code: func GetPeerURL(localEndpoint *kubeadmapi.APIEndpoint) string {
  	return "https://" + net.JoinHostPort(localEndpoint.AdvertiseAddress, strconv.Itoa(constants.EtcdListenPeerPort))
  }
docs: // GetPeerURL creates an HTTPS URL that uses the configured advertise
  // address and peer port for the API controller