Find the forwarders in /etc/resolv.conf, default to 8.8.8.8 and
    8.8.4.4

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