Automation is critical to improving efficiency and scaling resources in today’s cloud environment. One such automation is the creation of Amazon Machine Images (AMIs), which ensures consistency and ease of deployment for various applications. In this blog, we’ll walk through automating AMI creation in AWS, setting up a golden image pipeline, and leveraging AWS services like SNS, Lambda, and CloudFormation for a smooth workflow.

Introduction to Automated AMI Creation

An Amazon Machine Image (AMI) is a pre-configured template for launching EC2 instances. Automated AMI creation helps standardize the environment for your applications and eliminates manual processes that can introduce inconsistencies. Automating the process ensures that every AMI is created based on a set of defined steps that can be repeated across environments without human intervention.

Setting Up the Golden Image Pipeline

A golden image pipeline is a critical component in the automation of AMI creation. This pipeline involves steps to standardize the base image (often called the golden image) that will be used to deploy EC2 instances. The pipeline includes the following steps:

  1. Start with a base AMI, which may consist of only the operating system.
  2. Install necessary security updates, application dependencies, and system configurations.
  3. Create the AMI from this configured instance.
  4. Automate this process using AWS services such as CodePipeline or a combination of Lambda functions.

Configuring SNS Topics for Notifications

Amazon Simple Notification Service (SNS) is critical in informing users or systems about crucial events during the AMI creation process. SNS topics can be configured to send notifications when specific events, such as the successful creation of an AMI or errors in the pipeline, occur.

Steps to configure SNS:

  1. Create an SNS topic through the AWS Management Console.
  2. Subscribe to the topic by adding email addresses or integrating with other services such as Lambda.
  3. Ensure that the pipeline or Lambda function sends messages to this topic at each critical step of the AMI creation process.

Creating the Application AMI CloudFormation Template

AWS CloudFormation enables infrastructure as code, making it easy to define and automate the deployment of your AMI creation resources. You can define the following resources in a CloudFormation template:

  • EC2 instance to serve as the base for the AMI.
  • Security groups, IAM roles, and instance profiles for secure AMI creation.
  • Lambda functions to handle automation tasks.

A basic example of a CloudFormation template might look like this:

Resources:

  MyInstance:

    Type: “AWS::EC2::Instance”

    Properties:

      InstanceType: “t2.micro”

      ImageId: !Ref BaseAMIId

      IamInstanceProfile: !Ref InstanceProfile

      SecurityGroupIds: [ !Ref SecurityGroup ]

  MyImage:

    Type: “AWS::EC2::Image”

    Properties:

      InstanceId: !Ref MyInstance

Implementing Lambda Function for Automation

The power of AWS Lambda comes into play when you need to automate the AMI creation process. A Lambda function can be triggered to perform tasks such as:

  • Starting the EC2 instance with a base AMI.
  • Running configuration scripts (e.g., using AWS Systems Manager).
  • Stopping the instance and creating the AMI.

For example, the following Lambda function code triggers the creation of an AMI:

import boto3

def lambda_handler(event, context):

    ec2 = boto3.client(‘ec2’)

    instance_id = event[‘instance_id’]

    

    # Stop instance to prepare for AMI creation

    ec2.stop_instances(InstanceIds=[instance_id])

    waiter = ec2.get_waiter(‘instance_stopped’)

    waiter.wait(InstanceIds=[instance_id])

    

    # Create the AMI

    response = ec2.create_image(

        InstanceId=instance_id,

        Name=’MyApp-AMI-‘ + instance_id,

        NoReboot=True

    )

    return response[‘ImageId’]

Subscribing Lambda to SNS Topic for Triggering

To fully automate the AMI creation process, subscribe to the Lambda function on an SNS topic. This way, whenever an event, such as a schedule or a successful step in your pipeline, occurs, the SNS topic triggers the Lambda function to create an AMI.

Steps:

  1. In the SNS console, find the topic you created earlier.
  2. Create a subscription and select AWS Lambda as the protocol.
  3. Choose the Lambda function that is responsible for creating the AMI.

Whenever the SNS topic is triggered, the Lambda function will automatically run, ensuring your AMI is created without manual intervention.

Executing the Golden Image Pipeline

Once everything is set up, you can execute your golden image pipeline, which automates the entire process:

  1. The pipeline initiates by launching an EC2 instance with the base AMI.
  2. System updates and software installations are performed (via AWS Systems Manager or user data).
  3. Once the instance is configured, it is stopped, and a new AMI is created.
  4. The SNS topic sends notifications at each critical step, ensuring real-time monitoring.
  5. The final AMI is stored for future use in application deployments.

Conclusion: Automating AMI Creation for Efficient Deployments

Automating the AMI creation process with AWS services like Lambda, SNS, and CloudFormation simplifies application deployment, ensures consistency, and reduces the potential for human error. By setting up a golden image pipeline, you can streamline the AMI creation process, improving the efficiency and reliability of your application deployments.

References

Create AMIs with AWS CodePipeline

Amazon Machine Images in Amazon EC2