Merge pull request #4428 from matrix-org/rav/matrix_federation_agent

Move SRV magic into an Agent-like thing
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Richard van der Hoff 2019-01-23 15:50:25 +00:00 committed by GitHub
commit a0ae475219
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9 changed files with 548 additions and 251 deletions

1
changelog.d/4428.misc Normal file
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@ -0,0 +1 @@
Move SRV logic into the Agent layer

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@ -13,15 +13,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import random
import re
from twisted.internet import defer
from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
from twisted.internet.error import ConnectError
from synapse.http.federation.srv_resolver import Server, resolve_service
logger = logging.getLogger(__name__)
@ -88,140 +81,3 @@ def parse_and_validate_server_name(server_name):
))
return host, port
def matrix_federation_endpoint(reactor, destination, tls_client_options_factory=None,
timeout=None):
"""Construct an endpoint for the given matrix destination.
Args:
reactor: Twisted reactor.
destination (unicode): The name of the server to connect to.
tls_client_options_factory
(synapse.crypto.context_factory.ClientTLSOptionsFactory):
Factory which generates TLS options for client connections.
timeout (int): connection timeout in seconds
"""
domain, port = parse_server_name(destination)
endpoint_kw_args = {}
if timeout is not None:
endpoint_kw_args.update(timeout=timeout)
if tls_client_options_factory is None:
transport_endpoint = HostnameEndpoint
default_port = 8008
else:
# the SNI string should be the same as the Host header, minus the port.
# as per https://github.com/matrix-org/synapse/issues/2525#issuecomment-336896777,
# the Host header and SNI should therefore be the server_name of the remote
# server.
tls_options = tls_client_options_factory.get_options(domain)
def transport_endpoint(reactor, host, port, timeout):
return wrapClientTLS(
tls_options,
HostnameEndpoint(reactor, host, port, timeout=timeout),
)
default_port = 8448
if port is None:
return SRVClientEndpoint(
reactor, "matrix", domain, protocol="tcp",
default_port=default_port, endpoint=transport_endpoint,
endpoint_kw_args=endpoint_kw_args
)
else:
return transport_endpoint(
reactor, domain, port, **endpoint_kw_args
)
class SRVClientEndpoint(object):
"""An endpoint which looks up SRV records for a service.
Cycles through the list of servers starting with each call to connect
picking the next server.
Implements twisted.internet.interfaces.IStreamClientEndpoint.
"""
def __init__(self, reactor, service, domain, protocol="tcp",
default_port=None, endpoint=HostnameEndpoint,
endpoint_kw_args={}):
self.reactor = reactor
self.service_name = "_%s._%s.%s" % (service, protocol, domain)
if default_port is not None:
self.default_server = Server(
host=domain,
port=default_port,
)
else:
self.default_server = None
self.endpoint = endpoint
self.endpoint_kw_args = endpoint_kw_args
self.servers = None
self.used_servers = None
@defer.inlineCallbacks
def fetch_servers(self):
self.used_servers = []
self.servers = yield resolve_service(self.service_name)
def pick_server(self):
if not self.servers:
if self.used_servers:
self.servers = self.used_servers
self.used_servers = []
self.servers.sort()
elif self.default_server:
return self.default_server
else:
raise ConnectError(
"No server available for %s" % self.service_name
)
# look for all servers with the same priority
min_priority = self.servers[0].priority
weight_indexes = list(
(index, server.weight + 1)
for index, server in enumerate(self.servers)
if server.priority == min_priority
)
total_weight = sum(weight for index, weight in weight_indexes)
target_weight = random.randint(0, total_weight)
for index, weight in weight_indexes:
target_weight -= weight
if target_weight <= 0:
server = self.servers[index]
# XXX: this looks totally dubious:
#
# (a) we never reuse a server until we have been through
# all of the servers at the same priority, so if the
# weights are A: 100, B:1, we always do ABABAB instead of
# AAAA...AAAB (approximately).
#
# (b) After using all the servers at the lowest priority,
# we move onto the next priority. We should only use the
# second priority if servers at the top priority are
# unreachable.
#
del self.servers[index]
self.used_servers.append(server)
return server
@defer.inlineCallbacks
def connect(self, protocolFactory):
if self.servers is None:
yield self.fetch_servers()
server = self.pick_server()
logger.info("Connecting to %s:%s", server.host, server.port)
endpoint = self.endpoint(
self.reactor, server.host, server.port, **self.endpoint_kw_args
)
connection = yield endpoint.connect(protocolFactory)
defer.returnValue(connection)

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@ -0,0 +1,124 @@
# -*- coding: utf-8 -*-
# Copyright 2019 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.
import logging
from zope.interface import implementer
from twisted.internet import defer
from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
from twisted.web.client import URI, Agent, HTTPConnectionPool
from twisted.web.iweb import IAgent
from synapse.http.endpoint import parse_server_name
from synapse.http.federation.srv_resolver import SrvResolver, pick_server_from_list
from synapse.util.logcontext import make_deferred_yieldable
logger = logging.getLogger(__name__)
@implementer(IAgent)
class MatrixFederationAgent(object):
"""An Agent-like thing which provides a `request` method which will look up a matrix
server and send an HTTP request to it.
Doesn't implement any retries. (Those are done in MatrixFederationHttpClient.)
Args:
reactor (IReactor): twisted reactor to use for underlying requests
tls_client_options_factory (ClientTLSOptionsFactory|None):
factory to use for fetching client tls options, or none to disable TLS.
srv_resolver (SrvResolver|None):
SRVResolver impl to use for looking up SRV records. None to use a default
implementation.
"""
def __init__(
self, reactor, tls_client_options_factory, _srv_resolver=None,
):
self._reactor = reactor
self._tls_client_options_factory = tls_client_options_factory
if _srv_resolver is None:
_srv_resolver = SrvResolver()
self._srv_resolver = _srv_resolver
self._pool = HTTPConnectionPool(reactor)
self._pool.retryAutomatically = False
self._pool.maxPersistentPerHost = 5
self._pool.cachedConnectionTimeout = 2 * 60
@defer.inlineCallbacks
def request(self, method, uri, headers=None, bodyProducer=None):
"""
Args:
method (bytes): HTTP method: GET/POST/etc
uri (bytes): Absolute URI to be retrieved
headers (twisted.web.http_headers.Headers|None):
HTTP headers to send with the request, or None to
send no extra headers.
bodyProducer (twisted.web.iweb.IBodyProducer|None):
An object which can generate bytes to make up the
body of this request (for example, the properly encoded contents of
a file for a file upload). Or None if the request is to have
no body.
Returns:
Deferred[twisted.web.iweb.IResponse]:
fires when the header of the response has been received (regardless of the
response status code). Fails if there is any problem which prevents that
response from being received (including problems that prevent the request
from being sent).
"""
parsed_uri = URI.fromBytes(uri)
server_name_bytes = parsed_uri.netloc
host, port = parse_server_name(server_name_bytes.decode("ascii"))
# XXX disabling TLS is really only supported here for the benefit of the
# unit tests. We should make the UTs cope with TLS rather than having to make
# the code support the unit tests.
if self._tls_client_options_factory is None:
tls_options = None
else:
tls_options = self._tls_client_options_factory.get_options(host)
if port is not None:
target = (host, port)
else:
server_list = yield self._srv_resolver.resolve_service(server_name_bytes)
if not server_list:
target = (host, 8448)
logger.debug("No SRV record for %s, using %s", host, target)
else:
target = pick_server_from_list(server_list)
class EndpointFactory(object):
@staticmethod
def endpointForURI(_uri):
logger.info("Connecting to %s:%s", target[0], target[1])
ep = HostnameEndpoint(self._reactor, host=target[0], port=target[1])
if tls_options is not None:
ep = wrapClientTLS(tls_options, ep)
return ep
agent = Agent.usingEndpointFactory(self._reactor, EndpointFactory(), self._pool)
res = yield make_deferred_yieldable(
agent.request(method, uri, headers, bodyProducer)
)
defer.returnValue(res)

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@ -15,6 +15,7 @@
# limitations under the License.
import logging
import random
import time
import attr
@ -51,74 +52,118 @@ class Server(object):
expires = attr.ib(default=0)
@defer.inlineCallbacks
def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=time):
"""Look up a SRV record, with caching
def pick_server_from_list(server_list):
"""Randomly choose a server from the server list
Args:
server_list (list[Server]): list of candidate servers
Returns:
Tuple[bytes, int]: (host, port) pair for the chosen server
"""
if not server_list:
raise RuntimeError("pick_server_from_list called with empty list")
# TODO: currently we only use the lowest-priority servers. We should maintain a
# cache of servers known to be "down" and filter them out
min_priority = min(s.priority for s in server_list)
eligible_servers = list(s for s in server_list if s.priority == min_priority)
total_weight = sum(s.weight for s in eligible_servers)
target_weight = random.randint(0, total_weight)
for s in eligible_servers:
target_weight -= s.weight
if target_weight <= 0:
return s.host, s.port
# this should be impossible.
raise RuntimeError(
"pick_server_from_list got to end of eligible server list.",
)
class SrvResolver(object):
"""Interface to the dns client to do SRV lookups, with result caching.
The default resolver in twisted.names doesn't do any caching (it has a CacheResolver,
but the cache never gets populated), so we add our own caching layer here.
Args:
service_name (unicode|bytes): record to look up
dns_client (twisted.internet.interfaces.IResolver): twisted resolver impl
cache (dict): cache object
clock (object): clock implementation. must provide a time() method.
Returns:
Deferred[list[Server]]: a list of the SRV records, or an empty list if none found
get_time (callable): clock implementation. Should return seconds since the epoch
"""
# TODO: the dns client handles both unicode names (encoding via idna) and pre-encoded
# byteses; however they will obviously end up as separate entries in the cache. We
# should pick one form and stick with it.
cache_entry = cache.get(service_name, None)
if cache_entry:
if all(s.expires > int(clock.time()) for s in cache_entry):
servers = list(cache_entry)
defer.returnValue(servers)
def __init__(self, dns_client=client, cache=SERVER_CACHE, get_time=time.time):
self._dns_client = dns_client
self._cache = cache
self._get_time = get_time
try:
answers, _, _ = yield make_deferred_yieldable(
dns_client.lookupService(service_name),
)
except DNSNameError:
# TODO: cache this. We can get the SOA out of the exception, and use
# the negative-TTL value.
defer.returnValue([])
except DomainError as e:
# We failed to resolve the name (other than a NameError)
# Try something in the cache, else rereaise
cache_entry = cache.get(service_name, None)
@defer.inlineCallbacks
def resolve_service(self, service_name):
"""Look up a SRV record
Args:
service_name (bytes): record to look up
Returns:
Deferred[list[Server]]:
a list of the SRV records, or an empty list if none found
"""
now = int(self._get_time())
if not isinstance(service_name, bytes):
raise TypeError("%r is not a byte string" % (service_name,))
cache_entry = self._cache.get(service_name, None)
if cache_entry:
logger.warn(
"Failed to resolve %r, falling back to cache. %r",
service_name, e
if all(s.expires > now for s in cache_entry):
servers = list(cache_entry)
defer.returnValue(servers)
try:
answers, _, _ = yield make_deferred_yieldable(
self._dns_client.lookupService(service_name),
)
defer.returnValue(list(cache_entry))
else:
raise e
except DNSNameError:
# TODO: cache this. We can get the SOA out of the exception, and use
# the negative-TTL value.
defer.returnValue([])
except DomainError as e:
# We failed to resolve the name (other than a NameError)
# Try something in the cache, else rereaise
cache_entry = self._cache.get(service_name, None)
if cache_entry:
logger.warn(
"Failed to resolve %r, falling back to cache. %r",
service_name, e
)
defer.returnValue(list(cache_entry))
else:
raise e
if (len(answers) == 1
and answers[0].type == dns.SRV
and answers[0].payload
and answers[0].payload.target == dns.Name(b'.')):
raise ConnectError("Service %s unavailable" % service_name)
if (len(answers) == 1
and answers[0].type == dns.SRV
and answers[0].payload
and answers[0].payload.target == dns.Name(b'.')):
raise ConnectError("Service %s unavailable" % service_name)
servers = []
servers = []
for answer in answers:
if answer.type != dns.SRV or not answer.payload:
continue
for answer in answers:
if answer.type != dns.SRV or not answer.payload:
continue
payload = answer.payload
payload = answer.payload
servers.append(Server(
host=payload.target.name,
port=payload.port,
priority=payload.priority,
weight=payload.weight,
expires=int(clock.time()) + answer.ttl,
))
servers.append(Server(
host=payload.target.name,
port=payload.port,
priority=payload.priority,
weight=payload.weight,
expires=now + answer.ttl,
))
servers.sort() # FIXME: get rid of this (it's broken by the attrs change)
cache[service_name] = list(servers)
defer.returnValue(servers)
self._cache[service_name] = list(servers)
defer.returnValue(servers)

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@ -32,7 +32,7 @@ from twisted.internet import defer, protocol
from twisted.internet.error import DNSLookupError
from twisted.internet.task import _EPSILON, Cooperator
from twisted.web._newclient import ResponseDone
from twisted.web.client import Agent, FileBodyProducer, HTTPConnectionPool
from twisted.web.client import FileBodyProducer
from twisted.web.http_headers import Headers
import synapse.metrics
@ -44,7 +44,7 @@ from synapse.api.errors import (
RequestSendFailed,
SynapseError,
)
from synapse.http.endpoint import matrix_federation_endpoint
from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent
from synapse.util.async_helpers import timeout_deferred
from synapse.util.logcontext import make_deferred_yieldable
from synapse.util.metrics import Measure
@ -66,20 +66,6 @@ else:
MAXINT = sys.maxint
class MatrixFederationEndpointFactory(object):
def __init__(self, hs):
self.reactor = hs.get_reactor()
self.tls_client_options_factory = hs.tls_client_options_factory
def endpointForURI(self, uri):
destination = uri.netloc.decode('ascii')
return matrix_federation_endpoint(
self.reactor, destination, timeout=10,
tls_client_options_factory=self.tls_client_options_factory
)
_next_id = 1
@ -187,12 +173,10 @@ class MatrixFederationHttpClient(object):
self.signing_key = hs.config.signing_key[0]
self.server_name = hs.hostname
reactor = hs.get_reactor()
pool = HTTPConnectionPool(reactor)
pool.retryAutomatically = False
pool.maxPersistentPerHost = 5
pool.cachedConnectionTimeout = 2 * 60
self.agent = Agent.usingEndpointFactory(
reactor, MatrixFederationEndpointFactory(hs), pool=pool
self.agent = MatrixFederationAgent(
hs.get_reactor(),
hs.tls_client_options_factory,
)
self.clock = hs.get_clock()
self._store = hs.get_datastore()
@ -316,9 +300,9 @@ class MatrixFederationHttpClient(object):
headers_dict[b"Authorization"] = auth_headers
logger.info(
"{%s} [%s] Sending request: %s %s",
"{%s} [%s] Sending request: %s %s; timeout %fs",
request.txn_id, request.destination, request.method,
url_str,
url_str, _sec_timeout,
)
try:
@ -338,12 +322,11 @@ class MatrixFederationHttpClient(object):
reactor=self.hs.get_reactor(),
)
response = yield make_deferred_yieldable(
request_deferred,
)
response = yield request_deferred
except DNSLookupError as e:
raise_from(RequestSendFailed(e, can_retry=retry_on_dns_fail), e)
except Exception as e:
logger.info("Failed to send request: %s", e)
raise_from(RequestSendFailed(e, can_retry=True), e)
logger.info(

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@ -0,0 +1,183 @@
# -*- coding: utf-8 -*-
# Copyright 2019 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.
import logging
from mock import Mock
import treq
from twisted.internet import defer
from twisted.internet.protocol import Factory
from twisted.protocols.tls import TLSMemoryBIOFactory
from twisted.test.ssl_helpers import ServerTLSContext
from twisted.web.http import HTTPChannel
from synapse.crypto.context_factory import ClientTLSOptionsFactory
from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent
from synapse.util.logcontext import LoggingContext
from tests.server import FakeTransport, ThreadedMemoryReactorClock
from tests.unittest import TestCase
logger = logging.getLogger(__name__)
class MatrixFederationAgentTests(TestCase):
def setUp(self):
self.reactor = ThreadedMemoryReactorClock()
self.mock_resolver = Mock()
self.agent = MatrixFederationAgent(
reactor=self.reactor,
tls_client_options_factory=ClientTLSOptionsFactory(None),
_srv_resolver=self.mock_resolver,
)
def _make_connection(self, client_factory):
"""Builds a test server, and completes the outgoing client connection
Returns:
HTTPChannel: the test server
"""
# build the test server
server_tls_protocol = _build_test_server()
# now, tell the client protocol factory to build the client protocol (it will be a
# _WrappingProtocol, around a TLSMemoryBIOProtocol, around an
# HTTP11ClientProtocol) and wire the output of said protocol up to the server via
# a FakeTransport.
#
# Normally this would be done by the TCP socket code in Twisted, but we are
# stubbing that out here.
client_protocol = client_factory.buildProtocol(None)
client_protocol.makeConnection(FakeTransport(server_tls_protocol, self.reactor))
# tell the server tls protocol to send its stuff back to the client, too
server_tls_protocol.makeConnection(FakeTransport(client_protocol, self.reactor))
# finally, give the reactor a pump to get the TLS juices flowing.
self.reactor.pump((0.1,))
# fish the test server back out of the server-side TLS protocol.
return server_tls_protocol.wrappedProtocol
@defer.inlineCallbacks
def _make_get_request(self, uri):
"""
Sends a simple GET request via the agent, and checks its logcontext management
"""
with LoggingContext("one") as context:
fetch_d = self.agent.request(b'GET', uri)
# Nothing happened yet
self.assertNoResult(fetch_d)
# should have reset logcontext to the sentinel
_check_logcontext(LoggingContext.sentinel)
try:
fetch_res = yield fetch_d
defer.returnValue(fetch_res)
finally:
_check_logcontext(context)
def test_get(self):
"""
happy-path test of a GET request
"""
self.reactor.lookups["testserv"] = "1.2.3.4"
test_d = self._make_get_request(b"matrix://testserv:8448/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8448)
# make a test server, and wire up the client
http_server = self._make_connection(client_factory)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b'GET')
self.assertEqual(request.path, b'/foo/bar')
self.assertEqual(
request.requestHeaders.getRawHeaders(b'host'),
[b'testserv:8448']
)
content = request.content.read()
self.assertEqual(content, b'')
# Deferred is still without a result
self.assertNoResult(test_d)
# send the headers
request.responseHeaders.setRawHeaders(b'Content-Type', [b'application/json'])
request.write('')
self.reactor.pump((0.1,))
response = self.successResultOf(test_d)
# that should give us a Response object
self.assertEqual(response.code, 200)
# Send the body
request.write('{ "a": 1 }'.encode('ascii'))
request.finish()
self.reactor.pump((0.1,))
# check it can be read
json = self.successResultOf(treq.json_content(response))
self.assertEqual(json, {"a": 1})
def _check_logcontext(context):
current = LoggingContext.current_context()
if current is not context:
raise AssertionError(
"Expected logcontext %s but was %s" % (context, current),
)
def _build_test_server():
"""Construct a test server
This builds an HTTP channel, wrapped with a TLSMemoryBIOProtocol
Returns:
TLSMemoryBIOProtocol
"""
server_factory = Factory.forProtocol(HTTPChannel)
# Request.finish expects the factory to have a 'log' method.
server_factory.log = _log_request
server_tls_factory = TLSMemoryBIOFactory(
ServerTLSContext(), isClient=False, wrappedFactory=server_factory,
)
return server_tls_factory.buildProtocol(None)
def _log_request(request):
"""Implements Factory.log, which is expected by Request.finish"""
logger.info("Completed request %s", request)

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@ -21,7 +21,7 @@ from twisted.internet.defer import Deferred
from twisted.internet.error import ConnectError
from twisted.names import dns, error
from synapse.http.federation.srv_resolver import resolve_service
from synapse.http.federation.srv_resolver import SrvResolver
from synapse.util.logcontext import LoggingContext
from tests import unittest
@ -43,13 +43,13 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock.lookupService.return_value = result_deferred
cache = {}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
@defer.inlineCallbacks
def do_lookup():
with LoggingContext("one") as ctx:
resolve_d = resolve_service(
service_name, dns_client=dns_client_mock, cache=cache
)
resolve_d = resolver.resolve_service(service_name)
self.assertNoResult(resolve_d)
@ -83,16 +83,15 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock = Mock()
dns_client_mock.lookupService.return_value = defer.fail(error.DNSServerError())
service_name = "test_service.example.com"
service_name = b"test_service.example.com"
entry = Mock(spec_set=["expires"])
entry.expires = 0
cache = {service_name: [entry]}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
servers = yield resolve_service(
service_name, dns_client=dns_client_mock, cache=cache
)
servers = yield resolver.resolve_service(service_name)
dns_client_mock.lookupService.assert_called_once_with(service_name)
@ -106,17 +105,18 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock = Mock(spec_set=['lookupService'])
dns_client_mock.lookupService = Mock(spec_set=[])
service_name = "test_service.example.com"
service_name = b"test_service.example.com"
entry = Mock(spec_set=["expires"])
entry.expires = 999999999
cache = {service_name: [entry]}
servers = yield resolve_service(
service_name, dns_client=dns_client_mock, cache=cache, clock=clock
resolver = SrvResolver(
dns_client=dns_client_mock, cache=cache, get_time=clock.time,
)
servers = yield resolver.resolve_service(service_name)
self.assertFalse(dns_client_mock.lookupService.called)
self.assertEquals(len(servers), 1)
@ -128,12 +128,13 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock.lookupService.return_value = defer.fail(error.DNSServerError())
service_name = "test_service.example.com"
service_name = b"test_service.example.com"
cache = {}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
with self.assertRaises(error.DNSServerError):
yield resolve_service(service_name, dns_client=dns_client_mock, cache=cache)
yield resolver.resolve_service(service_name)
@defer.inlineCallbacks
def test_name_error(self):
@ -141,13 +142,12 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock.lookupService.return_value = defer.fail(error.DNSNameError())
service_name = "test_service.example.com"
service_name = b"test_service.example.com"
cache = {}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
servers = yield resolve_service(
service_name, dns_client=dns_client_mock, cache=cache
)
servers = yield resolver.resolve_service(service_name)
self.assertEquals(len(servers), 0)
self.assertEquals(len(cache), 0)
@ -162,10 +162,9 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock = Mock()
dns_client_mock.lookupService.return_value = lookup_deferred
cache = {}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
resolve_d = resolve_service(
service_name, dns_client=dns_client_mock, cache=cache
)
resolve_d = resolver.resolve_service(service_name)
self.assertNoResult(resolve_d)
# returning a single "." should make the lookup fail with a ConenctError
@ -187,10 +186,9 @@ class SrvResolverTestCase(unittest.TestCase):
dns_client_mock = Mock()
dns_client_mock.lookupService.return_value = lookup_deferred
cache = {}
resolver = SrvResolver(dns_client=dns_client_mock, cache=cache)
resolve_d = resolve_service(
service_name, dns_client=dns_client_mock, cache=cache
)
resolve_d = resolver.resolve_service(service_name)
self.assertNoResult(resolve_d)
lookup_deferred.callback((

View File

@ -15,6 +15,7 @@
from mock import Mock
from twisted.internet import defer
from twisted.internet.defer import TimeoutError
from twisted.internet.error import ConnectingCancelledError, DNSLookupError
from twisted.test.proto_helpers import StringTransport
@ -26,11 +27,20 @@ from synapse.http.matrixfederationclient import (
MatrixFederationHttpClient,
MatrixFederationRequest,
)
from synapse.util.logcontext import LoggingContext
from tests.server import FakeTransport
from tests.unittest import HomeserverTestCase
def check_logcontext(context):
current = LoggingContext.current_context()
if current is not context:
raise AssertionError(
"Expected logcontext %s but was %s" % (context, current),
)
class FederationClientTests(HomeserverTestCase):
def make_homeserver(self, reactor, clock):
@ -43,6 +53,70 @@ class FederationClientTests(HomeserverTestCase):
self.cl = MatrixFederationHttpClient(self.hs)
self.reactor.lookups["testserv"] = "1.2.3.4"
def test_client_get(self):
"""
happy-path test of a GET request
"""
@defer.inlineCallbacks
def do_request():
with LoggingContext("one") as context:
fetch_d = self.cl.get_json("testserv:8008", "foo/bar")
# Nothing happened yet
self.assertNoResult(fetch_d)
# should have reset logcontext to the sentinel
check_logcontext(LoggingContext.sentinel)
try:
fetch_res = yield fetch_d
defer.returnValue(fetch_res)
finally:
check_logcontext(context)
test_d = do_request()
self.pump()
# Nothing happened yet
self.assertNoResult(test_d)
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8008)
# complete the connection and wire it up to a fake transport
protocol = factory.buildProtocol(None)
transport = StringTransport()
protocol.makeConnection(transport)
# that should have made it send the request to the transport
self.assertRegex(transport.value(), b"^GET /foo/bar")
# Deferred is still without a result
self.assertNoResult(test_d)
# Send it the HTTP response
res_json = '{ "a": 1 }'.encode('ascii')
protocol.dataReceived(
b"HTTP/1.1 200 OK\r\n"
b"Server: Fake\r\n"
b"Content-Type: application/json\r\n"
b"Content-Length: %i\r\n"
b"\r\n"
b"%s" % (len(res_json), res_json)
)
self.pump()
res = self.successResultOf(test_d)
# check the response is as expected
self.assertEqual(res, {"a": 1})
def test_dns_error(self):
"""
If the DNS lookup returns an error, it will bubble up.
@ -54,6 +128,28 @@ class FederationClientTests(HomeserverTestCase):
self.assertIsInstance(f.value, RequestSendFailed)
self.assertIsInstance(f.value.inner_exception, DNSLookupError)
def test_client_connection_refused(self):
d = self.cl.get_json("testserv:8008", "foo/bar", timeout=10000)
self.pump()
# Nothing happened yet
self.assertNoResult(d)
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8008)
e = Exception("go away")
factory.clientConnectionFailed(None, e)
self.pump(0.5)
f = self.failureResultOf(d)
self.assertIsInstance(f.value, RequestSendFailed)
self.assertIs(f.value.inner_exception, e)
def test_client_never_connect(self):
"""
If the HTTP request is not connected and is timed out, it'll give a

View File

@ -1,4 +1,5 @@
import json
import logging
from io import BytesIO
from six import text_type
@ -22,6 +23,8 @@ from synapse.util import Clock
from tests.utils import setup_test_homeserver as _sth
logger = logging.getLogger(__name__)
class TimedOutException(Exception):
"""
@ -339,7 +342,7 @@ def get_clock():
return (clock, hs_clock)
@attr.s
@attr.s(cmp=False)
class FakeTransport(object):
"""
A twisted.internet.interfaces.ITransport implementation which sends all its data
@ -414,6 +417,11 @@ class FakeTransport(object):
self.buffer = self.buffer + byt
def _write():
if not self.buffer:
# nothing to do. Don't write empty buffers: it upsets the
# TLSMemoryBIOProtocol
return
if getattr(self.other, "transport") is not None:
self.other.dataReceived(self.buffer)
self.buffer = b""
@ -421,7 +429,10 @@ class FakeTransport(object):
self._reactor.callLater(0.0, _write)
_write()
# always actually do the write asynchronously. Some protocols (notably the
# TLSMemoryBIOProtocol) get very confused if a read comes back while they are
# still doing a write. Doing a callLater here breaks the cycle.
self._reactor.callLater(0.0, _write)
def writeSequence(self, seq):
for x in seq: