Ansible/Roles

Playbook Roles

What are Ansible roles?

Roles allow you to split your playbook into different parts for different servers.

For example, a webapp with a database backend can define a webserver role and a database role, and it becomes much easier to modify the playbook to run these on the same host or on different hosts.

Feature: pre-tasks and post-tasks

In the playbook you can specify a pre-task and a post-task for a role.

For example, suppose you want to update aptitude before deploying the web server, and you want to send a notification to Slack when you are finished.

Then you could use the following playbook, which defines a pre_tasks list of things to do before the roles are defined, and a post_task list of things to do once the roles have been carried out.

- name: deploy mezzanine on vagrant
  hosts: web
  vars_files:
    - secrets.yml
  pre_tasks:
    - name: update the apt cache
      apt: update_cache=yes
  roles:
    - role: mezzanine
      database_host: "{{ hostvars.db.ansible_eth1.ipv4.address }}"
      live_hostname: 192.168.33.10.xip.io
      domains:
        - 192.168.33.10.xip.io
        - www.192.168.33.10.xip.io
  post_tasks:
    - name: notify Slack that the servers have been updated
      local_action: >
        slack
        domain=acme.slack.com
        token={{ slack_token }}
        msg="web server {{ inventory_hostname }} configured"