CDK Lambda Function and API Gateway

This CDK project simplifies the process of creating a Lambda function and API Gateway using AWS Cloud Development Kit (CDK) and TypeScript.

Prerequisites

Before you begin, ensure you have the following installed and set up:

• Node.js and npm
• AWS CLI configured with necessary credentials and permissions

Steps

1. Create a New Project Folder

Create a new folder for your CDK project. Replace your-project-name with a suitable name for your project.

mkdir your-project-name
cd your-project-name

2. Initialize the CDK Project

Inside your project folder, initialize a new CDK project with TypeScript.

cdk init app --language javascript

3. Add Lambda Function and API Gateway Code

Edit the lib/your-project-name-stack.ts file and add your Lambda function and API Gateway code to the YourProjectNameStack class. You can use AWS Lambda and API Gateway classes provided by CDK for this purpose.

Example code for creating a Lambda function and API Gateway:

const { Stack } = require('aws-cdk-lib');
// const sqs = require('aws-cdk-lib/aws-sqs');
const s3 = require('aws-cdk-lib/aws-s3');
const lambda = require('aws-cdk-lib/aws-lambda');
const apigw = require('aws-cdk-lib/aws-apigateway');
 

class CdkTestStack extends Stack {
  /**
   *
   * @param {Construct} scope
   * @param {string} id
   * @param {StackProps=} props
   */
  constructor(scope, id, props) {
    super(scope, id, props);

    // Lambda function that outptus "Hello World" connected to an API Gateway HTTP endpoint /hello
    const hello = new lambda.Function(this, 'my-cdk-hello-handler', {
      runtime: lambda.Runtime.NODEJS_18_X,
      code: lambda.Code.fromAsset('lambda'),
      handler: 'hello.handler',
    });

    // define an API Gateway REST API resource backed by our "hello" function.
    // name the API Gateway resource "my-cdk-api-gw"
    // the API Gateway endpoint will be /hello GET only 
    const gw = new apigw.LambdaRestApi(this, 'my-cdk-api-gw', {
      handler: hello,
      proxy: false,
    }); 

    // add a resource to the API Gateway endpoint
    // name the resource "hello"
    // the resource will be /hello
    const helloResource = gw.root.addResource('hello');

    // add a method to the API Gateway endpoint
    // name the method "GET"
    // the method will be GET
    // the method will be backed by the hello Lambda function
    helloResource.addMethod('GET', new apigw.LambdaIntegration(hello));
    
    
  }
}

module.exports = { CdkTestStack }

4. Synthesize the CDK Project

Generate the CloudFormation template for your CDK project.

cdk synth

5. Deploy the CDK Project

Deploy your CDK project, which will create the Lambda function and API Gateway resources in AWS.

cdk deploy

Clean Up

To avoid incurring unnecessary costs, make sure to destroy the resources when you are done with your project.

cdk destroy

This will remove all the resources created by your CDK stack.