The `k8s_cp` module doesn't support initContainers

[spatterIight]

SUMMARY

The k8s_cp module doesn't support initContainers. When specifying the container parameter value as the name of an initContainer it still fails with the error: Pod has no container container-name

ISSUE TYPE

• Bug Report

COMPONENT NAME

k8s_cp

ANSIBLE VERSION

ansible [core 2.18.1]
  config file = /home/x1/Documents/deployment/ansible.cfg
  configured module search path = ['/home/x1/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /home/x1/Documents/deployment/collections-galaxy
  executable location = /usr/bin/ansible
  python version = 3.13.3 (main, Jun 16 2025, 18:15:32) [GCC 14.2.0] (/usr/bin/python3)
  jinja version = 3.1.5
  libyaml = True

COLLECTION VERSION

  - name: kubernetes.core.git
    type: git
    version: 6.0.0

STEPS TO REPRODUCE

- name: Copy local tiledata to remote
  delegate_to: 127.0.0.1
  kubernetes.core.k8s_cp:
    local_path: "{{ tileserver_gl_tiledata_local_directory }}/{{ tileserver_gl_tiledata_local_filename }}"
    namespace: "{{ tileserver_gl_helm_namespace }}"
    pod: "{{ selected_tileserver_gl_pods.metadata.name }}"
    container: "tileserver-gl-init"
    remote_path: "{{ tileserver_gl_tiledata_temp_remote_path }}"
    no_preserve: true
  tags: tileserver-gl

EXPECTED RESULTS

I expected the module to copy data into initContainers the same as normal containers.

ACTUAL RESULTS

The task failed with the error Pod has no container container-name

TASK [role : Copy local data to remote] ************************************************************************************
fatal: [node-01 -> 127.0.0.1]: FAILED! => 
    changed: false
    msg: Pod has no container container-name

[yurnov]

It's probably due to the fact that cp operation will work only for running container and will not work (and it's not supported by Kubernetes) for container that is not running (i.e. completed or not started yet).

You try kubectl cp -n <namespace> <localfilename> <pod-name>:<destination-initContainer>:<destination-path> and most probably you will have the same/similar error. And than you can check kubectl describe -n <namespace> <pod-name> to see that initContainer not running (compleated, most probably)

[spatterIight]

It's probably due to the fact that cp operation will work only for running container and will not work (and it's not supported by Kubernetes) for container that is not running (i.e. completed or not started yet).

You try kubectl cp -n <namespace> <localfilename> <pod-name>:<destination-initContainer>:<destination-path> and most probably you will have the same/similar error. And than you can check kubectl describe -n <namespace> <pod-name> to see that initContainer not running (compleated, most probably)

Thanks for the quick response! Interestingly kubectl cp commands work just fine! For example:

- name: Copy local tiledata to remote using kubectl
  delegate_to: 127.0.0.1
  ansible.builtin.shell: |
    kubectl cp "{{ tileserver_gl_tiledata_local_directory }}/{{ tileserver_gl_tiledata_local_filename }}" \
    "{{ tileserver_gl_helm_namespace }}/{{ selected_tileserver_gl_pods.metadata.name }}:{{ tileserver_gl_tiledata_temp_remote_path }}" \
    -c tileserver-gl-init
  tags: tileserver-gl

This worked without an error.

And than you can check kubectl describe -n to see that initContainer not running (compleated, most probably)

In this case the initContainer will not complete until the data is copied into it, so it is awaiting a successful cp operation.

[spatterIight]

Here is a basic playbook demonstrating the bug:

---
- name: Reproduce k8s_cp initContainer Issue
  hosts: k8_clusters_master
  connection: local
  become: false
  gather_facts: true
  environment:
    KUBECONFIG: "{{ kubeconfig_file_path }}"
  vars:
    namespace: "default"
    pod_name: "test-pod-with-initcontainer"
    init_container_name: "init-container"
    main_container_name: "main-container"
    test_file_local: "/tmp/test-file.txt"
    test_file_remote: "/tmp/test-file-remote.txt"
  tasks:
    - block:
      - name: Create test file locally
        ansible.builtin.copy:
          content: |
            This is a test file for reproducing the k8s_cp initContainer issue.
            Timestamp: {{ ansible_date_time.iso8601 }}
          dest: "{{ test_file_local }}"

      - name: Deploy pod with initContainer that waits for file
        kubernetes.core.k8s:
          definition:
            apiVersion: v1
            kind: Pod
            metadata:
              name: "{{ pod_name }}"
              namespace: "{{ namespace }}"
            spec:
              initContainers:
                - name: "{{ init_container_name }}"
                  image: busybox:latest
                  command: ["/bin/sh"]
                  args:
                    - "-c"
                    - |
                      echo "Init container started, waiting for file..."
                      # Wait for the file to be copied
                      while [ ! -f "{{ test_file_remote }}" ]; do
                        echo "Waiting for file {{ test_file_remote }}..."
                        sleep 5
                      done
                      echo "File received! Init container completing..."
                      cat "{{ test_file_remote }}"
                  volumeMounts:
                    - name: shared-data
                      mountPath: /tmp
              containers:
                - name: "{{ main_container_name }}"
                  image: busybox:latest
                  command: ["/bin/sh"]
                  args:
                    - "-c"
                    - |
                      echo "Main container started"
                      # Check if init container completed successfully
                      if [ -f "{{ test_file_remote }}" ]; then
                        echo "Init container succeeded - file exists"
                        cat "{{ test_file_remote }}"
                      else
                        echo "Init container may have failed - file not found"
                      fi
                      # Keep container running for testing
                      sleep 300
                  volumeMounts:
                    - name: shared-data
                      mountPath: /tmp
              volumes:
                - name: shared-data
                  emptyDir: {}

      - name: Wait for pod to be created
        kubernetes.core.k8s_info:
          api_version: v1
          kind: Pod
          name: "{{ pod_name }}"
          namespace: "{{ namespace }}"
          wait: true
          wait_condition:
            type: PodScheduled
            status: "True"
          wait_timeout: 60

      - name: Get pod info
        kubernetes.core.k8s_info:
          api_version: v1
          kind: Pod
          name: "{{ pod_name }}"
          namespace: "{{ namespace }}"
        register: pod_info

      - name: Display pod status
        ansible.builtin.debug:
          msg: |
            Pod Phase: {{ pod_info.resources[0].status.phase }}
            Init Container Status: {{ pod_info.resources[0].status.initContainerStatuses[0].state }}

      - name: Wait for initContainer to be running
        kubernetes.core.k8s_info:
          api_version: v1
          kind: Pod
          name: "{{ pod_name }}"
          namespace: "{{ namespace }}"
        register: pod_status
        until: pod_status.resources[0].status.initContainerStatuses[0].state.running is defined
        retries: 12
        delay: 5

      - name: Display current initContainer state
        ansible.builtin.debug:
          msg: "Init container is now running and waiting for file"

      # THIS IS THE FAILING CASE - k8s_cp with initContainer
      - name: "[BUG REPRODUCTION] Try to copy file using k8s_cp to initContainer"
        kubernetes.core.k8s_cp:
          local_path: "{{ test_file_local }}"
          namespace: "{{ namespace }}"
          pod: "{{ pod_name }}"
          container: "{{ init_container_name }}"
          remote_path: "{{ test_file_remote }}"
          no_preserve: true
        register: k8s_cp_result
        failed_when: false  # Don't fail the playbook on this expected failure

      - name: Display k8s_cp result (expected to fail)
        ansible.builtin.debug:
          msg: |
            k8s_cp Result: {{ k8s_cp_result }}
            Expected Error: "Pod has no container {{ init_container_name }}"

      # THIS IS THE WORKING CASE - kubectl cp with initContainer
      - name: "[WORKAROUND] Copy file using kubectl cp to initContainer"
        ansible.builtin.shell: |
          kubectl cp "{{ test_file_local }}" \
          "{{ namespace }}/{{ pod_name }}:{{ test_file_remote }}" \
          -c "{{ init_container_name }}"
        register: kubectl_cp_result

      - name: Display kubectl cp result (should work)
        ansible.builtin.debug:
          msg: |
            kubectl cp Result: {{ kubectl_cp_result }}
            Return Code: {{ kubectl_cp_result.rc }}

      - name: Wait for pod to complete initialization
        kubernetes.core.k8s_info:
          api_version: v1
          kind: Pod
          name: "{{ pod_name }}"
          namespace: "{{ namespace }}"
        register: final_pod_status
        until: final_pod_status.resources[0].status.phase == "Running"
        retries: 12
        delay: 5

      - name: Verify file was copied successfully
        kubernetes.core.k8s_exec:
          namespace: "{{ namespace }}"
          pod: "{{ pod_name }}"
          container: "{{ main_container_name }}"
          command: cat "{{ test_file_remote }}"
        register: file_content

      - name: Display copied file content
        ansible.builtin.debug:
          msg: |
            File successfully copied to initContainer and available in main container:
            {{ file_content.stdout }}

      # Test k8s_cp with main container (should work)
      - name: "[COMPARISON] Test k8s_cp with main container (should work)"
        kubernetes.core.k8s_cp:
          local_path: "{{ test_file_local }}"
          namespace: "{{ namespace }}"
          pod: "{{ pod_name }}"
          container: "{{ main_container_name }}"
          remote_path: "/tmp/test-file-main.txt"
          no_preserve: true
        register: main_container_cp_result

      - name: Display main container k8s_cp result
        ansible.builtin.debug:
          msg: |
            k8s_cp with main container: {{ main_container_cp_result.changed }}
            This should work fine, demonstrating the issue is specific to initContainers

      always:
        - name: Clean up test pod
          kubernetes.core.k8s:
            state: absent
            api_version: v1
            kind: Pod
            name: "{{ pod_name }}"
            namespace: "{{ namespace }}"
          ignore_errors: true

        - name: Clean up local test file
          ansible.builtin.file:
            path: "{{ test_file_local }}"
            state: absent
          ignore_errors: true

Output:

PLAY [Reproduce k8s_cp initContainer Issue] *********************************************************************************************

TASK [Gathering Facts] ******************************************************************************************************************
ok: [node]

TASK [Create test file locally] *********************************************************************************************************
changed: [node]

TASK [Deploy pod with initContainer that waits for file] ********************************************************************************
changed: [node]

TASK [Wait for pod to be created] *******************************************************************************************************
ok: [node]

TASK [Get pod info] *********************************************************************************************************************
ok: [node]

TASK [Display pod status] ***************************************************************************************************************
ok: [node] => 
    msg: |-
        Pod Phase: Pending
        Init Container Status: {'waiting': {'reason': 'PodInitializing'}}

TASK [Wait for initContainer to be running] *********************************************************************************************
ok: [node]

TASK [Display current initContainer state] **********************************************************************************************
ok: [node] => 
    msg: Init container is now running and waiting for file

TASK [[BUG REPRODUCTION] Try to copy file using k8s_cp to initContainer] ****************************************************************
ok: [node]

TASK [Display k8s_cp result (expected to fail)] *****************************************************************************************
ok: [node] => 
    msg: |-
        k8s_cp Result: {'failed': False, 'msg': 'Pod has no container init-container', 'changed': False, 'failed_when_result': False}
        Expected Error: "Pod has no container init-container"

TASK [[WORKAROUND] Copy file using kubectl cp to initContainer] *************************************************************************
changed: [node]

TASK [Display kubectl cp result (should work)] ******************************************************************************************
ok: [node] => 
    msg: |-
        kubectl cp Result: {'changed': True, 'stdout': '', 'stderr': '', 'rc': 0, 'cmd': 'kubectl cp "/tmp/test-file.txt" "default/test-pod-with-initcontainer:/tmp/test-file-remote.txt" -c "init-container"\n', 'start': '2025-07-15 12:47:11.642161', 'end': '2025-07-15 12:47:12.210218', 'delta': '0:00:00.568057', 'msg': '', 'stdout_lines': [], 'stderr_lines': [], 'failed': False}
        Return Code: 0

TASK [Wait for pod to complete initialization] ******************************************************************************************
FAILED - RETRYING: [node]: Wait for pod to complete initialization (12 retries left).
ok: [node]

TASK [Verify file was copied successfully] **********************************************************************************************
changed: [node]

TASK [Display copied file content] ******************************************************************************************************
ok: [node] => 
    msg: |-
        File successfully copied to initContainer and available in main container:
        This is a test file for reproducing the k8s_cp initContainer issue.
        Timestamp: 2025-07-15T16:47:02Z

TASK [[COMPARISON] Test k8s_cp with main container (should work)] ***********************************************************************
changed: [node]

TASK [Display main container k8s_cp result] *********************************************************************************************
ok: [node] => 
    msg: |-
        k8s_cp with main container: True
        This should work fine, demonstrating the issue is specific to initContainers

TASK [Clean up test pod] ****************************************************************************************************************
changed: [node]

TASK [Clean up local test file] *********************************************************************************************************
changed: [node]

PLAY RECAP ******************************************************************************************************************************
node            : ok=19   changed=7    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

[yurnov]

Needs to be investigated https://github.com/ansible-collections/kubernetes.core/blob/main/plugins/module_utils/copy.py#L119

[yorick1989]

To get familiar with this collection I'd pick up this issue and created a fix in the PR 971. Please, check if this resolved the issue for you. It still need to be reviewed, but a small test from others never hurts =).

Grtz,

Yorick

[spatterIight]

To get familiar with this collection I'd pick up this issue and created a fix in the PR 971. Please, check if this resolved the issue for you. It still need to be reviewed, but a small test from others never hurts =).

Grtz,

Yorick

Will do, thank you for the hard work