AWS Terraform Infrastructure

This repository contains a fully automated, production-ready AWS infrastructure built using Terraform.
It includes VPC networking, subnets, NAT gateways, bastion host, application servers, Network Load Balancer (NLB), Route53 DNS, ACM TLS certificates, Redis, RDS MySQL, Auto Scaling Group (ASG), and more.

Architecture Overview

The Terraform code provisions:

Networking

• 1 VPC
• Public and private subnets
• Internet Gateway
• NAT Gateway
• Route tables and routing configuration
• Security groups for public, private, database, and cache layers

Compute

• Bastion host (public subnet)
• Auto Scaling Group (private subnet)
  • Launch Template based instances
  • Min 1, Max 3
  • CPU-based scale-in/scale-out

Load Balancing

• Network Load Balancer (NLB)
  • Listener ports: 80/TCP, 443/TLS, 8080/TCP
• Target Group automatically populated by ASG instances

Domain & TLS

• Hosted Zone via Route53
• ALIAS record → NLB
• ACM certificate with DNS validation
• TLS termination on NLB (port 443)

Databases

• RDS MySQL
• ElastiCache Redis (Redis 6.x)

Architecture Diagram (Conceptual)

Internet
   │
Route53 (api.insung-terraform.com)
   │
ACM (TLS Certificate)
   │
Network Load Balancer (80 / 443 / 8080)
   │
┌────────────────────────────────────────────┐
│                 AWS VPC                    │
│   ┌───────────────────────────┐            │
│   │     Public Subnets        │            │
│   │  - Bastion Host           │            │
│   │  - NAT Gateway            │            │
│   │  - RDS MySQL              │            │
│   └───────────────────────────┘            │
│   ┌───────────────────────────┐            │
│   │     Private Subnets       │            │
│   │  - ASG Auto EC2 (1~3)     │            │
│   │  - Redis (ElastiCache)    │            │
│   └───────────────────────────┘            │
└────────────────────────────────────────────┘

Architecture Diagram (draw.io)

Repository Structure

AWS-terraform/
├── vpc.tf
├── security.tf
├── ec2.tf
├── launch_template.tf
├── autoscaling.tf
├── nlb.tf
├── route53.tf
├── acm.tf
├── redis.tf
├── database.tf
├── variables.tf
├── outputs.tf
└── provider.tf

Auto Scaling Behavior

Condition	Action
CPU ≥ 40%	Scale-Out (+1 instance)
CPU ≤ 20%	Scale-In (–1 instance)
Min Size	Always 1
Max Size	Up to 3

Requirements

• Terraform 1.3+
• AWS Account
• AWS CLI installed (aws configure)
• SSH keypair named terraform_key
• Route53 domain access

Deployment

Initialize

terraform init

Plan infrastructure

terraform plan

Apply infrastructure

terraform apply

Destroy infrastructure

terraform destroy

Access Instructions

Bastion Host

ssh -i terraform_key.pem ubuntu@<bastion_public_ip>

Private EC2 (via Bastion)

ssh ec2-user@<private_ec2_ip>

Application Endpoint

http://api.insung-terraform.com
https://api.insung-terraform.com

Future Enhancements

• Multi-VPC + Transit Gateway
• WAF integration
• CloudFront CDN
• ECS Fargate or EKS migration
• Centralized logging (OpenSearch)
• Terraform backend (S3 + DynamoDB)
• GitHub Actions CI/CD