In this section, we will delve into the process of creating and sharing roles in Ansible. Roles are a powerful way to organize and reuse Ansible code, making your playbooks more modular and maintainable. By the end of this section, you will understand how to create roles, structure them properly, and share them using Ansible Galaxy.

A role in Ansible is a way to group related tasks, variables, files, templates, and handlers into a single unit. Roles help in organizing playbooks and make them reusable and easier to manage.

1. Create a Role Directory Structure: Use the ansible-galaxy command to create a new role. This command will generate the necessary directory structure for you.

   ansible-galaxy init my_role
   

   This will create a directory named my_role with the following structure:

   my_role/
   ├── defaults
   │   └── main.yml
   ├── files
   ├── handlers
   │   └── main.yml
   ├── meta
   │   └── main.yml
   ├── tasks
   │   └── main.yml
   ├── templates
   ├── tests
   │   ├── inventory
   │   └── test.yml
   └── vars
       └── main.yml
   

2. Define Tasks: Add tasks to the tasks/main.yml file. Tasks are the core of a role and define the actions to be performed.

   # my_role/tasks/main.yml
   - name: Install Nginx
     apt:
       name: nginx
       state: present
   

3. Set Default Variables: Define default variables in the defaults/main.yml file. These variables can be overridden by the user.

   # my_role/defaults/main.yml
   nginx_port: 80
   

4. Add Handlers: Handlers are tasks that are triggered by other tasks. Define them in the handlers/main.yml file.

   # my_role/handlers/main.yml
   - name: restart nginx
     service:
       name: nginx
       state: restarted
   

5. Include Files and Templates: Place any files or templates your role needs in the files and templates directories, respectively.

   # my_role/templates/nginx.conf.j2
   server {
       listen {{ nginx_port }};
       server_name localhost;
   }
   

6. Meta Information: Provide metadata about your role in the meta/main.yml file. This includes information like the author, license, and dependencies.

   # my_role/meta/main.yml
   galaxy_info:
     author: Your Name
     description: Install and configure Nginx
     license: MIT
     min_ansible_version: 2.9
   

Ansible Galaxy is a hub for finding, reusing, and sharing Ansible roles. To share your role on Ansible Galaxy, follow these steps:

1. Create a Galaxy Account: Sign up for an account on Ansible Galaxy.

2. Prepare Your Role: Ensure your role follows the best practices and includes all necessary metadata in the meta/main.yml file.

3. Publish Your Role: Use the ansible-galaxy command to publish your role.

   ansible-galaxy import username my_role
   

   Replace username with your Galaxy username and my_role with the name of your role.

4. Versioning: Tag your role with a version number using Git. This helps users to track changes and use specific versions of your role.

   git tag 1.0.0
   git push origin 1.0.0
   

You can also share your roles via GitHub. Simply push your role to a GitHub repository and provide the URL to users.

1. Create a Role: Create a role named webserver that installs and configures Apache.

2. Define Tasks: Add tasks to install Apache and start the service.

3. Set Default Variables: Define a default variable for the Apache port.

4. Add Handlers: Add a handler to restart Apache.

5. Share the Role: Publish the role on Ansible Galaxy or share it via GitHub.

1. Create a Role:

   ansible-galaxy init webserver
   

2. Define Tasks:

   # webserver/tasks/main.yml
   - name: Install Apache
     apt:
       name: apache2
       state: present
   
   - name: Start Apache
     service:
       name: apache2
       state: started
       enabled: true
   

3. Set Default Variables:

   # webserver/defaults/main.yml
   apache_port: 80
   

4. Add Handlers:

   # webserver/handlers/main.yml
   - name: restart apache
     service:
       name: apache2
       state: restarted
   

5. Share the Role: Follow the steps mentioned above to publish the role on Ansible Galaxy or share it via GitHub.

In this section, we covered the creation and sharing of Ansible roles. Roles help in organizing and reusing Ansible code, making your playbooks more modular and maintainable. We also explored how to share roles using Ansible Galaxy and GitHub. In the next module, we will dive into Ansible Tower and learn how to manage projects and inventories.