AWS Infrastructure with Terraform

This project creates a complete AWS infrastructure using Terraform, including:

• VPC with public and private subnets across 2 availability zones
• Internet Gateway and NAT Gateways for internet access
• Auto Scaling Group with Launch Template
• Application Load Balancer
• Bastion host for secure access
• Security Groups with appropriate rules

Architecture

Setup Instructions

1. Clone this repository

   git clone <your-repo-url>

2. Initialize Terraform

   terraform init

3. Plan the deployment

   terraform plan

4. Apply the configuration

   terraform apply

   Type yes when prompted.

Accessing Your Infrastructure

Bastion Host

• SSH into the bastion host using its public IP:

  ssh -i /path/to/your/key.pem ubuntu@<bastion-public-ip>

Private Instances

• From the bastion host, SSH into private instances:

  ssh -i /path/to/your/key.pem ubuntu@<private-instance-ip>

• Create the web content:

  vim index.html

• Start the Python web server:

  python3 -m http.server 8000

Accessing the Web Application

• The web application is accessible through the Application Load Balancer

• Get the Load Balancer DNS name from the Terraform output

• Access your application at: http://<load-balancer-dns-name>

• The load balancer forwards traffic to the private instances running the web server on port 8000

Key Components

VPC and Networking

• VPC: 10.0.0.0/16 CIDR block
• Public Subnets: 10.0.1.0/24, 10.0.2.0/24
• Private Subnets: 10.0.3.0/24, 10.0.4.0/24
• NAT Gateways: One in each availability zone for private subnet internet access

Security Groups

• Bastion SG: Allows SSH (port 22) from anywhere
• Private SG: Allows SSH from bastion and HTTP (port 8000) from load balancer
• ALB SG: Allows HTTP (port 80) from anywhere

Auto Scaling

• Min Size: 1 instance
• Max Size: 3 instances
• Desired: 2 instances
• Instance Type: t2.micro

Project Flow

1. Infrastructure Deployment: Terraform creates the complete AWS infrastructure
2. Bastion Access: Use bastion host to securely access private instances
3. Web Server Setup: Create index.html and start Python HTTP server on port 8000
4. Load Balancer Integration: ALB automatically detects and routes traffic to healthy instances
5. Public Access: Users can access the web application through the load balancer's public endpoint

Cleanup

To destroy all created resources:

terraform destroy

Type yes when prompted.