Refactor code for turning HttpResponseException into SynapseError

This commit replaces SynapseError.from_http_response_exception with
HttpResponseException.to_synapse_error.

The new method actually returns a ProxiedRequestError, which allows us to pass
through additional metadata from the API call.
This commit is contained in:
Richard van der Hoff 2018-08-01 14:58:16 +01:00
parent fa7dc889f1
commit 018d75a148
3 changed files with 56 additions and 34 deletions

View File

@ -105,38 +105,28 @@ 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.
Attributes:
errcode (str): Matrix error code e.g 'M_FORBIDDEN'
"""
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)
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:
"""
# 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)
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):
@ -361,7 +351,7 @@ 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):
"""
@ -369,7 +359,39 @@ 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)

View File

@ -506,7 +506,7 @@ class FederationClient(FederationBase):
)
except HttpResponseException as e:
if not 500 <= e.code < 600:
raise SynapseError.from_http_response_exception(e)
raise e.to_synapse_error()
else:
logger.warn(
"Failed to %s via %s: %i %s",
@ -682,7 +682,7 @@ class FederationClient(FederationBase):
)
except HttpResponseException as e:
if e.code == 403:
raise SynapseError.from_http_response_exception(e)
raise e.to_synapse_error()
raise
pdu_dict = content["event"]

View File

@ -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: