Role Name

An Ansible role for bootstrapping a consul cluster on docker hosts.

Requirements

A respectably recent version of Docker should be already installed on the target machine.

Role Variables

consul_hostname: server-1.my.company.lan
consul_command: -server -advertise {{ ansible_default_ipv4['address'] }} -bootstrap-expect 3

The consul_command can be any valid consul command. You might want to bootstrap the primary server with this command:

consul_command: "-server -advertise {{ ansible_default_ipv4['address'] }} -bootstrap-expect 3"

and then start the secondary servers with this command:

consul_command: "-server -advertise {{ ansible_default_ipv4['address'] }} -join {{ hostvars[groups['docker_cluster_primary'][0]]['ansible_default_ipv4']['address'] }}"

where the join IP is the IP of the first consul instance.

Dependencies

This role requires the emmetog.docker-compose role since docker-compose is used to start the consul services.

Usage

First install the role from ansible galaxy:

$ ansible-galaxy install emmetog.consul

Then use the role in a playbook as follows:

- hosts: server_primary
  roles:
     - {
        role: emmetog.consul,
        consul_command: "-server -advertise {{ ansible_default_ipv4['address'] }} -bootstrap-expect 3"
     }
- hosts: server_secondaries
  roles:
     - {
        role: emmetog.consul,
        consul_command: "-server -advertise {{ ansible_default_ipv4['address'] }} -join {{ hostvars[groups['server_primary'][0]]['ansible_default_ipv4']['address'] }}"
     }

In reality you can use any consul command you want to, the example above will get you started with a simple consul cluster.

For example, you could alternatively set up a single consul instance using this:

- hosts: server_primary
  roles:
     - {
        role: emmetog.consul,
        consul_command: "-server -advertise {{ ansible_default_ipv4['address'] }} -bootstrap"
     }

License

MIT

Author Information

Made with love by Emmet O'Grady.

I am the founder of NimbleCI which builds Docker containers for feature branch workflow projects in Github.

I blog on my personal blog and about Docker related things on the NimbleCI blog.