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, + )