Isn’t the solution you are looking for just:
require 'socket'
addr_infos = Socket.ip_address_list
Since a machine can have multiple interfaces and multiple IP Addresses, this method returns an array of Addrinfo.
You can fetch the exact IP addresses like this:
addr_infos.each do |addr_info|
puts addr_info.ip_address
end
You can further filter the list by rejecting loopback and private addresses, as they are usually not what you’re interested in, like so:
addr_infos.reject( &:ipv4_loopback? )
.reject( &:ipv6_loopback? )
.reject( &:ipv4_private? )