Ansible/Separate Playbooks by Role

Separating Playbooks by Role

For Ansible playbooks involving multiple roles, top level playbooks should be separated by role.

Here is the simplest possible top-level playbook, which includes two sub-playbooks:

- import_playbook: webservers.yml
- import_playbook: dbservers.yml

These files are both at the top level, and

Using Separate Playbooks

Now that you have multiple roles split across playbooks, you can either configure your whole infrastructure, by running site.yml with ansible-playbook, or you can configure particular pieces of infrastructure, for example by only running dbservers.yml.

To limit which playbooks are run, either run the whole site-wide playbook with the --limit flag, or run with the sub-playbook:

ansible-playbook site.yml --limit webservers
ansible-playbook webservers.yml

Further Examples of Using Separate Playbooks

If you further separate your tasks (things to do) and handlers (things to do that are triggered by other things being done) by role, you can start to do lots of different things.

To reconfigure all of the infrastructure:

ansible-playbook -i production site.yml

To reconfigure NTP only:

ansible-playbook -i production site.yml --tags ntp

To reconfigure webservers only, use the webservers sub-playbook:

ansible-playbook -i production webservers.yml

To reconfigure webservers in Boston only, use the webservers sub-playbook plus the limit tag for Boston:

ansible-playbook -i production webservers.yml --limit boston

Or, to only reconfigure a certain range of servers in Boston:

ansible-playbook -i production webservers.yml --limit boston[0:9]
ansible-playbook -i production webservers.yml --limit boston[10:19]

Basic ad-hoc stuff:

ansible boston -i production -m ping
ansible boston -i production -m command -a '/sbin/reboot'

Useful Commands

Other useful commands:

# confirm what task names would be run if I ran this command and said "just ntp tasks"
ansible-playbook -i production webservers.yml --tags ntp --list-tasks

# confirm what hostnames might be communicated with if I said "limit to boston"
ansible-playbook -i production webservers.yml --limit boston --list-hosts