Fix IP URL previews on Python 3 (#4215)

1 files changed, 12 insertions, 2 deletions

diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index d0ecf241b6..ba3ab1d37d 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -35,7 +35,7 @@ from twisted.web.resource import Resource
 from twisted.web.server import NOT_DONE_YET
 
 from synapse.api.errors import Codes, SynapseError
-from synapse.http.client import SpiderHttpClient
+from synapse.http.client import SimpleHttpClient
 from synapse.http.server import (
     respond_with_json,
     respond_with_json_bytes,
@@ -69,7 +69,12 @@ class PreviewUrlResource(Resource):
         self.max_spider_size = hs.config.max_spider_size
         self.server_name = hs.hostname
         self.store = hs.get_datastore()
-        self.client = SpiderHttpClient(hs)
+        self.client = SimpleHttpClient(
+            hs,
+            treq_args={"browser_like_redirects": True},
+            ip_whitelist=hs.config.url_preview_ip_range_whitelist,
+            ip_blacklist=hs.config.url_preview_ip_range_blacklist,
+        )
         self.media_repo = media_repo
         self.primary_base_path = media_repo.primary_base_path
         self.media_storage = media_storage
@@ -318,6 +323,11 @@ class PreviewUrlResource(Resource):
                 length, headers, uri, code = yield self.client.get_file(
                     url, output_stream=f, max_size=self.max_spider_size,
                 )
+            except SynapseError:
+                # Pass SynapseErrors through directly, so that the servlet
+                # handler will return a SynapseError to the client instead of
+                # blank data or a 500.
+                raise
             except Exception as e:
                 # FIXME: pass through 404s and other error messages nicely
                 logger.warn("Error downloading %s: %r", url, e)