diff --git a/cmd/kubeadm/app/cmd/alpha/alpha.go b/cmd/kubeadm/app/cmd/alpha/alpha.go
index 080e4e4f9a1..a8a980fb145 100644
--- a/cmd/kubeadm/app/cmd/alpha/alpha.go
+++ b/cmd/kubeadm/app/cmd/alpha/alpha.go
@@ -33,7 +33,7 @@ func NewCmdAlpha(in io.Reader, out io.Writer) *cobra.Command {
 
 	const shDeprecatedMessage = "self-hosting support in kubeadm is deprecated " +
 		"and will be removed in a future release"
-	shCommand := NewCmdSelfhosting(in)
+	shCommand := newCmdSelfhosting(in)
 	shCommand.Deprecated = shDeprecatedMessage
 	for _, cmd := range shCommand.Commands() {
 		cmd.Deprecated = shDeprecatedMessage
diff --git a/cmd/kubeadm/app/cmd/alpha/certs.go b/cmd/kubeadm/app/cmd/alpha/certs.go
index 5da5386aa99..7ce70c6e4ab 100644
--- a/cmd/kubeadm/app/cmd/alpha/certs.go
+++ b/cmd/kubeadm/app/cmd/alpha/certs.go
@@ -100,7 +100,7 @@ func NewCmdCertsUtility(out io.Writer) *cobra.Command {
 
 	cmd.AddCommand(newCmdCertsRenewal(out))
 	cmd.AddCommand(newCmdCertsExpiration(out, constants.KubernetesDir))
-	cmd.AddCommand(NewCmdCertificateKey())
+	cmd.AddCommand(newCmdCertificateKey())
 	cmd.AddCommand(newCmdGenCSR())
 	return cmd
 }
@@ -178,8 +178,8 @@ func runGenCSR(config *genCSRConfig) error {
 	return nil
 }
 
-// NewCmdCertificateKey returns cobra.Command for certificate key generate
-func NewCmdCertificateKey() *cobra.Command {
+// newCmdCertificateKey returns cobra.Command for certificate key generate
+func newCmdCertificateKey() *cobra.Command {
 	return &cobra.Command{
 		Use:   "certificate-key",
 		Short: "Generate certificate keys",
diff --git a/cmd/kubeadm/app/cmd/alpha/selfhosting.go b/cmd/kubeadm/app/cmd/alpha/selfhosting.go
index 6037b55caa0..5617b6abc0a 100644
--- a/cmd/kubeadm/app/cmd/alpha/selfhosting.go
+++ b/cmd/kubeadm/app/cmd/alpha/selfhosting.go
@@ -56,8 +56,8 @@ var (
 		`)
 )
 
-// NewCmdSelfhosting returns the self-hosting Cobra command
-func NewCmdSelfhosting(in io.Reader) *cobra.Command {
+// newCmdSelfhosting returns the self-hosting Cobra command
+func newCmdSelfhosting(in io.Reader) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:     "selfhosting",
 		Aliases: []string{"selfhosted", "self-hosting"},
diff --git a/cmd/kubeadm/app/cmd/cmd.go b/cmd/kubeadm/app/cmd/cmd.go
index 64002f1f235..81a84c94603 100644
--- a/cmd/kubeadm/app/cmd/cmd.go
+++ b/cmd/kubeadm/app/cmd/cmd.go
@@ -81,13 +81,13 @@ func NewKubeadmCommand(in io.Reader, out, err io.Writer) *cobra.Command {
 
 	cmds.ResetFlags()
 
-	cmds.AddCommand(NewCmdCompletion(out, ""))
-	cmds.AddCommand(NewCmdConfig(out))
-	cmds.AddCommand(NewCmdInit(out, nil))
-	cmds.AddCommand(NewCmdJoin(out, nil))
-	cmds.AddCommand(NewCmdReset(in, out, nil))
-	cmds.AddCommand(NewCmdVersion(out))
-	cmds.AddCommand(NewCmdToken(out, err))
+	cmds.AddCommand(newCmdCompletion(out, ""))
+	cmds.AddCommand(newCmdConfig(out))
+	cmds.AddCommand(newCmdInit(out, nil))
+	cmds.AddCommand(newCmdJoin(out, nil))
+	cmds.AddCommand(newCmdReset(in, out, nil))
+	cmds.AddCommand(newCmdVersion(out))
+	cmds.AddCommand(newCmdToken(out, err))
 	cmds.AddCommand(upgrade.NewCmdUpgrade(out))
 	cmds.AddCommand(alpha.NewCmdAlpha(in, out))
 	options.AddKubeadmOtherFlags(cmds.PersistentFlags(), &rootfsPath)
diff --git a/cmd/kubeadm/app/cmd/completion.go b/cmd/kubeadm/app/cmd/completion.go
index 6663d2f50e1..4ff1d63dbaa 100644
--- a/cmd/kubeadm/app/cmd/completion.go
+++ b/cmd/kubeadm/app/cmd/completion.go
@@ -96,8 +96,8 @@ func GetSupportedShells() []string {
 	return shells
 }
 
-// NewCmdCompletion returns the "kubeadm completion" command
-func NewCmdCompletion(out io.Writer, boilerPlate string) *cobra.Command {
+// newCmdCompletion returns the "kubeadm completion" command
+func newCmdCompletion(out io.Writer, boilerPlate string) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:     "completion SHELL",
 		Short:   "Output shell completion code for the specified shell (bash or zsh)",
diff --git a/cmd/kubeadm/app/cmd/completion_test.go b/cmd/kubeadm/app/cmd/completion_test.go
index d74c1d2111e..2955daa380b 100644
--- a/cmd/kubeadm/app/cmd/completion_test.go
+++ b/cmd/kubeadm/app/cmd/completion_test.go
@@ -31,15 +31,15 @@ func TestNewCmdCompletion(t *testing.T) {
 	if len(shells) == 0 {
 		t.Errorf(shellsError)
 	}
-	// test NewCmdCompletion with a valid shell.
-	// use a dummy parent command as NewCmdCompletion needs it.
+	// test newCmdCompletion with a valid shell.
+	// use a dummy parent command as newCmdCompletion needs it.
 	parentCmd := &cobra.Command{}
 	args := []string{"completion", shells[0]}
 	parentCmd.SetArgs(args)
-	cmd := NewCmdCompletion(&out, "")
+	cmd := newCmdCompletion(&out, "")
 	parentCmd.AddCommand(cmd)
 	if err := parentCmd.Execute(); err != nil {
-		t.Errorf("Cannot exectute NewCmdCompletion: %v", err)
+		t.Errorf("Cannot exectute newCmdCompletion: %v", err)
 	}
 }
 
diff --git a/cmd/kubeadm/app/cmd/config.go b/cmd/kubeadm/app/cmd/config.go
index ad99a04f56b..5f722836734 100644
--- a/cmd/kubeadm/app/cmd/config.go
+++ b/cmd/kubeadm/app/cmd/config.go
@@ -63,8 +63,8 @@ var (
 	}
 )
 
-// NewCmdConfig returns cobra.Command for "kubeadm config" command
-func NewCmdConfig(out io.Writer) *cobra.Command {
+// newCmdConfig returns cobra.Command for "kubeadm config" command
+func newCmdConfig(out io.Writer) *cobra.Command {
 	var kubeConfigFile string
 
 	cmd := &cobra.Command{
@@ -87,15 +87,15 @@ func NewCmdConfig(out io.Writer) *cobra.Command {
 	options.AddKubeConfigFlag(cmd.PersistentFlags(), &kubeConfigFile)
 
 	kubeConfigFile = cmdutil.GetKubeConfigPath(kubeConfigFile)
-	cmd.AddCommand(NewCmdConfigPrint(out))
-	cmd.AddCommand(NewCmdConfigMigrate(out))
-	cmd.AddCommand(NewCmdConfigView(out, &kubeConfigFile))
-	cmd.AddCommand(NewCmdConfigImages(out))
+	cmd.AddCommand(newCmdConfigPrint(out))
+	cmd.AddCommand(newCmdConfigMigrate(out))
+	cmd.AddCommand(newCmdConfigView(out, &kubeConfigFile))
+	cmd.AddCommand(newCmdConfigImages(out))
 	return cmd
 }
 
-// NewCmdConfigPrint returns cobra.Command for "kubeadm config print" command
-func NewCmdConfigPrint(out io.Writer) *cobra.Command {
+// newCmdConfigPrint returns cobra.Command for "kubeadm config print" command
+func newCmdConfigPrint(out io.Writer) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "print",
 		Short: "Print configuration",
@@ -104,18 +104,18 @@ func NewCmdConfigPrint(out io.Writer) *cobra.Command {
 			For details, see: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2`),
 		RunE: cmdutil.SubCmdRunE("print"),
 	}
-	cmd.AddCommand(NewCmdConfigPrintInitDefaults(out))
-	cmd.AddCommand(NewCmdConfigPrintJoinDefaults(out))
+	cmd.AddCommand(newCmdConfigPrintInitDefaults(out))
+	cmd.AddCommand(newCmdConfigPrintJoinDefaults(out))
 	return cmd
 }
 
-// NewCmdConfigPrintInitDefaults returns cobra.Command for "kubeadm config print init-defaults" command
-func NewCmdConfigPrintInitDefaults(out io.Writer) *cobra.Command {
+// newCmdConfigPrintInitDefaults returns cobra.Command for "kubeadm config print init-defaults" command
+func newCmdConfigPrintInitDefaults(out io.Writer) *cobra.Command {
 	return newCmdConfigPrintActionDefaults(out, "init", getDefaultInitConfigBytes)
 }
 
-// NewCmdConfigPrintJoinDefaults returns cobra.Command for "kubeadm config print join-defaults" command
-func NewCmdConfigPrintJoinDefaults(out io.Writer) *cobra.Command {
+// newCmdConfigPrintJoinDefaults returns cobra.Command for "kubeadm config print join-defaults" command
+func newCmdConfigPrintJoinDefaults(out io.Writer) *cobra.Command {
 	return newCmdConfigPrintActionDefaults(out, "join", getDefaultNodeConfigBytes)
 }
 
@@ -249,8 +249,8 @@ func getDefaultNodeConfigBytes() ([]byte, error) {
 	return configutil.MarshalKubeadmConfigObject(internalcfg)
 }
 
-// NewCmdConfigMigrate returns cobra.Command for "kubeadm config migrate" command
-func NewCmdConfigMigrate(out io.Writer) *cobra.Command {
+// newCmdConfigMigrate returns cobra.Command for "kubeadm config migrate" command
+func newCmdConfigMigrate(out io.Writer) *cobra.Command {
 	var oldCfgPath, newCfgPath string
 	cmd := &cobra.Command{
 		Use:   "migrate",
@@ -300,8 +300,8 @@ func NewCmdConfigMigrate(out io.Writer) *cobra.Command {
 	return cmd
 }
 
-// NewCmdConfigView returns cobra.Command for "kubeadm config view" command
-func NewCmdConfigView(out io.Writer, kubeConfigFile *string) *cobra.Command {
+// newCmdConfigView returns cobra.Command for "kubeadm config view" command
+func newCmdConfigView(out io.Writer, kubeConfigFile *string) *cobra.Command {
 	return &cobra.Command{
 		Use:        "view",
 		Short:      "View the kubeadm configuration stored inside the cluster",
@@ -337,20 +337,20 @@ func RunConfigView(out io.Writer, client clientset.Interface) error {
 	return nil
 }
 
-// NewCmdConfigImages returns the "kubeadm config images" command
-func NewCmdConfigImages(out io.Writer) *cobra.Command {
+// newCmdConfigImages returns the "kubeadm config images" command
+func newCmdConfigImages(out io.Writer) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "images",
 		Short: "Interact with container images used by kubeadm",
 		RunE:  cmdutil.SubCmdRunE("images"),
 	}
-	cmd.AddCommand(NewCmdConfigImagesList(out, nil))
-	cmd.AddCommand(NewCmdConfigImagesPull())
+	cmd.AddCommand(newCmdConfigImagesList(out, nil))
+	cmd.AddCommand(newCmdConfigImagesPull())
 	return cmd
 }
 
-// NewCmdConfigImagesPull returns the `kubeadm config images pull` command
-func NewCmdConfigImagesPull() *cobra.Command {
+// newCmdConfigImagesPull returns the `kubeadm config images pull` command
+func newCmdConfigImagesPull() *cobra.Command {
 	externalClusterCfg := &kubeadmapiv1beta2.ClusterConfiguration{}
 	kubeadmscheme.Scheme.Default(externalClusterCfg)
 	externalInitCfg := &kubeadmapiv1beta2.InitConfiguration{}
@@ -410,8 +410,8 @@ func PullControlPlaneImages(runtime utilruntime.ContainerRuntime, cfg *kubeadmap
 	return nil
 }
 
-// NewCmdConfigImagesList returns the "kubeadm config images list" command
-func NewCmdConfigImagesList(out io.Writer, mockK8sVersion *string) *cobra.Command {
+// newCmdConfigImagesList returns the "kubeadm config images list" command
+func newCmdConfigImagesList(out io.Writer, mockK8sVersion *string) *cobra.Command {
 	externalcfg := &kubeadmapiv1beta2.ClusterConfiguration{}
 	kubeadmscheme.Scheme.Default(externalcfg)
 	var cfgPath, featureGatesString string
diff --git a/cmd/kubeadm/app/cmd/config_test.go b/cmd/kubeadm/app/cmd/config_test.go
index 7b55af9ff48..c40f9699703 100644
--- a/cmd/kubeadm/app/cmd/config_test.go
+++ b/cmd/kubeadm/app/cmd/config_test.go
@@ -56,7 +56,7 @@ var (
 func TestNewCmdConfigImagesList(t *testing.T) {
 	var output bytes.Buffer
 	mockK8sVersion := dummyKubernetesVersionStr
-	images := NewCmdConfigImagesList(&output, &mockK8sVersion)
+	images := newCmdConfigImagesList(&output, &mockK8sVersion)
 	if err := images.RunE(nil, nil); err != nil {
 		t.Fatalf("Error from running the images command: %v", err)
 	}
@@ -401,7 +401,7 @@ func TestMigrate(t *testing.T) {
 	defer cleanup()
 
 	var output bytes.Buffer
-	command := NewCmdConfigMigrate(&output)
+	command := newCmdConfigMigrate(&output)
 	if err := command.Flags().Set("old-config", configFile); err != nil {
 		t.Fatalf("failed to set old-config flag")
 	}
@@ -447,7 +447,7 @@ func TestNewCmdConfigPrintActionDefaults(t *testing.T) {
 				constants.ClusterConfigurationKind,
 				constants.InitConfigurationKind,
 			},
-			cmdProc: NewCmdConfigPrintInitDefaults,
+			cmdProc: newCmdConfigPrintInitDefaults,
 		},
 		{
 			name: "InitConfiguration: KubeProxyConfiguration",
@@ -457,7 +457,7 @@ func TestNewCmdConfigPrintActionDefaults(t *testing.T) {
 				"KubeProxyConfiguration",
 			},
 			componentConfigs: "KubeProxyConfiguration",
-			cmdProc:          NewCmdConfigPrintInitDefaults,
+			cmdProc:          newCmdConfigPrintInitDefaults,
 		},
 		{
 			name: "InitConfiguration: KubeProxyConfiguration and KubeletConfiguration",
@@ -468,14 +468,14 @@ func TestNewCmdConfigPrintActionDefaults(t *testing.T) {
 				"KubeletConfiguration",
 			},
 			componentConfigs: "KubeProxyConfiguration,KubeletConfiguration",
-			cmdProc:          NewCmdConfigPrintInitDefaults,
+			cmdProc:          newCmdConfigPrintInitDefaults,
 		},
 		{
 			name: "JoinConfiguration: No component configs",
 			expectedKinds: []string{
 				constants.JoinConfigurationKind,
 			},
-			cmdProc: NewCmdConfigPrintJoinDefaults,
+			cmdProc: newCmdConfigPrintJoinDefaults,
 		},
 		{
 			name: "JoinConfiguration: KubeProxyConfiguration",
@@ -484,7 +484,7 @@ func TestNewCmdConfigPrintActionDefaults(t *testing.T) {
 				"KubeProxyConfiguration",
 			},
 			componentConfigs: "KubeProxyConfiguration",
-			cmdProc:          NewCmdConfigPrintJoinDefaults,
+			cmdProc:          newCmdConfigPrintJoinDefaults,
 		},
 		{
 			name: "JoinConfiguration: KubeProxyConfiguration and KubeletConfiguration",
@@ -494,7 +494,7 @@ func TestNewCmdConfigPrintActionDefaults(t *testing.T) {
 				"KubeletConfiguration",
 			},
 			componentConfigs: "KubeProxyConfiguration,KubeletConfiguration",
-			cmdProc:          NewCmdConfigPrintJoinDefaults,
+			cmdProc:          newCmdConfigPrintJoinDefaults,
 		},
 	}
 
diff --git a/cmd/kubeadm/app/cmd/init.go b/cmd/kubeadm/app/cmd/init.go
index d67b1b84e78..c2a0457b6d3 100644
--- a/cmd/kubeadm/app/cmd/init.go
+++ b/cmd/kubeadm/app/cmd/init.go
@@ -127,10 +127,10 @@ type initData struct {
 	patchesDir              string
 }
 
-// NewCmdInit returns "kubeadm init" command.
+// newCmdInit returns "kubeadm init" command.
 // NB. initOptions is exposed as parameter for allowing unit testing of
 //     the newInitOptions method, that implements all the command options validation logic
-func NewCmdInit(out io.Writer, initOptions *initOptions) *cobra.Command {
+func newCmdInit(out io.Writer, initOptions *initOptions) *cobra.Command {
 	if initOptions == nil {
 		initOptions = newInitOptions()
 	}
diff --git a/cmd/kubeadm/app/cmd/init_test.go b/cmd/kubeadm/app/cmd/init_test.go
index 335916b7e19..bb2e988ad89 100644
--- a/cmd/kubeadm/app/cmd/init_test.go
+++ b/cmd/kubeadm/app/cmd/init_test.go
@@ -153,7 +153,7 @@ func TestNewInitData(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			// initialize an external init option and inject it to the init cmd
 			initOptions := newInitOptions()
-			cmd := NewCmdInit(nil, initOptions)
+			cmd := newCmdInit(nil, initOptions)
 
 			// sets cmd flags (that will be reflected on the init options)
 			for f, v := range tc.flags {
diff --git a/cmd/kubeadm/app/cmd/join.go b/cmd/kubeadm/app/cmd/join.go
index aaedd6c471c..b7ce3fc940e 100644
--- a/cmd/kubeadm/app/cmd/join.go
+++ b/cmd/kubeadm/app/cmd/join.go
@@ -147,10 +147,10 @@ type joinData struct {
 	patchesDir            string
 }
 
-// NewCmdJoin returns "kubeadm join" command.
+// newCmdJoin returns "kubeadm join" command.
 // NB. joinOptions is exposed as parameter for allowing unit testing of
 //     the newJoinData method, that implements all the command options validation logic
-func NewCmdJoin(out io.Writer, joinOptions *joinOptions) *cobra.Command {
+func newCmdJoin(out io.Writer, joinOptions *joinOptions) *cobra.Command {
 	if joinOptions == nil {
 		joinOptions = newJoinOptions()
 	}
diff --git a/cmd/kubeadm/app/cmd/join_test.go b/cmd/kubeadm/app/cmd/join_test.go
index e9146d739b0..db086257419 100644
--- a/cmd/kubeadm/app/cmd/join_test.go
+++ b/cmd/kubeadm/app/cmd/join_test.go
@@ -255,7 +255,7 @@ func TestNewJoinData(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			// initialize an external join option and inject it to the join cmd
 			joinOptions := newJoinOptions()
-			cmd := NewCmdJoin(nil, joinOptions)
+			cmd := newCmdJoin(nil, joinOptions)
 
 			// sets cmd flags (that will be reflected on the join options)
 			for f, v := range tc.flags {
diff --git a/cmd/kubeadm/app/cmd/reset.go b/cmd/kubeadm/app/cmd/reset.go
index e7389ec8fda..bd95d16a001 100644
--- a/cmd/kubeadm/app/cmd/reset.go
+++ b/cmd/kubeadm/app/cmd/reset.go
@@ -158,8 +158,8 @@ func AddResetFlags(flagSet *flag.FlagSet, resetOptions *resetOptions) {
 	cmdutil.AddCRISocketFlag(flagSet, &resetOptions.criSocketPath)
 }
 
-// NewCmdReset returns the "kubeadm reset" command
-func NewCmdReset(in io.Reader, out io.Writer, resetOptions *resetOptions) *cobra.Command {
+// newCmdReset returns the "kubeadm reset" command
+func newCmdReset(in io.Reader, out io.Writer, resetOptions *resetOptions) *cobra.Command {
 	if resetOptions == nil {
 		resetOptions = newResetOptions()
 	}
diff --git a/cmd/kubeadm/app/cmd/token.go b/cmd/kubeadm/app/cmd/token.go
index 8f242fde1b0..264b3f28b65 100644
--- a/cmd/kubeadm/app/cmd/token.go
+++ b/cmd/kubeadm/app/cmd/token.go
@@ -54,8 +54,8 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/output"
 )
 
-// NewCmdToken returns cobra.Command for token management
-func NewCmdToken(out io.Writer, errW io.Writer) *cobra.Command {
+// newCmdToken returns cobra.Command for token management
+func newCmdToken(out io.Writer, errW io.Writer) *cobra.Command {
 	var kubeConfigFile string
 	var dryRun bool
 	tokenCmd := &cobra.Command{
@@ -149,7 +149,7 @@ func NewCmdToken(out io.Writer, errW io.Writer) *cobra.Command {
 	bto.AddDescriptionFlag(createCmd.Flags())
 
 	tokenCmd.AddCommand(createCmd)
-	tokenCmd.AddCommand(NewCmdTokenGenerate(out))
+	tokenCmd.AddCommand(newCmdTokenGenerate(out))
 
 	outputFlags := output.NewOutputFlags(&tokenTextPrintFlags{}).WithTypeSetter(outputapischeme.Scheme).WithDefaultOutput(output.TextOutput)
 
@@ -208,8 +208,8 @@ func NewCmdToken(out io.Writer, errW io.Writer) *cobra.Command {
 	return tokenCmd
 }
 
-// NewCmdTokenGenerate returns cobra.Command to generate new token
-func NewCmdTokenGenerate(out io.Writer) *cobra.Command {
+// newCmdTokenGenerate returns cobra.Command to generate new token
+func newCmdTokenGenerate(out io.Writer) *cobra.Command {
 	return &cobra.Command{
 		Use:   "generate",
 		Short: "Generate and print a bootstrap token, but do not create it on the server",
diff --git a/cmd/kubeadm/app/cmd/token_test.go b/cmd/kubeadm/app/cmd/token_test.go
index 45b241f1960..1da30a8673c 100644
--- a/cmd/kubeadm/app/cmd/token_test.go
+++ b/cmd/kubeadm/app/cmd/token_test.go
@@ -186,7 +186,7 @@ func TestNewCmdTokenGenerate(t *testing.T) {
 	var buf bytes.Buffer
 	args := []string{}
 
-	cmd := NewCmdTokenGenerate(&buf)
+	cmd := newCmdTokenGenerate(&buf)
 	cmd.SetArgs(args)
 
 	if err := cmd.Execute(); err != nil {
@@ -242,8 +242,8 @@ func TestNewCmdToken(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			// the command is created for each test so that the kubeConfigFile
-			// variable in NewCmdToken() is reset.
-			cmd := NewCmdToken(&buf, &bufErr)
+			// variable in newCmdToken() is reset.
+			cmd := newCmdToken(&buf, &bufErr)
 			if _, err = f.WriteString(tc.configToWrite); err != nil {
 				t.Errorf("Unable to write test file %q: %v", fullPath, err)
 			}
@@ -255,7 +255,7 @@ func TestNewCmdToken(t *testing.T) {
 			cmd.SetArgs(tc.args)
 			err := cmd.Execute()
 			if (err != nil) != tc.expectedError {
-				t.Errorf("Test case %q: NewCmdToken expected error: %v, saw: %v", tc.name, tc.expectedError, (err != nil))
+				t.Errorf("Test case %q: newCmdToken expected error: %v, saw: %v", tc.name, tc.expectedError, (err != nil))
 			}
 			// restore the environment variable.
 			os.Setenv(clientcmd.RecommendedConfigPathEnvVar, storedEnv)
diff --git a/cmd/kubeadm/app/cmd/upgrade/apply.go b/cmd/kubeadm/app/cmd/upgrade/apply.go
index 1b9b3417c53..b781310775b 100644
--- a/cmd/kubeadm/app/cmd/upgrade/apply.go
+++ b/cmd/kubeadm/app/cmd/upgrade/apply.go
@@ -59,8 +59,8 @@ func (f *applyFlags) sessionIsInteractive() bool {
 	return !(f.nonInteractiveMode || f.dryRun || f.force)
 }
 
-// NewCmdApply returns the cobra command for `kubeadm upgrade apply`
-func NewCmdApply(apf *applyPlanFlags) *cobra.Command {
+// newCmdApply returns the cobra command for `kubeadm upgrade apply`
+func newCmdApply(apf *applyPlanFlags) *cobra.Command {
 	flags := &applyFlags{
 		applyPlanFlags:   apf,
 		imagePullTimeout: defaultImagePullTimeout,
diff --git a/cmd/kubeadm/app/cmd/upgrade/diff.go b/cmd/kubeadm/app/cmd/upgrade/diff.go
index 53935f2021e..500d176f5a9 100644
--- a/cmd/kubeadm/app/cmd/upgrade/diff.go
+++ b/cmd/kubeadm/app/cmd/upgrade/diff.go
@@ -54,8 +54,8 @@ var (
 	defaultSchedulerManifestPath         = constants.GetStaticPodFilepath(constants.KubeScheduler, constants.GetStaticPodDirectory())
 )
 
-// NewCmdDiff returns the cobra command for `kubeadm upgrade diff`
-func NewCmdDiff(out io.Writer) *cobra.Command {
+// newCmdDiff returns the cobra command for `kubeadm upgrade diff`
+func newCmdDiff(out io.Writer) *cobra.Command {
 	flags := &diffFlags{
 		kubeConfigPath: constants.GetAdminKubeConfigPath(),
 		out:            out,
diff --git a/cmd/kubeadm/app/cmd/upgrade/node.go b/cmd/kubeadm/app/cmd/upgrade/node.go
index cb6c3b0f0bf..af48a373c0b 100644
--- a/cmd/kubeadm/app/cmd/upgrade/node.go
+++ b/cmd/kubeadm/app/cmd/upgrade/node.go
@@ -62,8 +62,8 @@ type nodeData struct {
 	ignorePreflightErrors sets.String
 }
 
-// NewCmdNode returns the cobra command for `kubeadm upgrade node`
-func NewCmdNode() *cobra.Command {
+// newCmdNode returns the cobra command for `kubeadm upgrade node`
+func newCmdNode() *cobra.Command {
 	nodeOptions := newNodeOptions()
 	nodeRunner := workflow.NewRunner()
 
diff --git a/cmd/kubeadm/app/cmd/upgrade/plan.go b/cmd/kubeadm/app/cmd/upgrade/plan.go
index 1939f7236c3..5f8e824589e 100644
--- a/cmd/kubeadm/app/cmd/upgrade/plan.go
+++ b/cmd/kubeadm/app/cmd/upgrade/plan.go
@@ -44,8 +44,8 @@ type planFlags struct {
 	*applyPlanFlags
 }
 
-// NewCmdPlan returns the cobra command for `kubeadm upgrade plan`
-func NewCmdPlan(apf *applyPlanFlags) *cobra.Command {
+// newCmdPlan returns the cobra command for `kubeadm upgrade plan`
+func newCmdPlan(apf *applyPlanFlags) *cobra.Command {
 	flags := &planFlags{
 		applyPlanFlags: apf,
 	}
diff --git a/cmd/kubeadm/app/cmd/upgrade/upgrade.go b/cmd/kubeadm/app/cmd/upgrade/upgrade.go
index 554ee1376ce..f65376b6f0b 100644
--- a/cmd/kubeadm/app/cmd/upgrade/upgrade.go
+++ b/cmd/kubeadm/app/cmd/upgrade/upgrade.go
@@ -57,10 +57,10 @@ func NewCmdUpgrade(out io.Writer) *cobra.Command {
 		RunE:  cmdutil.SubCmdRunE("upgrade"),
 	}
 
-	cmd.AddCommand(NewCmdApply(flags))
-	cmd.AddCommand(NewCmdPlan(flags))
-	cmd.AddCommand(NewCmdDiff(out))
-	cmd.AddCommand(NewCmdNode())
+	cmd.AddCommand(newCmdApply(flags))
+	cmd.AddCommand(newCmdPlan(flags))
+	cmd.AddCommand(newCmdDiff(out))
+	cmd.AddCommand(newCmdNode())
 	return cmd
 }
 
diff --git a/cmd/kubeadm/app/cmd/version.go b/cmd/kubeadm/app/cmd/version.go
index edd7d45a716..f26fbcd2f8d 100644
--- a/cmd/kubeadm/app/cmd/version.go
+++ b/cmd/kubeadm/app/cmd/version.go
@@ -35,8 +35,8 @@ type Version struct {
 	ClientVersion *apimachineryversion.Info `json:"clientVersion"`
 }
 
-// NewCmdVersion provides the version information of kubeadm.
-func NewCmdVersion(out io.Writer) *cobra.Command {
+// newCmdVersion provides the version information of kubeadm.
+func newCmdVersion(out io.Writer) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "version",
 		Short: "Print the version of kubeadm",
diff --git a/cmd/kubeadm/app/cmd/version_test.go b/cmd/kubeadm/app/cmd/version_test.go
index 3e93a44f630..d4469410d3a 100644
--- a/cmd/kubeadm/app/cmd/version_test.go
+++ b/cmd/kubeadm/app/cmd/version_test.go
@@ -26,7 +26,7 @@ import (
 
 func TestNewCmdVersion(t *testing.T) {
 	var buf bytes.Buffer
-	cmd := NewCmdVersion(&buf)
+	cmd := newCmdVersion(&buf)
 	if err := cmd.Execute(); err != nil {
 		t.Errorf("Cannot execute version command: %v", err)
 	}
@@ -36,7 +36,7 @@ func TestRunVersion(t *testing.T) {
 	var buf bytes.Buffer
 	iface := make(map[string]interface{})
 	flagNameOutput := "output"
-	cmd := NewCmdVersion(&buf)
+	cmd := newCmdVersion(&buf)
 
 	testCases := []struct {
 		name              string