filter metrics endpoint for get only

frontend/frontend.go

@@ -80,7 +80,7 @@ func NewFrontend(logger *slog.Logger, listener net.Listener, emitter metrics.Emi
 	mux.HandleFunc(MuxPattern(http.MethodGet, "healthz", "ready"), f.HealthzReady)
 
 	// Expose Prometheus metrics endpoint
-	mux.Handle("/metrics", allowGETOnly(promhttp.Handler()))
+	mux.Handle(MuxPattern(http.MethodGet, "metrics"), promhttp.Handler())
 
 	// Authenticated routes
 	postMuxMiddleware := NewMiddleware(
@@ -328,14 +328,3 @@ func (f *Frontend) ArmSubscriptionAction(writer http.ResponseWriter, request *ht
 		f.logger.Error(err.Error())
 	}
 }
-
-// Wrap the Prometheus handler to only allow GET requests
-func allowGETOnly(h http.Handler) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != http.MethodGet {
-			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
-			return
-		}
-		h.ServeHTTP(w, r)
-	})
-}