# ☁️ AWS Setup: VPC, EC2 & Nginx Web Server

## 🏗️ HIGH-LEVEL ARCHITECTURE

```text
VPC
├── Public Subnet (EC2-1)
├── Public Subnet (EC2-2)
├── Internet Gateway
└── Route Table → Internet

⚙️ PHASE 1: INFRASTRUCTURE (Algorithm Style)

🔹 STEP 1: Create VPC

Go to VPC Dashboard

Click Create VPC

Enter:

• Name: MyVPC
• CIDR: 10.0.0.0/16

Click Create

👉 This is your private network.

🔹 STEP 2: Create 2 Subnets

Go to Subnets → Create subnet

Subnet 1

• Name: Public-Subnet-1
• CIDR: 10.0.1.0/24
• AZ: Any

Subnet 2

• Name: Public-Subnet-2
• CIDR: 10.0.2.0/24
• AZ: Any (Different from Subnet 1 recommended)

👉 Both are PUBLIC (configured next).

🔹 STEP 3: Create Internet Gateway

Go to Internet Gateways

Create:

• Name: MyIGW

Attach it to your VPC.

👉 Now your VPC can access the internet.

🔹 STEP 4: Create Route Table

Go to Route Tables → Create

• Name: Public-RT

Attach to VPC.

Add Route:

• Destination: 0.0.0.0/0
• Target: Internet Gateway

👉 Sends all internet traffic outside.

🔹 STEP 5: Associate Subnets

Open Route Table → Subnet Associations

Attach:

• Public-Subnet-1
• Public-Subnet-2

👉 Both subnets are now PUBLIC.

🔹 STEP 6: Enable Auto Public IP

For each subnet:

Edit subnet settings → Enable:

• Auto-assign public IP

👉 Without this, EC2 won't get public IPs automatically.

🔹 STEP 7: Create Security Group

Go to:

EC2 → Security Groups

Create:

• Name: Web-SG

Inbound Rules

👉 Allows SSH + web traffic.

🔹 STEP 8: Create Key Pair

Go to:

EC2 → Key Pairs

Create:

• Name: my-key

Download:

• my-key.pem

👉 Needed for SSH access.

🔹 STEP 9: Launch EC2 Instance 1

Go to:

EC2 → Launch Instance

Configure:

• Name: EC2-1
• AMI: Amazon Linux
• Instance type: t2.micro
• Key pair: my-key

Network Settings

• VPC: MyVPC
• Subnet: Public-Subnet-1
• Auto IP: Enabled
• Security Group: Web-SG

Click Launch

🔹 STEP 10: Launch EC2 Instance 2

Same settings, change:

• Name: EC2-2
• Subnet: Public-Subnet-2

🔹 STEP 11: SSH into EC2

chmod 400 my-key.pem
ssh -i my-key.pem ec2-user@<PUBLIC-IP>

👉 You are now inside your server.

🌐 (OPTIONAL) STEP 12: Create Load Balancer

Go to:

EC2 → Load Balancers

Create Application Load Balancer

Choose:

• Internet-facing
• Select your VPC
• Select both subnets

Create Target Group

Add:

• EC2-1
• EC2-2

Attach Target Group to Load Balancer.

👉 Traffic will be distributed across both servers.

🧠 FINAL UNDERSTANDING (Phase 1)

You built:

• VPC = Network
• Subnets = Zones
• IGW = Internet Access
• Route Table = Traffic Rules
• Security Group = Firewall
• EC2 = Servers
• Load Balancer = Traffic Distributor

⚙️ PHASE 2: NGINX CONFIGURATION

⚙️ STEP 1: Verification

Ensure both instances:

• Are in a public subnet

• Have a public IP

• Security Group allows:

  • HTTP (80)
  • SSH (22)

🔐 STEP 2: SSH into EC2-1

ssh -i my-key.pem ec2-user@<EC2-1-PUBLIC-IP>

📦 STEP 3: Install Nginx on EC2-1

sudo yum update -y
sudo yum install nginx -y

Start and enable:

sudo systemctl start nginx
sudo systemctl enable nginx

Check status:

systemctl status nginx

🌐 STEP 4: Test EC2-1

Open:

http://<EC2-1-PUBLIC-IP>

👉 You should see Nginx Welcome Page

🔁 STEP 5: SSH into EC2-2

ssh -i my-key.pem ec2-user@<EC2-2-PUBLIC-IP>

📦 STEP 6: Install Nginx on EC2-2

sudo yum update -y
sudo yum install nginx -y
sudo systemctl start nginx
sudo systemctl enable nginx

🌐 STEP 7: Test EC2-2

Open:

http://<EC2-2-PUBLIC-IP>

👉 You should see Nginx Welcome Page

🎨 (OPTIONAL) STEP 8: Customize Each Server

On EC2-1

echo "Hello from EC2-1" | sudo tee /usr/share/nginx/html/index.html

On EC2-2

echo "Hello from EC2-2" | sudo tee /usr/share/nginx/html/index.html

Test

• EC2-1 IP → Hello from EC2-1
• EC2-2 IP → Hello from EC2-2

🧠 WHAT IS HAPPENING?

• Nginx listens on port 80
• EC2 public IP routes traffic to the instance
• Security Group allows HTTP traffic
• Nginx serves the HTML page

⚠️ COMMON MISTAKES

❌ No HTTP Rule in Security Group

• Page times out

❌ Nginx Not Started

• Connection refused

❌ Using Private IP in Browser

• Won't work from your local computer

❌ Wrong AMI Commands

Amazon Linux:

yum

Ubuntu:

apt

🚀 NEXT LEVEL

Upgrade this setup:

• Add a Load Balancer
• Use one DNS instead of multiple IPs
• Enable failover if one EC2 goes down