Direct integration example between API Gateway and Amazon EventBridge

orders-service.ts

const eventBus: IEventBus = EventBus.fromEventBusName(
  this,
  "OnlineOrders",
  "OnlineOrdersEventBus"
);

// event bridge options for the api gateway integration
const eventBridgeOptions: apigw.IntegrationOptions = {
  credentialsRole: apigwRole,
  requestParameters: {
    "integration.request.header.X-Amz-Target": "'AWSEvents.PutEvents'",
    "integration.request.header.Content-Type":
      "'application/x-amz-json-1.1'",
  },
  requestTemplates: {
    "application/json": `{"Entries": [{"Source": "com.lee.pizza", "Detail":"$util.escapeJavaScript($input.json('$'))", "DetailType": "CreateOrder", "EventBusName": "${eventBus.eventBusName}"}]}`,
  },
  integrationResponses: [
    {
      statusCode: "200",
      responseTemplates: {
        "application/json": "Created",
      },
    },
  ],
};

// the create order endpoint persists a message directly on eventbridge
orders.addMethod(
  "POST",
  new apigw.Integration({
    type: apigw.IntegrationType.AWS,
    uri: `arn:aws:apigateway:${cdk.Aws.REGION}:events:path//`,
    integrationHttpMethod: "POST",
    options: eventBridgeOptions,
  }),
  { methodResponses: [{ statusCode: "200" }] }
);

const createOrdersDlq: sqs.Queue = new sqs.Queue(this, "CreateOrdersDlq", {
  removalPolicy: RemovalPolicy.DESTROY,
  queueName: "create-orders-dlq",
});

new events.Rule(this, "CreateOrderLambdaProcessorRule", {
  eventBus,
  eventPattern: { source: ["com.lee.pizza"] },
  targets: [
    new targets.LambdaFunction(createOrderHandler, {
      deadLetterQueue: createOrdersDlq,
    }),
  ],
});