synapse-product/synapse/http/client.py

269 lines
8.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014 OpenMarket 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 twisted.internet import defer, reactor
from twisted.internet.error import DNSLookupError
from twisted.web.client import _AgentBase, _URI, readBody
from twisted.web.http_headers import Headers
from synapse.http.endpoint import matrix_endpoint
from synapse.util.async import sleep
from syutil.jsonutil import encode_canonical_json
from synapse.api.errors import CodeMessageException, SynapseError
import json
import logging
import urllib
logger = logging.getLogger(__name__)
# FIXME: SURELY these should be killed?!
_destination_mappings = {
"red": "localhost:8080",
"blue": "localhost:8081",
"green": "localhost:8082",
}
class HttpClient(object):
""" Interface for talking json over http
"""
RETRY_DNS_LOOKUP_FAILURES = "__retry_dns"
def put_json(self, destination, path, data):
""" Sends the specifed json data using PUT
Args:
destination (str): The remote server to send the HTTP request
to.
path (str): The HTTP path.
data (dict): A dict containing the data that will be used as
the request body. This will be encoded as JSON.
Returns:
Deferred: Succeeds when we get a 2xx HTTP response. The result
will be the decoded JSON body. On a 4xx or 5xx error response a
CodeMessageException is raised.
"""
pass
def get_json(self, destination, path, args=None):
""" Get's some json from the given host homeserver and path
Args:
destination (str): The remote server to send the HTTP request
to.
path (str): The HTTP path.
args (dict): A dictionary used to create query strings, defaults to
None.
**Note**: The value of each key is assumed to be an iterable
and *not* a string.
Returns:
Deferred: Succeeds when we get *any* HTTP response.
The result of the deferred is a tuple of `(code, response)`,
where `response` is a dict representing the decoded JSON body.
"""
pass
class MatrixHttpAgent(_AgentBase):
def __init__(self, reactor, pool=None):
_AgentBase.__init__(self, reactor, pool)
def request(self, destination, endpoint, method, path, params, query,
headers, body_producer):
host = b""
port = 0
fragment = b""
parsed_URI = _URI(b"http", destination, host, port, path, params,
query, fragment)
# Set the connection pool key to be the destination.
key = destination
return self._requestWithEndpoint(key, endpoint, method, parsed_URI,
headers, body_producer,
parsed_URI.originForm)
class TwistedHttpClient(HttpClient):
""" Wrapper around the twisted HTTP client api.
Attributes:
agent (twisted.web.client.Agent): The twisted Agent used to send the
requests.
"""
def __init__(self, hs):
self.agent = MatrixHttpAgent(reactor)
self.hs = hs
@defer.inlineCallbacks
def put_json(self, destination, path, data):
if destination in _destination_mappings:
destination = _destination_mappings[destination]
response = yield self._create_request(
destination.encode("ascii"),
"PUT",
path.encode("ascii"),
producer=_JsonProducer(data),
headers_dict={"Content-Type": ["application/json"]}
)
logger.debug("Getting resp body")
body = yield readBody(response)
logger.debug("Got resp body")
defer.returnValue((response.code, body))
@defer.inlineCallbacks
def get_json(self, destination, path, args={}):
if destination in _destination_mappings:
destination = _destination_mappings[destination]
logger.debug("get_json args: %s", args)
retry_on_dns_fail = True
if HttpClient.RETRY_DNS_LOOKUP_FAILURES in args:
# FIXME: This isn't ideal, but the interface exposed in get_json
# isn't comprehensive enough to give caller's any control over
# their connection mechanics.
retry_on_dns_fail = args.pop(HttpClient.RETRY_DNS_LOOKUP_FAILURES)
query_bytes = urllib.urlencode(args, True)
logger.debug("Query bytes: %s Retry DNS: %s", args, retry_on_dns_fail)
response = yield self._create_request(
destination.encode("ascii"),
"GET",
path.encode("ascii"),
query_bytes=query_bytes,
retry_on_dns_fail=retry_on_dns_fail
)
body = yield readBody(response)
defer.returnValue(json.loads(body))
@defer.inlineCallbacks
def _create_request(self, destination, method, path_bytes, param_bytes=b"",
query_bytes=b"", producer=None, headers_dict={},
retry_on_dns_fail=True):
""" Creates and sends a request to the given url
"""
headers_dict[b"User-Agent"] = [b"Synapse"]
headers_dict[b"Host"] = [destination]
logger.debug("Sending request to %s: %s %s;%s?%s",
destination, method, path_bytes, param_bytes, query_bytes)
logger.debug(
"Types: %s",
[
type(destination), type(method), type(path_bytes),
type(param_bytes),
type(query_bytes)
]
)
retries_left = 5
# TODO: setup and pass in an ssl_context to enable TLS
endpoint = matrix_endpoint(
reactor, destination, timeout=10,
ssl_context_factory=self.hs.tls_context_factory
)
while True:
try:
response = yield self.agent.request(
destination,
endpoint,
method,
path_bytes,
param_bytes,
query_bytes,
Headers(headers_dict),
producer
)
logger.debug("Got response to %s", method)
break
except Exception as e:
if not retry_on_dns_fail and isinstance(e, DNSLookupError):
logger.warn("DNS Lookup failed to %s with %s", destination,
e)
raise SynapseError(400, "Domain specified not found.")
logger.exception("Got error in _create_request")
_print_ex(e)
if retries_left:
yield sleep(2 ** (5 - retries_left))
retries_left -= 1
else:
raise
if 200 <= response.code < 300:
# We need to update the transactions table to say it was sent?
pass
else:
# :'(
# Update transactions table?
logger.error(
"Got response %d %s", response.code, response.phrase
)
raise CodeMessageException(
response.code, response.phrase
)
defer.returnValue(response)
def _print_ex(e):
if hasattr(e, "reasons") and e.reasons:
for ex in e.reasons:
_print_ex(ex)
else:
logger.exception(e)
class _JsonProducer(object):
""" Used by the twisted http client to create the HTTP body from json
"""
def __init__(self, jsn):
self.body = encode_canonical_json(jsn)
self.length = len(self.body)
def startProducing(self, consumer):
consumer.write(self.body)
return defer.succeed(None)
def pauseProducing(self):
pass
def stopProducing(self):
pass