docs: def get_forwarders(resolv="resolv.conf"):
      """ Find the forwarders in /etc/resolv.conf, default to 8.8.8.8 and
      8.8.4.4 """
      ns = []
      if os.path.exists(resolv):
          for l in open(resolv):
              if l.startswith("nameserver"):
                  address = l.strip().split(" ", 2)[1]
                  # forwarding to ourselves would be bad
                  if not address.startswith("127"):
                      ns.append(address)
      if not ns:
          ns = ['8.8.8.8', '8.8.4.4']
      return ns