fix metrics

cmd/swim/main.go

@@ -22,17 +22,20 @@ func main() {
 	envFlag(&args.MetricsPort, "METRICS", "metrics", "6060", "metrics port")
 	flag.Parse()
 
-	go func() {
-		http.Handle("/metrics", promhttp.Handler())
-		http.ListenAndServe(":"+args.MetricsPort, nil)
-	}()
-
 	log.Printf("starting %s: bind=%s fs=%s home=%s metrics=:%s",
 		args.Name,
 		args.Bind(),
 		args.Fs,
 		args.Home,
 		args.MetricsPort)
+	go func() {
+		http.Handle("/metrics", promhttp.Handler())
+		http.Handle("/metrics/", promhttp.Handler())
+		err := http.ListenAndServe(":"+args.MetricsPort, nil)
+		if err != nil {
+			panic(err)
+		}
+	}()
 	srv, err := swim.NewServer(args)
 	if err != nil {
 		panic(err)