Fix invalid rpc id metrics (heroiclabs#1304)

Do not report custom RPC endpoints that are invoked with an invalid id (404) to the prometheus RPC calls counts.

Author: sesposito

CHANGELOG.md

@@ -7,6 +7,7 @@ The format is based on [keep a changelog](http://keepachangelog.com) and this pr
 ### Fixed
 - Ensure persisted chat messages listing returns correct order.
 - Return correct tournament details in console API leaderboard details endpoint.
+- Do not report invalid http RPC ids to prometheus counts.
 
 ## [3.25.0] - 2024-11-25
 ### Added

server/api_rpc.go

@@ -107,16 +107,9 @@ func (s *ApiServer) RpcFuncHttp(w http.ResponseWriter, r *http.Request) {
 	}
 
 	start := time.Now()
-	var success bool
+
 	var recvBytes, sentBytes int
 	var err error
-	var id string
-
-	// After this point the RPC will be captured in metrics.
-	defer func() {
-		s.metrics.ApiRpc(id, time.Since(start), int64(recvBytes), int64(sentBytes), !success)
-	}()
-
 	// Check the RPC function ID.
 	maybeID, ok := mux.Vars(r)["id"]
 	if !ok || maybeID == "" {
@@ -129,7 +122,8 @@ func (s *ApiServer) RpcFuncHttp(w http.ResponseWriter, r *http.Request) {
 		}
 		return
 	}
-	id = strings.ToLower(maybeID)
+
+	id := strings.ToLower(maybeID)
 
 	// Find the correct RPC function.
 	fn := s.runtime.Rpc(id)
@@ -144,6 +138,12 @@ func (s *ApiServer) RpcFuncHttp(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	var success bool
+	// After this point the RPC will be captured in metrics.
+	defer func() {
+		s.metrics.ApiRpc(id, time.Since(start), int64(recvBytes), int64(sentBytes), !success)
+	}()
+
 	// Check if we need to mimic existing GRPC Gateway behaviour or expect to receive/send unwrapped data.
 	// Any value for this query parameter, including the parameter existing with an empty value, will
 	// indicate that raw behaviour is expected.