Ansible role: Docker Swarm

Install and configure docker with swarm

Requirements

• Ansible >= 2.10
• Debian Bookworm

Role variables

Name	Type	Required	Default	Comment
swarm_init	bool	no	false	init the cluster, run once with the ansible option -e swarm_init=true
swarm_manager	bool	no	false	set the cluster role
swarm_advertise_addr	str	no		listen address
swarm_join_token_manager	str	no		join token for manager
swarm_join_token_worker	str	no		join token for worker
swarm_remote_addrs	str	no		manager addresses for slave node
swarm_networks	dict	no		array with the docker networks
swarm_services	dict	no		hash with the service to manage
swarm_registry_logins	dict	no		hash with the registry logins
swarm_proxy_url	str	no		set a proxy url for http and https requests
swarm_proxy_ignore	list(str)	no		array with ignore host or subnet

swarm_networks

Name	Type	Required	Default	Comment
key	str	yes		network name
driver	str	no	overlay	docker drive to use
state	str	no	present	create network if present, or delete if absent

Example:

proxy:
  state: present

swarm_services

Name	Type	Required	Default	Comment
key	str	yes		Service name
image	str	yes		Service image path and tag
args	list(str)	no		List arguments to be passed to the container
mounts	list(dict)	no		List of dictionaries describing the service mounts
networks	list(str)	no		List of the service networks name
publish	list(dict)	no		List of dictionaries describing the service published ports
replicas	int	no	1	Number of containers instantiated in the service
limits	dict	no		Configures service resource limits
env	dict	no		List or dictionary of the service environment variables
container_labels	dict	no		Dictionary of key value pairs.
state	str	no	present

Example:

wordpress:
  image: wordpress:latest
  args:
    - "--api"
  mounts:
    - source: /opt/data
      target: /usr/local/data
      type: bind
  networks:
    - net
  publish:
    - published_port: 80
      target_port: 8000
  replicas: 3
  limits:
    cpus: 0.5
    memory: 100M
  env:
    WORDPRESS_DB_HOST: db:3306
    WORDPRESS_DB_USER: wordpress
    WORDPRESS_DB_PASSWORD: wordpress
  container_labels:
    region: FR
  state: present

swarm_services -> mounts

See all options documentation

Name	Type	Required	Default	Comment
source	str	no		Mount source, must be specified if type is not tmpfs
target	str	yes		Container path
type	str	no	bind	The mount type

swarm_services -> publish

Name	Type	Required	Default	Comment
mode	str	yes		What publish mode to use. ingress or host
protocol	str	no	tcp	What protocol to use. tcp or udp
published_port	int	yes		The port to make externally available
target_port	int	yes		The port inside the container to expose

swarm_services -> limits

Name	Type	Required	Default	Comment
cpus	float	no		Service CPU limit
memory	str	no		Service memory limit in format <number>[<unit>]

swarm_registry_logins

Name	Type	Required	Default	Comment
key	str	yes		registry name
registry_url	str	yes		registry url
registry_username	str	yes		registry username for authentification
registry_password	str	yes		registry password
user	str	no	ansible_user_id

Example:

gitlab:
  registry_url: registry.gitlab.com
  registry_username: myaccount
  registry_password: secret
  user: www-data

How to use

• On the first machine, init cluster ansible-playbook swarm.yml -e swarm_init=true

• Get docker manager and worker join token and set variable docker_swarm_join_token_manager and dockerèswarm_joint_token_worker

  docker swarm join-token manager -q
  docker swarm join-token worker -q
  

• Run playbook normally on other machine

- hosts: server
  roles:
    - swarm
  swarm_manager: true
  swarm_remote_addrs:
    - 192.168.0.1
    - 192.168.0.2
    - 192.168.0.3
  swarm_init: true
  swarm_join_token_worker: SWMTKN-1-2z1gzk9jdbpfw1paskodk6zc1fm5g0n5c293oz1taqii310a8u-1mjm55313up7tiksb0s3nr9lr
  swarm_join_token_manager: SWMTKN-1-2z1gzk9jdbpfw1paskodk6zc1fm5g0n5c293oz1taqii310a8u-5644pyqmiexexfke6e1ycn11z
  swarm_networks:
    proxy:
      driver: overlay
      scope: swarm
  swarm_services:
    traefik:
      image: traefik:3.0
      networks:
        - proxy
      args:
        - "--providers.swarm=true"
        - "--providers.swarm.network=proxy"
        - "--entrypoints.http.address=:80"
      publish:
        - published_port: 80
          target_port: 80
      mounts:
        - source: /var/run/docker.sock
          target: /var/run/docker.sock

Development

Test with molecule and docker

• install docker
• install python3 and python3-pip
• install molecule and dependencies pip3 install molecule 'molecule[docker]' docker ansible-lint testinfra yamllint
• run molecule test

License

Copyright (c) 2018 Adrien Waksberg

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.