Merge pull request #100505 from lauchokyip/fixDescribe

Fixed kubectl describe ingress causing SEGFAULT if API Group is not specified

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

@@ -2556,7 +2556,11 @@ func (i *IngressDescriber) describeBackendV1(ns string, backend *networkingv1.In
 	}
 	if backend.Resource != nil {
 		ic := backend.Resource
-		return fmt.Sprintf("APIGroup: %v, Kind: %v, Name: %v", *ic.APIGroup, ic.Kind, ic.Name)
+		apiGroup := "<none>"
+		if ic.APIGroup != nil {
+			apiGroup = fmt.Sprintf("%v", *ic.APIGroup)
+		}
+		return fmt.Sprintf("APIGroup: %v, Kind: %v, Name: %v", apiGroup, ic.Kind, ic.Name)
 	}
 	return ""
 }

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

@@ -2213,6 +2213,12 @@ func TestDescribeIngress(t *testing.T) {
 			Name:     "bar",
 		},
 	}
+	backendResourceNoAPIGroup := networkingv1.IngressBackend{
+		Resource: &corev1.TypedLocalObjectReference{
+			Kind: "foo",
+			Name: "bar",
+		},
+	}
 
 	tests := map[string]struct {
 		input  *fake.Clientset
@@ -2280,6 +2286,42 @@ Rules:
   foo.bar.com  
                /foo   APIGroup: example.com, Kind: foo, Name: bar
 Annotations:   <none>
+Events:        <none>` + "\n",
+		},
+		"IngressRule.HTTP.Paths.Backend.Resource v1 Without APIGroup": {
+			input: fake.NewSimpleClientset(&networkingv1.Ingress{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "bar",
+					Namespace: "foo",
+				},
+				Spec: networkingv1.IngressSpec{
+					Rules: []networkingv1.IngressRule{
+						{
+							Host: "foo.bar.com",
+							IngressRuleValue: networkingv1.IngressRuleValue{
+								HTTP: &networkingv1.HTTPIngressRuleValue{
+									Paths: []networkingv1.HTTPIngressPath{
+										{
+											Path:    "/foo",
+											Backend: backendResourceNoAPIGroup,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}),
+			output: `Name:             bar
+Namespace:        foo
+Address:          
+Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
+Rules:
+  Host         Path  Backends
+  ----         ----  --------
+  foo.bar.com  
+               /foo   APIGroup: <none>, Kind: foo, Name: bar
+Annotations:   <none>
 Events:        <none>` + "\n",
 		},
 		"Spec.DefaultBackend.Service & IngressRule.HTTP.Paths.Backend.Service v1": {