Set Server header in SynapseRequest

(instead of everywhere that writes a response. Or rather, the subset of places
which write responses where we haven't forgotten it).

This also means that we don't have to have the mysterious version_string
attribute in anything with a request handler.

Unfortunately it does mean that we have to pass the version string wherever we
instantiate a SynapseSite, which has been c&ped 150 times, but that is code
that ought to be cleaned up anyway really.

23 files changed, 28 insertions, 27 deletions

diff --git a/synapse/app/appservice.py b/synapse/app/appservice.py
index 58f2c9d68c..b1efacc9f8 100644
--- a/synapse/app/appservice.py
+++ b/synapse/app/appservice.py
@@ -74,6 +74,7 @@ class AppserviceServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/client_reader.py b/synapse/app/client_reader.py
index 267d34c881..38b98382c6 100644
--- a/synapse/app/client_reader.py
+++ b/synapse/app/client_reader.py
@@ -98,6 +98,7 @@ class ClientReaderServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/event_creator.py b/synapse/app/event_creator.py
index b915d12d53..bd7f3d5679 100644
--- a/synapse/app/event_creator.py
+++ b/synapse/app/event_creator.py
@@ -114,6 +114,7 @@ class EventCreatorServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/federation_reader.py b/synapse/app/federation_reader.py
index c1dc66dd17..6e10b27b9e 100644
--- a/synapse/app/federation_reader.py
+++ b/synapse/app/federation_reader.py
@@ -87,6 +87,7 @@ class FederationReaderServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/federation_sender.py b/synapse/app/federation_sender.py
index a08af83a4c..6f24e32d6d 100644
--- a/synapse/app/federation_sender.py
+++ b/synapse/app/federation_sender.py
@@ -101,6 +101,7 @@ class FederationSenderServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/frontend_proxy.py b/synapse/app/frontend_proxy.py
index b349e3e3ce..0f700ee786 100644
--- a/synapse/app/frontend_proxy.py
+++ b/synapse/app/frontend_proxy.py
@@ -152,6 +152,7 @@ class FrontendProxyServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index a0e465d644..75f40fd5a4 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -140,6 +140,7 @@ class SynapseHomeServer(HomeServer):
                     site_tag,
                     listener_config,
                     root_resource,
+                    self.version_string,
                 ),
                 self.tls_server_context_factory,
             )
@@ -153,6 +154,7 @@ class SynapseHomeServer(HomeServer):
                     site_tag,
                     listener_config,
                     root_resource,
+                    self.version_string,
                 )
             )
         logger.info("Synapse now listening on port %d", port)
diff --git a/synapse/app/media_repository.py b/synapse/app/media_repository.py
index fc8282bbc1..9c93195f0a 100644
--- a/synapse/app/media_repository.py
+++ b/synapse/app/media_repository.py
@@ -94,6 +94,7 @@ class MediaRepositoryServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/pusher.py b/synapse/app/pusher.py
index 26930d1b3b..3912eae48c 100644
--- a/synapse/app/pusher.py
+++ b/synapse/app/pusher.py
@@ -104,6 +104,7 @@ class PusherServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/synchrotron.py b/synapse/app/synchrotron.py
index 7152b1deb4..c6294a7a0c 100644
--- a/synapse/app/synchrotron.py
+++ b/synapse/app/synchrotron.py
@@ -281,6 +281,7 @@ class SynchrotronServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/app/user_dir.py b/synapse/app/user_dir.py
index 5ba7e9b416..53eb3474da 100644
--- a/synapse/app/user_dir.py
+++ b/synapse/app/user_dir.py
@@ -126,6 +126,7 @@ class UserDirectoryServer(HomeServer):
                 site_tag,
                 listener_config,
                 root_resource,
+                self.version_string,
             )
         )
 
diff --git a/synapse/http/additional_resource.py b/synapse/http/additional_resource.py
index d9e7f5dfb7..a797396ade 100644
--- a/synapse/http/additional_resource.py
+++ b/synapse/http/additional_resource.py
@@ -42,8 +42,7 @@ class AdditionalResource(Resource):
         Resource.__init__(self)
         self._handler = handler
 
-        # these are required by the request_handler wrapper
-        self.version_string = hs.version_string
+        # required by the request_handler wrapper
         self.clock = hs.get_clock()
 
     def render(self, request):
diff --git a/synapse/http/server.py b/synapse/http/server.py
index f29e36f490..b6e2ae14a2 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -51,8 +51,8 @@ def wrap_json_request_handler(h):
     Also adds logging as per wrap_request_handler_with_logging.
 
     The handler method must have a signature of "handle_foo(self, request)",
-    where "self" must have "version_string" and "clock" attributes (and
-    "request" must be a SynapseRequest).
+    where "self" must have a "clock" attribute (and "request" must be a
+    SynapseRequest).
 
     The handler must return a deferred. If the deferred succeeds we assume that
     a response has been sent. If the deferred fails with a SynapseError we use
@@ -75,7 +75,6 @@ def wrap_json_request_handler(h):
             respond_with_json(
                 request, code, cs_exception(e), send_cors=True,
                 pretty_print=_request_user_agent_is_curl(request),
-                version_string=self.version_string,
             )
 
         except Exception:
@@ -98,7 +97,6 @@ def wrap_json_request_handler(h):
                 },
                 send_cors=True,
                 pretty_print=_request_user_agent_is_curl(request),
-                version_string=self.version_string,
             )
 
     return wrap_request_handler_with_logging(wrapped_request_handler)
@@ -192,7 +190,6 @@ class JsonResource(HttpServer, resource.Resource):
         self.canonical_json = canonical_json
         self.clock = hs.get_clock()
         self.path_regexs = {}
-        self.version_string = hs.version_string
         self.hs = hs
 
     def register_paths(self, method, path_patterns, callback):
@@ -275,7 +272,6 @@ class JsonResource(HttpServer, resource.Resource):
             send_cors=True,
             response_code_message=response_code_message,
             pretty_print=_request_user_agent_is_curl(request),
-            version_string=self.version_string,
             canonical_json=self.canonical_json,
         )
 
@@ -326,7 +322,7 @@ class RootRedirect(resource.Resource):
 
 def respond_with_json(request, code, json_object, send_cors=False,
                       response_code_message=None, pretty_print=False,
-                      version_string="", canonical_json=True):
+                      canonical_json=True):
     # could alternatively use request.notifyFinish() and flip a flag when
     # the Deferred fires, but since the flag is RIGHT THERE it seems like
     # a waste.
@@ -348,12 +344,11 @@ def respond_with_json(request, code, json_object, send_cors=False,
         request, code, json_bytes,
         send_cors=send_cors,
         response_code_message=response_code_message,
-        version_string=version_string
     )
 
 
 def respond_with_json_bytes(request, code, json_bytes, send_cors=False,
-                            version_string="", response_code_message=None):
+                            response_code_message=None):
     """Sends encoded JSON in response to the given request.
 
     Args:
@@ -367,7 +362,6 @@ def respond_with_json_bytes(request, code, json_bytes, send_cors=False,
 
     request.setResponseCode(code, message=response_code_message)
     request.setHeader(b"Content-Type", b"application/json")
-    request.setHeader(b"Server", version_string)
     request.setHeader(b"Content-Length", b"%d" % (len(json_bytes),))
     request.setHeader(b"Cache-Control", b"no-cache, no-store, must-revalidate")
 
diff --git a/synapse/http/site.py b/synapse/http/site.py
index bfd9832aa0..202a990508 100644
--- a/synapse/http/site.py
+++ b/synapse/http/site.py
@@ -77,6 +77,11 @@ class SynapseRequest(Request):
     def get_user_agent(self):
         return self.requestHeaders.getRawHeaders(b"User-Agent", [None])[-1]
 
+    def render(self, resrc):
+        # override the Server header which is set by twisted
+        self.setHeader("Server", self.site.server_version_string)
+        return Request.render(self, resrc)
+
     def _started_processing(self, servlet_name):
         self.start_time = int(time.time() * 1000)
         self.request_metrics = RequestMetrics()
@@ -151,6 +156,8 @@ class SynapseRequest(Request):
                 It is possible to update this afterwards by updating
                 self.request_metrics.servlet_name.
         """
+        # TODO: we should probably just move this into render() and finish(),
+        # to save having to call a separate method.
         self._started_processing(servlet_name)
         yield
         self._finished_processing()
@@ -191,7 +198,8 @@ class SynapseSite(Site):
     Subclass of a twisted http Site that does access logging with python's
     standard logging
     """
-    def __init__(self, logger_name, site_tag, config, resource, *args, **kwargs):
+    def __init__(self, logger_name, site_tag, config, resource,
+                 server_version_string, *args, **kwargs):
         Site.__init__(self, resource, *args, **kwargs)
 
         self.site_tag = site_tag
@@ -199,6 +207,7 @@ class SynapseSite(Site):
         proxied = config.get("x_forwarded", False)
         self.requestFactory = SynapseRequestFactory(self, proxied)
         self.access_logger = logging.getLogger(logger_name)
+        self.server_version_string = server_version_string
 
     def log(self, request):
         pass
diff --git a/synapse/rest/client/v1/pusher.py b/synapse/rest/client/v1/pusher.py
index 0206e664c1..40e523cc5f 100644
--- a/synapse/rest/client/v1/pusher.py
+++ b/synapse/rest/client/v1/pusher.py
@@ -176,7 +176,6 @@ class PushersRemoveRestServlet(RestServlet):
 
         request.setResponseCode(200)
         request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
-        request.setHeader(b"Server", self.hs.version_string)
         request.setHeader(b"Content-Length", b"%d" % (
             len(PushersRemoveRestServlet.SUCCESS_HTML),
         ))
diff --git a/synapse/rest/client/v2_alpha/auth.py b/synapse/rest/client/v2_alpha/auth.py
index 8e5577148f..d6f3a19648 100644
--- a/synapse/rest/client/v2_alpha/auth.py
+++ b/synapse/rest/client/v2_alpha/auth.py
@@ -129,7 +129,6 @@ class AuthRestServlet(RestServlet):
             html_bytes = html.encode("utf8")
             request.setResponseCode(200)
             request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
-            request.setHeader(b"Server", self.hs.version_string)
             request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),))
 
             request.write(html_bytes)
@@ -175,7 +174,6 @@ class AuthRestServlet(RestServlet):
             html_bytes = html.encode("utf8")
             request.setResponseCode(200)
             request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
-            request.setHeader(b"Server", self.hs.version_string)
             request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),))
 
             request.write(html_bytes)
diff --git a/synapse/rest/key/v1/server_key_resource.py b/synapse/rest/key/v1/server_key_resource.py
index bd4fea5774..1498d188c1 100644
--- a/synapse/rest/key/v1/server_key_resource.py
+++ b/synapse/rest/key/v1/server_key_resource.py
@@ -49,7 +49,6 @@ class LocalKey(Resource):
     """
 
     def __init__(self, hs):
-        self.version_string = hs.version_string
         self.response_body = encode_canonical_json(
             self.response_json_object(hs.config)
         )
@@ -84,7 +83,6 @@ class LocalKey(Resource):
     def render_GET(self, request):
         return respond_with_json_bytes(
             request, 200, self.response_body,
-            version_string=self.version_string
         )
 
     def getChild(self, name, request):
diff --git a/synapse/rest/key/v2/local_key_resource.py b/synapse/rest/key/v2/local_key_resource.py
index be68d9a096..04775b3c45 100644
--- a/synapse/rest/key/v2/local_key_resource.py
+++ b/synapse/rest/key/v2/local_key_resource.py
@@ -63,7 +63,6 @@ class LocalKey(Resource):
     isLeaf = True
 
     def __init__(self, hs):
-        self.version_string = hs.version_string
         self.config = hs.config
         self.clock = hs.clock
         self.update_response_body(self.clock.time_msec())
@@ -115,5 +114,4 @@ class LocalKey(Resource):
             self.update_response_body(time_now)
         return respond_with_json_bytes(
             request, 200, self.response_body,
-            version_string=self.version_string
         )
diff --git a/synapse/rest/key/v2/remote_key_resource.py b/synapse/rest/key/v2/remote_key_resource.py
index 17b3077926..21b4c1175e 100644
--- a/synapse/rest/key/v2/remote_key_resource.py
+++ b/synapse/rest/key/v2/remote_key_resource.py
@@ -93,7 +93,6 @@ class RemoteKey(Resource):
     def __init__(self, hs):
         self.keyring = hs.get_keyring()
         self.store = hs.get_datastore()
-        self.version_string = hs.version_string
         self.clock = hs.get_clock()
         self.federation_domain_whitelist = hs.config.federation_domain_whitelist
 
@@ -242,5 +241,4 @@ class RemoteKey(Resource):
 
             respond_with_json_bytes(
                 request, 200, result_io.getvalue(),
-                version_string=self.version_string
             )
diff --git a/synapse/rest/media/v1/download_resource.py b/synapse/rest/media/v1/download_resource.py
index 3fc3f64d62..8cf8820c31 100644
--- a/synapse/rest/media/v1/download_resource.py
+++ b/synapse/rest/media/v1/download_resource.py
@@ -37,9 +37,8 @@ class DownloadResource(Resource):
         self.media_repo = media_repo
         self.server_name = hs.hostname
 
-        # Both of these are expected by @request_handler()
+        # this is expected by @wrap_json_request_handler
         self.clock = hs.get_clock()
-        self.version_string = hs.version_string
 
     def render_GET(self, request):
         self._async_render_GET(request)
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index 6b089689b4..2839207abc 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -58,7 +58,6 @@ class PreviewUrlResource(Resource):
 
         self.auth = hs.get_auth()
         self.clock = hs.get_clock()
-        self.version_string = hs.version_string
         self.filepaths = media_repo.filepaths
         self.max_spider_size = hs.config.max_spider_size
         self.server_name = hs.hostname
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 6c12d79f56..aae6e464e8 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -44,7 +44,6 @@ class ThumbnailResource(Resource):
         self.media_storage = media_storage
         self.dynamic_thumbnails = hs.config.dynamic_thumbnails
         self.server_name = hs.hostname
-        self.version_string = hs.version_string
         self.clock = hs.get_clock()
 
     def render_GET(self, request):
diff --git a/synapse/rest/media/v1/upload_resource.py b/synapse/rest/media/v1/upload_resource.py
index 7d01c57fd1..7567476fce 100644
--- a/synapse/rest/media/v1/upload_resource.py
+++ b/synapse/rest/media/v1/upload_resource.py
@@ -41,7 +41,6 @@ class UploadResource(Resource):
         self.server_name = hs.hostname
         self.auth = hs.get_auth()
         self.max_upload_size = hs.config.max_upload_size
-        self.version_string = hs.version_string
         self.clock = hs.get_clock()
 
     def render_POST(self, request):