added metadata helper tool

pkg/fs/fs.go

@@ -18,6 +18,7 @@ import (
 
 type FS struct {
 	log     logr.Logger
+	done    chan struct{}
 	cancel  func()
 	NoCache http.Handler
 	src     string
@@ -45,6 +46,7 @@ func NewFS(quota int64, max int, src, dst, metadata string, log logr.Logger) (fs
 
 	fs = &FS{
 		log:     log,
+		done:    make(chan struct{}),
 		cancel:  cancel,
 		NoCache: http.FileServer(http.Dir(src)),
 		src:     src,
@@ -249,6 +251,7 @@ func (fs *FS) CacheStatus(name string) int {
 
 func (fs *FS) Close() {
 	fs.cancel()
+	<-fs.done
 }
 
 func dirEmpty(name string) (bool, error) {