AMI Hands On

🔹 1. Launch a Base EC2 Instance

• Choose Amazon Linux 2

• Select instance type: t3.micro

• Pick any key pair

• Use an existing security group

🔹 2. Add User Data (Install Apache Only)

Paste this script — skip the last line that creates the HTML page:

#!/bin/bash
# Install httpd (Amazon Linux 2)
yum update -y
yum install -y httpd
systemctl start httpd
systemctl enable httpd

echo "<h1>Hello World from $(hostname -f)</h1>" > /var/www/html/index.html 

What it does:

• Installs Apache (HTTPD)

• Starts and enables the service on boot

🔹 3. Wait for Initialization ⏳

Instance status = Running ≠ ready.

• User data still runs in the background

• Takes ~1–2 minutes to finish

Then visit:

http://<Public IPv4 address>

✅ You should see the Apache default test page

🧱 4. Create Your Custom AMI

• Right-click the instance or Select Instance and Click Actions

• Go to Image and templates → Create Image

• Name it demo-image

• Keep everything as Default and Click Create Image

Behind the scenes: AWS creates an AMI and an EBS snapshot automatically.

Wait for it:

• Go to AMIs

• Status moves from ⏳ Pending → ✅ Available

⚡ 5. Launch a New Instance from the AMI

• Click Launch Instance from AMI

• Name it From AMI

• Go to My AMIs - Owned by me

• Select demo-image

• Select key pair or Create new

• Select Existing Security Group from Network Setting or Create new

🔹 6. Add Minimal User Data (HTML Only)

• Scroll down to bottom

• Go to Advanced Details → User data

• Click Launch Instance

#!/bin/bash
# Use this for your user data (script from top to bottom)
# install httpd (Linux 2 version)
echo "<h1>Hello World from $(hostname -f)</h1>" > /var/www/html/index.html

Notice:

• ❌ No Apache install needed

• ✅ Already baked into the AMI

🚀 7. Result

• Wait a few minutes for the instance to finish initializing

• Select the instance launched from your AMI

• Copy its Public IPv4 address

• Paste it into your browser to see the result

🔥 Why This Matters

🧹 Cleanup

Delete From AMI instance or any other extra insantaces keep one primary instance only

🎯 Key Takeaways

• AMIs = pre-configured, reusable environments

• Save setup time on every new launch

• Improve consistency across instances

• Enable fast, repeatable scaling