fix: add doDeleteFile option for filer backup

weed/command/filer_backup.go

@@ -20,6 +20,7 @@ type FilerBackupOptions struct {
 	excludeFileName *string
 	debug           *bool
 	proxyByFiler    *bool
+	doDeleteFiles   *bool
 	timeAgo         *time.Duration
 	retentionDays   *int
 }
@@ -35,10 +36,10 @@ func init() {
 	filerBackupOptions.excludePaths = cmdFilerBackup.Flag.String("filerExcludePaths", "", "exclude directories to sync on filer")
 	filerBackupOptions.excludeFileName = cmdFilerBackup.Flag.String("filerExcludeFileName", "", "exclude file names that match the regexp to sync on filer")
 	filerBackupOptions.proxyByFiler = cmdFilerBackup.Flag.Bool("filerProxy", false, "read and write file chunks by filer instead of volume servers")
+	filerBackupOptions.doDeleteFiles = cmdFilerBackup.Flag.Bool("doDeleteFiles", false, "delete files on the destination")
 	filerBackupOptions.debug = cmdFilerBackup.Flag.Bool("debug", false, "debug mode to print out received files")
 	filerBackupOptions.timeAgo = cmdFilerBackup.Flag.Duration("timeAgo", 0, "start time before now. \"300ms\", \"1.5h\" or \"2h45m\". Valid time units are \"ns\", \"us\" (or \"µs\"), \"ms\", \"s\", \"m\", \"h\"")
 	filerBackupOptions.retentionDays = cmdFilerBackup.Flag.Int("retentionDays", 0, "incremental backup retention days")
-
 }
 
 var cmdFilerBackup = &Command{
@@ -129,7 +130,7 @@ func doFilerBackup(grpcDialOption grpc.DialOption, backupOption *FilerBackupOpti
 		*backupOption.proxyByFiler)
 	dataSink.SetSourceFiler(filerSource)
 
-	processEventFn := genProcessFunction(sourcePath, targetPath, excludePaths, reExcludeFileName, dataSink, debug)
+	processEventFn := genProcessFunction(sourcePath, targetPath, excludePaths, reExcludeFileName, dataSink, *backupOption.doDeleteFiles, debug)
 
 	processEventFnWithOffset := pb.AddOffsetFunc(processEventFn, 3*time.Second, func(counter int64, lastTsNs int64) error {
 		glog.V(0).Infof("backup %s progressed to %v %0.2f/sec", sourceFiler, time.Unix(0, lastTsNs), float64(counter)/float64(3))