add --cloud-provider-gce-lb-src-cidrs for *-controller-manager, and add test

cmd/controller-manager/app/options/globalflags.go

@@ -0,0 +1,35 @@
+/*
+Copyright 2018 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 options
+
+import (
+	"github.com/spf13/pflag"
+
+	"k8s.io/apiserver/pkg/util/globalflag"
+
+	// ensure libs have a chance to globally register their flags
+	_ "k8s.io/kubernetes/pkg/cloudprovider/providers"
+)
+
+// AddCustomGlobalFlags explicitly registers flags that internal packages register
+// against the global flagsets from "flag". We do this in order to prevent
+// unwanted flags from leaking into the *-controller-manager's flagset.
+func AddCustomGlobalFlags(fs *pflag.FlagSet) {
+	// lookup flags in global flag set and re-register the values with our flagset
+	// adds flags from k8s.io/kubernetes/pkg/cloudprovider/providers
+	globalflag.Register(fs, "cloud-provider-gce-lb-src-cidrs")
+}

cmd/controller-manager/app/options/globalflags_test.go

@@ -0,0 +1,60 @@
+/*
+Copyright 2018 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 options
+
+import (
+	"flag"
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/spf13/pflag"
+
+	apiserverflag "k8s.io/apiserver/pkg/util/flag"
+	"k8s.io/apiserver/pkg/util/globalflag"
+)
+
+func TestAddCustomGlobalFlags(t *testing.T) {
+	namedFlagSets := &apiserverflag.NamedFlagSets{}
+	// Note that we will register all flags (including klog flags) into the same
+	// flag set. This allows us to test against all global flags from
+	// flags.CommandLine.
+	nfs := namedFlagSets.FlagSet("generic")
+	globalflag.AddGlobalFlags(nfs, "test-cmd")
+	AddCustomGlobalFlags(nfs)
+
+	actualFlag := []string{}
+	nfs.VisitAll(func(flag *pflag.Flag) {
+		actualFlag = append(actualFlag, flag.Name)
+	})
+
+	// Get all flags from flags.CommandLine, except flag `test.*`.
+	wantedFlag := []string{"help"}
+	pflag.CommandLine.SetNormalizeFunc(apiserverflag.WordSepNormalizeFunc)
+	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+	pflag.VisitAll(func(flag *pflag.Flag) {
+		if !strings.Contains(flag.Name, "test.") {
+			wantedFlag = append(wantedFlag, flag.Name)
+		}
+	})
+	sort.Strings(wantedFlag)
+
+	if !reflect.DeepEqual(wantedFlag, actualFlag) {
+		t.Errorf("Got different flags than expected: expected %+v, got %+v", wantedFlag, actualFlag)
+	}
+}