There are a few different ways to invoke one or more roles in a playbook.

• roles (this article)
• import_playbook
• import_role
• include_role
• include_tasks
• import_tasks

With roles, you will need to create the roles directories, subdirectories, and files. You can:

• Use the ansible-galaxy init command to create the roles files and directories
• Use the ansible-galaxy install command to create the roles files and directories
• Use the git clone command to create the roles files and directories
• Manually create the roles files and directories

Here is an example of the directory structure used with roles.

├── /usr/local
│   ├── main.yml
│   ├── roles
│   │   ├── foo
│   │   ├── ├── defaults
│   │   ├── ├── ├── main.yml
│   │   ├── ├── files
│   │   ├── ├── ├── main.yml
│   │   ├── ├── handlers
│   │   ├── ├── ├── main.yml
│   │   ├── ├── meta
│   │   ├── ├── ├── main.yml
│   │   ├── ├── tasks
│   │   ├── ├── ├── main.yml
│   │   ├── ├── templates
│   │   ├── ├── ├── main.yml
│   │   ├── ├── vars
│   │   ├── ├── ├── main.yml

Where should the "roles" files and directories reside?

Let's say your playbook wants to use the "foo" role.

---
- hosts: all
  roles:
    - foo
...

Or like this.

---
- hosts: all
  roles:
    - role: foo
...

Ansible will search the following directories for the "foo" role:

• The directory that contains your playbook (e.g. /home/john.doe/)
• /etc/ansible/roles/

Let's say you define some other roles_path in ansible.cfg.

roles_path = /usr/local/ansible/roles

Or using the ANSIBLE_ROLES_PATH variable.

export ANSIBLE_ROLES_PATH=/usr/local/ansible/roles

Now Ansible will search the following directories for the "foo" role:

• The directory that contains your playbook (e.g. /home/john.doe/)
• /usr/local/ansible/roles

It is noteworthy that if you have a role that resides in some other directory, say /usr/local/testing/roles, the role can be used by including the absolute path to the role in your playbook.

---
- hosts: all
  roles:
    - /usr/local/testing/roles/foo
...

It is also possible to pull in roles from a Git repository.

Variables

Each role can have it's own unique set of variables. Refer to Role Variables.

pre_tasks and post_tasks

When using the roles module, tasks will be performed in this order:

• pre_tasks
• If the pre_tasks include the notify module, the handlers will be run. 
• If the role contains any dependencies, the dependencies will be run.
• tasks
• If the tasks include the notify module, the handlers will be run. 
• post_tasks
• If the post_tasks include the notify module, the handlers will be run. 

Perform tasks on the control node

Refer to run tasks on the control node if you want to run this module on your control node.