---
- name: Install Docker 
  # 'all' is okay here, because the fail task will force the user to specify a limit on the command line, using -l or --limit
  hosts: all 
  become: true
  tasks:
    - name: checking limit arg
      fail:
        msg: "you must use -l or --limit - when you really want to use all hosts, use -l 'all'"
      when: ansible_limit is not defined
      run_once: true

    - name: Install required system packages
      apt:
        pkg: 
          - ca-certificates 
          - curl
          - gnupg
          - lsb-release
          - python3-pip
        state: latest
        update_cache: yes
    
    - name: Add Docker GPG Key
      apt_key:
        url: https://download.docker.com/linux/ubuntu/gpg
        state: present

    - name: Add Docker Repository
      apt_repository:
        repo: "deb [arch={{ arch }}] https://download.docker.com/linux/{{ansible_distribution|lower}} {{ansible_distribution_release}} stable"
        state: present

    - name: Install Docker packages
      apt: 
        update_cache: yes
        pkg:
          - docker-ce
          - docker-ce-cli
          - containerd.io

    - name: Install docker-compose using pip 
      pip:
        name:
          - docker-compose

    - name: add user to docker group
      user:
        name: "{{ ansible_user_id }}"
        groups: 
          - docker
        append: yes