🚀 3-Tier Auto-Deployed Web App on AWS — Fully Automated with Terraform & CodePipeline

A production-grade, CI/CD-powered 3-Tier Application built from scratch using AWS & DevOps tools — fully deployed with one commit. Built an end-to-end 3-Tier Application with automated infrastructure provisioning and CI/CD pipeline on AWS. Implemented Terraform for IaC, Docker for containerization, and AWS CodePipeline for continuous delivery, ensuring each GitHub commit triggers a complete, hands-free deployment of frontend, backend, and database services.

---

🧠 Project Overview

This project demonstrates how to design, provision, and automate the deployment of a complete 3-tier web application using modern DevOps practices.

With a single git push, the entire pipeline triggers:

• Infrastructure provisioning via Terraform
• Application build & containerization via Docker
• Deployment across a frontend, backend, and database tier
• Load balancing, auto-scaling, and secure networking handled automatically by AWS

This showcases end-to-end automation — from infrastructure to application — without manual intervention.

---

💡 Key Highlights

Category	Technologies & Tools
Infrastructure as Code (IaC)	Terraform
Cloud Platform	AWS (EC2, RDS, ALB, VPC, IAM, S3, CodePipeline, CodeBuild)
Automation / CI-CD	AWS CodePipeline + CodeBuild
Containers	Docker
Frontend	HTML, CSS, JavaScript
Backend	Python Flask
Database	MySQL (Amazon RDS)
Networking	VPC with Public + Private Subnets, Security Groups, NAT Gateway
Monitoring	AWS CloudWatch
Version Control	GitHub

---

🏗️ Architecture

3-Tier Architecture Breakdown

1. Frontend Tier (Public Subnet)

   • Deployed as a Docker container exposed on port 80
   • Served behind an Application Load Balancer (ALB)
   • Displays product catalog & communicates with backend API

2. Backend Tier (Private Subnet)

   • Python Flask app running inside Docker on port 8080
   • Communicates with RDS over private network
   • Exposes REST APIs (/api/products, /api/checkout)

3. Database Tier (Private Subnet)

   • Amazon RDS (MySQL) securely connected to backend
   • Stores products, orders, and transactions

4. CI/CD Layer (AWS CodePipeline)

   • Detects every commit in GitHub
   • Triggers CodeBuild to build Docker images
   • Pushes updates to EC2 via Terraform-provisioned infrastructure

---

⚙️ End-to-End Automation Flow

1. Terraform applies infrastructure:

   • Creates VPC, subnets, security groups, RDS, ALB, and EC2.

2. User Data bootstraps EC2:

   • Installs Docker, Git, clones the app repo, builds and runs containers.

3. Docker containers spin up automatically:

   • Backend Flask API → port 8080
   • Frontend static app → port 80

4. Load Balancer routes traffic to the frontend.

5. Auto Scaling Group Makes Instance Balance during traffic hike.

6. Flask app interacts securely with RDS MySQL in a private subnet.

7. CodePipeline + CodeBuild automate future updates:

   • Any code change in GitHub triggers new build + deployment automatically.

---

📁 Repository Structure

3tierapp_aws/
├── backend/
│   ├── app.py
│   ├── Dockerfile
│   ├── requirements.txt

├── frontend/
│   ├── index.html
│   ├── Dockerfile

├── terraform/
│   ├── main.tf
│   ├── variables.tf
│   ├── outputs.tf
│   ├── compute.tf
│   ├── database.tf
│   ├── versions.tf
│   ├── provider.tf
│   ├── security.tf

├── Scripts/
│   ├── user_data.sh
│   ├── Codebuild.yml

└── Docker-compose.yml    
└── README.md

---

🧩 Backend (Flask API)

• Handles product listing, checkout, and order creation.
• Automatically initializes database + tables on first startup.
• Connects to RDS using env variables injected by Terraform.

---

🖥️ Frontend (HTML + JS)

• Clean, minimal, responsive UI.
• Fetches product list dynamically from backend /api/products.
• Built to demonstrate API communication + frontend integration.

---

☁️ Terraform Highlights

• Modular & reusable architecture.
• Automatically exports RDS credentials into EC2 user data.
• Integrates IAM roles for CodePipeline and S3 artifact storage.
• Outputs ALB DNS name for instant access to frontend.

Example Apply:

terraform init
terraform apply -auto-approve

---

🛠️ CI/CD (CodePipeline Integration)

• Source Stage: GitHub repo connected via webhook.
• Build Stage: CodeBuild compiles and packages the app.
• Deploy Stage: Automatically updates the EC2 environment.

Each push to main branch triggers a full rebuild + redeploy.

---

🔐 Security & Networking

• Backend + DB run in private subnets, isolated from the internet.
• Frontend runs in public subnet via ALB.
• NAT Gateway enables backend access for updates.
• RDS accessible only from backend EC2 SG.
• Encrypted storage + IAM least privilege policies.

---

📈 Skills Demonstrated

✅ Terraform (IaC) – automated multi-tier infrastructure ✅ AWS Cloud Architecture – secure, scalable VPC design ✅ Docker – app containerization for portability ✅ CI/CD (CodePipeline) – end-to-end automation from GitHub ✅ Flask + MySQL – backend API design and DB integration ✅ Load Balancing & Health Checks – ALB integration with private targets ✅ Debugging & Observability – log monitoring, DNS/network diagnostics

---

---

✨ Author

👨‍💻 Muthuraj Rajarathinam DevOps Engineer | AWS | Terraform | Docker | CI/CD | Cloud Architecture 🔗 GitHub • LinkedIn

---

🧭 Final Words

“This project represents my ability to build, automate, and deploy production-grade systems on AWS — bridging the gap between development and cloud operations with real-world DevOps skills.”