Ansible Role: Docker

An Ansible Role that installs Docker on Linux.

Requirements

None.

Role Variables

Available variables are listed below, along with default values (see defaults/main.yml):

# Edition can be one of: 'ce' (Community Edition) or 'ee' (Enterprise Edition).
docker_edition: 'ce'
docker_package: "docker-{{ docker_edition }}"
docker_package_state: present

The docker_edition should be either ce (Community Edition) or ee (Enterprise Edition). You can also specify a specific version of Docker to install using a format like docker-{{ docker_edition }}-<VERSION>. And you can control whether the package is installed, uninstalled, or at the latest version by setting docker_package_state to present, absent, or latest, respectively.

docker_install_compose: true
docker_compose_version: "1.15.0"
docker_compose_path: /usr/local/bin/docker-compose

Docker Compose installation options.

docker_apt_release_channel: stable
docker_apt_repository: "deb https://download.docker.com/linux/{{ ansible_distribution|lower }} {{ ansible_distribution_release }} {{ docker_apt_release_channel }}"

(Used only for Debian/Ubuntu.) You can switch the channel to edge if you want to use the Edge release.

docker_yum_repo_url: https://download.docker.com/linux/centos/docker-{{ docker_edition }}.repo
docker_yum_repo_enable_edge: 0
docker_yum_repo_enable_test: 0

(Used only for RedHat/CentOS.) You can enable the Edge or Test repo by setting the respective vars to 1.

devicemapper

Out of the box this role deploys docker with the overlay driver, but the only officially supported configuration of Docker on RedHat/CentOS is to use device mapper as the storage driver (Not to be confused with docker volume). Docker can configure the lvm thin provisioning when provided a raw block device (such as a second disk). To deploy this configuration, set the following variables in your deploy:

docker_devicemapper_raw_device: /dev/sdb # Or /dev/vdb or ...
docker_configure_daemon: true

For more information, see the device mapper driver documentation.

Docker daemon configuration

To configure devicemapper as the storage driver, this role has to configure the docker daemon via daemon.json, but you can also use this to configure the daemon as you wish by overriding docker_daemon_config. This yaml hash is then converted to json. Making changes to daemon.json then require a restart of the service, but this role does not default to restarting the service. To trigger a restart when reconfiguring the daemon, set docker_restart to true.

Use with Ansible (and docker Python library)

Many users of this role wish to also use Ansible to then build Docker images and manage Docker containers on the server where Docker is installed. In this case, you can easily add in the docker Python library using the geerlingguy.pip role:

- hosts: all

  vars:
    pip_install_packages:
      - name: docker

  roles:
    - geerlingguy.pip
    - geerlingguy.docker

Dependencies

None.

Example Playbook

- hosts: all
  roles:
    - geerlingguy.docker

License

MIT / BSD

Author Information

This role was created in 2017 by Jeff Geerling, author of Ansible for DevOps.