Doc API group suffix, add test to catch new groups

pkg/master/import_known_versions_test.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package master
+
+import (
+	"strings"
+	"testing"
+
+	"k8s.io/kubernetes/pkg/apimachinery/registered"
+	"k8s.io/kubernetes/pkg/util/sets"
+)
+
+func TestGroupVersions(t *testing.T) {
+	// legacyUnsuffixedGroups contains the groups released prior to deciding that kubernetes API groups should be dns-suffixed
+	// new groups should be suffixed with ".k8s.io" (https://github.com/kubernetes/kubernetes/pull/31887#issuecomment-244462396)
+	legacyUnsuffixedGroups := sets.NewString(
+		"",
+		"apps",
+		"autoscaling",
+		"batch",
+		"componentconfig",
+		"extensions",
+		"federation",
+		"policy",
+	)
+
+	// No new groups should be added to the legacyUnsuffixedGroups exclusion list
+	if len(legacyUnsuffixedGroups) != 8 {
+		t.Errorf("No additional unnamespaced groups should be created")
+	}
+
+	for _, gv := range registered.RegisteredGroupVersions() {
+		if !strings.HasSuffix(gv.Group, ".k8s.io") && !legacyUnsuffixedGroups.Has(gv.Group) {
+			t.Errorf("Group %s does not have the standard kubernetes API group suffix of .k8s.io", gv.Group)
+		}
+	}
+}