Amazon Machine Images (AMIs) in AWS - Mini Project: Build & Apply

Amazon Machine Images (AMIs)

📖 Scenario: You are setting up a cloud environment where you want to create a custom Amazon Machine Image (AMI) to launch virtual servers with your preferred software and settings.

🎯 Goal: Build a simple AWS CloudFormation template step-by-step that defines an EC2 instance and creates an AMI from it.

📋 What You'll Learn

Create a CloudFormation template with an EC2 instance resource

Add a parameter for the base AMI ID

Use the parameter to specify the AMI for the EC2 instance

Add a resource to create an AMI from the EC2 instance

💡 Why This Matters

🌍 Real World

Creating custom AMIs helps launch EC2 instances quickly with pre-installed software and settings, saving time and ensuring consistency.

💼 Career

Cloud architects and DevOps engineers often create and manage AMIs to optimize infrastructure deployment and maintenance.

1

Create the base CloudFormation template with an EC2 instance

Create a CloudFormation template with a resource named MyInstance of type AWS::EC2::Instance. Set the ImageId property to ami-0abcdef1234567890 and InstanceType to t2.micro.

AWS

# Your CloudFormation template starts here
Resources:
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0abcdef1234567890
      InstanceType: t2.micro

Hint

Define the Resources section with an EC2 instance named MyInstance. Use the exact AMI ID and instance type given.

2

Add a parameter for the base AMI ID

Add a Parameters section with a parameter named BaseAmiId of type AWS::EC2::Image::Id. Remove the hardcoded ImageId from MyInstance and instead reference the parameter BaseAmiId using !Ref BaseAmiId.

AWS

Parameters:
  BaseAmiId:
    Type: AWS::EC2::Image::Id

Resources:
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref BaseAmiId
      InstanceType: t2.micro
# Add the parameter and update ImageId to use it

Hint

Use the Parameters section to allow the AMI ID to be passed in. Reference it in the EC2 instance.

3

Add a resource to create an AMI from the EC2 instance

Add a resource named MyAmi of type AWS::EC2::Image. Set the InstanceId property to reference MyInstance using !Ref MyInstance. Set the Name property to MyCustomAMI.

AWS

Parameters:
  BaseAmiId:
    Type: AWS::EC2::Image::Id

Resources:
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref BaseAmiId
      InstanceType: t2.micro
  MyAmi:
    Type: AWS::EC2::Image
    Properties:
      InstanceId: !Ref MyInstance
      Name: MyCustomAMI
# Add the AMI creation resource

Hint

Use the AWS::EC2::Image resource to create an AMI from the EC2 instance.

4

Add a tag to the AMI resource

Add a Tags property to the MyAmi resource. Add a tag with Key set to Purpose and Value set to CustomImage.

AWS

Parameters:
  BaseAmiId:
    Type: AWS::EC2::Image::Id

Resources:
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref BaseAmiId
      InstanceType: t2.micro
  MyAmi:
    Type: AWS::EC2::Image
    Properties:
      InstanceId: !Ref MyInstance
      Name: MyCustomAMI
      Tags:
        - Key: Purpose
          Value: CustomImage
# Add a tag to the AMI resource

Hint

Tags help identify your AMI. Add the Tags property with the specified key and value.

Practice

1. What is the main purpose of an Amazon Machine Image (AMI)?

easy

A. To monitor server performance

B. To store user data in the cloud

C. To save a server setup so it can be reused later

D. To manage network traffic

Solution

1. Step 1: Understand what an AMI represents

   An AMI is a snapshot of a server's setup including its software and settings.

2. Step 2: Identify the main use of AMIs

   AMIs allow you to reuse this saved setup to launch new servers quickly.

3. Final Answer:

   To save a server setup so it can be reused later -> Option C

4. Quick Check:

   AMI = reusable server setup [OK]

Hint: AMI saves server setup for reuse [OK]

Common Mistakes:

• Confusing AMI with data storage
• Thinking AMI monitors performance
• Assuming AMI manages network

2. Which AWS CLI command correctly creates an AMI from a running instance with ID i-1234567890abcdef0?

easy

A. aws ec2 start-image --instance i-1234567890abcdef0 --name MyServerImage

B. aws ec2 launch-image --instance-id i-1234567890abcdef0 --name MyServerImage

C. aws ec2 make-ami --id i-1234567890abcdef0 --image-name MyServerImage

D. aws ec2 create-image --instance-id i-1234567890abcdef0 --name MyServerImage

Solution

1. Step 1: Identify the correct AWS CLI command for creating an AMI

   The correct command is aws ec2 create-image with the instance ID and a name.

2. Step 2: Match the command syntax with the options

   aws ec2 create-image --instance-id i-1234567890abcdef0 --name MyServerImage uses the correct command and parameters.

3. Final Answer:

   aws ec2 create-image --instance-id i-1234567890abcdef0 --name MyServerImage -> Option D

4. Quick Check:

   create-image + instance-id = create AMI [OK]

Hint: Use 'create-image' with instance ID to make AMI [OK]

Common Mistakes:

• Using wrong command like start-image or launch-image
• Mixing up parameter names
• Omitting instance ID

3. You run this AWS CLI command:
aws ec2 create-image --instance-id i-0abc123def456 --name TestImage
What will be the immediate result?

medium

A. An AMI creation request is started; image becomes available after processing

B. The instance is stopped and then an AMI is created

C. A new AMI is created and available instantly

D. The command fails because instance ID is invalid

Solution

1. Step 1: Understand the behavior of create-image command

   The command starts the AMI creation process but the image is not instantly ready.

2. Step 2: Identify the correct immediate result

   The AMI creation runs in background; the image becomes available after some time.

3. Final Answer:

   An AMI creation request is started; image becomes available after processing -> Option A

4. Quick Check:

   AMI creation is asynchronous [OK]

Hint: AMI creation takes time; not instant [OK]

Common Mistakes:

• Assuming AMI is ready immediately
• Thinking instance stops automatically
• Believing command fails without error

4. You tried to create an AMI with this command:
aws ec2 create-image --instance i-0abc123def456 --name MyImage
But it failed. What is the error?

medium

A. Instance ID format is incorrect

B. Missing required parameter --instance-id

C. AMI name is invalid

D. You cannot create AMI from a running instance

Solution

1. Step 1: Check the command parameters

   The command uses --instance instead of the required --instance-id parameter.

2. Step 2: Identify the cause of failure

   The AWS CLI expects --instance-id to specify the instance; missing this causes failure.

3. Final Answer:

   Missing required parameter --instance-id -> Option B

4. Quick Check:

   Use --instance-id to specify instance [OK]

Hint: Use --instance-id, not --instance [OK]

Common Mistakes:

• Using wrong parameter name
• Assuming instance ID format error
• Thinking AMI can't be made from running instance

5. You want to launch multiple identical servers quickly using an AMI. Which steps should you follow?

hard

A. Create an AMI from a configured instance, then launch new instances using that AMI

B. Launch new instances, then manually configure each one separately

C. Create snapshots of volumes, then attach them to new instances

D. Use AWS Lambda to copy instance settings to new servers

Solution

1. Step 1: Understand how to reuse server setups

   Creating an AMI from a configured instance saves its setup for reuse.

2. Step 2: Use the AMI to launch new instances

   Launching new servers from the AMI ensures they have the same software and settings quickly.

3. Final Answer:

   Create an AMI from a configured instance, then launch new instances using that AMI -> Option A

4. Quick Check:

   AMI enables fast identical server launches [OK]

Hint: Create AMI first, then launch servers from it [OK]

Common Mistakes:

• Configuring each server manually
• Using snapshots instead of AMIs for full setup
• Thinking AWS Lambda copies server setups