Allow an empty service

pkg/api/validation/validation.go

@@ -438,9 +438,12 @@ func ValidateService(service *api.Service, lister ServiceLister, ctx api.Context
 	} else if !supportedPortProtocols.Has(strings.ToUpper(string(service.Spec.Protocol))) {
 		allErrs = append(allErrs, errs.NewFieldNotSupported("spec.protocol", service.Spec.Protocol))
 	}
-	if labels.Set(service.Spec.Selector).AsSelector().Empty() {
-		allErrs = append(allErrs, errs.NewFieldRequired("spec.selector", service.Spec.Selector))
+
+	if service.Spec.Selector != nil {
+		allErrs = append(allErrs, validateLabels(service.Spec.Selector, "spec.selector")...)
 	}
+	allErrs = append(allErrs, validateLabels(service.Labels, "labels")...)
+
 	if service.Spec.CreateExternalLoadBalancer {
 		services, err := lister.ListServices(ctx)
 		if err != nil {
@@ -456,8 +459,6 @@ func ValidateService(service *api.Service, lister ServiceLister, ctx api.Context
 			}
 		}
 	}
-	allErrs = append(allErrs, validateLabels(service.Labels, "labels")...)
-	allErrs = append(allErrs, validateLabels(service.Spec.Selector, "selector")...)
 	return allErrs
 }
 

pkg/api/validation/validation_test.go

@@ -710,8 +710,8 @@ func TestValidateService(t *testing.T) {
 					Port: 8675,
 				},
 			},
-			// Should fail because the selector is missing.
-			numErrs: 1,
+			// Should be ok because the selector is missing.
+			numErrs: 0,
 		},
 		{
 			name: "valid 1",
@@ -824,12 +824,25 @@ func TestValidateService(t *testing.T) {
 						"NoUppercaseOrSpecialCharsLike=Equals": "bar",
 					},
 				},
+				Spec: api.ServiceSpec{
+					Port: 8675,
+				},
+			},
+			numErrs: 1,
+		},
+		{
+			name: "invalid selector",
+			svc: api.Service{
+				ObjectMeta: api.ObjectMeta{
+					Name:      "abc123",
+					Namespace: api.NamespaceDefault,
+				},
 				Spec: api.ServiceSpec{
 					Port:     8675,
 					Selector: map[string]string{"foo": "bar", "NoUppercaseOrSpecialCharsLike=Equals": "bar"},
 				},
 			},
-			numErrs: 2,
+			numErrs: 1,
 		},
 	}