Report recent requests in management view, for easy visibility.

Makefile

@@ -32,7 +32,7 @@ $(ENV)/COMPLETE: requirements.txt
 
 .PHONY: serve
 serve: | $(ENV)/COMPLETE
-	$(ENV)/bin/gunicorn --paste ./syncserver.ini
+	$(ENV)/bin/gunicorn --paste ./syncserver.ini --workers 1
 
 .PHONY: clean
 clean:

syncserver/management.html

@@ -15,5 +15,9 @@
     <input type="hidden" name="cmd" value="reset" />
     <input type="submit" value="Reset" />
   </form>
+  <p>
+    Most recent server requests:<br/>
+    {recent_requests}
+  </p>
 </body>
-</html>
+</html>

syncserver/tweens.py

@@ -2,11 +2,16 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
 
+import collections
+
 from pyramid import httpexceptions
 
 import syncserver.migration
 
 
+RECENT_REQUESTS = collections.deque(maxlen=30)
+
+
 def interpose_migration_state_errors(handler, registry):
     """Tween to send errors from storage endpoint based on migration state.
     
@@ -37,6 +42,25 @@ def interpose_migration_state_errors(handler, registry):
     return interpose_migration_state_errors_tween
 
 
+def log_recent_requests_in_memory(handler, registry):
+    """Keep a log of recent requests in memory, for easy visibility.
+
+    This is a little debugging aid for folks using the server to test
+    client behaviour, they can see the recent requests without having
+    to trawl through the server logs.
+
+    This only really works if you have a single worker, but that's
+    fine for our purposes here.
+    """
+
+    def log_recent_requests_in_memory_tween(request):
+        RECENT_REQUESTS.appendleft("{} {}".format(request.method, request.path))
+        return handler(request)
+
+    return log_recent_requests_in_memory_tween
+
+
 def includeme(config):
     """Include all the SyncServer tweens into the given config."""
     config.add_tween("syncserver.tweens.interpose_migration_state_errors")
+    config.add_tween("syncserver.tweens.log_recent_requests_in_memory")

syncserver/views.py

@@ -33,6 +33,7 @@ from pyramid.response import Response
 from pyramid.interfaces import IAuthenticationPolicy
 
 import syncserver.migration
+import syncserver.tweens
 
 # A GET on / returns a simple management interface,
 # while POST requests control the state of the server.
@@ -46,7 +47,8 @@ def _management(request):
     with open(src) as f:
         content = f.read()
     content = content.format(
-        migration_state=request.registry["MigrationStateManager"].current_state_name()
+        migration_state=request.registry["MigrationStateManager"].current_state_name(),
+        recent_requests="<br/>".join(syncserver.tweens.RECENT_REQUESTS),
     )
     return Response(content, content_type="text/html")