Update extension mechanism and related sample.

cmd/cloud-controller-manager/main.go

@@ -41,10 +41,15 @@ import (
 	_ "k8s.io/component-base/metrics/prometheus/clientgo" // load all the prometheus client-go plugins
 	_ "k8s.io/component-base/metrics/prometheus/version"  // for version metric registration
 	"k8s.io/klog/v2"
+	nodeipamcontrolleroptions "k8s.io/kubernetes/cmd/kube-controller-manager/app/options"
+	nodeipamconfig "k8s.io/kubernetes/pkg/controller/nodeipam/config"
 	// For existing cloud providers, the option to import legacy providers is still available.
 	// e.g. _"k8s.io/legacy-cloud-providers/<provider>"
 )
 
+var nodeIPAMControllerConfiguration nodeipamconfig.NodeIPAMControllerConfiguration
+var nodeIPAMControllerOptions nodeipamcontrolleroptions.NodeIPAMControllerOptions
+
 func main() {
 	rand.Seed(time.Now().UnixNano())
 
@@ -59,11 +64,14 @@ func main() {
 	//delete(controllerInitializers, "cloud-node-lifecycle")
 
 	// Here is an example to add an controller(NodeIpamController) which will be used by cloud provider
-	// generate nodeIPAMConfig. Here is an sample code. Please pass the right parameter in your code.
+	// generate nodeIPAMConfig. Here is an sample code.
 	// If you do not need additional controller, please ignore.
+	nodeIPAMControllerOptions.NodeIPAMControllerConfiguration = &nodeIPAMControllerConfiguration
+	fs := pflag.NewFlagSet("fs", pflag.ContinueOnError)
+	nodeIPAMControllerOptions.AddFlags(fs)
 	controllerInitializers["nodeipam"] = startNodeIpamControllerWrapper
 
-	command := app.NewCloudControllerManagerCommand(ccmOptions, cloudInitializer, controllerInitializers, wait.NeverStop)
+	command := app.NewCloudControllerManagerCommand(ccmOptions, cloudInitializer, controllerInitializers, fs, wait.NeverStop)
 
 	// TODO: once we switch everything over to Cobra commands, we can go back to calling
 	// utilflag.InitFlags() (by removing its pflag.Parse() call). For now, we have to set the

staging/src/k8s.io/cloud-provider/app/controllermanager.go

@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	cacheddiscovery "k8s.io/client-go/discovery/cached"
@@ -65,7 +66,7 @@ const (
 
 // NewCloudControllerManagerCommand creates a *cobra.Command object with default parameters
 // initFuncConstructor is a map of named controller groups (you can start more than one in an init func) paired to their InitFuncConstructor.
-func NewCloudControllerManagerCommand(s *options.CloudControllerManagerOptions, cloudInitializer InitCloudFunc, initFuncConstructor map[string]InitFuncConstructor, stopCh <-chan struct{}) *cobra.Command {
+func NewCloudControllerManagerCommand(s *options.CloudControllerManagerOptions, cloudInitializer InitCloudFunc, initFuncConstructor map[string]InitFuncConstructor, additionalFlags *pflag.FlagSet, stopCh <-chan struct{}) *cobra.Command {
 
 	cmd := &cobra.Command{
 		Use: "cloud-controller-manager",
@@ -117,6 +118,9 @@ the cloud specific control loops shipped with Kubernetes.`,
 	for _, f := range namedFlagSets.FlagSets {
 		fs.AddFlagSet(f)
 	}
+	if additionalFlags != nil {
+		fs.AddFlagSet(additionalFlags)
+	}
 	usageFmt := "Usage:\n  %s\n"
 	cols, _, _ := term.TerminalSize(cmd.OutOrStdout())
 	cmd.SetUsageFunc(func(cmd *cobra.Command) error {

staging/src/k8s.io/cloud-provider/app/testing/testserver.go

@@ -102,7 +102,7 @@ func StartTestServer(t Logger, customFlags []string) (result TestServer, err err
 		}
 		return cloud
 	}
-	command := app.NewCloudControllerManagerCommand(s, cloudInitializer, app.DefaultInitFuncConstructors, stopCh)
+	command := app.NewCloudControllerManagerCommand(s, cloudInitializer, app.DefaultInitFuncConstructors, nil, stopCh)
 	pflag.CommandLine.SetNormalizeFunc(flag.WordSepNormalizeFunc)
 
 	commandArgs := []string{}

staging/src/k8s.io/cloud-provider/sample/basic_main.go

@@ -48,7 +48,7 @@ func main() {
 		klog.Fatalf("unable to initialize command options: %v", err)
 	}
 
-	command := app.NewCloudControllerManagerCommand(ccmOptions, cloudInitializer, app.DefaultInitFuncConstructors, wait.NeverStop)
+	command := app.NewCloudControllerManagerCommand(ccmOptions, cloudInitializer, app.DefaultInitFuncConstructors, nil, wait.NeverStop)
 
 	// TODO: once we switch everything over to Cobra commands, we can go back to calling
 	// utilflag.InitFlags() (by removing its pflag.Parse() call). For now, we have to set the