Fix kubeadm upgrade TODOs

cmd/kubeadm/app/cmd/upgrade/BUILD

@@ -16,6 +16,7 @@ go_library(
         "//cmd/kubeadm/app/apis/kubeadm:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm/v1alpha3:go_default_library",
         "//cmd/kubeadm/app/apis/kubeadm/validation:go_default_library",
+        "//cmd/kubeadm/app/cmd/options:go_default_library",
         "//cmd/kubeadm/app/cmd/util:go_default_library",
         "//cmd/kubeadm/app/constants:go_default_library",
         "//cmd/kubeadm/app/features:go_default_library",

cmd/kubeadm/app/cmd/upgrade/diff.go

@@ -26,6 +26,7 @@ import (
 	"github.com/spf13/cobra"
 	corev1 "k8s.io/api/core/v1"
 	kubeadmapiv1alpha3 "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1alpha3"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	"k8s.io/kubernetes/cmd/kubeadm/app/phases/controlplane"
@@ -65,8 +66,7 @@ func NewCmdDiff(out io.Writer) *cobra.Command {
 		},
 	}
 
-	// TODO: Use the generic options.AddConfigFlag method instead
-	cmd.Flags().StringVar(&flags.cfgPath, "config", flags.cfgPath, "Path to kubeadm config file. WARNING: Usage of a configuration file is experimental!")
+	options.AddConfigFlag(cmd.Flags(), &flags.cfgPath)
 	cmd.Flags().StringVar(&flags.apiServerManifestPath, "api-server-manifest", defaultAPIServerManifestPath, "path to API server manifest")
 	cmd.Flags().StringVar(&flags.controllerManagerManifestPath, "controller-manager-manifest", defaultControllerManagerManifestPath, "path to controller manifest")
 	cmd.Flags().StringVar(&flags.schedulerManifestPath, "scheduler-manifest", defaultSchedulerManifestPath, "path to scheduler manifest")

cmd/kubeadm/app/cmd/upgrade/node.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/spf13/cobra"
 
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	kubeletphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/kubelet"
@@ -87,8 +88,7 @@ func NewCmdUpgradeNodeConfig() *cobra.Command {
 		},
 	}
 
-	// TODO: Unify the registration of common flags and e.g. use the generic options.AddKubeConfigFlag method instead
-	cmd.Flags().StringVar(&flags.kubeConfigPath, "kubeconfig", flags.kubeConfigPath, "The KubeConfig file to use when talking to the cluster.")
+	options.AddKubeConfigFlag(cmd.Flags(), &flags.kubeConfigPath)
 	cmd.Flags().BoolVar(&flags.dryRun, "dry-run", flags.dryRun, "Do not change any state, just output the actions that would be performed.")
 	cmd.Flags().StringVar(&flags.kubeletVersionStr, "kubelet-version", flags.kubeletVersionStr, "The *desired* version for the kubelet after the upgrade.")
 	return cmd

cmd/kubeadm/app/cmd/upgrade/upgrade.go

@@ -24,6 +24,7 @@ import (
 	"github.com/spf13/pflag"
 
 	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	"k8s.io/kubernetes/cmd/kubeadm/app/features"
 )
@@ -70,9 +71,8 @@ func NewCmdUpgrade(out io.Writer) *cobra.Command {
 }
 
 func addApplyPlanFlags(fs *pflag.FlagSet, flags *applyPlanFlags) {
-	// TODO: Use the generic options.AddKubeConfigFlag and options.AddConfigFlag methods instead
-	fs.StringVar(&flags.kubeConfigPath, "kubeconfig", flags.kubeConfigPath, "The KubeConfig file to use when talking to the cluster.")
-	fs.StringVar(&flags.cfgPath, "config", flags.cfgPath, "Path to kubeadm config file. WARNING: Usage of a configuration file is experimental!")
+	options.AddKubeConfigFlag(fs, &flags.kubeConfigPath)
+	options.AddConfigFlag(fs, &flags.cfgPath)
 
 	fs.BoolVar(&flags.allowExperimentalUpgrades, "allow-experimental-upgrades", flags.allowExperimentalUpgrades, "Show unstable versions of Kubernetes as an upgrade alternative and allow upgrading to an alpha/beta/release candidate versions of Kubernetes.")
 	fs.BoolVar(&flags.allowRCUpgrades, "allow-release-candidate-upgrades", flags.allowRCUpgrades, "Show release candidate versions of Kubernetes as an upgrade alternative and allow upgrading to a release candidate versions of Kubernetes.")