- Ansible Playbook Essentials
- Gourav Shah
- 278字
- 2021-07-16 20:47:49
Creating the www playbook
We created a site-wide playbook and used an include statement to call another playbook by the name www.yml. We will now create this file with one play, which maps our web server hosts to the Nginx role:
---
#www.yml : playbook for web servers
- hosts: www
remote_user: vagrant
sudo: yes
roles:
- nginx
The above code works as follows:
- Run this code on any host that maps to the
[www]group specified in the hosts file. - For each directory inside the
roles/nginx/*file, includeroles/nginx/*/main.ymlto the play. This includestasks,handlers,vars,meta,default,and so on. This is where the auto include rules apply.
The default and custom role paths
By default, Ansible looks inside the roles/ subdirectory of the project that we create playbooks for. Being top-class devops engineers, we will follow the best practice to have a centralized, version-controlled repository to store all your roles. We may also end up reusing the roles created by community. Once we do this, we can reuse these roles across multiple projects. In such cases, we will check out the code at one or more locations, for example:
/deploy/ansible/roles/deploy/ansible/community/roles
For nondefault paths, we will need to add the roles_path parameter to ansible.cfg as shown in the following command:
roles_path = /deploy/ansible/roles:/deploy/ansible/community/roles
Parameterizing the roles
At times, we may need to override default parameters specified inside vars or the default directory of a role, for example, running web servers on port 8080 instead of 80. In such cases, we can also pass parameters to roles in the preceding playbook, as follows:
---
#www.yml : playbook for web servers
- hosts: www
roles:
- { role: nginx, port: 8080 }