Azure Load Balancer with NGINX (Terraform)

Production-grade high availability architecture using Azure Load Balancer with private backend VMs, health probes, and Terraform (IaC).

This project demonstrates a highly available web application architecture deployed on Microsoft Azure using Terraform.

Architecture Diagram

🔄 Traffic Flow

1. Client sends request to Load Balancer Public IP
2. Load Balancer checks backend health via HTTP probe
3. Traffic is distributed across healthy VMs
4. NGINX serves the response

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Architecture Overview

• Azure Virtual Network (VNet)
• Subnet (10.0.1.0/24) hosting backend VMs
• 2x Ubuntu Virtual Machines (Private IP only)
• Azure Public Load Balancer (Layer 4)
• Backend Pool (VMs)
• Health Probe (HTTP:80)
• Load Balancing Rule (80 → 80)

• Backend VMs use private IPs only (no direct internet exposure)

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Load Balancer Traffic Distribution (Proof)

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Deployment

cd terraform
terraform init
terraform apply

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Testing

curl http://<LOAD-BALANCER-PUBLIC-IP>

Loop test:

for i in {1..10}; do curl http://<LOAD-BALANCER-PUBLIC-IP>; echo; done

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📁 Project Structure

terraform/   → Infrastructure as Code
images/      → Diagram & results
docs/        → Detailed architecture explanation

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Key Concepts

• Azure Load Balancer (Layer 4)
• Backend Pool & Health Probes
• Terraform Infrastructure as Code
• Custom Script Extension

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Future Improvements

• Replace VMs with VM Scale Set (VMSS)
• Add Azure Application Gateway (Layer 7)
• Enable HTTPS (SSL)
• Integrate Azure Monitor & Logging

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👨‍💻 Author

Muktar Mohamed Azure Cloud Engineer