fix: flagz endpoint to return parsed flags value

cmd/kube-apiserver/app/options/completion.go

@@ -57,7 +57,7 @@ func (s *ServerRunOptions) Complete(ctx context.Context) (CompletedOptions, erro
 	if err != nil {
 		return CompletedOptions{}, err
 	}
-	controlplane, err := s.Options.Complete(ctx, s.Flags(), []string{"kubernetes.default.svc", "kubernetes.default", "kubernetes"}, []net.IP{apiServerServiceIP})
+	controlplane, err := s.Options.Complete(ctx, *s.ParsedFlags, []string{"kubernetes.default.svc", "kubernetes.default", "kubernetes"}, []net.IP{apiServerServiceIP})
 	if err != nil {
 		return CompletedOptions{}, err
 	}

cmd/kube-apiserver/app/options/options.go

@@ -41,6 +41,8 @@ type ServerRunOptions struct {
 	CloudProvider                  *kubeoptions.CloudProviderOptions
 
 	Extra
+	// ParsedFlags hold the parsed CLI flags.
+	ParsedFlags *cliflag.NamedFlagSets
 }
 
 type Extra struct {
@@ -100,6 +102,9 @@ func NewServerRunOptions() *ServerRunOptions {
 
 // Flags returns flags for a specific APIServer by section name
 func (s *ServerRunOptions) Flags() (fss cliflag.NamedFlagSets) {
+	if s.ParsedFlags != nil {
+		return *s.ParsedFlags
+	}
 	s.Options.AddFlags(&fss)
 	s.CloudProvider.AddFlags(fss.FlagSet("cloud provider"))
 
@@ -156,5 +161,6 @@ func (s *ServerRunOptions) Flags() (fss cliflag.NamedFlagSets) {
 		"The number of apiservers running in the cluster, must be a positive number. (In use when --endpoint-reconciler-type=master-count is enabled.)")
 	fs.MarkDeprecated("apiserver-count", "apiserver-count is deprecated and will be removed in a future version.")
 
+	s.ParsedFlags = &fss
 	return fss
 }

cmd/kube-apiserver/app/options/options_test.go

@@ -334,6 +334,7 @@ func TestAddFlags(t *testing.T) {
 			CloudConfigFile: "/cloud-config",
 			CloudProvider:   "azure",
 		},
+		ParsedFlags: s.ParsedFlags,
 	}
 
 	expected.Authentication.OIDC.UsernameClaim = "sub"

cmd/kube-apiserver/app/server.go

@@ -124,6 +124,7 @@ cluster's shared state through which all other components interact.`,
 
 	fs := cmd.Flags()
 	namedFlagSets := s.Flags()
+	s.ParsedFlags = &namedFlagSets
 	verflag.AddFlags(namedFlagSets.FlagSet("global"))
 	globalflag.AddGlobalFlags(namedFlagSets.FlagSet("global"), cmd.Name(), logs.SkipLoggingConfigurationFlags())
 	options.AddCustomGlobalFlags(namedFlagSets.FlagSet("generic"))