kubeconfig, err := clientcmd.LoadFromFile(kubeconfigPath)
	if err != nil {
		return errors.Wrapf(err, "could not load %q", kubeconfigPath)
	}

	// Perform basic validation. The errors here can only happen if the kubelet.conf was corrupted.
	if len(kubeconfig.CurrentContext) == 0 {
		return errors.Errorf("the file %q does not have current context set", kubeconfigPath)
	}

		return nil, err
	}

	kubeconfigPath := cfg.Meta.String(kubeconfigMetaKey)
	kubeconfigPath, err = file.NormalizePath(kubeconfigPath)
	if err != nil {
		return nil, err
	}

	var client istioKube.CLIClient
	if len(cfg.HTTPProxy) > 0 {
		proxyURL, err := url.Parse(cfg.HTTPProxy)
		if err != nil {
			return nil, err
		}
		client, err = buildClientWithProxy(kubeconfigPath, proxyURL)
		if err != nil {

	}))
	defer server.Close()

	kubeconfigPath := filepath.Join(tmpDir, "config.kubeconfig")
	if err := os.WriteFile(kubeconfigPath, []byte(fmt.Sprintf(fakeKubeconfig, server.URL)), os.FileMode(0600)); err != nil {
		t.Fatal(err)
	}

	for morph := range knownMorphs {
		morph := morph
		t.Run(morph, func(t *testing.T) {
			s := &hollowNodeConfig{
				KubeconfigPath: kubeconfigPath,
				Morph:          morph,
			}

	if _, err := os.Stat(filepath); os.IsNotExist(err) {
		isControlPlaneNode = false
	}
	if len(nodeOptions.kubeConfigPath) == 0 {
		// Update the kubeconfig path depending on whether this is a control plane node or not.
		nodeOptions.kubeConfigPath = constants.GetKubeletKubeConfigPath()
		if isControlPlaneNode {
			nodeOptions.kubeConfigPath = constants.GetAdminKubeConfigPath()
		}
	}

	externalCfg := &v1beta4.UpgradeConfiguration{}

	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(testUpgradeDiffManifest)

	kubeConfigPath, err := createTestRunDiffFile([]byte(testConfigToken))
	if err != nil {
		t.Fatal(err)
	}
	//nolint:errcheck
	defer os.Remove(kubeConfigPath)

	flags := &diffFlags{
		cfgPath: "",
		out:     io.Discard,
	}

	testCases := []struct {
		name            string

}

func (c *hollowNodeConfig) createClientConfigFromFile() (*restclient.Config, error) {
	clientConfig, err := clientcmd.LoadFromFile(c.KubeconfigPath)
	if err != nil {
		return nil, fmt.Errorf("error while loading kubeconfig from file %v: %v", c.KubeconfigPath, err)
	}
	config, err := clientcmd.NewDefaultClientConfig(*clientConfig, &clientcmd.ConfigOverrides{}).ClientConfig()
	if err != nil {

type expirationFlags struct {
	cfgPath        string
	kubeconfigPath string
	cfg            kubeadmapiv1.ClusterConfiguration
}

func addExpirationFlags(cmd *cobra.Command, flags *expirationFlags) {
	options.AddConfigFlag(cmd.Flags(), &flags.cfgPath)
	options.AddCertificateDirFlag(cmd.Flags(), &flags.cfg.CertificatesDir)
	options.AddKubeConfigFlag(cmd.Flags(), &flags.kubeconfigPath)
}

func SetDefaults_FileDiscovery(obj *FileDiscovery) {
	// Make sure file URL becomes path
	if len(obj.KubeConfigPath) != 0 {
		u, err := url.Parse(obj.KubeConfigPath)
		if err == nil && u.Scheme == "file" {
			obj.KubeConfigPath = u.Path
		}
	}
}

// SetDefaults_BootstrapTokens sets the defaults for the .BootstrapTokens field

	fs.StringVar(kubeConfigFile, KubeconfigPath, *kubeConfigFile, "The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.")
	// Note that DefValue is the text shown in the terminal and not the default value assigned to the flag
	fs.Lookup(KubeconfigPath).DefValue = constants.GetAdminKubeConfigPath()
}

	phase := workflow.Phase{
		Name:  "control-plane",
		Short: "Upgrade the control plane instance deployed on this node, if any",
		Run:   runControlPlane(),
		InheritFlags: []string{
			options.DryRun,
			options.KubeconfigPath,
			options.CertificateRenewal,
			options.EtcdUpgrade,
			options.Patches,
		},
	}
	return phase
}

func runControlPlane() func(c workflow.RunData) error {
	return func(c workflow.RunData) error {