rcserver: implement prometheus metrics on a dedicated port - fixes #7940

fs/rc/rcserver/rcserver.go

@@ -18,13 +18,9 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5/middleware"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/rclone/rclone/fs"
-	"github.com/rclone/rclone/fs/accounting"
 	"github.com/rclone/rclone/fs/cache"
 	"github.com/rclone/rclone/fs/config"
-	"github.com/rclone/rclone/fs/fshttp"
 	"github.com/rclone/rclone/fs/list"
 	"github.com/rclone/rclone/fs/rc"
 	"github.com/rclone/rclone/fs/rc/jobs"
@@ -35,21 +31,6 @@ import (
 	"github.com/skratchdot/open-golang/open"
 )
 
-var promHandler http.Handler
-
-func init() {
-	rcloneCollector := accounting.NewRcloneCollector(context.Background())
-	prometheus.MustRegister(rcloneCollector)
-
-	m := fshttp.NewMetrics("rclone")
-	for _, c := range m.Collectors() {
-		prometheus.MustRegister(c)
-	}
-	fshttp.DefaultMetrics = m
-
-	promHandler = promhttp.Handler()
-}
-
 // Start the remote control server if configured
 //
 // If the server wasn't configured the *Server returned may be nil
@@ -376,7 +357,7 @@ func (s *Server) handleGet(w http.ResponseWriter, r *http.Request, path string)
 		s.serveRemote(w, r, fsMatchResult[2], fsMatchResult[1])
 		return
 	case path == "metrics" && s.opt.EnableMetrics:
-		promHandler.ServeHTTP(w, r)
+		promHandlerFunc(w, r)
 		return
 	case path == "*" && s.opt.Serve:
 		// Serve /* as the remote listing