---
- name: Update Docker Daemon configuration to use Docker Mirror
  hosts: all
  become: yes
  tasks:   
    - name: Read current Docker daemon.json
      ansible.builtin.slurp:
        src: /etc/docker/daemon.json
      register: current_daemon_json

    - name: Parse current Docker daemon.json
      set_fact:
        current_daemon_config: "{{ current_daemon_json['content'] | b64decode | from_json }}"

    - name: Check current registry-mirrors setting
      set_fact:
        registry_mirrors_current: "{{ current_daemon_config['registry-mirrors'] | default('not_set') }}"

    - name: Update Docker daemon.json with registry-mirrors configuration if registry-mirrors not set or not equals
      ansible.builtin.copy:
        dest: /etc/docker/daemon.json
        content: "{{ updated_daemon_json | to_nice_json }}"
      vars:
        registry_config: {
            "registry-mirrors": ["https://dim.servercow.com"]
        }
        updated_daemon_json: "{{ current_daemon_config | combine(registry_config) }}"
      when: registry_mirrors_current != 'https://dim.servercow.com' or log is undefined
      register: daemon_update

    - name: Restart Docker to apply changes
      ansible.builtin.systemd:
        name: docker
        state: restarted
      when: daemon_update.changed