index: additional logging for malformed return data

index.py

@@ -160,9 +160,16 @@ class HttpDispatcher(resource.Resource):
 
         if type(ret) == str:
             return ret.encode()
-        elif type(ret) == bytes:
+        
+        elif type(ret) == bytes or type(ret) == tuple: # allow for bytes or tuple (data, response code) responses
             return ret
+        
+        elif ret is None:
+            self.logger.warn(f"None returned by controller for {request.uri.decode()} endpoint")
+            return b""
+        
         else:
+            self.logger.warn(f"Unknown data type returned by controller for {request.uri.decode()} endpoint")
             return b""