shows how to wire admission control in a sample api server.

staging/src/k8s.io/sample-apiserver/pkg/cmd/server/BUILD

@@ -13,6 +13,7 @@ go_library(
     tags = ["automanaged"],
     deps = [
         "//vendor/github.com/spf13/cobra:go_default_library",
+        "//vendor/github.com/spf13/pflag:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/server:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/server/options:go_default_library",
         "//vendor/k8s.io/sample-apiserver/pkg/apis/wardle/v1alpha1:go_default_library",

staging/src/k8s.io/sample-apiserver/pkg/cmd/server/start.go

@@ -22,6 +22,7 @@ import (
 	"net"
 
 	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
 
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	genericoptions "k8s.io/apiserver/pkg/server/options"
@@ -33,6 +34,7 @@ const defaultEtcdPathPrefix = "/registry/wardle.kubernetes.io"
 
 type WardleServerOptions struct {
 	RecommendedOptions *genericoptions.RecommendedOptions
+	Admission          *genericoptions.AdmissionOptions
 
 	StdOut io.Writer
 	StdErr io.Writer
@@ -41,6 +43,7 @@ type WardleServerOptions struct {
 func NewWardleServerOptions(out, errOut io.Writer) *WardleServerOptions {
 	o := &WardleServerOptions{
 		RecommendedOptions: genericoptions.NewRecommendedOptions(defaultEtcdPathPrefix, apiserver.Scheme, apiserver.Codecs.LegacyCodec(v1alpha1.SchemeGroupVersion)),
+		Admission:          genericoptions.NewAdmissionOptions(),
 
 		StdOut: out,
 		StdErr: errOut,
@@ -49,6 +52,11 @@ func NewWardleServerOptions(out, errOut io.Writer) *WardleServerOptions {
 	return o
 }
 
+func (o *WardleServerOptions) addFlags(flags *pflag.FlagSet) {
+	o.RecommendedOptions.AddFlags(flags)
+	o.Admission.AddFlags(flags)
+}
+
 // NewCommandStartMaster provides a CLI handler for 'start master' command
 func NewCommandStartWardleServer(out, errOut io.Writer, stopCh <-chan struct{}) *cobra.Command {
 	o := NewWardleServerOptions(out, errOut)
@@ -71,7 +79,7 @@ func NewCommandStartWardleServer(out, errOut io.Writer, stopCh <-chan struct{})
 	}
 
 	flags := cmd.Flags()
-	o.RecommendedOptions.AddFlags(flags)
+	o.addFlags(flags)
 
 	return cmd
 }
@@ -95,6 +103,10 @@ func (o WardleServerOptions) Config() (*apiserver.Config, error) {
 		return nil, err
 	}
 
+	if err := o.Admission.ApplyTo(serverConfig); err != nil {
+		return nil, err
+	}
+
 	config := &apiserver.Config{
 		GenericConfig: serverConfig,
 	}