In a virtual host, or when your application could run on a multiple type of OS,
it could be difficult to get the IP address corresponding to your default gateway.
Here a solution, which should be 'universal'.
This snippets try to send a datagramme on a distant host (no matter if datagrame
arrive), and retrieve the local IP with the return-value of the connect :
UDPSocket.open do |s|
s.connect '18.104.22.168', 1 # wikipedia, connection don't need to be effective
This option must be positionned :
If not, your ruby machine will try to find DNS name of wikipedia, which could
take a very long time if host is isolated.