I have found the solution:
Since Omniauth uses Faraday, we just need to specify proxy for Faraday.
We can do it, putting this code in our omniauth.rb
initializer:
require 'socket'
ip=Socket.ip_address_list.detect{|intf| intf.ipv4_private?}
my_ip = ip.ip_address if ip
if my_ip == "172.*.1*0.233"
module Faraday
class Connection
alias_method :old_initialize, :initialize
def initialize(url = nil, options = {})
proxy = 'http://172.16.3.160:4226'
(url.is_a?(Hash) ? url : options).merge!(proxy: proxy)
old_initialize(url, options)
end
end
end
end