Ansible playbooks

• Ansible playbook is written in YAML file and is collection of play’s.
• Each Play is collection of tasks (and handlers)
• Each task represents a unit of activity which is acheived by module.

Ansible module

• This is smallest (atomic) unit in ansible where we can express desired state.
• Ansible comes inbuilt with many modules. In addition to this we can add community modules and we can develop our own modules.

Sample playbook

• Sample Ansible playbook

---
- name: install apache
  become: yes
  hosts: all
  tasks:
    - name: update packages and install apache
      ansible.builtin.apt:
        name: apache2
        update_cache: yes
        state: present
    - name: enable and start apache service
      ansible.builtin.systemd:
        name: apache2
        enabled: yes
        state: started

• The equivelent of this in shell script

#!/bin/bash
sudo apt update
sudo apt install apache2 -y
sudo systemctl enable apache2
sudo systemctl start apache2

Basic playbook structure

• Playbook is collection of plays

- name: play1
- name: play2
..
- name: playn

• Each play will have tasks and
  • hosts: we need to tell where to execute
  • become: do i need to run this entire play with sudo
  • tasks: here we describe the desired state of individual steps

```yaml
- name: play1
  hosts: <where to run>
  become: yes
  tasks:
    - name: task1
      <module>:
         parameter1: <value1>
         ..
         parametern: <valuen>
         state: <desired state>

WOW (Ways of Working)

• Find out all the manual steps required to configure
• Ensure they are working
• For each step(s) try to find a ansible module where you can express desired state.

Example 1: Lets install Apache and PHP using Ansible playbook

Manual steps

• Create a vm for manual steps
• Find out commands to install apache and php

1. Update System Packages

Before installing any new software, it’s always good practice to update your package index:

sudo apt update

2. Install Apache Web Server

To install (or ensure you have) the Apache2 web server:

sudo apt install apache2 -y

• Start Apache and enable it to start at boot:
  bash
sudo systemctl start apache2
sudo systemctl enable apache2
• Check Apache status:
  bash
sudo systemctl status apache2

You can verify installation by visiting http://YOUR_SERVER_IP in a browser — you should see the Apache default welcome page.

3. Install PHP

Ubuntu 24.04 comes with PHP 8.x in its default repositories. Install PHP and the Apache PHP module:

sudo apt install php libapache2-mod-php -y

• For some common extensions needed in web development:
  bash
sudo apt install php-cli php libapache2-mod-php -y
• Verify PHP installation:
  bash
php -v
• (Optional) To see loaded PHP modules:
  bash
php -m

With this, Apache will auto-process .php files.

4. Test Apache + PHP

You can create a test.php file in /var/www/html/ to verify PHP is working with Apache:

echo '<?php phpinfo(); ?>' | sudo tee /var/www/html/test.php

Visit http://YOUR_SERVER_IP/test.php in your browser. If you see the PHP info page, installation is successful.

Finding modules

• find the command

sudo apt install xyz -y => apt
sudo dnf install xyz -y => dnf
sudo systemctl restart xyz => systemctl

• Now open google and type <command> in ansible
  
  
• Now fill the task section Refer Here for the changes done.
• Now to run the playbook command is

ansible-playbook -i hosts apache.yaml