Docker Engine

{
  "become": true,
  "docker_user": "ubuntu",
  "enable_buildx": true
}

---
# User added to the docker group so they can run docker without sudo.
docker_user: ubuntu
# Install docker-buildx-plugin alongside the compose plugin.
enable_buildx: true
# Elevate to root via sudo.
become: true

---
# Rendered from template: Docker Engine
- name: Install Docker Engine
  hosts: all
  become: true
  gather_facts: false
  tasks:
    - name: Bootstrap Python if missing
      ansible.builtin.raw: |
        if command -v python3 >/dev/null 2>&1; then
          echo 'python3 present'
          exit 0
        fi
        if command -v apt-get >/dev/null 2>&1; then
          export DEBIAN_FRONTEND=noninteractive
          apt-get update -y
          apt-get install -y python3
          echo 'python3 installed'
          exit 0
        fi
        echo 'python3 missing and apt-get is unavailable' >&2
        exit 1
      register: bootstrap_python
      changed_when: "'python3 installed' in bootstrap_python.stdout"
    - name: Gather facts after Python bootstrap
      ansible.builtin.setup:
    - name: Detect upstream Debian/Ubuntu distro id for Docker repo
      ansible.builtin.shell: |
        set -e
        . /etc/os-release
        if [ "$ID" = "ubuntu" ] || [ "$ID" = "debian" ]; then
          echo "$ID"
        elif echo "${ID_LIKE:-}" | grep -qw ubuntu; then
          echo ubuntu
        elif echo "${ID_LIKE:-}" | grep -qw debian; then
          echo debian
        else
          echo "unsupported: $ID" >&2; exit 1
        fi
      register: docker_distro_id
      changed_when: false
      when: ansible_os_family == 'Debian'
    - name: Detect upstream Debian/Ubuntu codename for Docker repo
      ansible.builtin.shell: |
        set -e
        . /etc/os-release
        if [ -n "${UBUNTU_CODENAME:-}" ]; then
          echo "$UBUNTU_CODENAME"
        elif [ -n "${DEBIAN_CODENAME:-}" ]; then
          echo "$DEBIAN_CODENAME"
        elif [ "$ID" = "ubuntu" ] || [ "$ID" = "debian" ]; then
          echo "${VERSION_CODENAME:-}"
        else
          echo "${VERSION_CODENAME:-}"
        fi
      register: docker_distro_codename
      changed_when: false
      when: ansible_os_family == 'Debian'
    - name: Install prerequisites
      ansible.builtin.apt:
        name: [ca-certificates, curl, gnupg, lsb-release]
        state: present
        update_cache: true
      when: ansible_os_family == 'Debian'
    - name: Detect Debian package architecture for Docker repo
      ansible.builtin.command: dpkg --print-architecture
      register: docker_deb_arch
      changed_when: false
      when: ansible_os_family == 'Debian'
    - name: Ensure keyrings dir
      ansible.builtin.file:
        path: /etc/apt/keyrings
        state: directory
        mode: '0755'
      when: ansible_os_family == 'Debian'
    - name: Add Docker apt key
      ansible.builtin.get_url:
        url: https://download.docker.com/linux/{{ docker_distro_id.stdout }}/gpg
        dest: /etc/apt/keyrings/docker.asc
        mode: '0644'
        force: true
      when: ansible_os_family == 'Debian'
    - name: Add Docker apt repo
      ansible.builtin.apt_repository:
        repo: >-
          deb [arch={{ docker_deb_arch.stdout }} signed-by=/etc/apt/keyrings/docker.asc]
          https://download.docker.com/linux/{{ docker_distro_id.stdout }}
          {{ docker_distro_codename.stdout }} stable
        filename: docker
        state: present
        update_cache: true
      when: ansible_os_family == 'Debian'
    - name: Install docker packages
      ansible.builtin.apt:
        name:
          - docker-ce
          - docker-ce-cli
          - containerd.io
          - docker-compose-plugin
          - docker-buildx-plugin
        state: present
        update_cache: true
      when: ansible_os_family == 'Debian'
    - name: Enable and start docker
      ansible.builtin.service:
        name: docker
        state: started
        enabled: true
    - name: Add ubuntu to docker group
      ansible.builtin.user:
        name: ubuntu
        groups: docker
        append: true
      when: ansible_os_family == 'Debian'