Use Facebook user agent for openGraph queries

We found that some websites return opengraph information based on the user agent. Since Facebook is the creator of opengraph, using the Facebook user agent when requesting the opengraph metadata should work in the widest variety of situations. https://developers.facebook.com/docs/sharing/webmasters/#user-agent Signed-off-by: Andrew Ryan <andrewryanchama@clover.club>
matrix-org · Feb 13, 2022 · de64d72 · de64d72
1 parent 55113dd
commit de64d72
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diff --git a/changelog.d/11985.misc b/changelog.d/11985.misc
@@ -0,0 +1 @@
+Use Facebook user agent for openGraph queries
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
@@ -402,7 +402,10 @@ async def _download_url(self, url: str, output_stream: BinaryIO) -> DownloadResu
                 url,
                 output_stream=output_stream,
                 max_size=self.max_spider_size,
-                headers={"Accept-Language": self.url_preview_accept_language},
+                headers={
+                    "Accept-Language": self.url_preview_accept_language,
+                    "User-Agent": "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)"
+                },
                 is_allowed_content_type=_is_previewable,
             )
         except SynapseError: