RHCE 9.0 Practice Exam: Using Ansible Galaxy Roles for Load Balancing and PHP Configuration

📌 Article Overview

This tutorial is designed for RHCE 9.0 certification candidates and explains how to use pre-installed Ansible roles (balancer and phpinfo) to configure load balancing and deploy PHP web applications.

💡 What You Will Learn:

✅ How to create an Ansible Playbook to use Galaxy roles
✅ How to configure a Load Balancer using the balancer role
✅ How to deploy a PHP web application using the phpinfo role
✅ How to verify load balancing across multiple web servers
✅ How to check PHP configuration via a browser

📜 1. Task Requirements

📍 1.1. Problem Statement

1. Use the balancer role to configure a load balancer:
   • Runs on all nodes in the balancers group.
   • Balances HTTP requests across all webservers.
2. Use the phpinfo role to configure PHP:
   • Runs on all nodes in the webservers group.
   • Also displays detailed PHP configuration.

Visiting /hello.php should display:

Hello PHP World from node3.lab.example.com

or

Hello PHP World from node4.lab.example.com

Visiting http://172.25.250.13 should alternately show:

Welcome to node3.lab.example.com on 172.25.250.11
Welcome to node4.lab.example.com on 172.25.250.12

📜 2. Creating the Ansible Playbook

📍 2.1. Open the Playbook File

$ vim /home/greg/ansible/roles.yml

📄 Add the Following Content:

---
- name: Configure PHP on Web Servers
  hosts: webservers
  roles:
    - phpinfo

- name: Configure Load Balancer
  hosts: balancers
  roles:
    - balancer

📌 Key Points:

• Defines two plays:
  • First applies the phpinfo role to webservers.
  • Second applies the balancer role to balancers.

💾 Save and exit: (ESC → :wq)

📜 3. Running the Playbook

📍 3.1. Execute the Playbook

$ ansible-navigator run /home/greg/ansible/roles.yml -m stdout

📌 Expected Output

PLAY [Configure PHP on Web Servers] *******************************************

TASK [phpinfo : Install required PHP packages] ********************************
changed: [node3]
changed: [node4]

TASK [phpinfo : Deploy hello.php file] ***************************************
changed: [node3]
changed: [node4]

PLAY [Configure Load Balancer] ***********************************************

TASK [balancer : Install HAProxy or equivalent] *******************************
changed: [node1]

TASK [balancer : Configure Load Balancer] ************************************
changed: [node1]

TASK [balancer : Restart Load Balancer Service] ******************************
ok: [node1]

PLAY RECAP *******************************************************************
node3       : ok=2    changed=2    unreachable=0    failed=0
node4       : ok=2    changed=2    unreachable=0    failed=0
node1       : ok=3    changed=2    unreachable=0    failed=0

✅ The playbook successfully configures PHP and load balancing.

📜 4. Verifying Load Balancing

📍 4.1. Check Hosts in the balancers Group

$ ansible balancers --list-hosts

📌 Expected Output

hosts (1):
  node1

✅ The load balancer runs on node1 (172.25.250.13).

📍 4.2. Test Load Balancer

Run the following curl command multiple times:

$ curl http://172.25.250.13

📌 Expected Alternating Outputs

Welcome to node3.lab.example.com on 172.25.250.11

Welcome to node4.lab.example.com on 172.25.250.12

✅ The load balancer is correctly distributing requests!

📜 5. Verifying PHP Configuration

📍 5.1. Check Hosts in the webservers Group

$ ansible webservers --list-hosts

📌 Expected Output

hosts (2):
  node3
  node4

✅ PHP is deployed on node3 and node4.

📍 5.2. Test PHP Application

Visit the following URLs in a web browser:

• http://172.25.250.11/hello.php
• http://172.25.250.12/hello.php

Alternatively, use curl:

$ curl http://172.25.250.11/hello.php

📌 Expected Output

Hello PHP World from node3.lab.example.com

$ curl http://172.25.250.12/hello.php

📌 Expected Output

Hello PHP World from node4.lab.example.com

✅ Both PHP servers return the correct hostname!

📜 6. Final Browser Verification

🔹 Open a web browser and navigate to:

• http://172.25.250.11/hello.php
• http://172.25.250.12/hello.php

📌 Expected Web Page Appearance

• Main Title: "Hello PHP World from nodeX.lab.example.com"
• Background: Purple
• PHP Configuration: Displayed below the text

✅ The PHP page is accessible, and PHP configuration details are displayed!

📜 7. Scoring Criteria

✅ Total Score: 45 points

📜 8. Common Issues & Troubleshooting

🔴 Issue 1: Load balancer is not alternating requests

✅ Solution:

$ systemctl restart haproxy
$ systemctl restart httpd

🔴 Issue 2: PHP page is not displaying

✅ Solution: Ensure phpinfo is correctly installed:

$ yum list installed | grep php

If missing, reinstall PHP:

$ yum install -y php php-cli php-common php-fpm
$ systemctl restart httpd

🚀 Congratulations! You have successfully deployed an Ansible Playbook that configures a Load Balancer and a PHP Web Server for RHCE 9.0! 🚀
📢 If you found this guide helpful, share it with your RHCE 9.0 study group! 📢

🔥 Good luck on your RHCE 9.0 exam! 🔥