Web Application Deployment and Load Balancing with Ansible

Introduction

Excellent progress! You’ve reached the final phase of your environment deployment. With your infrastructure, domain services, and user accounts configured, it’s time to deploy the actual application that will serve your development teams.

Final Support Ticket #004 - Application Deployment

This exercise demonstrates how Ansible can orchestrate complex, multi-tier application deployments across hybrid infrastructure while ensuring high availability through load balancing.

Learning Objectives

By the end of this lab, you will be able to:

Deploy web applications across both Windows and RHEL platforms using platform-specific configurations
Configure load balancing with HAProxy for high availability and traffic distribution
Implement service discovery and dynamic server configuration
Orchestrate complete application stacks from infrastructure to application deployment

Lab Environment Setup

Your DNS domain for this lab is: [[ Instruqt-Var key="DOMAIN" hostname="control" ]]

This lab represents the final phase of your environment deployment, building upon all previously configured infrastructure including domain services, user accounts, and server deployments.

Exercise 1: Multi-Platform Web Application Deployment

You’ll deploy the same web application across both Windows and RHEL platforms, demonstrating Ansible’s ability to manage heterogeneous environments with consistent results.

Step 1: Deploy Windows Web Application

First, let’s deploy the web application on your Windows server using IIS:

Navigate to your AAP tab and login
Go to Automation Execution → Templates
Launch the Windows Deploy WebApp template

This automation will:

Configure IIS web server on Windows
Deploy application files and dependencies
Configure proper security and access permissions
Start necessary Windows services

Step 2: Verify Windows Deployment

Once the template completes:

Navigate to the webapp-windows tab
View the deployed web application

The application should be running successfully on IIS with proper Windows-specific configuration.

Step 3: Deploy RHEL Web Application

Now deploy the same application on your RHEL server using Apache:

Navigate to Automation Execution → Templates
Launch the RHEL Deploy WebApp template

This automation will:

Configure Apache web server on RHEL
Clone application source code from repository
Deploy and configure application files
Start Apache services with proper configuration

Step 4: Verify RHEL Deployment

Once the template completes:

Navigate to the webapp-rhel tab
View the deployed web application

Both deployments use the same source application but with platform-specific configurations, demonstrating Ansible’s ability to abstract deployment complexity while maintaining consistency.

Exercise 2: Load Balancer Configuration

With both application servers deployed, you need to configure load balancing to distribute traffic and provide high availability.

Step 1: Verify Current Load Balancer State

Navigate to the loadbalancer tab
Refresh the page

As expected, there’s nothing configured yet - the load balancer needs to be told about your application servers.

Step 2: Configure Load Balancer with RHEL Server

Navigate to Automation Execution → Templates
Launch the Configure Loadbalancer template
When prompted for hostname, provide: node01.{dns_domain}

This will configure HAProxy to include your RHEL server in the load balancing pool.

Step 3: Add Windows Server to Load Balancer

Re-run the Configure Loadbalancer template
When prompted for hostname, provide: dbserver.{dns_domain}

The load balancer will now distribute traffic between both your Windows and RHEL application servers.

Step 4: Test Complete Application Stack

Before final testing:

Verify each individual application server is responding correctly
Check the webapp-windows tab for Windows server availability
Check the webapp-rhel tab for RHEL server availability
Navigate to the loadbalancer tab to test load-balanced access

The load balancer will now rotate traffic between your two application servers, providing redundancy and distributing the load.

The environment is now ready for handover to your development teams! They have a fully redundant, load-balanced web application running across hybrid infrastructure.

Code Reference

HAProxy Load Balancer Configuration

Here’s the automation code for configuring HAProxy load balancing:

tasks:
  - name: Resolve DNS server hostname to IP
    set_fact:
      host_ip: "{{ lookup('dig', host) }}"

  - name: Add static hosts to load balancer
    ansible.builtin.lineinfile:
      path: /etc/haproxy/haproxy.cfg
      line: "server static-{{ host}} {{ host_ip }}:80 check"
      insertafter: '^## STATIC CONFIG ANSIBLE'
      state: present

  - name: Add webapp hosts to load balancer
    ansible.builtin.lineinfile:
      path: /etc/haproxy/haproxy.cfg
      line: "server webapp-{{ host }} {{ host_ip }}:80 check"
      insertafter: '^## APP CONFIG ANSIBLE'
      state: present
    notify:
      - restart haproxy

handlers:
  - name: restart haproxy
    service:
      name: haproxy
      state: restarted

RHEL Web Application Deployment

Here’s the code for deploying web applications on RHEL systems:

tasks:
  - name: clone a git repo
    ansible.builtin.git:
      repo: https://github.com/nmartins0611/aap25-roadshow-content.git
      dest: /tmp/repo

  - name: copy all files from one directory to another
    ansible.builtin.copy:
      src: /tmp/repo/lab-resources/
      dest: /var/www/html
      remote_src: true

  - name: Tag the page
    ansible.builtin.lineinfile:
      path: /var/www/html/index.html
      line: "This is running on the RHEL Host"
      insertafter: "<p>&copy; 2024 TMM - Where comedy lives. All rights reserved.</p>"

  - name: Start httpd service
    ansible.builtin.service:
      name: httpd
      state: started