Attempt to figure out what's going on with timeouts (#3857)

2 files changed, 198 insertions, 1 deletions

diff --git a/tests/http/test_fedclient.py b/tests/http/test_fedclient.py
new file mode 100644
index 0000000000..1c46c9cfeb
--- /dev/null
+++ b/tests/http/test_fedclient.py
@@ -0,0 +1,157 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from mock import Mock
+
+from twisted.internet.defer import TimeoutError
+from twisted.internet.error import ConnectingCancelledError, DNSLookupError
+from twisted.web.client import ResponseNeverReceived
+
+from synapse.http.matrixfederationclient import MatrixFederationHttpClient
+
+from tests.unittest import HomeserverTestCase
+
+
+class FederationClientTests(HomeserverTestCase):
+    def make_homeserver(self, reactor, clock):
+
+        hs = self.setup_test_homeserver(reactor=reactor, clock=clock)
+        hs.tls_client_options_factory = None
+        return hs
+
+    def prepare(self, reactor, clock, homeserver):
+
+        self.cl = MatrixFederationHttpClient(self.hs)
+        self.reactor.lookups["testserv"] = "1.2.3.4"
+
+    def test_dns_error(self):
+        """
+        If the DNS raising returns an error, it will bubble up.
+        """
+        d = self.cl._request("testserv2:8008", "GET", "foo/bar", timeout=10000)
+        self.pump()
+
+        f = self.failureResultOf(d)
+        self.assertIsInstance(f.value, DNSLookupError)
+
+    def test_client_never_connect(self):
+        """
+        If the HTTP request is not connected and is timed out, it'll give a
+        ConnectingCancelledError.
+        """
+        d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
+
+        self.pump()
+
+        # Nothing happened yet
+        self.assertFalse(d.called)
+
+        # Make sure treq is trying to connect
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        self.assertEqual(clients[0][0], '1.2.3.4')
+        self.assertEqual(clients[0][1], 8008)
+
+        # Deferred is still without a result
+        self.assertFalse(d.called)
+
+        # Push by enough to time it out
+        self.reactor.advance(10.5)
+        f = self.failureResultOf(d)
+
+        self.assertIsInstance(f.value, ConnectingCancelledError)
+
+    def test_client_connect_no_response(self):
+        """
+        If the HTTP request is connected, but gets no response before being
+        timed out, it'll give a ResponseNeverReceived.
+        """
+        d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
+
+        self.pump()
+
+        # Nothing happened yet
+        self.assertFalse(d.called)
+
+        # Make sure treq is trying to connect
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        self.assertEqual(clients[0][0], '1.2.3.4')
+        self.assertEqual(clients[0][1], 8008)
+
+        conn = Mock()
+        client = clients[0][2].buildProtocol(None)
+        client.makeConnection(conn)
+
+        # Deferred is still without a result
+        self.assertFalse(d.called)
+
+        # Push by enough to time it out
+        self.reactor.advance(10.5)
+        f = self.failureResultOf(d)
+
+        self.assertIsInstance(f.value, ResponseNeverReceived)
+
+    def test_client_gets_headers(self):
+        """
+        Once the client gets the headers, _request returns successfully.
+        """
+        d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
+
+        self.pump()
+
+        conn = Mock()
+        clients = self.reactor.tcpClients
+        client = clients[0][2].buildProtocol(None)
+        client.makeConnection(conn)
+
+        # Deferred does not have a result
+        self.assertFalse(d.called)
+
+        # Send it the HTTP response
+        client.dataReceived(b"HTTP/1.1 200 OK\r\nServer: Fake\r\n\r\n")
+
+        # We should get a successful response
+        r = self.successResultOf(d)
+        self.assertEqual(r.code, 200)
+
+    def test_client_headers_no_body(self):
+        """
+        If the HTTP request is connected, but gets no response before being
+        timed out, it'll give a ResponseNeverReceived.
+        """
+        d = self.cl.post_json("testserv:8008", "foo/bar", timeout=10000)
+
+        self.pump()
+
+        conn = Mock()
+        clients = self.reactor.tcpClients
+        client = clients[0][2].buildProtocol(None)
+        client.makeConnection(conn)
+
+        # Deferred does not have a result
+        self.assertFalse(d.called)
+
+        # Send it the HTTP response
+        client.dataReceived(
+            (b"HTTP/1.1 200 OK\r\nContent-Type: application/json\r\n"
+             b"Server: Fake\r\n\r\n")
+        )
+
+        # Push by enough to time it out
+        self.reactor.advance(10.5)
+        f = self.failureResultOf(d)
+
+        self.assertIsInstance(f.value, TimeoutError)
diff --git a/tests/server.py b/tests/server.py
index a2c3ca61f6..420ec4e088 100644
--- a/tests/server.py
+++ b/tests/server.py
@@ -4,9 +4,14 @@ from io import BytesIO
 from six import text_type
 
 import attr
+from zope.interface import implementer
 
-from twisted.internet import address, threads
+from twisted.internet import address, threads, udp
+from twisted.internet._resolver import HostResolution
+from twisted.internet.address import IPv4Address
 from twisted.internet.defer import Deferred
+from twisted.internet.error import DNSLookupError
+from twisted.internet.interfaces import IReactorPluggableNameResolver
 from twisted.python.failure import Failure
 from twisted.test.proto_helpers import MemoryReactorClock
 
@@ -154,11 +159,46 @@ def render(request, resource, clock):
     wait_until_result(clock, request)
 
 
+@implementer(IReactorPluggableNameResolver)
 class ThreadedMemoryReactorClock(MemoryReactorClock):
     """
     A MemoryReactorClock that supports callFromThread.
     """
 
+    def __init__(self):
+        self._udp = []
+        self.lookups = {}
+
+        class Resolver(object):
+            def resolveHostName(
+                _self,
+                resolutionReceiver,
+                hostName,
+                portNumber=0,
+                addressTypes=None,
+                transportSemantics='TCP',
+            ):
+
+                resolution = HostResolution(hostName)
+                resolutionReceiver.resolutionBegan(resolution)
+                if hostName not in self.lookups:
+                    raise DNSLookupError("OH NO")
+
+                resolutionReceiver.addressResolved(
+                    IPv4Address('TCP', self.lookups[hostName], portNumber)
+                )
+                resolutionReceiver.resolutionComplete()
+                return resolution
+
+        self.nameResolver = Resolver()
+        super(ThreadedMemoryReactorClock, self).__init__()
+
+    def listenUDP(self, port, protocol, interface='', maxPacketSize=8196):
+        p = udp.Port(port, protocol, interface, maxPacketSize, self)
+        p.startListening()
+        self._udp.append(p)
+        return p
+
     def callFromThread(self, callback, *args, **kwargs):
         """
         Make the callback fire in the next reactor iteration.