feat(ecs): allow users to provide a CloudMap service to associate with an ECS service

packages/@aws-cdk/aws-ecs/README.md

@@ -728,6 +728,20 @@ new ecs.Ec2Service(stack, 'Service', {
 });
 ```
 
+### Associate With a Specific CloudMap Service
+
+You may associate an ECS service with a specific CloudMap service. To do
+this, use the service's `associateCloudMapService` method:
+
+```ts
+const cloudMapService = new cloudmap.Service(...);
+const ecsService = new ecs.FargateService(...);
+
+ecsService.associateCloudMapService({
+  service: cloudMapService,
+});
+```
+
 ## Capacity Providers
 
 Currently, only `FARGATE` and `FARGATE_SPOT` capacity providers are supported.

packages/@aws-cdk/aws-ecs/lib/base/base-service.ts

@@ -601,6 +601,27 @@ export abstract class BaseService extends Resource
     return cloudmapService;
   }
 
+  /**
+   * Associates this service with a CloudMap service
+   */
+  public associateCloudMapService(options: AssociateCloudMapServiceOptions): void {
+    const service = options.service;
+
+    const { containerName, containerPort } = determineContainerNameAndPort({
+      taskDefinition: this.taskDefinition,
+      dnsRecordType: service.dnsRecordType,
+      container: options.container,
+      containerPort: options.containerPort,
+    });
+
+    // add Cloudmap service to the ECS Service's serviceRegistry
+    this.addServiceRegistry({
+      arn: service.serviceArn,
+      containerName,
+      containerPort,
+    });
+  }
+
   /**
    * This method returns the specified CloudWatch metric name for this service.
    */
@@ -748,6 +769,10 @@ export abstract class BaseService extends Resource
    * Associate Service Discovery (Cloud Map) service
    */
   private addServiceRegistry(registry: ServiceRegistry) {
+    if (this.serviceRegistries.length >= 1) {
+      throw new Error('Cannot associate with the given service discovery registry. ECS supports at most one service registry per service.');
+    }
+
     const sr = this.renderServiceRegistry(registry);
     this.serviceRegistries.push(sr);
   }
@@ -816,6 +841,28 @@ export interface CloudMapOptions {
   readonly containerPort?: number;
 }
 
+/**
+ * The options for using a cloudmap service.
+ */
+export interface AssociateCloudMapServiceOptions {
+  /**
+   * The cloudmap service to register with.
+   */
+  readonly service: cloudmap.IService;
+
+  /**
+   * The container to point to for a SRV record.
+   * @default - the task definition's default container
+   */
+  readonly container?: ContainerDefinition;
+
+  /**
+   * The port to point to for a SRV record.
+   * @default - the default port of the task definition's default container
+   */
+  readonly containerPort?: number;
+}
+
 /**
  * Service Registry for ECS service
  */

packages/@aws-cdk/aws-ecs/test/fargate/fargate-service.test.ts

@@ -262,6 +262,101 @@ nodeunitShim({
       test.done();
     },
 
+    'with user-provided cloudmap service'(test: Test) {
+      // GIVEN
+      const stack = new cdk.Stack();
+      const vpc = new ec2.Vpc(stack, 'MyVpc', {});
+      const cluster = new ecs.Cluster(stack, 'EcsCluster', { vpc });
+      const taskDefinition = new ecs.FargateTaskDefinition(stack, 'FargateTaskDef');
+
+      const container = taskDefinition.addContainer('web', {
+        image: ecs.ContainerImage.fromRegistry('amazon/amazon-ecs-sample'),
+        memoryLimitMiB: 512,
+      });
+      container.addPortMappings({ containerPort: 8000 });
+
+      const cloudMapNamespace = new cloudmap.PrivateDnsNamespace(stack, 'TestCloudMapNamespace', {
+        name: 'scorekeep.com',
+        vpc,
+      });
+
+      const cloudMapService = new cloudmap.Service(stack, 'Service', {
+        name: 'service-name',
+        namespace: cloudMapNamespace,
+        dnsRecordType: cloudmap.DnsRecordType.SRV,
+      });
+
+      const ecsService = new ecs.FargateService(stack, 'FargateService', {
+        cluster,
+        taskDefinition,
+      });
+
+      // WHEN
+      ecsService.associateCloudMapService({
+        service: cloudMapService,
+        container: container,
+        containerPort: 8000,
+      });
+
+      // THEN
+      expect(stack).to(haveResource('AWS::ECS::Service', {
+        ServiceRegistries: [
+          {
+            ContainerName: 'web',
+            ContainerPort: 8000,
+            RegistryArn: { 'Fn::GetAtt': ['ServiceDBC79909', 'Arn'] },
+          },
+        ],
+      }));
+
+      test.done();
+    },
+
+    'errors when more than one service registry used'(test: Test) {
+      // GIVEN
+      const stack = new cdk.Stack();
+      const vpc = new ec2.Vpc(stack, 'MyVpc', {});
+      const cluster = new ecs.Cluster(stack, 'EcsCluster', { vpc });
+      const taskDefinition = new ecs.FargateTaskDefinition(stack, 'FargateTaskDef');
+
+      const container = taskDefinition.addContainer('web', {
+        image: ecs.ContainerImage.fromRegistry('amazon/amazon-ecs-sample'),
+        memoryLimitMiB: 512,
+      });
+      container.addPortMappings({ containerPort: 8000 });
+
+      const cloudMapNamespace = new cloudmap.PrivateDnsNamespace(stack, 'TestCloudMapNamespace', {
+        name: 'scorekeep.com',
+        vpc,
+      });
+
+      const ecsService = new ecs.FargateService(stack, 'FargateService', {
+        cluster,
+        taskDefinition,
+      });
+
+      ecsService.enableCloudMap({
+        cloudMapNamespace,
+      });
+
+      const cloudMapService = new cloudmap.Service(stack, 'Service', {
+        name: 'service-name',
+        namespace: cloudMapNamespace,
+        dnsRecordType: cloudmap.DnsRecordType.SRV,
+      });
+
+      // WHEN / THEN
+      test.throws(() => {
+        ecsService.associateCloudMapService({
+          service: cloudMapService,
+          container: container,
+          containerPort: 8000,
+        });
+      }, /at most one service registry/i);
+
+      test.done();
+    },
+
     'with all properties set'(test: Test) {
       // GIVEN
       const stack = new cdk.Stack();