Make the output of kubectl describe service more informative (#125117)

* kubectl: add internalTrafficPolicy to Service describer

* kubectl: add loadBalancer ipMode to Service describer

* kubectl: fix duplicate IP fields in Service describer

For a LoadBalancer Service, there were two "IP" fields in the output of
`kubectl describe service` if its loadBalancerIP is not empty, which
looks ambiguous.

staging/src/k8s.io/kubectl/pkg/describe/describe.go

@@ -2984,6 +2984,9 @@ func buildIngressString(ingress []corev1.LoadBalancerIngress) string {
 		}
 		if ingress[i].IP != "" {
 			buffer.WriteString(ingress[i].IP)
+			if ingress[i].IPMode != nil {
+				buffer.WriteString(fmt.Sprintf(" (%s)", *ingress[i].IPMode))
+			}
 		} else {
 			buffer.WriteString(ingress[i].Hostname)
 		}
@@ -3027,7 +3030,7 @@ func describeService(service *corev1.Service, endpointSlices []discoveryv1.Endpo
 			w.Write(LEVEL_0, "External IPs:\t%v\n", strings.Join(service.Spec.ExternalIPs, ","))
 		}
 		if service.Spec.LoadBalancerIP != "" {
-			w.Write(LEVEL_0, "IP:\t%s\n", service.Spec.LoadBalancerIP)
+			w.Write(LEVEL_0, "Desired LoadBalancer IP:\t%s\n", service.Spec.LoadBalancerIP)
 		}
 		if service.Spec.ExternalName != "" {
 			w.Write(LEVEL_0, "External Name:\t%s\n", service.Spec.ExternalName)
@@ -3058,6 +3061,9 @@ func describeService(service *corev1.Service, endpointSlices []discoveryv1.Endpo
 		if service.Spec.ExternalTrafficPolicy != "" {
 			w.Write(LEVEL_0, "External Traffic Policy:\t%s\n", service.Spec.ExternalTrafficPolicy)
 		}
+		if service.Spec.InternalTrafficPolicy != nil {
+			w.Write(LEVEL_0, "Internal Traffic Policy:\t%s\n", *service.Spec.InternalTrafficPolicy)
+		}
 		if service.Spec.HealthCheckNodePort != 0 {
 			w.Write(LEVEL_0, "HealthCheck NodePort:\t%d\n", service.Spec.HealthCheckNodePort)
 		}

staging/src/k8s.io/kubectl/pkg/describe/describe_test.go

@@ -710,8 +710,19 @@ func TestDescribeService(t *testing.T) {
 					LoadBalancerIP:        "5.6.7.8",
 					SessionAffinity:       corev1.ServiceAffinityNone,
 					ExternalTrafficPolicy: corev1.ServiceExternalTrafficPolicyLocal,
+					InternalTrafficPolicy: ptr.To(corev1.ServiceInternalTrafficPolicyCluster),
 					HealthCheckNodePort:   32222,
 				},
+				Status: corev1.ServiceStatus{
+					LoadBalancer: corev1.LoadBalancerStatus{
+						Ingress: []corev1.LoadBalancerIngress{
+							{
+								IP:     "5.6.7.8",
+								IPMode: ptr.To(corev1.LoadBalancerIPModeVIP),
+							},
+						},
+					},
+				},
 			},
 			endpointSlices: []*discoveryv1.EndpointSlice{{
 				ObjectMeta: metav1.ObjectMeta{
@@ -742,13 +753,15 @@ func TestDescribeService(t *testing.T) {
 				IP Families:              IPv4
 				IP:                       1.2.3.4
 				IPs:                      <none>
-				IP:                       5.6.7.8
+				Desired LoadBalancer IP:  5.6.7.8
+				LoadBalancer Ingress:     5.6.7.8 (VIP)
 				Port:                     port-tcp  8080/TCP
 				TargetPort:               9527/TCP
 				NodePort:                 port-tcp  31111/TCP
 				Endpoints:                10.244.0.1:9527,10.244.0.2:9527,10.244.0.3:9527
 				Session Affinity:         None
 				External Traffic Policy:  Local
+				Internal Traffic Policy:  Cluster
 				HealthCheck NodePort:     32222
 				Events:                   <none>
 			`)[1:],
@@ -775,8 +788,18 @@ func TestDescribeService(t *testing.T) {
 					LoadBalancerIP:        "5.6.7.8",
 					SessionAffinity:       corev1.ServiceAffinityNone,
 					ExternalTrafficPolicy: corev1.ServiceExternalTrafficPolicyLocal,
+					InternalTrafficPolicy: ptr.To(corev1.ServiceInternalTrafficPolicyLocal),
 					HealthCheckNodePort:   32222,
 				},
+				Status: corev1.ServiceStatus{
+					LoadBalancer: corev1.LoadBalancerStatus{
+						Ingress: []corev1.LoadBalancerIngress{
+							{
+								IP: "5.6.7.8",
+							},
+						},
+					},
+				},
 			},
 			endpointSlices: []*discoveryv1.EndpointSlice{
 				{
@@ -827,13 +850,15 @@ func TestDescribeService(t *testing.T) {
 				IP Families:              IPv4
 				IP:                       1.2.3.4
 				IPs:                      <none>
-				IP:                       5.6.7.8
+				Desired LoadBalancer IP:  5.6.7.8
+				LoadBalancer Ingress:     5.6.7.8
 				Port:                     port-tcp  8080/TCP
 				TargetPort:               targetPort/TCP
 				NodePort:                 port-tcp  31111/TCP
 				Endpoints:                10.244.0.1:9527,10.244.0.2:9527,10.244.0.3:9527 + 2 more...
 				Session Affinity:         None
 				External Traffic Policy:  Local
+				Internal Traffic Policy:  Local
 				HealthCheck NodePort:     32222
 				Events:                   <none>
 			`)[1:],
@@ -890,7 +915,7 @@ func TestDescribeService(t *testing.T) {
 				IP Families:              IPv4
 				IP:                       1.2.3.4
 				IPs:                      <none>
-				IP:                       5.6.7.8
+				Desired LoadBalancer IP:  5.6.7.8
 				Port:                     port-tcp  8080/TCP
 				TargetPort:               targetPort/TCP
 				NodePort:                 port-tcp  31111/TCP
@@ -939,7 +964,7 @@ func TestDescribeService(t *testing.T) {
 				IP Families:              IPv4
 				IP:                       1.2.3.4
 				IPs:                      1.2.3.4
-				IP:                       5.6.7.8
+				Desired LoadBalancer IP:  5.6.7.8
 				Port:                     port-tcp  8080/TCP
 				TargetPort:               targetPort/TCP
 				NodePort:                 port-tcp  31111/TCP