playbooks-retailor/roles/docker/README.md

docker

Installs Docker CE from the official Docker apt repository on Ubuntu/Debian.

What changed from the original role

The original role had several bugs that would have made it fail or behave unpredictably:

• tasks/main.yml was dead code that duplicated install.yml incorrectly. Nothing ever included it (only main-distro-check.yml was wired up), and it referenced undefined variables (install_packages, clean_install_remove_packages had no become, etc). It's been replaced by a single real entrypoint.
• install.yml added the apt repo but never fetched the GPG key, so apt-get update would fail signature verification. Key download and repo registration are now in one idempotent flow using get_url + apt_repository instead of raw shell commands.
• check_distro.yml used meta: end_play, which ends the entire Ansible run for all hosts in the play, not just this role/host. This is almost never what you want in a multi-host play. It's replaced with a docker_distro_supported fact that gates subsequent tasks, with an optional hard fail (docker_fail_on_unsupported_distro, default true).
• service.yml had the exact same task listed twice (one with a when guard, one without). Deduplicated into a single task.
• Package state latest was used for prerequisites and Docker itself, which causes unnecessary upgrades (and potential breakage) on every run. Changed to present; use docker_install_packages + your own update strategy if you want upgrades.
• No handler was ever notified. Installing/upgrading Docker packages now notifies the Restart Docker handler.
• docker group creation used the user module to create a "user" named docker, which is not the same as a group and wasn't added to any actual user. Replaced with a proper group task plus a docker_users list you populate to add real users to the group.
• All tasks now use fully-qualified module names (ansible.builtin.*) and name:/state: keyword syntax instead of the deprecated key=value shorthand.

Role variables

See defaults/main.yml for the full list. Commonly overridden:

docker_users:
  - deploy
  - ci

docker_install_packages:
  - docker-ce
  - docker-ce-cli
  - containerd.io
  - docker-buildx-plugin
  - docker-compose-plugin

docker_fail_on_unsupported_distro: true

Example playbook

- hosts: docker_hosts
  become: true
  roles:
    - role: docker
      vars:
        docker_users:
          - "{{ ansible_user }}"

Tags

• docker_check_distro
• docker_install
• docker_users
• docker_service