readme.md

Installing Apache2 with Handlers in Ansible

Duration

Approximately 30 minutes

Objective

In this lab, you will learn how to use Ansible handlers to respond to change events in your tasks. Specifically, you'll be installing the apache2 package and, upon its successful installation, triggering handlers to display success messages.

Prerequisites:

• Ansible installed on your machine.
• A target host or set of hosts configured in your Ansible inventory under the group webserver.
• The target host should have apt package manager (typically an Ubuntu/Debian machine).

Step-by-step guide:

Step A: Setting up the Playbook

• Start by creating a new playbook named apache_install_handlers.yml.
• Define the playbook structure:

---
- hosts: webserver
  name: Install Apache2 with Handlers
  become: yes
  become_user: root
  gather_facts: no

Step B: Installing Apache2 Package

• Add the task that installs the Apache2 package using the apt module:

  tasks:
    - name: update package
      apt: 
        update_cache: yes
      
    - name: Install Package
      apt:
        name: apache2
      notify:
        - sucs_msg
        - sucs_msg_b

This task instructs Ansible to install the apache2 package. If the package installation changes the state of the machine (e.g., installing or updating the package), the notify directive will trigger the named handlers.

Step C: Define Handlers for Post-installation Messages

• Beneath the tasks, define handlers that display success messages:

  handlers:
    - name: sucs_msg
      debug:
        msg: Package has been Installed

    - name: sucs_msg_b
      debug:
        msg: Package has been Installed B

Handlers are special types of tasks in Ansible that run only if notified by another task. In our playbook, upon successful installation of the Apache2 package, both handlers will be triggered, displaying their respective success messages.

Step D: Running the Playbook

• Save the apache_install_handlers.yml file.
• Execute the playbook using the following command:

ansible-playbook apache_install_handlers.yml

Watch as Ansible installs the Apache2 package on the target webserver host(s). If the package gets installed or updated, you'll see the success messages from the handlers.

Final File

You can compare your playbook with the apache_install_handlers.yml file in the current directory.

Summary

Handlers provide a powerful way to execute tasks in response to changes detected by other tasks. They are useful for cases where you want to restart a service after its configuration changes or, like in this lab, provide feedback once a certain task has completed successfully. Mastering handlers can help you create more efficient and responsive playbooks.