👋 Introduction
In this hands-on project, I built a production-ready AWS architecture using core services like VPC, Application Load Balancer, Auto Scaling Group, EC2, and NAT Gateway.
This setup follows AWS best practices:
Secure networking
High availability
Automatic scaling
Zero public access to EC2 instances
This guide is beginner-friendly, yet interview-ready.
🧠 What You Will Learn
✅ How to design a secure AWS VPC
✅ Public vs Private Subnets (real use-case)
✅ Application Load Balancer (ALB)
✅ Auto Scaling Group (ASG)
✅ NAT Gateway for outbound internet
✅ Real-world architecture used in companies
🏗️ Architecture Overview
Internet
|
▼
Application Load Balancer (Public Subnets)
|
▼
Target Group
|
▼
Auto Scaling Group
(EC2 Instances in Private Subnets)
|
▼
NAT Gateway → Internet (Outbound Only)
🔒 EC2 instances have NO public IPs
🌐 Only ALB is exposed to the internet
🛠️ Services Used
Amazon VPC
EC2 (Ubuntu)
Application Load Balancer
Auto Scaling Group
Target Groups
NAT Gateway
Elastic IP
Security Groups
🚦 Step-by-Step Implementation
1️⃣ Create a Custom VPC
CIDR: 10.0.0.0/16
Enable:
DNS Hostnames
DNS Resolution
2️⃣ Create Subnets
Create 4 subnets:
Public Subnets
Public-Subnet-1 (ALB)
Public-Subnet-2 (NAT Gateway)
Private Subnets
Private-Subnet-1 (EC2)
Private-Subnet-2 (EC2)
⚠️ Enable Auto-assign Public IP = YES only for public subnets
3️⃣ Internet Gateway
Create and attach an Internet Gateway to the VPC
Required for ALB and NAT Gateway
4️⃣ NAT Gateway (CRITICAL)
Create NAT Gateway in public subnet
Attach Elastic IP
Allows private EC2 to access internet securely
5️⃣ Route Tables
Public Route Table
0.0.0.0/0 → Internet Gateway
Private Route Table
0.0.0.0/0 → NAT Gateway
Associate correctly with subnets.
6️⃣ Security Groups
🔹 ALB Security Group
HTTP (80) → 0.0.0.0/0
🔹 EC2 Security Group
HTTP (80) → ALB Security Group
SSH (22) → Your IP (optional)
🔐 EC2 is accessible only via ALB
7️⃣ Launch Template (EC2)
AMI: Ubuntu 22.04
Instance Type: t2.micro
🧾 User Data Script
!/bin/bash
apt update -y
apt install apache2 -y
systemctl start apache2
systemctl enable apache2
echo "
Welcome from ALB + Auto Scaling
Hostname: $(hostname)
" > /var/www/html/index.html8️⃣ Target Group
Target Type: Instance
Protocol: HTTP
Port: 80
Health Check Path: /
9️⃣ Application Load Balancer
Type: Internet-facing
Subnets: Public Subnets
Listener: HTTP 80
Forward to Target Group
🔟 Auto Scaling Group
Use Launch Template
Subnets: Private Subnets
Desired: 2
Min: 1
Max: 3
Attach to ALB Target Group
📈 Optional: CPU-based scaling policy
✅ Final Verification
Copy ALB DNS name
Paste into browser
Refresh multiple times
🎉 You will see different hostnames
This confirms:
Load balancing
Auto scaling
High availability
📂 GitHub Repository
🔗 Project Source Code & Documentation
👉 https://github.com/IrfanPasha05/aws-alb-autoscaling-project
Includes:
Folder structure
User-data scripts
Setup steps
Troubleshooting guide
🎯 Why This Project Matters
This architecture is used in:
Real production environments
Enterprise applications
DevOps & Cloud Engineer roles
Perfect for:
Resume
Interviews
Portfolio
LinkedIn & DEV
🧩 Future Enhancements
HTTPS with ACM
Custom domain (Route 53)
CloudFront CDN
Monitoring with CloudWatch
🙌 Final Thoughts
This project strengthened my understanding of AWS networking, security, and scalability. If you’re learning AWS or preparing for cloud roles — build this once, and you’ll remember it forever.
Happy Clouding ☁️🚀
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