Terraform 2-Tier Architecture with RDS

Production-grade 2-tier web application infrastructure on AWS with VPC, ALB, Auto Scaling, and RDS Multi-AZ.

Architecture

Internet --> ALB
              |
              v
         Public Subnets (2 AZs)
         [EC2 Auto Scaling Group]
              |
              v
         Private Subnets (2 AZs)
         [RDS MySQL Multi-AZ]
              |
         Secrets Manager
         (DB Credentials)

Key Features

• VPC - 4 subnets across 2 AZs (2 public, 2 private)
• RDS Multi-AZ - MySQL with automatic failover and Performance Insights
• Auto Scaling - EC2 instances scale based on demand
• ALB - Application Load Balancer with health checks
• Secrets Manager - Secure, rotatable database credentials
• CloudWatch - Alarms for CPU, connections, and storage
• NAT Gateway - Secure outbound access from private subnets

Modules

Module	Purpose
vpc	VPC, subnets, NAT Gateway, route tables
database	RDS MySQL Multi-AZ, parameter groups
ec2	Launch template, ASG, ALB, target groups

Prerequisites

• AWS CLI v2
• Terraform >= 1.5.0

Deployment

terraform init
terraform plan
terraform apply

Cleanup

terraform destroy

License

MIT