3-Tier Architecture Application Deployment on AWS

📖 Overview

This repository documents the deployment of a 3-tier architecture on AWS, consisting of:

• Web Tier (Nginx + Node.js)
• Application Tier (Node.js + Internal Load Balancer)
• Database Tier (Amazon RDS MySQL)

The setup ensures scalability, security, and high availability using VPC, Security Groups, Load Balancers, Auto Scaling Groups, and Route53.

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📂 Repository Structure

aws-blue-green-deployment/
|
├── 3tier-app-deployment-aws-main/
│     ├── application-code
│           ├── apptier/
│           ├── webtier/
├── install.sh
├── screenshots/
│   ├── Images
├── README.md
└── architecture.png

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🏗️ Architecture

• VPC: Custom VPC (CIDR: 192.168.0.0/16) with 2 public and 4 private subnets.
• Security Groups: Separate SGs for Web ALB, Web Server, App ALB, App Server, and Database.
• Storage: S3 private bucket for application code and configuration files.
• IAM: Role for EC2 with SSM permissions.
• Database: RDS MySQL instance with private subnet group.
• App Tier: Node.js application servers behind an internal ALB.
• Web Tier: Nginx servers behind an external ALB with HTTPS via ACM.
• Scaling: Auto Scaling Groups for both Web and App tiers.
• DNS: Route53 for domain mapping.

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🚀 Deployment Steps

1. Networking

• Create VPC: 192.168.0.0/16
• Subnets: 2 public, 4 private
• NAT Gateway in one AZ
• Security Groups:
  • Web ALB SG → allow HTTP/HTTPS from 0.0.0.0/0
  • Web SG → allow traffic from Web ALB SG
  • App ALB SG → allow traffic from Web SG
  • App SG → allow TCP 4000 from App ALB SG
  • DB SG → allow MySQL (3306) from App SG

2. Storage

• Create S3 bucket: 3-tier-project-demo
• Upload application code and install.sh
• Update configs:
  • DbConfig.js → RDS credentials
  • nginx.conf → Internal ALB DNS

3. IAM

• Create role: 3-tier-role
• Trusted entity: EC2
• Permissions: AmazonEC2RoleforSSM

4. Database

• Create DB Subnet Group (tier-Subnet-Group)
• Launch RDS MySQL instance (my3tierdb)
• Update App Tier config with DB endpoint and credentials

5. Application Tier

• Launch EC2 (Amazon Linux 2/2023, t2.micro) in private subnet
• Attach IAM role
• Connect via SSM
• Install Node.js, PM2, MySQL client
• Deploy app from S3
• Configure internal ALB + target group (port 4000, health check /health)

6. Web Tier

• Launch EC2 (Amazon Linux 2/2023, t2.micro) in public subnet
• Install Node.js, Nginx
• Deploy web code from S3
• Replace default nginx.conf with custom config
• Configure external ALB + target group (port 80, health check /)

7. HTTPS & DNS

• Create ACM certificate
• Attach certificate to external ALB listener
• Configure Route53 domain: https://3tier-webapp.com

8. Auto Scaling

• Create AMIs for App and Web servers
• Define Launch Templates
• Create ASGs with min/max/desired capacity
• Attach respective ALBs

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🛠️ Usage

Once deployed:

• Access the application via the Route53 domain.
• Web tier forwards requests to App tier through internal ALB.
• App tier communicates with RDS MySQL database.

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🤝 Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/new-feature)
3. Commit changes (git commit -m 'Add new feature')
4. Push to branch (git push origin feature/new-feature)
5. Open a Pull Request

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📜 License

This project is licensed under the MIT License.