Roles

• Roles are a way to organize ansible tasks (not plays) in order to allow them to be reused and easily shared
• They provide a predefined structure that allows to group tasks with variables, templates, files, etc.
• Similar to modules in terraform
• In the playbooks they can be called like:

- hosts: all
  become: true
  roles:
    - myrole

Roles can also be used in a task with import_role. When running with roles ansible will execute the roles after any pre_task but before any other task in the play. When calling it from a task with import_role the order is respected.

Most importantly, import_roles is dynamic, which allows to do things like have variables for the role name, use loops to execute them, skip them.

---
- hosts: webservers
  tasks:
    - name: Print a message
      ansible.builtin.debug:
        msg: "this task runs before the example role"

    - name: Include the example role
      include_role:
        name: example

    - name: Print a message
      ansible.builtin.debug:
        msg: "this task runs after the example role"

Defined Structure

For each role, ansible expect a folder inside the roles directory named as the role (e.g roles/myrole)

Inside each role folder, the following structure is standard:

• tasks to put the taskbooks in, with the default one always being main.yml
• defaults to put low precedence default values for role variables in, with the default one always being main.yml
• handlers to put the handlers that will be imported in the parent play in, with the default one always being main.yml
• vars to put high precedence variables provided by the role with the default one always being main.yml
• files to put any files referenced in the role tasks (like in copy)
• templates to put any role templates
• metadata metadata for the role, including role dependencies and optional Galaxy metadata such as platforms supported. This is required for uploading into galaxy as a standalone role, but not for using the role in your play. With the default one always being main.yml

The command ansible-galaxy init role_name can be used to initialize this folder directory quickly

Sharing roles

• Roles can be downloaded and shared via ansible galaxy, which is an online open-source, public repository of Ansible content
• Community roles can be installed and then called from playbooks