url := formatURL(localEndpointIP.String(), localEndpointPort)
	return url.String(), nil
}

// ParseHostPort parses a network address of the form "host:port", "ipv4:port", "[ipv6]:port" into host and port;
// ":port" can be eventually omitted.
// If the string is not a valid representation of network address, ParseHostPort returns an error.
func ParseHostPort(hostport string) (string, string, error) {
	var host, port string
	var err error

			hostport:      "[1200::AB00:1234::2552:7777:1313]:1234",
			expectedError: true,
		},
	}

	for _, rt := range tests {
		t.Run(rt.name, func(t *testing.T) {
			actualHost, actualPort, actualError := ParseHostPort(rt.hostport)

			if (actualError != nil) && !rt.expectedError {
				t.Errorf("%s unexpected failure: %v", rt.name, actualError)
				return
			} else if (actualError == nil) && rt.expectedError {

	// the bindPort number of the APIEndpoint.
	// This will allow join of additional control plane instances with different bindPort number
	if cfg.ControlPlaneEndpoint != "" {
		host, port, err := kubeadmutil.ParseHostPort(cfg.ControlPlaneEndpoint)
		if err != nil {
			return err
		}
		if port == "" {
			cfg.ControlPlaneEndpoint = net.JoinHostPort(host, strconv.FormatInt(int64(localAPIEndpoint.BindPort), 10))
		}
	}

			internalAPIServerVirtualIP,
			advertiseAddress,
		},
	}

	// add cluster controlPlaneEndpoint if present (dns or ip)
	if len(cfg.ControlPlaneEndpoint) > 0 {
		if host, _, err := kubeadmutil.ParseHostPort(cfg.ControlPlaneEndpoint); err == nil {
			if ip := netutils.ParseIPSloppy(host); ip != nil {
				altNames.IPs = append(altNames.IPs, ip)
			} else {
				altNames.DNSNames = append(altNames.DNSNames, host)
			}

	return allErrs
}

// ValidateHostPort validates host[:port] endpoints
func ValidateHostPort(endpoint string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if _, _, err := kubeadmutil.ParseHostPort(endpoint); endpoint != "" && err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath, endpoint, "endpoint is not valid"))
	}
	return allErrs
}