---
- name: Move Docker data-root to /data/docker
  hosts: google-sdk
  become: true
  vars:
    new_docker_root: /data/docker
    old_docker_root: /var/lib/docker
  tasks:
    - name: Ensure rsync installed
      package:
        name: rsync
        state: present

    - name: Stop Docker service
      service:
        name: docker
        state: stopped
      ignore_errors: true

    - name: Create new data root
      file:
        path: "{{ new_docker_root }}"
        state: directory
        mode: '0755'

    - name: Check old docker root exists
      stat:
        path: "{{ old_docker_root }}"
      register: old_docker_root_stat

    - name: Sync old data to new root (if old exists)
      command: rsync -aHAX --numeric-ids --delete {{ old_docker_root }}/ {{ new_docker_root }}/
      when: old_docker_root_stat.stat.exists
      args:
        warn: false

    - name: Backup old directory
      command: mv {{ old_docker_root }} {{ old_docker_root }}.bak
      args:
        creates: "{{ old_docker_root }}.bak"
      when: old_docker_root_stat.stat.exists

    - name: Ensure /etc/docker exists
      file:
        path: /etc/docker
        state: directory
        mode: '0755'

    - name: Write daemon.json
      copy:
        dest: /etc/docker/daemon.json
        mode: '0644'
        content: |
          {
            "data-root": "{{ new_docker_root }}",
            "storage-driver": "overlay2",
            "log-driver": "json-file",
            "log-opts": { "max-size": "10m", "max-file": "3" }
          }

    - name: Start Docker
      service:
        name: docker
        state: started
        enabled: true

    - name: Verify root dir
      command: docker info --format '{% raw %}{{json .DockerRootDir}}{% endraw %}'
      register: docker_root
      changed_when: false

    - name: Show result
      debug:
        msg: "DockerRootDir = {{ docker_root.stdout }}"

    - name: Fail if not moved
      fail:
        msg: "迁移失败，当前仍是旧目录"
      when: docker_root.stdout.find(new_docker_root) == -1