Add Cloud Map service to Application Load Balancer created by ApplicationLoadBalancedFargateService - amazon-web-services

Question

I've got the following Fargate service created by an ecs pattern. The CloudMap I create here only points to the underlying task which is a private IP and runs on port 8080 (Tomcat). The ALB forwards properly from 80->8080. How can I get the DNS to properly route to the task? Can I get the DNS service to route directly to the ALB?
const service = new ecs_patterns.ApplicationLoadBalancedFargateService(this, 'MyAppWebstartFargateService', {
serviceName: "myapp-service",
cluster: cluster,
cpu: 512,
memoryLimitMiB: 2048,
cloudMapOptions: {
name: "myapp",
containerPort: 8080,
cloudMapNamespace: namespace,
dnsRecordType: svc_dsc.DnsRecordType.A,
dnsTtl: Duration.seconds(300),
},
desiredCount: 1,
publicLoadBalancer: false,
securityGroups: [sg],
listenerPort: 80,
openListener: true,
healthCheckGracePeriod: Duration.seconds(300),
targetProtocol: elbv2.ApplicationProtocol.HTTP,
protocol: elbv2.ApplicationProtocol.HTTP,
enableExecuteCommand: true,
taskImageOptions: {
containerName: "myapp-container",
containerPort: 8080,
enableLogging: true,
image: ecs.ContainerImage.fromEcrRepository(repository, "latest"),
},
});

Answer 1

I figured it out! I needed to call registerLoadBalancer on the Cloud Map service and give it the resulting LB from the Fargate pattern. Hope this helps someone down the road b/c I could not find any solution to this exact use case.
const namespace = svc_dsc.PrivateDnsNamespace.fromPrivateDnsNamespaceAttributes(this, "MyAppCloudMapNamespace", {
namespaceArn: "*****************",
namespaceId: "999999999999999",
namespaceName: "mydomain.com"
});
const mapService = new svc_dsc.Service(this, 'MyAppCloudMapService', {
namespace: namespace,
dnsRecordType: svc_dsc.DnsRecordType.A,
dnsTtl: Duration.seconds(300),
name: "myapp",
routingPolicy: svc_dsc.RoutingPolicy.WEIGHTED,
loadBalancer: true // Important! If you choose WEIGHTED but don't set this, the routing policy will default to MULTIVALUE instead
});
const service = new ecs_patterns.ApplicationLoadBalancedFargateService(this, 'MyAppWebstartFargateService', {
serviceName: "myapp-service",
cluster: cluster,
cpu: 512,
memoryLimitMiB: 2048,
desiredCount: 1,
publicLoadBalancer: false,
securityGroups: [sg],
listenerPort: 80,
openListener: true,
healthCheckGracePeriod: Duration.seconds(300),
targetProtocol: elbv2.ApplicationProtocol.HTTP,
protocol: elbv2.ApplicationProtocol.HTTP,
enableExecuteCommand: true,
taskImageOptions: {
containerName: "myapp-container",
containerPort: 8080,
enableLogging: true,
image: ecs.ContainerImage.fromEcrRepository(repository, "latest"),
},
});
mapService.registerLoadBalancer("MyAppLoadBalancer", service.loadBalancer);