Creating Roles | Roles | Ansible Tutorial

Introduction

Ansible roles allow you to break down your playbooks into reusable components. Roles are a way to group multiple tasks together in a reusable and organized manner. This tutorial will guide you through the process of creating roles in Ansible from start to finish.

Step 1: Setting Up Your Project Directory

Before we create a role, we need to set up our project directory. This directory will contain all your Ansible configurations.

mkdir my-ansible-project

cd my-ansible-project

Step 2: Creating the Role Directory Structure

Ansible provides a command to create the basic directory structure for a role. This structure includes directories for tasks, handlers, variables, and more.

ansible-galaxy init my_role

- my_role/
  - defaults/
    - main.yml
  - files/
  - handlers/
    - main.yml
  - meta/
    - main.yml
  - tasks/
    - main.yml
  - templates/
  - tests/
    - inventory
    - test.yml
  - vars/
    - main.yml

Step 3: Defining Tasks

Tasks are the actions that your role will perform. Tasks are defined in the tasks/main.yml file. Let's add a simple task to install a package.

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

Step 4: Using Variables

Variables allow you to make your roles more flexible and reusable. You can define default variables in the defaults/main.yml file.

defaults/main.yml:
nginx_package: nginx
tasks/main.yml:
- name: Install Nginx
  apt:
    name: "{{ nginx_package }}"
    state: present

Step 5: Adding Handlers

Handlers are special tasks that are run only when notified. They are typically used to restart services. Handlers are defined in the handlers/main.yml file.

handlers/main.yml:
- name: restart nginx
  service:
    name: nginx
    state: restarted
tasks/main.yml:
- name: Install Nginx
  apt:
    name: "{{ nginx_package }}"
    state: present
  notify: restart nginx

Step 6: Using Templates

Templates allow you to create files dynamically based on variables. Templates are placed in the templates directory and typically use the Jinja2 templating language.

templates/nginx.conf.j2:
server {
    listen 80;
    server_name {{ nginx_host }};
    location / {
        proxy_pass http://127.0.0.1:8080;
    }
}
tasks/main.yml:
- name: Install Nginx
  apt:
    name: "{{ nginx_package }}"
    state: present
  notify: restart nginx
- name: Deploy Nginx Configuration
  template:
    src: nginx.conf.j2
    dest: /etc/nginx/nginx.conf
  notify: restart nginx
defaults/main.yml:
nginx_package: nginx
nginx_host: localhost

Step 7: Testing Your Role

To test your role, you can create a simple playbook in the root of your project directory. This playbook will include your role.

test.yml:
- hosts: localhost
  roles:
    - my_role
inventory:
localhost ansible_connection=local

ansible-playbook -i inventory test.yml

Creating Roles in Ansible