akkerman.swarm

Ansible Role for Docker Swarm

Configures docker swarm on ubuntu bionic.

Requirements

None

Role Variables

Role variables with their defaults:

docker_swarm_leader: "{{ groups['docker_swarm_managers'][0] }}"
docker_swarm_interface: "eth1"

The first entry in the inventory group docker_swarm_managers will be the one that's initialized first and all subsequent managers and workers will join. When changing this, make sure the node is also in the docker_swarm_mangers for consistency.

The ipv4 address will be gathered from the ethernet interface specified by docker_swarm_interface. This is the address the docker_swarm_leader will listen on and should be reachable by all other nodes that want to join the cluster. Check the docker swarm documentation, to know about open protocols and ports between the hosts.

Dependencies

None, just make sure that:

Docker is installed
The user running the playbook belongs to docker group (or specify become: yes in the playbook)

Example Playbook

---
- hosts: all
    roles:
        - akkerman.swarm

Example inventory

[docker_swarm_managers]
node-0

[docker_swarm_workers]
node-1
node-2

A minimum of one host should be in the docker_swarm_managers group. The role only changes the host if the swarm on that node is inactive, i.e. you cannot move a node to another group and expect the cluster to adapt.