---
- name: Ensure older Docker versions aren't installed.
  apt:
    name:
      - docker
      - docker-engine
      - docker.io
      - containerd
      - runc
    state: absent

- name: Add Docker GPG key.
  apt_key:
    url: https://download.docker.com/linux/ubuntu/gpg
    state: present

- name: Add Docker PPA.
  apt_repository:
    # https://gist.github.com/rbq/886587980894e98b23d0eee2a1d84933
    repo: deb [arch=amd64] https://download.docker.com/{{ ansible_system | lower }}/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable
    state: present

- name: Install Docker, docker-compose & cron.
  apt:
    name:
      - docker-ce
      - docker-ce-cli
      - containerd.io
      - docker-compose
      - cron
    state: present

- name: Ensure Docker is running & enabled.
  service:
    name: docker
    state: started
    enabled: true

- name: Add Docker prune cronjob.
  cron:
    name: Prune the Docker system.
    hour: 4
    minute: 0
    job: docker system prune -af