Start tracing client requests from the servlet

Author: JorikSchellekens

synapse/http/servlet.py

@@ -20,6 +20,7 @@
 from canonicaljson import json
 
 from synapse.api.errors import Codes, SynapseError
+from synapse.util.tracerutils import trace_servlet
 
 logger = logging.getLogger(__name__)
 
@@ -290,7 +291,9 @@ def register(self, http_server):
             for method in ("GET", "PUT", "POST", "OPTIONS", "DELETE"):
                 if hasattr(self, "on_%s" % (method,)):
                     method_handler = getattr(self, "on_%s" % (method,))
-                    http_server.register_paths(method, patterns, method_handler)
+                    http_server.register_paths(
+                        method, patterns, trace_servlet(method_handler)
+                    )
 
         else:
             raise NotImplementedError("RestServlet must register something.")

synapse/util/tracerutils.py

@@ -29,6 +29,8 @@
 import re
 from functools import wraps
 
+from twisted.internet import defer
+
 logger = logging.getLogger(__name__)
 
 
@@ -305,3 +307,24 @@ def inject_active_span_byte_dict(headers, destination):
 
     for key, value in carrier.items():
         headers[key.encode()] = [value.encode()]
+
+
+def trace_servlet(func):
+    @wraps(func)
+    @defer.inlineCallbacks
+    def f(request, *args, **kwargs):
+        with start_active_span_from_context(
+            request.requestHeaders,
+            "incoming-client-request",
+            tags={
+                "request_id": request.get_request_id(),
+                tags.SPAN_KIND: tags.SPAN_KIND_RPC_SERVER,
+                tags.HTTP_METHOD: request.get_method(),
+                tags.HTTP_URL: request.get_redacted_uri(),
+                tags.PEER_HOST_IPV6: request.getClientIP(),
+            },
+        ):
+            result = yield defer.maybeDeferred(func, request, *args, **kwargs)
+            defer.returnValue(result)
+
+    return f