Lambda@Edge - AWS Serverless

1. Introduction

Lambda@Edge is a feature of Amazon CloudFront that allows you to run serverless functions (AWS Lambda functions) at AWS locations closer to your users, enhancing performance and reducing latency.

2. Key Concepts

• **Serverless Computing**: Execute code without provisioning or managing servers.
• **CloudFront**: A content delivery network (CDN) that delivers data, videos, applications, and APIs to customers globally with low latency.
• **Lambda Function**: A piece of code that runs in response to events, such as HTTP requests from CloudFront.

3. Step-by-Step Guide

3.1 Creating a Lambda@Edge Function

1. Log in to the AWS Management Console and navigate to AWS Lambda.
2. Click on "Create function".
3. Select "Author from scratch".
4. Enter a name for your function and choose a runtime (e.g., Node.js).
5. In the "Function code" section, add your code. Example:

exports.handler = async (event) => {
    const request = event.Records[0].cf.request;
    // Modify the request as needed
    return request;
};
            

3.2 Deploying Your Function

1. Under "Designer", select "Add trigger".
2. Choose "CloudFront" as the trigger.
3. Select the CloudFront distribution you want to associate with your Lambda function.
4. Choose the event type (e.g., Viewer Request, Origin Request).
5. Click "Deploy" to activate your Lambda@Edge function.

4. Best Practices

• **Test Locally**: Use AWS SAM or similar tools to test your Lambda functions locally before deploying.
• **Monitor Performance**: Use Amazon CloudWatch to monitor the execution of your Lambda@Edge functions.
• **Optimize Cold Starts**: Keep your functions lightweight and avoid using large dependencies to minimize cold start times.

5. FAQ