << EOF | ansible-playbook /dev/stdin
- hosts: localhost
  gather_facts: False
  tasks:

  - ansible.builtin.copy:
      content: |
        Hi there
      dest: /tmp/yorick.txt

  - name: Deploy pod with initContainer with an unlimited while loop
    kubernetes.core.k8s:
      kubeconfig: "~/.kube/config"
      definition:
        apiVersion: v1
        kind: Pod
        metadata:
          name: "yorick"
          namespace: "default"
        spec:
          initContainers:
            - name: "yorick-init"
              image: busybox:latest
              command: ["/bin/sh"]
              args:
                - "-c"
                - |
                  echo "Init container started, waiting for file..."
                  # Wait for the file to be copied
                  while :;do
                    echo "Waiting for file"
                    sleep 5
                  done
                  echo "File received! Init container completing..."
          containers:
            - name: "yorick-container"
              image: busybox:latest
              command: ["/bin/sh"]
              args:
                - "-c"
                - |
                  # Keep container running for testing
                  sleep 300

  - kubernetes.core.k8s_info:
      kubeconfig: "~/.kube/config"
      api_version: v1
      kind: Pod
      name: "yorick"
      namespace: "default"
    register: pod_status
    until: >-
      pod_status.resources|length > 0
      and 'initContainerStatuses' in pod_status.resources.0.status
      and pod_status.resources.0.status.initContainerStatuses|length > 0
      and pod_status.resources.0.status.initContainerStatuses.0.started|bool

  - name: Copy /tmp/yorick.txt to the yorick-init init container
    kubernetes.core.k8s_cp:
      kubeconfig: "~/.kube/config"
      namespace: default
      pod: yorick
      remote_path: /tmp/yorick.txt
      local_path: /tmp/yorick.txt
      container: yorick-init

  - name: Execute a command
    kubernetes.core.k8s_exec:
      kubeconfig: "~/.kube/config"
      namespace: default
      pod: yorick
      container: yorick-init
      command: cat /tmp/yorick.txt
    register: exec_out

  - ansible.builtin.debug:
      var: exec_out.stdout

  - name: Try to copy /tmp/yorick.txt to the yorick-container container
    kubernetes.core.k8s_cp:
      kubeconfig: "~/.kube/config"
      namespace: default
      pod: yorick
      remote_path: /tmp/yorick.txt
      local_path: /tmp/yorick.txt
      container: yorick-container
EOF
Output:
PLAY [localhost] ********************************************************************************************************************************************************************

TASK [ansible.builtin.copy] *********************************************************************************************************************************************************
Thursday 31 July 2025  02:01:21 +0200 (0:00:00.016)       0:00:00.016 *********
ok: [localhost]

TASK [Deploy pod with initContainer with an unlimited while loop] *******************************************************************************************************************
Thursday 31 July 2025  02:01:21 +0200 (0:00:00.788)       0:00:00.804 *********
changed: [localhost]

TASK [kubernetes.core.k8s_info] *****************************************************************************************************************************************************
Thursday 31 July 2025  02:01:25 +0200 (0:00:03.963)       0:00:04.768 *********
FAILED - RETRYING: [localhost]: kubernetes.core.k8s_info (3 retries left).
ok: [localhost]

TASK [Copy /tmp/yorick.txt to the yorick-init init container] ***********************************************************************************************************************
Thursday 31 July 2025  02:01:32 +0200 (0:00:06.598)       0:00:11.366 *********
changed: [localhost]

TASK [Execute a command] ************************************************************************************************************************************************************
Thursday 31 July 2025  02:01:39 +0200 (0:00:07.017)       0:00:18.383 *********
changed: [localhost]

TASK [ansible.builtin.debug] ********************************************************************************************************************************************************
Thursday 31 July 2025  02:01:40 +0200 (0:00:00.644)       0:00:19.028 *********
ok: [localhost] => {
    "exec_out.stdout": "Hi there\n"
}

TASK [Try to copy /tmp/yorick.txt to the yorick-container container] ****************************************************************************************************************
Thursday 31 July 2025  02:01:40 +0200 (0:00:00.021)       0:00:19.050 *********
fatal: [localhost]: FAILED! => {
    "changed": false
}

MSG:

Pod container yorick-container is not started

PLAY RECAP **************************************************************************************************************************************************************************
localhost                  : ok=6    changed=3    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

Playbook run took 0 days, 0 hours, 0 minutes, 21 seconds

Reviewed-by: spatterlight
Reviewed-by: Yorick Gruijthuijzen <yorick-1989@hotmail.com>
Reviewed-by: Bianca Henderson <beeankha@gmail.com>
Reviewed-by: Bikouo Aubin

changelogs/fragments/20250731-fix-k8s_cp-initcontainers.yaml

@@ -0,0 +1,3 @@
+---
+bugfixes:
+  - Update the `k8s_cp` module to also work for init containers (https://github.com/ansible-collections/kubernetes.core/pull/971).

plugins/module_utils/copy.py

@@ -96,7 +96,7 @@ class K8SCopy(metaclass=ABCMeta):
             return error, stdout, stderr
         except Exception as e:
             self.module.fail_json(
-                msg="Error while running/parsing from pod {1}/{2} command='{0}' : {3}".format(
+                msg="Error while running/parsing from pod {0}/{1} command='{2}' : {3}".format(
                     self.namespace, self.name, cmd, to_native(e)
                 )
             )
@@ -435,11 +435,21 @@ def check_pod(svc):
 
     try:
         result = svc.client.get(resource, name=name, namespace=namespace)
-        containers = [
-            c["name"] for c in result.to_dict()["status"]["containerStatuses"]
-        ]
-        if container and container not in containers:
+        containers = dict(
+            {
+                c["name"]: c
+                for cl in ["initContainerStatuses", "containerStatuses"]
+                for c in result.to_dict()["status"].get(cl, [])
+            }
+        )
+        if container and container not in containers.keys():
             module.fail_json(msg="Pod has no container {0}".format(container))
-        return containers
+        if (
+            container
+            and container in containers
+            and not bool(containers[container].get("started", False))
+        ):
+            module.fail_json(msg="Pod container {0} is not started".format(container))
+        return containers.keys()
     except Exception as exc:
         _fail(exc)

plugins/modules/k8s_cp.py

@@ -79,6 +79,7 @@ options:
 
 notes:
     - the tar binary is required on the container when copying from local filesystem to pod.
+    - the (init) container has to be started before you copy files or directories to it.
 """
 
 EXAMPLES = r"""

tests/integration/targets/k8s_copy/defaults/main.yml

@@ -14,3 +14,9 @@ pod_with_two_container:
 
 pod_without_executable_find:
   name: openjdk-pod
+
+pod_with_initcontainer_and_container:
+  name: pod-copy-2
+  container:
+  - container-20
+  - container-21

tests/integration/targets/k8s_copy/tasks/main.yml

@@ -18,6 +18,23 @@
         wait: yes
         template: pods_definition.j2
 
+    - name: Create Init Pod
+      k8s:
+        namespace: '{{ copy_namespace }}'
+        template: pods_definition_init.j2
+
+    - kubernetes.core.k8s_info:
+        api_version: v1
+        kind: Pod
+        name: '{{ pod_with_initcontainer_and_container.name }}'
+        namespace: '{{ copy_namespace }}'
+      register: init_pod_status
+      until: >-
+        init_pod_status.resources|length > 0
+        and 'initContainerStatuses' in init_pod_status.resources.0.status
+        and init_pod_status.resources.0.status.initContainerStatuses|length > 0
+        and init_pod_status.resources.0.status.initContainerStatuses.0.started|bool
+
     - include_tasks: test_copy_errors.yml
     - include_tasks: test_check_mode.yml
     - include_tasks: test_copy_file.yml
@@ -25,6 +42,7 @@
     - include_tasks: test_copy_directory.yml
     - include_tasks: test_copy_large_file.yml
     - include_tasks: test_copy_item_with_space_in_its_name.yml
+    - include_tasks: test_init_container_pod.yml
 
   always:
 

tests/integration/targets/k8s_copy/tasks/test_copy_errors.yml

@@ -67,3 +67,21 @@
     that:
       - copy_fake_container is failed
       - copy_fake_container.msg == "Pod has no container this_is_a_fake_container"
+
+# copy file to not started container in pod should fail
+- name: copy file to not started container in pod should fail
+  k8s_cp:
+    namespace: '{{ copy_namespace }}'
+    pod: '{{ pod_with_initcontainer_and_container.name }}'
+    remote_path: /tmp
+    local_path: files/simple_file.txt
+    state: to_pod
+    container: '{{ pod_with_initcontainer_and_container.container[1] }}'
+  ignore_errors: true
+  register: copy_not_started_container
+
+- name: check that error message is as expected
+  assert:
+    that:
+      - copy_not_started_container is failed
+      - copy_not_started_container.msg == "Pod container {{ pod_with_initcontainer_and_container.container[1] }} is not started"

tests/integration/targets/k8s_copy/tasks/test_init_container_pod.yml

@@ -0,0 +1,25 @@
+---
+- set_fact:
+    random_content: "{{ lookup('password', '/dev/null chars=ascii_lowercase,digits,punctuation length=128') }}"
+
+- name: Copy content into init container
+  k8s_cp:
+    namespace: '{{ copy_namespace }}'
+    pod: '{{ pod_with_initcontainer_and_container.name }}'
+    remote_path: /file_from_localhost.txt
+    content: '{{ random_content }}'
+    container: '{{ pod_with_initcontainer_and_container.container[0] }}'
+    state: to_pod
+
+- name: Get the content from copied file
+  kubernetes.core.k8s_exec:
+    namespace: '{{ copy_namespace }}'
+    pod: '{{ pod_with_initcontainer_and_container.name }}'
+    container: '{{ pod_with_initcontainer_and_container.container[0] }}'
+    command: cat /file_from_localhost.txt
+  register: exec_out
+
+- name: check that content is found and the same as generated earlier
+  assert:
+    that:
+      - exec_out.stdout == random_content

tests/integration/targets/k8s_copy/templates/pods_definition_init.j2

@@ -0,0 +1,20 @@
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: '{{ pod_with_initcontainer_and_container.name }}'
+spec:
+  initContainers:
+  - name: '{{ pod_with_initcontainer_and_container.container[0] }}'
+    image: busybox
+    command:
+      - /bin/sh
+      - -c
+      - while true;do date;sleep 5; done
+  containers:
+  - name: '{{ pod_with_initcontainer_and_container.container[1] }}'
+    image: busybox
+    command:
+      - /bin/sh
+      - -c
+      - while true;do date;sleep 5; done