Service E2Es: ensure pods can communicate using src port equal to nod…

…e port

Signed-off-by: Martin Kennelly <mkennell@redhat.com>

test/e2e/service.go

@@ -72,6 +72,33 @@ var _ = ginkgo.Describe("Services", func() {
 	udpPort := int32(rand.Intn(1000) + 10000)
 	udpPortS := fmt.Sprintf("%d", udpPort)
 
+	ginkgo.It("Allow connection to an external IP using a source port that is equal to a node port", func() {
+		const (
+			nodePort    = 31990
+			connTimeout = "2"
+			dstIP       = "1.1.1.1"
+			dstPort     = "80"
+		)
+		ginkgo.By("create node port service")
+		jig := e2eservice.NewTestJig(cs, f.Namespace.Name, serviceName)
+		_, err := jig.CreateTCPService(context.TODO(), func(svc *v1.Service) {
+			svc.Spec.Type = v1.ServiceTypeNodePort
+			svc.Spec.Ports[0].NodePort = nodePort
+		})
+		framework.ExpectNoError(err, "failed to create TCP node port service")
+		ginkgo.By("create pod selected by node port service")
+		serverPod := e2epod.NewAgnhostPod(f.Namespace.Name, "svc-backend", nil, nil, nil)
+		serverPod.Labels = jig.Labels
+		e2epod.NewPodClient(f).CreateSync(context.TODO(), serverPod)
+		ginkgo.By("create pod which will connect externally")
+		clientPod := e2epod.NewAgnhostPod(f.Namespace.Name, "client-for-external", nil, nil, nil)
+		e2epod.NewPodClient(f).CreateSync(context.TODO(), clientPod)
+		ginkgo.By("connect externally pinning the source port to equal the node port")
+		_, err = e2ekubectl.RunKubectl(clientPod.Namespace, "exec", clientPod.Name, "--", "nc",
+			"-p", strconv.Itoa(nodePort), "-z", "-w", connTimeout, dstIP, dstPort)
+		framework.ExpectNoError(err, "expected connection to succeed using source port identical to node port")
+	})
+
 	ginkgo.It("Creates a host-network service, and ensures that host-network pods can connect to it", func() {
 		namespace := f.Namespace.Name
 		jig := e2eservice.NewTestJig(cs, namespace, serviceName)