Kill off MatrixCodeMessageException

This code brings the SimpleHttpClient into line with the
MatrixFederationHttpClient by having it raise HttpResponseExceptions when a
request fails (rather than trying to parse for matrix errors and maybe raising
MatrixCodeMessageException).

Then, whenever we were checking for MatrixCodeMessageException and turning them
into SynapseErrors, we now need to check for HttpResponseExceptions and call
to_synapse_error.

synapse/http/client.py

@@ -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))
 
-        defer.returnValue(json.loads(body))
+        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)
+        body = yield self.get_raw(uri, args, headers=headers)
+        defer.returnValue(json.loads(body))
 
     @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.