How would you implement role management and their structure in Ansible for infrastructure automation?

In Ansible, role management and their structure are implemented through the use of the built-in roles mechanism, which allows organizing code into reusable and isolated blocks.

Main steps:

1. Create roles using the command ansible-galaxy init <role_name>, which will create a standard directory structure (tasks, handlers, vars, defaults, files, templates, meta).

2. In each role, describe the necessary tasks in tasks/main.yml, variables in vars or defaults, handlers in handlers.

3. In playbooks, include roles via the roles key, which simplifies management and reuse.

4. For complex structures, you can create role dependencies in the meta/main.yml file, which allows building a hierarchy and execution order.

Example of using a role in a playbook:

- hosts: webservers
  roles:
    - common
    - webserver

This approach ensures modularity, ease of maintenance, and scalability of infrastructure automation.