What components and files does a role in DevOps…

The role in DevOps, most often implemented through Ansible, consists of the following main components and files:

tasks/: Directory containing tasks executed by the role. The main file is main.yml.

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

handlers/: Directory containing event handlers. The main file is main.yml. Handlers are executed only when there is a change in the tasks that notify them.
```
// handlers/main.yml
- name: restart nginx
  service:
    name: nginx
    state: restarted
```
defaults/: Directory containing default variable values for the role. The main file is main.yml. These variables have the lowest priority.
```
// defaults/main.yml
nginx_port: 80
```
vars/: Directory containing role-specific variables. The main file is main.yml. These variables have a higher priority than those in defaults/.
```
// vars/main.yml
nginx_user: www-data
```

files/: Directory containing files that will be copied to target machines without changes.

// tasks/main.yml
- name: Copy static file
  copy:
    src: my_static_file.conf
    dest: /etc/nginx/conf.d/my_static_file.conf

templates/: Directory containing template files (usually in Jinja2 format) that will be copied to target machines after processing (variable substitution).

// templates/nginx.conf.j2
server {
    listen {{ nginx_port }};
    ...
}

// tasks/main.yml
- name: Configure nginx
  template:
    src: nginx.conf.j2
    dest: /etc/nginx/nginx.conf
  notify: restart nginx

meta/: Directory containing role metadata, such as dependencies. The main file is main.yml.
```
// meta/main.yml
dependencies:
  - role: another_role
    variable: value
```
library/: (Optional) Directory for custom Ansible modules.
module_utils/: (Optional) Directory for custom utility scripts used in modules.
lookup_plugins/, filter_plugins/, etc.: (Optional) Directories for custom plugins of various types.

A typical role structure looks like this:

my_role/
├── tasks/
│   └── main.yml
├── handlers/
│   └── main.yml
├── defaults/
│   └── main.yml
├── vars/
│   └── main.yml
├── files/
│   └── my_static_file.conf
├── templates/
│   └── nginx.conf.j2
└── meta/
    └── main.yml

These components allow organizing automation of installation, configuration, and management of services and systems in a structured and reusable way.

What components and files does a role in DevOps consist of?