pi-ansible/roles/docker/tasks/services.yml

# vim: ft=yaml.ansible
---
- name: Copy Docker daemon config file
  template:
    src: daemon.json.j2
    dest: /etc/docker/daemon.json
    owner: root
    mode: u=rw,g=r,o=r
  register: daemon_config

- name: (Disable and) start Docker daemon
  service:
    name: "{{ item }}"
    enabled: false
    state: "{{ 'restarted' if daemon_config.changed else 'started' }}"
  loop:
    - docker.socket
    - docker.service

- name: Create base directory for Docker volumes
  file:
    name: "{{ base_volume }}"
    owner: "{{ ansible_user }}"
    mode: u=rwx,g=rx,o=rx
    state: directory

- name: Deploy services
  include_tasks: "services/{{ item.service.file }}"
  loop: "{{ services | dict2items(value_name='service') }}"
  when: single_service is not defined and
        item.service.file is defined

- name: Deploy single service
  include_tasks: "services/{{ services[single_service].file }}"
  when: single_service is defined and
        single_service in services and
        services[single_service].file is defined