🎭 Ansible Roles & Project Structure

🎯 What is an Ansible Role?

An Ansible Role is a predefined structure used to organize your automation.

👉 Simple meaning:

Instead of writing everything in one big playbook, we split into reusable parts

📦 Real-Life Example

Think like this:

🍽️ Hotel Kitchen

• Chef (Playbook)
• Different sections:

* 🍛 Cooking team

* 🧹 Cleaning team

* 🧾 Billing team

Each section = Role

💡 Easy Definition

• Role = Reusable automation module
• Helps to:

* Organize code

* Reuse tasks

* Maintain easily

📁 Role Structure (Important)

When you create a role, it follows a standard folder structure:

my-role/
│
├── tasks/
│   └── main.yml
│
├── handlers/
│   └── main.yml
│
├── templates/
│
├── files/
│
├── vars/
│   └── main.yml
│
├── defaults/
│   └── main.yml
│
├── meta/
│   └── main.yml

🔍 Folder Explanation (Very Important 🔥)

📌 tasks/

👉 Main வேலை இங்க தான் நடக்கும்

• Contains actual tasks
• Entry file: main.yml

Example:

- name: Install nginx
  apt:
    name: nginx
    state: present

🔁 handlers/

👉 Used for restart/reload services

Example:

- name: restart nginx
  service:
    name: nginx
    state: restarted

Called only when needed (notify)

📂 templates/

👉 Dynamic files (Jinja2 templates)

Example:

• nginx.conf.j2

📁 files/

👉 Static files

• No variables
• Direct copy

📊 vars/

👉 Variables (high priority)

port: 80

⚙️ defaults/

👉 Default variables (low priority)

port: 8080

👉 If user doesn’t override → this value used

🔗 meta/

👉 Role dependencies

Example:

dependencies:
  - role: common

🧱 Project Structure (Full Project)

Now let’s see how a real Ansible project looks

my-ansible-project/
│
├── inventory
│
├── playbook.yml
│
├── roles/
│   ├── webserver/
│   ├── database/
│   └── common/
│
├── group_vars/
├── host_vars/

📌 Explanation

📄 inventory

👉 Target servers list

[web]
192.168.1.10

▶️ playbook.yml

👉 Main entry point

Example:

- hosts: web
  roles:
    - webserver

🎭 roles/

👉 Contains all roles

• webserver
• database
• common

🧾 group_vars/

👉 Variables for group

🖥️ host_vars/

👉 Variables per server

🔄 How Everything Works Together

1. You run playbook

2. Playbook calls role

3. Role runs tasks

4. Tasks use variables

5. Handlers trigger when needed

🍰 Real-Life Example (Like your Docker one)

Think of building a website server

• Role = Setup kit
• tasks = steps (install nginx, copy config)
• templates = config file with variables
• handlers = restart nginx
• playbook = instruction manual

🔥 Key Difference (Like Image vs Container style)

| Concept | Meaning |

| -------- | ----------------- |

| Playbook | Main controller |

| Role | Reusable module |

| Tasks | Actual work |

| Handlers | Triggered actions |

🧠 Short Summary

• Role = structured, reusable automation
• Helps large projects
• Makes DevOps life easy 😄