5 files changed, 14 insertions, 12 deletions
diff --git a/weed/command/backup.go b/weed/command/backup.go
index 4c37c2763..b9973c6a9 100644
--- a/weed/command/backup.go
+++ b/weed/command/backup.go
@@ -72,7 +72,7 @@ func runBackup(cmd *Command, args []string) bool {
 	vid := needle.VolumeId(*s.volumeId)
 
 	// find volume location, replication, ttl info
-	lookup, err := operation.Lookup(*s.master, vid.String())
+	lookup, err := operation.Lookup(func()string{return *s.master}, vid.String())
 	if err != nil {
 		fmt.Printf("Error looking up volume %d: %v\n", vid, err)
 		return true
diff --git a/weed/command/benchmark.go b/weed/command/benchmark.go
index 370ec9eaf..e1b6d8d6c 100644
--- a/weed/command/benchmark.go
+++ b/weed/command/benchmark.go
@@ -238,12 +238,12 @@ func writeFiles(idChan chan int, fileIdLineChan chan string, s *stat) {
 			Replication: *b.replication,
 			DiskType:    *b.diskType,
 		}
-		if assignResult, err := operation.Assign(b.masterClient.GetMaster(), b.grpcDialOption, ar); err == nil {
+		if assignResult, err := operation.Assign(b.masterClient.GetMaster, b.grpcDialOption, ar); err == nil {
 			fp.Server, fp.Fid, fp.Collection = assignResult.Url, assignResult.Fid, *b.collection
 			if !isSecure && assignResult.Auth != "" {
 				isSecure = true
 			}
-			if _, err := fp.Upload(0, b.masterClient.GetMaster(), false, assignResult.Auth, b.grpcDialOption); err == nil {
+			if _, err := fp.Upload(0, b.masterClient.GetMaster, false, assignResult.Auth, b.grpcDialOption); err == nil {
 				if random.Intn(100) < *b.deletePercentage {
 					s.total++
 					delayedDeleteChan <- &delayedFile{time.Now().Add(time.Second), fp}
diff --git a/weed/command/download.go b/weed/command/download.go
index f7588fbf0..5da1f57d9 100644
--- a/weed/command/download.go
+++ b/weed/command/download.go
@@ -44,15 +44,15 @@ var cmdDownload = &Command{
 
 func runDownload(cmd *Command, args []string) bool {
 	for _, fid := range args {
-		if e := downloadToFile(*d.server, fid, util.ResolvePath(*d.dir)); e != nil {
+		if e := downloadToFile(func()string{return *d.server}, fid, util.ResolvePath(*d.dir)); e != nil {
 			fmt.Println("Download Error: ", fid, e)
 		}
 	}
 	return true
 }
 
-func downloadToFile(server, fileId, saveDir string) error {
-	fileUrl, lookupError := operation.LookupFileId(server, fileId)
+func downloadToFile(masterFn operation.GetMasterFn, fileId, saveDir string) error {
+	fileUrl, lookupError := operation.LookupFileId(masterFn, fileId)
 	if lookupError != nil {
 		return lookupError
 	}
@@ -83,7 +83,7 @@ func downloadToFile(server, fileId, saveDir string) error {
 		fids := strings.Split(string(content), "\n")
 		for _, partId := range fids {
 			var n int
-			_, part, err := fetchContent(*d.server, partId)
+			_, part, err := fetchContent(masterFn, partId)
 			if err == nil {
 				n, err = f.Write(part)
 			}
@@ -103,8 +103,8 @@ func downloadToFile(server, fileId, saveDir string) error {
 	return nil
 }
 
-func fetchContent(server string, fileId string) (filename string, content []byte, e error) {
-	fileUrl, lookupError := operation.LookupFileId(server, fileId)
+func fetchContent(masterFn operation.GetMasterFn, fileId string) (filename string, content []byte, e error) {
+	fileUrl, lookupError := operation.LookupFileId(masterFn, fileId)
 	if lookupError != nil {
 		return "", nil, lookupError
 	}
diff --git a/weed/command/filer_copy.go b/weed/command/filer_copy.go
index 20f00a3eb..bf64e72b3 100644
--- a/weed/command/filer_copy.go
+++ b/weed/command/filer_copy.go
@@ -463,7 +463,9 @@ func (worker *FileCopyWorker) uploadFileInChunks(task FileCopyTask, f *os.File,
 		for _, chunk := range chunks {
 			fileIds = append(fileIds, chunk.FileId)
 		}
-		operation.DeleteFiles(copy.masters[0], false, worker.options.grpcDialOption, fileIds)
+		operation.DeleteFiles(func() string {
+			return copy.masters[0]
+		}, false, worker.options.grpcDialOption, fileIds)
 		return uploadError
 	}
 
diff --git a/weed/command/upload.go b/weed/command/upload.go
index 85d6e5c09..effcf8836 100644
--- a/weed/command/upload.go
+++ b/weed/command/upload.go
@@ -96,7 +96,7 @@ func runUpload(cmd *Command, args []string) bool {
 					if e != nil {
 						return e
 					}
-					results, e := operation.SubmitFiles(*upload.master, grpcDialOption, parts, *upload.replication, *upload.collection, *upload.dataCenter, *upload.ttl, *upload.diskType, *upload.maxMB, *upload.usePublicUrl)
+					results, e := operation.SubmitFiles(func()string {return *upload.master}, grpcDialOption, parts, *upload.replication, *upload.collection, *upload.dataCenter, *upload.ttl, *upload.diskType, *upload.maxMB, *upload.usePublicUrl)
 					bytes, _ := json.Marshal(results)
 					fmt.Println(string(bytes))
 					if e != nil {
@@ -113,7 +113,7 @@ func runUpload(cmd *Command, args []string) bool {
 		if e != nil {
 			fmt.Println(e.Error())
 		}
-		results, _ := operation.SubmitFiles(*upload.master, grpcDialOption, parts, *upload.replication, *upload.collection, *upload.dataCenter, *upload.ttl, *upload.diskType, *upload.maxMB, *upload.usePublicUrl)
+		results, _ := operation.SubmitFiles(func()string {return *upload.master}, grpcDialOption, parts, *upload.replication, *upload.collection, *upload.dataCenter, *upload.ttl, *upload.diskType, *upload.maxMB, *upload.usePublicUrl)
 		bytes, _ := json.Marshal(results)
 		fmt.Println(string(bytes))
 	}