kube-apiserver: fix missing global flags for --help

Signed-off-by: Jay Lim <jay@imjching.com>

cmd/kube-apiserver/app/server.go

@@ -50,6 +50,7 @@ import (
 	serverstorage "k8s.io/apiserver/pkg/server/storage"
 	"k8s.io/apiserver/pkg/storage/etcd3/preflight"
 	apiserverflag "k8s.io/apiserver/pkg/util/flag"
+	"k8s.io/apiserver/pkg/util/globalflag"
 	"k8s.io/apiserver/pkg/util/webhook"
 	clientgoinformers "k8s.io/client-go/informers"
 	clientgoclientset "k8s.io/client-go/kubernetes"
@@ -117,6 +118,9 @@ cluster's shared state through which all other components interact.`,
 
 	fs := cmd.Flags()
 	namedFlagSets := s.Flags()
+	verflag.AddFlags(namedFlagSets.FlagSet("global"))
+	globalflag.AddGlobalFlags(namedFlagSets.FlagSet("global"), cmd.Name())
+	options.AddCustomGlobalFlags(namedFlagSets.FlagSet("generic"))
 	for _, f := range namedFlagSets.FlagSets {
 		fs.AddFlagSet(f)
 	}