Gmail IP Address: Ruby script to get the Gmail public IP adress

gmail_ip_address.rb

#!/usr/bin/env ruby

# From: https://support.google.com/a/answer/60764?hl=en

require 'resolv'
require 'pp'

DNS_SERVER = '8.8.8.8'
SPF_RECORD = "_spf.google.com"

def get_spf_record_array(dns_object, query, delimiter)
  response = dns_object.getresources(query , Resolv::DNS::Resource::IN::TXT)
  
  #  limpiamos la respuesta
  response = response.first.strings.first.gsub!(/v=spf1/,"").gsub!(/~all/,"")
  
  # Creamos el arreglo
  net_array = response.split(/#{delimiter}/)
  net_array.shift
  net_array
end

dns = Resolv::DNS.new(nameserver: DNS_SERVER)

spf_networks = get_spf_record_array(dns, "_spf.google.com", "include:")

spf_networks.each do |net|
  # Limpiamos el ultimo caracter que es un espacio
  net.chop!
  networks = get_spf_record_array(dns, net, "ip4:")
  puts networks
end