Terraform AWS Multi-Tier Web Application Infrastructure

This project demonstrates how to deploy a multi-tier web application on AWS using Terraform for Infrastructure as Code (IaC). The architecture includes a frontend and backend hosted on EC2 instances, with a managed RDS database, all secured and isolated within a custom VPC.

---

🎯 Objective

• Automate AWS infrastructure provisioning using Terraform
• Deploy a scalable and secure multi-tier architecture
• Practice Infrastructure as Code (IaC) using best practices
• Understand real-world cloud components like VPC, EC2, RDS, Security Groups

🛠️ Tools Used

Tool / Service	Purpose
Terraform	Infrastructure as Code (IaC) to provision AWS resources
AWS VPC	Provides isolated networking environment for the app
AWS EC2	Hosts the frontend and backend application servers
AWS RDS	Managed relational database service (e.g., MySQL or PostgreSQL)
Security Groups	Acts as a virtual firewall to control inbound and outbound access
AWS IAM	Manages roles and permissions

📂 Project Structure

terraform-aws-multitier-webapp/
├── main.tf                # Calls modules and connects everything
├── variables.tf           # Input variables for main config
├── outputs.tf             # Outputs from modules
├── modules/               # Reusable modules
│   ├── vpc/
│   ├── ec2/
│   └── rds/
└── README.md              # Project documentation

⚙️ What This Project Does

1. Creates a custom VPC with public and private subnets.
2. Launches EC2 instances in the public subnet for frontend.
3. Deploys an RDS instance in the private subnet for backend.
4. Configures Security Groups to:
   • Allow HTTP on port 80 to access from the internet to EC2 & SSH (port 22) to ssh into EC2.
   • Allow EC2 to access RDS on port 3306 (or 5432 for PostgreSQL)
5. Outputs useful details like public IP of EC2 and DB endpoint.

🏗️ Architecture Overview

---

🚀 How to Run This Project Locally

Make sure you have Terraform and an AWS account with configured credentials (aws configure).

Step 1: Clone the repository

git clone https://github.com/ahsan598/terraform-aws-multitier-webapp.git
cd multi-tier-terraform

Step 2: Create a terraform.tfvars file This file will hold your custom values for variables such as AWS region, VPC CIDR, database name, etc.

Ex:

aws_region = "us-east-1"
vpc_cidr   = "10.0.0.0/16"
db_name    = "mydb"
db_user    = "admin"
db_pass    = "StrongPassword123"

Note: terraform.tfvars is ignored by .gitignore to prevent committing sensitive information.

Step 3: Initialize Terraform

terraform init

Step 4: Validate and Plan

terraform validate
terraform plan -var-file="terraform.tfvars"

Step-5: Apply changes

terraform apply -var-file="terraform.tfvars"

Step 6: Confirm outputs Terraform will display outputs like:

ec2_public_ip = "13.234.56.78"
rds_endpoint  = "mydb.xxxxxx.us-east-1.rds.amazonaws.com"

Step 7: Clean up (Optional)

terraform destroy

🧪 Terraform Commands (Quick Overview)

Command	Description
terraform init	Initialize working directory and download providers.
terraform plan	Show execution plan without making changes.
terraform apply	Create or update infrastructure as per plan.
terraform destroy	Remove all managed infrastructure.

📚 What I Have Learned

• Building real-world infrastructure using Terraform modules
• Using input variables and outputs efficiently
• Structuring Terraform projects for clarity and reusability
• Understanding cloud networking and tiered architecture
• Applying security best practices with IAM and SGs

---

🔗 Learning Resources

• Terraform AWS Provider Docs
• Terraform VPC Tutorial
• AWS VPC Documentation
• Learn Terraform Modules