Headless services should not need to declare ports

pkg/api/validation/validation.go

@@ -1224,7 +1224,7 @@ func ValidateService(service *api.Service) errs.ValidationErrorList {
 	allErrs := errs.ValidationErrorList{}
 	allErrs = append(allErrs, ValidateObjectMeta(&service.ObjectMeta, true, ValidateServiceName).Prefix("metadata")...)
 
-	if len(service.Spec.Ports) == 0 {
+	if len(service.Spec.Ports) == 0 && service.Spec.ClusterIP != api.ClusterIPNone {
 		allErrs = append(allErrs, errs.NewFieldRequired("spec.ports"))
 	}
 	if service.Spec.Type == api.ServiceTypeLoadBalancer {

pkg/api/validation/validation_test.go

@@ -1793,6 +1793,14 @@ func TestValidateService(t *testing.T) {
 			numErrs: 1,
 		},
 		{
+			name: "missing ports but headless",
+			tweakSvc: func(s *api.Service) {
+				s.Spec.Ports = nil
+				s.Spec.ClusterIP = api.ClusterIPNone
+			},
+			numErrs: 0,
+		},
+		{
 			name: "empty port[0] name",
 			tweakSvc: func(s *api.Service) {
 				s.Spec.Ports[0].Name = ""