Merge pull request #3639 from matrix-org/rav/refactor_error_handling

Clean up handling of errors from outbound requests
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Richard van der Hoff 2018-08-02 17:38:24 +01:00 committed by GitHub
commit 1fa98495d0
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9 changed files with 124 additions and 142 deletions

1
changelog.d/3639.feature Normal file
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@ -0,0 +1 @@
When we fail to join a room over federation, pass the error code back to the client.

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@ -70,20 +70,6 @@ class CodeMessageException(RuntimeError):
self.code = code
self.msg = msg
def error_dict(self):
return cs_error(self.msg)
class MatrixCodeMessageException(CodeMessageException):
"""An error from a general matrix endpoint, eg. from a proxied Matrix API call.
Attributes:
errcode (str): Matrix error code e.g 'M_FORBIDDEN'
"""
def __init__(self, code, msg, errcode=Codes.UNKNOWN):
super(MatrixCodeMessageException, self).__init__(code, msg)
self.errcode = errcode
class SynapseError(CodeMessageException):
"""A base exception type for matrix errors which have an errcode and error
@ -109,38 +95,28 @@ class SynapseError(CodeMessageException):
self.errcode,
)
@classmethod
def from_http_response_exception(cls, err):
"""Make a SynapseError based on an HTTPResponseException
This is useful when a proxied request has failed, and we need to
decide how to map the failure onto a matrix error to send back to the
client.
class ProxiedRequestError(SynapseError):
"""An error from a general matrix endpoint, eg. from a proxied Matrix API call.
An attempt is made to parse the body of the http response as a matrix
error. If that succeeds, the errcode and error message from the body
are used as the errcode and error message in the new synapse error.
Otherwise, the errcode is set to M_UNKNOWN, and the error message is
set to the reason code from the HTTP response.
Args:
err (HttpResponseException):
Returns:
SynapseError:
Attributes:
errcode (str): Matrix error code e.g 'M_FORBIDDEN'
"""
# try to parse the body as json, to get better errcode/msg, but
# default to M_UNKNOWN with the HTTP status as the error text
try:
j = json.loads(err.response)
except ValueError:
j = {}
errcode = j.get('errcode', Codes.UNKNOWN)
errmsg = j.get('error', err.msg)
def __init__(self, code, msg, errcode=Codes.UNKNOWN, additional_fields=None):
super(ProxiedRequestError, self).__init__(
code, msg, errcode
)
if additional_fields is None:
self._additional_fields = {}
else:
self._additional_fields = dict(additional_fields)
res = SynapseError(err.code, errmsg, errcode)
return res
def error_dict(self):
return cs_error(
self.msg,
self.errcode,
**self._additional_fields
)
class ConsentNotGivenError(SynapseError):
@ -309,14 +285,6 @@ class LimitExceededError(SynapseError):
)
def cs_exception(exception):
if isinstance(exception, CodeMessageException):
return exception.error_dict()
else:
logger.error("Unknown exception type: %s", type(exception))
return {}
def cs_error(msg, code=Codes.UNKNOWN, **kwargs):
""" Utility method for constructing an error response for client-server
interactions.
@ -373,7 +341,7 @@ class HttpResponseException(CodeMessageException):
Represents an HTTP-level failure of an outbound request
Attributes:
response (str): body of response
response (bytes): body of response
"""
def __init__(self, code, msg, response):
"""
@ -381,7 +349,39 @@ class HttpResponseException(CodeMessageException):
Args:
code (int): HTTP status code
msg (str): reason phrase from HTTP response status line
response (str): body of response
response (bytes): body of response
"""
super(HttpResponseException, self).__init__(code, msg)
self.response = response
def to_synapse_error(self):
"""Make a SynapseError based on an HTTPResponseException
This is useful when a proxied request has failed, and we need to
decide how to map the failure onto a matrix error to send back to the
client.
An attempt is made to parse the body of the http response as a matrix
error. If that succeeds, the errcode and error message from the body
are used as the errcode and error message in the new synapse error.
Otherwise, the errcode is set to M_UNKNOWN, and the error message is
set to the reason code from the HTTP response.
Returns:
SynapseError:
"""
# try to parse the body as json, to get better errcode/msg, but
# default to M_UNKNOWN with the HTTP status as the error text
try:
j = json.loads(self.response)
except ValueError:
j = {}
if not isinstance(j, dict):
j = {}
errcode = j.pop('errcode', Codes.UNKNOWN)
errmsg = j.pop('error', self.msg)
return ProxiedRequestError(self.code, errmsg, errcode, j)

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@ -488,7 +488,7 @@ class FederationClient(FederationBase):
The [Deferred] result of callback, if it succeeds
Raises:
CodeMessageException if the chosen remote server returns a 300/400 code.
SynapseError if the chosen remote server returns a 300/400 code.
RuntimeError if no servers were reachable.
"""
@ -504,9 +504,9 @@ class FederationClient(FederationBase):
"Failed to %s via %s: %s",
description, destination, e,
)
except CodeMessageException as e:
except HttpResponseException as e:
if not 500 <= e.code < 600:
raise
raise e.to_synapse_error()
else:
logger.warn(
"Failed to %s via %s: %i %s",
@ -543,7 +543,7 @@ class FederationClient(FederationBase):
Deferred: resolves to a tuple of (origin (str), event (object))
where origin is the remote homeserver which generated the event.
Fails with a ``CodeMessageException`` if the chosen remote server
Fails with a ``SynapseError`` if the chosen remote server
returns a 300/400 code.
Fails with a ``RuntimeError`` if no servers were reachable.
@ -599,7 +599,7 @@ class FederationClient(FederationBase):
giving the serer the event was sent to, ``state`` (?) and
``auth_chain``.
Fails with a ``CodeMessageException`` if the chosen remote server
Fails with a ``SynapseError`` if the chosen remote server
returns a 300/400 code.
Fails with a ``RuntimeError`` if no servers were reachable.
@ -673,12 +673,17 @@ class FederationClient(FederationBase):
@defer.inlineCallbacks
def send_invite(self, destination, room_id, event_id, pdu):
time_now = self._clock.time_msec()
try:
code, content = yield self.transport_layer.send_invite(
destination=destination,
room_id=room_id,
event_id=event_id,
content=pdu.get_pdu_json(time_now),
)
except HttpResponseException as e:
if e.code == 403:
raise e.to_synapse_error()
raise
pdu_dict = content["event"]
@ -709,7 +714,7 @@ class FederationClient(FederationBase):
Return:
Deferred: resolves to None.
Fails with a ``CodeMessageException`` if the chosen remote server
Fails with a ``SynapseError`` if the chosen remote server
returns a 300/400 code.
Fails with a ``RuntimeError`` if no servers were reachable.

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@ -26,7 +26,7 @@ from twisted.internet import defer
from synapse.api.errors import (
CodeMessageException,
Codes,
MatrixCodeMessageException,
HttpResponseException,
SynapseError,
)
@ -85,7 +85,6 @@ class IdentityHandler(BaseHandler):
)
defer.returnValue(None)
data = {}
try:
data = yield self.http_client.get_json(
"https://%s%s" % (
@ -94,11 +93,9 @@ class IdentityHandler(BaseHandler):
),
{'sid': creds['sid'], 'client_secret': client_secret}
)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
logger.info("getValidated3pid failed with Matrix error: %r", e)
raise SynapseError(e.code, e.msg, e.errcode)
except CodeMessageException as e:
data = json.loads(e.msg)
raise e.to_synapse_error()
if 'medium' in data:
defer.returnValue(data)
@ -136,7 +133,7 @@ class IdentityHandler(BaseHandler):
)
logger.debug("bound threepid %r to %s", creds, mxid)
except CodeMessageException as e:
data = json.loads(e.msg)
data = json.loads(e.msg) # XXX WAT?
defer.returnValue(data)
@defer.inlineCallbacks
@ -209,12 +206,9 @@ class IdentityHandler(BaseHandler):
params
)
defer.returnValue(data)
except MatrixCodeMessageException as e:
logger.info("Proxied requestToken failed with Matrix error: %r", e)
raise SynapseError(e.code, e.msg, e.errcode)
except CodeMessageException as e:
except HttpResponseException as e:
logger.info("Proxied requestToken failed: %r", e)
raise e
raise e.to_synapse_error()
@defer.inlineCallbacks
def requestMsisdnToken(
@ -244,9 +238,6 @@ class IdentityHandler(BaseHandler):
params
)
defer.returnValue(data)
except MatrixCodeMessageException as e:
logger.info("Proxied requestToken failed with Matrix error: %r", e)
raise SynapseError(e.code, e.msg, e.errcode)
except CodeMessageException as e:
except HttpResponseException as e:
logger.info("Proxied requestToken failed: %r", e)
raise e
raise e.to_synapse_error()

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@ -39,12 +39,7 @@ from twisted.web.client import (
from twisted.web.http import PotentialDataLoss
from twisted.web.http_headers import Headers
from synapse.api.errors import (
CodeMessageException,
Codes,
MatrixCodeMessageException,
SynapseError,
)
from synapse.api.errors import Codes, HttpResponseException, SynapseError
from synapse.http import cancelled_to_request_timed_out_error, redact_uri
from synapse.http.endpoint import SpiderEndpoint
from synapse.util.async import add_timeout_to_deferred
@ -132,6 +127,11 @@ class SimpleHttpClient(object):
Returns:
Deferred[object]: parsed json
Raises:
HttpResponseException: On a non-2xx HTTP response.
ValueError: if the response was not JSON
"""
# TODO: Do we ever want to log message contents?
@ -155,7 +155,10 @@ class SimpleHttpClient(object):
body = yield make_deferred_yieldable(readBody(response))
if 200 <= response.code < 300:
defer.returnValue(json.loads(body))
else:
raise HttpResponseException(response.code, response.phrase, body)
@defer.inlineCallbacks
def post_json_get_json(self, uri, post_json, headers=None):
@ -169,6 +172,11 @@ class SimpleHttpClient(object):
Returns:
Deferred[object]: parsed json
Raises:
HttpResponseException: On a non-2xx HTTP response.
ValueError: if the response was not JSON
"""
json_str = encode_canonical_json(post_json)
@ -193,9 +201,7 @@ class SimpleHttpClient(object):
if 200 <= response.code < 300:
defer.returnValue(json.loads(body))
else:
raise self._exceptionFromFailedRequest(response, body)
defer.returnValue(json.loads(body))
raise HttpResponseException(response.code, response.phrase, body)
@defer.inlineCallbacks
def get_json(self, uri, args={}, headers=None):
@ -213,14 +219,12 @@ class SimpleHttpClient(object):
Deferred: Succeeds when we get *any* 2xx HTTP response, with the
HTTP body as JSON.
Raises:
On a non-2xx HTTP response. The response body will be used as the
error message.
HttpResponseException On a non-2xx HTTP response.
ValueError: if the response was not JSON
"""
try:
body = yield self.get_raw(uri, args, headers=headers)
defer.returnValue(json.loads(body))
except CodeMessageException as e:
raise self._exceptionFromFailedRequest(e.code, e.msg)
@defer.inlineCallbacks
def put_json(self, uri, json_body, args={}, headers=None):
@ -239,7 +243,9 @@ class SimpleHttpClient(object):
Deferred: Succeeds when we get *any* 2xx HTTP response, with the
HTTP body as JSON.
Raises:
On a non-2xx HTTP response.
HttpResponseException On a non-2xx HTTP response.
ValueError: if the response was not JSON
"""
if len(args):
query_bytes = urllib.urlencode(args, True)
@ -266,10 +272,7 @@ class SimpleHttpClient(object):
if 200 <= response.code < 300:
defer.returnValue(json.loads(body))
else:
# NB: This is explicitly not json.loads(body)'d because the contract
# of CodeMessageException is a *string* message. Callers can always
# load it into JSON if they want.
raise CodeMessageException(response.code, body)
raise HttpResponseException(response.code, response.phrase, body)
@defer.inlineCallbacks
def get_raw(self, uri, args={}, headers=None):
@ -287,8 +290,7 @@ class SimpleHttpClient(object):
Deferred: Succeeds when we get *any* 2xx HTTP response, with the
HTTP body at text.
Raises:
On a non-2xx HTTP response. The response body will be used as the
error message.
HttpResponseException on a non-2xx HTTP response.
"""
if len(args):
query_bytes = urllib.urlencode(args, True)
@ -311,16 +313,7 @@ class SimpleHttpClient(object):
if 200 <= response.code < 300:
defer.returnValue(body)
else:
raise CodeMessageException(response.code, body)
def _exceptionFromFailedRequest(self, response, body):
try:
jsonBody = json.loads(body)
errcode = jsonBody['errcode']
error = jsonBody['error']
return MatrixCodeMessageException(response.code, error, errcode)
except (ValueError, KeyError):
return CodeMessageException(response.code, body)
raise HttpResponseException(response.code, response.phrase, body)
# XXX: FIXME: This is horribly copy-pasted from matrixfederationclient.
# The two should be factored out.

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@ -36,7 +36,6 @@ from synapse.api.errors import (
Codes,
SynapseError,
UnrecognizedRequestError,
cs_exception,
)
from synapse.http.request_metrics import requests_counter
from synapse.util.caches import intern_dict
@ -77,16 +76,13 @@ def wrap_json_request_handler(h):
def wrapped_request_handler(self, request):
try:
yield h(self, request)
except CodeMessageException as e:
except SynapseError as e:
code = e.code
if isinstance(e, SynapseError):
logger.info(
"%s SynapseError: %s - %s", request, code, e.msg
)
else:
logger.exception(e)
respond_with_json(
request, code, cs_exception(e), send_cors=True,
request, code, e.error_dict(), send_cors=True,
pretty_print=_request_user_agent_is_curl(request),
)

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@ -18,7 +18,7 @@ import re
from twisted.internet import defer
from synapse.api.errors import MatrixCodeMessageException, SynapseError
from synapse.api.errors import HttpResponseException
from synapse.http.servlet import RestServlet, parse_json_object_from_request
from synapse.types import Requester, UserID
from synapse.util.distributor import user_joined_room, user_left_room
@ -56,11 +56,11 @@ def remote_join(client, host, port, requester, remote_room_hosts,
try:
result = yield client.post_json_get_json(uri, payload)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
# We convert to SynapseError as we know that it was a SynapseError
# on the master process that we should send to the client. (And
# importantly, not stack traces everywhere)
raise SynapseError(e.code, e.msg, e.errcode)
raise e.to_synapse_error()
defer.returnValue(result)
@ -92,11 +92,11 @@ def remote_reject_invite(client, host, port, requester, remote_room_hosts,
try:
result = yield client.post_json_get_json(uri, payload)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
# We convert to SynapseError as we know that it was a SynapseError
# on the master process that we should send to the client. (And
# importantly, not stack traces everywhere)
raise SynapseError(e.code, e.msg, e.errcode)
raise e.to_synapse_error()
defer.returnValue(result)
@ -131,11 +131,11 @@ def get_or_register_3pid_guest(client, host, port, requester,
try:
result = yield client.post_json_get_json(uri, payload)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
# We convert to SynapseError as we know that it was a SynapseError
# on the master process that we should send to the client. (And
# importantly, not stack traces everywhere)
raise SynapseError(e.code, e.msg, e.errcode)
raise e.to_synapse_error()
defer.returnValue(result)
@ -165,11 +165,11 @@ def notify_user_membership_change(client, host, port, user_id, room_id, change):
try:
result = yield client.post_json_get_json(uri, payload)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
# We convert to SynapseError as we know that it was a SynapseError
# on the master process that we should send to the client. (And
# importantly, not stack traces everywhere)
raise SynapseError(e.code, e.msg, e.errcode)
raise e.to_synapse_error()
defer.returnValue(result)

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@ -18,11 +18,7 @@ import re
from twisted.internet import defer
from synapse.api.errors import (
CodeMessageException,
MatrixCodeMessageException,
SynapseError,
)
from synapse.api.errors import CodeMessageException, HttpResponseException
from synapse.events import FrozenEvent
from synapse.events.snapshot import EventContext
from synapse.http.servlet import RestServlet, parse_json_object_from_request
@ -83,11 +79,11 @@ def send_event_to_master(clock, store, client, host, port, requester, event, con
# If we timed out we probably don't need to worry about backing
# off too much, but lets just wait a little anyway.
yield clock.sleep(1)
except MatrixCodeMessageException as e:
except HttpResponseException as e:
# We convert to SynapseError as we know that it was a SynapseError
# on the master process that we should send to the client. (And
# importantly, not stack traces everywhere)
raise SynapseError(e.code, e.msg, e.errcode)
raise e.to_synapse_error()
defer.returnValue(result)

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@ -379,7 +379,7 @@ class MediaRepository(object):
logger.warn("HTTP error fetching remote media %s/%s: %s",
server_name, media_id, e.response)
if e.code == twisted.web.http.NOT_FOUND:
raise SynapseError.from_http_response_exception(e)
raise e.to_synapse_error()
raise SynapseError(502, "Failed to fetch remote media")
except SynapseError: