code: func outboundIP() net.IP {
  	// This is not actually making a connection to 8.8.8.8.
  	// net.Dial() selects the IP address that would be used
  	// if an actual connection to 8.8.8.8 were made, so this
  	// choice of address is just meant to ensure that an
  	// external address is returned (as opposed to a local
  	// address like 127.0.0.1).
  	conn, err := net.Dial("udp", "8.8.8.8:80")
  	if err != nil {
  		log.Fatal(err)
  	}
  	defer conn.Close()
  
  	localAddr := conn.LocalAddr().(*net.UDPAddr)
  
  	return localAddr.IP
  }
docs: // outboundIP gets the preferred outbound ip of this machine.