Fix kubectl describe ingress when default backend is empty

Kubernetes-commit: 653edeb507c3caafd0e81f6cef0a44425ef8782c

pkg/describe/describe.go

@@ -2653,11 +2653,11 @@ func (i *IngressDescriber) describeIngressV1(ing *networkingv1.Ingress, events *
 		w.Write(LEVEL_0, "Ingress Class:\t%v\n", ingressClassName)
 		def := ing.Spec.DefaultBackend
 		ns := ing.Namespace
-		if def == nil {
-			w.Write(LEVEL_0, "Default backend:\t<default>\n")
-		} else {
-			w.Write(LEVEL_0, "Default backend:\t%s\n", i.describeBackendV1(ns, def))
+		defaultBackendDescribe := "<default>"
+		if def != nil {
+			defaultBackendDescribe = i.describeBackendV1(ns, def)
 		}
+		w.Write(LEVEL_0, "Default backend:\t%s\n", defaultBackendDescribe)
 		if len(ing.Spec.TLS) != 0 {
 			describeIngressTLSV1(w, ing.Spec.TLS)
 		}
@@ -2680,7 +2680,7 @@ func (i *IngressDescriber) describeIngressV1(ing *networkingv1.Ingress, events *
 			}
 		}
 		if count == 0 {
-			w.Write(LEVEL_1, "%s\t%s\t%s\n", "*", "*", i.describeBackendV1(ns, def))
+			w.Write(LEVEL_1, "%s\t%s\t%s\n", "*", "*", defaultBackendDescribe)
 		}
 		printAnnotationsMultiline(w, "Annotations", ing.Annotations)
 

pkg/describe/describe_test.go

@@ -2800,6 +2800,30 @@ Rules:
   *           *     default-backend:80 (<error: endpoints "default-backend" not found>)
 Annotations:  <none>
 Events:       <none>
+`,
+		},
+		"EmptyBackend": {
+			input: fake.NewSimpleClientset(&networkingv1.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "bar",
+					Namespace: "foo",
+				},
+				Spec: networkingv1.IngressSpec{
+					IngressClassName: &ingresClassName,
+				},
+			}),
+			output: `Name:             bar
+Labels:           <none>
+Namespace:        foo
+Address:          
+Ingress Class:    test
+Default backend:  <default>
+Rules:
+  Host        Path  Backends
+  ----        ----  --------
+  *           *     <default>
+Annotations:  <none>
+Events:       <none>
 `,
 		},
 		"EmptyIngressClassName": {