gistfile1.py

from twisted.names import dns, server, client, cache
from twisted.application import service, internet
from twisted.internet import defer
from twisted.python import log

class disResolverBackend(client.Resolver):
    def __init__(self, servers=None):
        client.Resolver.__init__(self, servers=servers)
        self.ttl = 5
        
    @defer.inlineCallbacks
    def _get_ip_addr(self, hostname, timeout):
        if ' ' in hostname:
            defer.returnValue([(dns.RRHeader(hostname, dns.A, dns.IN, self.ttl, dns.Record_A('127.0.0.1', self.ttl)),), (), ()])
        else:
            i = yield self._lookup(hostname, dns.IN, dns.A, timeout)
            defer.returnValue(i)
        
    def lookupAddress(self, name, timeout = None):
        return self._get_ip_addr(name, timeout)
       
def create_application():
    disBackend = disResolverBackend(servers=[('8.8.8.8', 53)])
    application = service.Application("dnass")
    srv_collection = service.IServiceCollection(application)

    dnsFactory = server.DNSServerFactory(caches=[cache.CacheResolver()], clients=[disBackend])

    internet.TCPServer(53, dnsFactory).setServiceParent(srv_collection)
    internet.UDPServer(53, dns.DNSDatagramProtocol(dnsFactory)).setServiceParent(srv_collection)
    return application

# .tac app
application = create_application()