Add initial validation of Service objects

pkg/api/validation.go

@@ -246,3 +246,14 @@ func ValidateManifest(manifest *ContainerManifest) []error {
 	allErrs.Append(validateContainers(manifest.Containers, allVolumes)...)
 	return []error(allErrs)
 }
+
+func ValidateService(service *Service) []error {
+	allErrs := errorList{}
+	if service.ID == "" {
+		allErrs.Append(fmt.Errorf("ID should not be empty: %#v", *service))
+	}
+	if len(service.Selector) == 0 {
+		allErrs.Append(fmt.Errorf("Service %#v missing a selector", *service))
+	}
+	return []error(allErrs)
+}

pkg/api/validation_test.go

@@ -262,3 +262,36 @@ func TestValidateManifest(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateService(t *testing.T) {
+	errs := ValidateService(&Service{
+		JSONBase: JSONBase{ID: "foo"},
+		Selector: map[string]string{
+			"foo": "bar",
+		},
+	})
+	if len(errs) != 0 {
+		t.Errorf("Unexpected non-zero error list: %#v", errs)
+	}
+
+	errs = ValidateService(&Service{
+		Selector: map[string]string{
+			"foo": "bar",
+		},
+	})
+	if len(errs) != 1 {
+		t.Errorf("Unexpected error list: %#v", errs)
+	}
+
+	errs = ValidateService(&Service{
+		JSONBase: JSONBase{ID: "foo"},
+	})
+	if len(errs) != 1 {
+		t.Errorf("Unexpected error list: %#v", errs)
+	}
+
+	errs = ValidateService(&Service{})
+	if len(errs) != 2 {
+		t.Errorf("Unexpected error list: %#v", errs)
+	}
+}

pkg/registry/service_registry.go

@@ -112,8 +112,9 @@ func (sr *ServiceRegistryStorage) Extract(body []byte) (interface{}, error) {
 
 func (sr *ServiceRegistryStorage) Create(obj interface{}) (<-chan interface{}, error) {
 	srv := obj.(api.Service)
-	if srv.ID == "" {
-		return nil, fmt.Errorf("ID should not be empty: %#v", srv)
+	errs := api.ValidateService(&srv)
+	if len(errs) > 0 {
+		return nil, fmt.Errorf("Validation errors: %v", errs)
 	}
 	return apiserver.MakeAsync(func() (interface{}, error) {
 		// TODO: Consider moving this to a rectification loop, so that we make/remove external load balancers