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

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)