kubeadm: deprecate --kubelet-version command line option

Author: SataQiu

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

@@ -37,8 +37,7 @@ var (
 	kubeletConfigLongDesc = cmdutil.LongDesc(`
 		Download the kubelet configuration from a ConfigMap of the form "kubelet-config-1.X" in the cluster,
 		where X is the minor version of the kubelet. kubeadm uses the KuberneteVersion field in the kubeadm-config
-		ConfigMap to determine what the _desired_ kubelet version is, but the user can override this by using the
-		--kubelet-version parameter.
+		ConfigMap to determine what the _desired_ kubelet version is.
 		`)
 )
 

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

@@ -114,6 +114,7 @@ func addUpgradeNodeFlags(flagSet *flag.FlagSet, nodeOptions *nodeOptions) {
 	options.AddKubeConfigFlag(flagSet, &nodeOptions.kubeConfigPath)
 	flagSet.BoolVar(&nodeOptions.dryRun, options.DryRun, nodeOptions.dryRun, "Do not change any state, just output the actions that would be performed.")
 	flagSet.StringVar(&nodeOptions.kubeletVersion, options.KubeletVersion, nodeOptions.kubeletVersion, "The *desired* version for the kubelet config after the upgrade. If not specified, the KubernetesVersion from the kubeadm-config ConfigMap will be used")
+	flagSet.MarkDeprecated(options.KubeletVersion, "This flag is deprecated and will be removed in a future version.")
 	flagSet.BoolVar(&nodeOptions.renewCerts, options.CertificateRenewal, nodeOptions.renewCerts, "Perform the renewal of certificates used by component changed during upgrades.")
 	flagSet.BoolVar(&nodeOptions.etcdUpgrade, options.EtcdUpgrade, nodeOptions.etcdUpgrade, "Perform the upgrade of etcd.")
 }