fix(elasticloadbalancingv2): validate port/protocol are not provided for lambda targets

packages/@aws-cdk/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts

@@ -134,6 +134,17 @@ export class ApplicationTargetGroup extends TargetGroupBase implements IApplicat
     this.protocol = protocol;
     this.port = port;
 
+    // this.targetType is lazy
+    this.node.addValidation({
+      validate: () => {
+        if (this.targetType === TargetType.LAMBDA && (this.port || this.protocol)) {
+          return ['port/protocol should not be specified for Lambda targets'];
+        } else {
+          return [];
+        }
+      },
+    });
+
     this.connectableMembers = [];
     this.listeners = [];
 

packages/@aws-cdk/aws-elasticloadbalancingv2/test/alb/target-group.test.ts

@@ -48,6 +48,35 @@ describe('tests', () => {
     expect(Object.keys(matches).length).toBe(0);
   });
 
+  test('Lambda target should not have port set', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app, 'Stack');
+
+    const tg = new elbv2.ApplicationTargetGroup(stack, 'TG2', {
+      protocol: elbv2.ApplicationProtocol.HTTPS,
+    });
+    tg.addTarget({
+      attachToApplicationTargetGroup(_targetGroup: elbv2.IApplicationTargetGroup): elbv2.LoadBalancerTargetProps {
+        return {
+          targetType: elbv2.TargetType.LAMBDA,
+          targetJson: { id: 'arn:aws:lambda:eu-west-1:123456789012:function:myFn' },
+        };
+      },
+    });
+    expect(() => app.synth()).toThrow(/port\/protocol should not be specified for Lambda targets/);
+  });
+
+  test('Lambda target should not have protocol set', () => {
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app, 'Stack');
+
+    new elbv2.ApplicationTargetGroup(stack, 'TG', {
+      port: 443,
+      targetType: elbv2.TargetType.LAMBDA,
+    });
+    expect(() => app.synth()).toThrow(/port\/protocol should not be specified for Lambda targets/);
+  });
+
   test('Can add self-registering target to imported TargetGroup', () => {
     // GIVEN
     const app = new cdk.App();