Docker Host

This role installs and configures Docker CE on Red Hat Enterprise Linux and CentOS 7 hosts. It also installs firewalld services and TLS certificates for Docker.

Requirements

This role requires Ansible 2.2 or higher, and platform requirements are listed in the metadata file.

Role Variables

The variables that can be passed to this role and a brief description about them are as follows.

# The Docker edition: docker-ce or docker-ee
# For docker-ce, a variant can be specified: stable, edge, test
docker_edition: 'docker-ce'
docker_ce_variant: 'stable'

# Host path to install TLS certificate files
docker_certs_dir: '~/docker'

# Source paths for TLS certificate files
docker_tlscacert: 'files/ca.pem'
docker_tlscert: 'cert.pem'
docker_tlskey: 'key.pem'

# Enable the Docker remote API and firewalld service
# 2375/tcp, 2376/tcp
enable_remote_api: true

# Enable firewalld service for overlay networks
# 4789/udp, 7946/tcp, 7946/udp
enable_swarm_overlay_networks: true

# Enable firewalld service for default published service ports
# 30000-32767/tcp
enable_swarm_service_ports: true

# Enable firewalld service for swarm manager ports
# 2377/tcp
enable_swarm_manager_ports: true

# Disable contacting legacy registries
dockerd_disable_legacy_registry: true

In addition to the defined variables, this role will also process any variable starting with dockerd_ into Docker daemon options, writing them into a daemon.json configuration file. Variables are processed by removing the leading dockerd_ and replacing _ characters with -. The following is an example of dockerd_ options and the resulting daemon.json configuration.

Playbook Variables:

dockerd_disable_legacy_registry: true
dockerd_experimental: true
dockerd_hosts:
  - unix:///var/run/docker.sock
  - tcp://0.0.0.0:2376
dockerd_metrics_addr: 0.0.0.0:9323

Daemon Configuration:

{
    "disable-legacy-registry": true,
    "experimental": true,
    "hosts": [
        "unix:///var/run/docker.sock",
        "tcp://0.0.0.0:2376"
    ],
    "metrics-addr": "0.0.0.0:9323"
}

Example Playbook

The following example sets up a Docker host with Docker CE (edge variant) and experimental mode enabled.

- hosts: all
  roles:
    - role: ucalgary.docker-host
      docker_ce_variant: 'edge'
      dockerd_experimental: true

License

Apache 2

Author Information

King Chung Huang