Examining the CDK code

As you’ve already guessed, the CDK code resides within the /infrastructure directory, with the CDK entry point being the /infrastructure/bin/chapter-3.ts file:

#!/usr/bin/env node
import 'source-map-support/register';
import * as cdk from 'aws-cdk-lib';
import { Chapter3Stack } from '../lib/chapter-3-stack';
const app = new cdk.App();
new Chapter3Stack(app, 'Chapter3Stack', {});

Nothing fancy is going on here. We are just telling it to load up the root stack of the CDK app, which is Chapter3Stack. Open /infrastructure/lib/chapter-3-stack.ts in your code editor:

export class Chapter3Stack extends Stack {
  public readonly dynamodb: Dynamodb;
  public readonly s3: S3;
  public readonly ecs: ECS;
  constructor(scope: Construct, id: string, props?: StackProps) {
    super(scope, id, props);
    this.dynamodb = new Dynamodb(this,...