fix(ecs): suppress shouldUseCircuitBreaker warning for DAEMON scheduling strategy services

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

@@ -1013,8 +1013,9 @@ export abstract class BaseService extends Resource
       Annotations.of(this)._addTrackableError(lit`CircuitBreakerRequiresEcsController`, 'Deployment circuit breaker requires the ECS deployment controller.');
     }
 
-    if (!props.circuitBreaker && this.isEcsDeploymentController) {
+    if (!props.circuitBreaker && this.isEcsDeploymentController && additionalProps?.schedulingStrategy !== 'DAEMON') {
       // If we *could* use a circuit breaker, then let's recommend users to do so. It makes detecting errors sooo much faster.
+      // The circuit breaker is not applicable to DAEMON services (its threshold is desiredCount-based and daemon services have no desiredCount).
       Annotations.of(this).addWarningV2('@aws-cdk/aws-ecs:shouldUseCircuitBreaker', 'Enable the \'circuitBreaker\' property to trigger a quicker deployment failure if tasks are failing to come start (without this setting deployments may take up to 3 hours to fail).');
     }
 

packages/aws-cdk-lib/aws-ecs/test/ec2/ec2-service.test.ts

@@ -94,6 +94,33 @@ describe('ec2 service', () => {
       }
     });
 
+    test('does not suggest circuitBreaker for DAEMON scheduling strategy services', () => {
+      // GIVEN
+      const app = new cdk.App();
+      const stack = new cdk.Stack(app, 'Stack');
+      const vpc = new ec2.Vpc(stack, 'MyVpc', {});
+      const cluster = new ecs.Cluster(stack, 'EcsCluster', { vpc });
+      addDefaultCapacityProvider(cluster, stack, vpc);
+      const taskDefinition = new ecs.Ec2TaskDefinition(stack, 'Ec2TaskDef');
+
+      taskDefinition.addContainer('web', {
+        image: ecs.ContainerImage.fromRegistry('amazon/amazon-ecs-sample'),
+        memoryLimitMiB: 512,
+      });
+
+      new ecs.Ec2Service(stack, 'Ec2Service', {
+        cluster,
+        taskDefinition,
+        daemon: true,
+        // no circuitBreaker — warning should NOT fire because daemon services
+        // have no desiredCount and the circuit breaker threshold is desiredCount-based
+      });
+
+      // THEN
+      const warnings = flattenMeta(app.synth().getStackByName('Stack').metadata)['/Stack/Ec2Service']?.['aws:cdk:warning'];
+      expect(warnings ?? []).not.toContainEqual(expect.stringContaining('Enable the \'circuitBreaker\' property'));
+    });
+
     [false, undefined].forEach((value) => {
       test('set cloudwatch permissions based on falsy feature flag when no cloudwatch log configured', () => {
         // GIVEN