ansible/roles/docker/tasks/main.yml

---
- name: Install docker
  package:
    name: 'docker-ce'
    state: present
  notify:
    - Restart Docker

- name: Install docker python module
  package:
    name: 'python2-docker'
    state: present

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

- name: Setup docker container logging settings
  json_mod:
    path: /etc/docker/daemon.json
    key: '' # the whole JSON document per https://tools.ietf.org/html/rfc6901
    # "value" must be wrapped in single quote "'" with extra space in front of "{" (ansible workaround)
    # reference: https://stackoverflow.com/questions/31969872
    value: ' { "log-driver": "json-file", "log-opts": { "max-size": "{{ docker.log_max_size }}", "max-file": "{{ docker.log_max_file }}" } }'

- name: Setup docker dns settings
  json_mod:
    path: /etc/docker/daemon.json
    key: dns
    # "value" must be wrapped in single quote "'" with extra space in front of "[" (ansible workaround)
    # reference: https://stackoverflow.com/questions/31969872
    value: ' [ "{{ hostvars[groups.infrastructure[0]].cluster_ip }}" ]'
  notify:
    - Restart Docker

- name: Force notified handlers to run at this point
  meta: flush_handlers

- name: Ensure docker is started
  systemd:
    name: docker
    state: started
    enabled: yes