delivery-stack.ts

import { Construct } from 'constructs';
import * as events from 'aws-cdk-lib/aws-events'
import { LambdaFunction as LambdaFunctionTarget } from 'aws-cdk-lib/aws-events-targets'
import * as nodeLambda from 'aws-cdk-lib/aws-lambda-nodejs'
import * as lambda from 'aws-cdk-lib/aws-lambda'
import { BaseStack, BaseStackProps } from './base-stack'
import { CfnOutput, Duration } from 'aws-cdk-lib';
import { RetentionDays } from 'aws-cdk-lib/aws-logs';
import { POWERTOOLS_METRICS_NAMESPACE } from '../src/lambda-common';

/**
 * Application to handle deliveries for orders
 * 
 * When an Order.Created event is received, this application "delivers" the order
 */
export class DeliveryServiceStack extends BaseStack {

  localBus: events.EventBus
  identifier: string

  constructor(scope: Construct, id: string, props: BaseStackProps) {
    super(scope, id, props);
    this.identifier = props.identifier
    this.createOrderDeliveryFunction()
  }

  createOrderDeliveryFunction() {
    const orderDeliveryFunction = new nodeLambda.NodejsFunction(this, 'OrderDeliveryFunction', {
      entry: './src/delivery-handler.ts',
      runtime: lambda.Runtime.NODEJS_18_X,
      handler: 'handleOrderCreated',
      environment: {
        BUS_ARN: this.globalBus.eventBusArn,
        SERVICE_IDENTIFIER: this.identifier,
        POWERTOOLS_SERVICE_NAME: 'OrderDelivery',
        POWERTOOLS_METRICS_NAMESPACE
      },
      timeout: Duration.seconds(10),
      logRetention: RetentionDays.ONE_WEEK,
      tracing: lambda.Tracing.ACTIVE,
    })
    orderDeliveryFunction.addToRolePolicy(this.globalBusPutEventsStatement)

    // The delivery function reacts to orders being created
    const orderDeliveryRule = new events.Rule(this, 'OrderDeliveryRule', {
      eventBus: this.localBus,
      ruleName: 'order-delivery-rule',
      eventPattern: {
        detailType: ['Order.Created'],
      },
    })
    orderDeliveryRule.addTarget(new LambdaFunctionTarget(orderDeliveryFunction))

    new CfnOutput(this, 'orderDeliveryRule', {
      value: orderDeliveryRule.ruleName
    })

    new CfnOutput(this, 'orderDeliveryRuleTarget', {
      value: 'Target0'
    })
  }
}