// Defaulted config we will use to get SAN certs
	defaultConfig := &kubeadmapiv1.InitConfiguration{
		LocalAPIEndpoint: kubeadmapiv1.APIEndpoint{
			// GetAPIServerAltNames errors without an AdvertiseAddress; this is as good as any.
			AdvertiseAddress: "127.0.0.1",
		},
	}

	defaultInternalConfig := &kubeadmapi.InitConfiguration{}

	kubeadmscheme.Scheme.Default(defaultConfig)

		return nil, err
	}

	colonPos := strings.LastIndex(addr, ":")
	if colonPos == -1 {
		colonPos = len(addr)
	}
	hostname := addr[:colonPos]

	if config == nil {
		config = defaultConfig()
	}
	// If no ServerName is set, infer the ServerName
	// from the hostname we're connecting to.
	if config.ServerName == "" {
		// Make a copy to avoid polluting argument or default.
		c := config.Clone()