diff --git a/changelog.d/7265.feature b/changelog.d/7265.feature
new file mode 100644
index 0000000000..345b63e0b7
--- /dev/null
+++ b/changelog.d/7265.feature
@@ -0,0 +1 @@
+Add a config option for specifying the value of the Accept-Language HTTP header when generating URL previews.
\ No newline at end of file
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 3417813750..81dccbd997 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -859,6 +859,31 @@ media_store_path: "DATADIR/media_store"
#
#max_spider_size: 10M
+# A list of values for the Accept-Language HTTP header used when
+# downloading webpages during URL preview generation. This allows
+# Synapse to specify the preferred languages that URL previews should
+# be in when communicating with remote servers.
+#
+# Each value is a IETF language tag; a 2-3 letter identifier for a
+# language, optionally followed by subtags separated by '-', specifying
+# a country or region variant.
+#
+# Multiple values can be provided, and a weight can be added to each by
+# using quality value syntax (;q=). '*' translates to any language.
+#
+# Defaults to "en".
+#
+# Example:
+#
+# url_preview_accept_language:
+# - en-UK
+# - en-US;q=0.9
+# - fr;q=0.8
+# - *;q=0.7
+#
+url_preview_accept_language:
+# - en
+
## Captcha ##
# See docs/CAPTCHA_SETUP for full details of configuring this.
diff --git a/synapse/config/repository.py b/synapse/config/repository.py
index 7d2dd27fd0..7193ea1114 100644
--- a/synapse/config/repository.py
+++ b/synapse/config/repository.py
@@ -192,6 +192,10 @@ class ContentRepositoryConfig(Config):
self.url_preview_url_blacklist = config.get("url_preview_url_blacklist", ())
+ self.url_preview_accept_language = config.get(
+ "url_preview_accept_language"
+ ) or ["en"]
+
def generate_config_section(self, data_dir_path, **kwargs):
media_store = os.path.join(data_dir_path, "media_store")
uploads_path = os.path.join(data_dir_path, "uploads")
@@ -329,6 +333,31 @@ class ContentRepositoryConfig(Config):
# The largest allowed URL preview spidering size in bytes
#
#max_spider_size: 10M
+
+ # A list of values for the Accept-Language HTTP header used when
+ # downloading webpages during URL preview generation. This allows
+ # Synapse to specify the preferred languages that URL previews should
+ # be in when communicating with remote servers.
+ #
+ # Each value is a IETF language tag; a 2-3 letter identifier for a
+ # language, optionally followed by subtags separated by '-', specifying
+ # a country or region variant.
+ #
+ # Multiple values can be provided, and a weight can be added to each by
+ # using quality value syntax (;q=). '*' translates to any language.
+ #
+ # Defaults to "en".
+ #
+ # Example:
+ #
+ # url_preview_accept_language:
+ # - en-UK
+ # - en-US;q=0.9
+ # - fr;q=0.8
+ # - *;q=0.7
+ #
+ url_preview_accept_language:
+ # - en
"""
% locals()
)
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index c46676f8fc..f68e18ea8a 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -86,6 +86,7 @@ class PreviewUrlResource(DirectServeResource):
self.media_storage = media_storage
self.url_preview_url_blacklist = hs.config.url_preview_url_blacklist
+ self.url_preview_accept_language = hs.config.url_preview_accept_language
# memory cache mapping urls to an ObservableDeferred returning
# JSON-encoded OG metadata
@@ -315,9 +316,12 @@ class PreviewUrlResource(DirectServeResource):
with self.media_storage.store_into_file(file_info) as (f, fname, finish):
try:
- logger.debug("Trying to get url '%s'", url)
+ logger.debug("Trying to get preview for url '%s'", url)
length, headers, uri, code = await self.client.get_file(
- url, output_stream=f, max_size=self.max_spider_size
+ url,
+ output_stream=f,
+ max_size=self.max_spider_size,
+ headers={"Accept-Language": self.url_preview_accept_language},
)
except SynapseError:
# Pass SynapseErrors through directly, so that the servlet
diff --git a/tests/rest/media/v1/test_url_preview.py b/tests/rest/media/v1/test_url_preview.py
index 852b8ab11c..2826211f32 100644
--- a/tests/rest/media/v1/test_url_preview.py
+++ b/tests/rest/media/v1/test_url_preview.py
@@ -74,6 +74,12 @@ class URLPreviewTests(unittest.HomeserverTestCase):
)
config["url_preview_ip_range_whitelist"] = ("1.1.1.1",)
config["url_preview_url_blacklist"] = []
+ config["url_preview_accept_language"] = [
+ "en-UK",
+ "en-US;q=0.9",
+ "fr;q=0.8",
+ "*;q=0.7",
+ ]
self.storage_path = self.mktemp()
self.media_store_path = self.mktemp()
@@ -507,3 +513,52 @@ class URLPreviewTests(unittest.HomeserverTestCase):
self.pump()
self.assertEqual(channel.code, 200)
self.assertEqual(channel.json_body, {})
+
+ def test_accept_language_config_option(self):
+ """
+ Accept-Language header is sent to the remote server
+ """
+ self.lookups["example.com"] = [(IPv4Address, "8.8.8.8")]
+
+ # Build and make a request to the server
+ request, channel = self.make_request(
+ "GET", "url_preview?url=http://example.com", shorthand=False
+ )
+ request.render(self.preview_url)
+ self.pump()
+
+ # Extract Synapse's tcp client
+ client = self.reactor.tcpClients[0][2].buildProtocol(None)
+
+ # Build a fake remote server to reply with
+ server = AccumulatingProtocol()
+
+ # Connect the two together
+ server.makeConnection(FakeTransport(client, self.reactor))
+ client.makeConnection(FakeTransport(server, self.reactor))
+
+ # Tell Synapse that it has received some data from the remote server
+ client.dataReceived(
+ b"HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/html\r\n\r\n"
+ % (len(self.end_content),)
+ + self.end_content
+ )
+
+ # Move the reactor along until we get a response on our original channel
+ self.pump()
+ self.assertEqual(channel.code, 200)
+ self.assertEqual(
+ channel.json_body, {"og:title": "~matrix~", "og:description": "hi"}
+ )
+
+ # Check that the server received the Accept-Language header as part
+ # of the request from Synapse
+ self.assertIn(
+ (
+ b"Accept-Language: en-UK\r\n"
+ b"Accept-Language: en-US;q=0.9\r\n"
+ b"Accept-Language: fr;q=0.8\r\n"
+ b"Accept-Language: *;q=0.7"
+ ),
+ server.data,
+ )
|
