[OpenSIPS-Users] mediaproxy+twisted 10.0, doesn't use /etc/hosts when DNS requests timeouts

[Nikita Kozlov]

Hello,

I think I have found a bug in media-relay if it's installed on a host 
without any name resolver (empty /etc/resolv.conf, only /etc/hosts).

If mediaproxy is used with twitsted 10.X, the twisted defers' will fail 
and we will enter in the _eb_no_srv callback but with a failure type of 
TimeoutError.
Since TimeoutError isn't "traped" in _eb_no_srv we are not trying to 
resolve it further because we are not executing reactor.resolve().

Feb 21 15:15:32 testnikiproxy2 media-relay[1086]: error: Unhandled error 
in Deferred:
Feb 21 15:15:32 testnikiproxy2 media-relay[1086]: TimeoutError: 
[Query('_sip._udp.testnikisip2', 33, 1)]

Note that I'm not sure if the error will happen with twisted 11.0+ since 
the method setTimeout and TimeoutError were deprecated...
http://twistedmatrix.com/trac/browser/tags/releases/twisted-10.0.0/twisted/internet/defer.py#L399 

http://twistedmatrix.com/trac/browser/tags/releases/twisted-11.0.0/twisted/internet/defer.py#L399   
(setTimeout is not longer defined)

Anyway, here is a patch to fix it for twisted 10.0 :

diff -rN -u old-mediaproxy/mediaproxy/relay.py 
new-mediaproxy/mediaproxy/relay.py
--- old-mediaproxy/mediaproxy/relay.py  2012-02-27 12:07:58.100162109 +0100
+++ new-mediaproxy/mediaproxy/relay.py  2012-02-27 12:07:58.123162912 +0100
@@ -16,7 +16,7 @@
  from twisted.protocols.basic import LineOnlyReceiver
  from twisted.internet.error import ConnectionDone, TCPTimedOutError, 
DNSLookupError
  from twisted.internet.protocol import ClientFactory
-from twisted.internet.defer import DeferredList, succeed
+from twisted.internet.defer import DeferredList, succeed, TimeoutError
  from twisted.internet import reactor
  from twisted.python import failure
  from twisted.names import dns
@@ -260,7 +260,7 @@
          raise DomainError

      def _eb_no_srv(self, failure, addr, port):
-        failure.trap(DomainError)
+        failure.trap(DomainError, TimeoutError)
          return reactor.resolve(addr).addCallback(lambda host: (host, 
port)).addErrback(self._eb_no_dns, addr)

      def _eb_no_dns(self, failure, addr):


Regards,
-- 
Nikita