---
id: MOD-002
type: module
status: active
title: Docker Role
created: 2026-09-09
updated: 2026-09-09
tags: [module, docker, ansible]
related: [MOD-001, MOD-006, REQ-002]
source_paths:
- roles/docker/
confidence: confirmed
---

# Docker Role

## Responsibility

Install Docker Engine from the official Docker apt repository.

## Source Paths

- `roles/docker/tasks/main.yml` → `install-docker.yml`
- Template: `roles/docker/templates/sources.list.j2`
- Handlers: `roles/docker/handlers/main.yml`

## Public Interfaces

- Playbook: `playbooks/docker.yml`
- Defaults: `docker_mirror` (download.docker.com/linux/debian),
  `os_version_codename` (derived from `ansible_facts['distribution_release']`),
  `docker_packages` (docker-ce, docker-ce-cli, containerd.io, buildx and
  compose plugins).

## Important Flows

1. Set up the official Docker apt repository (key + `sources.list.j2`).
2. Install `docker_packages` (handlers restart the service when needed).

## Dependencies

- Used standalone (`playbooks/docker.yml`) and composed by
  [bootstrap](./MOD-001-bootstrap-role.md). Prerequisite for
  [hawser](./MOD-006-hawser-role.md).

## Tests

- None automated.

## Notes For Agents

- Codename comes from host facts; no LXC-specific handling observed.