consistent with other commands

weed/shell/command_fs_meta_change_volume_id.go

@@ -58,6 +58,7 @@ func (c *commandFsMetaChangeVolumeId) Do(args []string, commandEnv *CommandEnv,
 	}
 
 	handleDeprecatedForceFlag(writer, fsMetaChangeVolumeIdCommand, applyChangesAlias, applyChanges)
+	infoAboutSimulationMode(writer, *applyChanges, "-apply")
 
 	// load the mapping
 	mapping := make(map[needle.VolumeId]needle.VolumeId)

weed/shell/command_volume_server_leave.go

@@ -4,11 +4,12 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io"
+
 	"github.com/seaweedfs/seaweedfs/weed/operation"
 	"github.com/seaweedfs/seaweedfs/weed/pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/volume_server_pb"
 	"google.golang.org/grpc"
-	"io"
 )
 
 func init() {
@@ -25,7 +26,7 @@ func (c *commandVolumeServerLeave) Name() string {
 func (c *commandVolumeServerLeave) Help() string {
 	return `stop a volume server from sending heartbeats to the master
 
-	volumeServer.leave -node <volume server host:port>
+	volumeServer.leave -node <volume server host:port> [-apply]
 
 	This command enables gracefully shutting down the volume server.
 	The volume server will stop sending heartbeats to the master.
@@ -43,11 +44,17 @@ func (c *commandVolumeServerLeave) Do(args []string, commandEnv *CommandEnv, wri
 
 	vsLeaveCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
 	volumeServer := vsLeaveCommand.String("node", "", "<host>:<port> of the volume server")
+	applyChanges := vsLeaveCommand.Bool("apply", false, "apply the changes")
+	// TODO: remove this alias
+	applyChangesAlias := vsLeaveCommand.Bool("force", false, "apply the changes (alias for -apply)")
 	if err = vsLeaveCommand.Parse(args); err != nil {
 		return nil
 	}
 
-	if err = commandEnv.confirmIsLocked(args); err != nil {
+	handleDeprecatedForceFlag(writer, vsLeaveCommand, applyChangesAlias, applyChanges)
+	infoAboutSimulationMode(writer, *applyChanges, "-apply")
+
+	if err = commandEnv.confirmIsLocked(args); err != nil && *applyChanges {
 		return
 	}
 
@@ -55,11 +62,15 @@ func (c *commandVolumeServerLeave) Do(args []string, commandEnv *CommandEnv, wri
 		return fmt.Errorf("need to specify volume server by -node=<host>:<port>")
 	}
 
-	return volumeServerLeave(commandEnv.option.GrpcDialOption, pb.ServerAddress(*volumeServer), writer)
+	return volumeServerLeave(commandEnv.option.GrpcDialOption, pb.ServerAddress(*volumeServer), writer, *applyChanges)
 
 }
 
-func volumeServerLeave(grpcDialOption grpc.DialOption, volumeServer pb.ServerAddress, writer io.Writer) (err error) {
+func volumeServerLeave(grpcDialOption grpc.DialOption, volumeServer pb.ServerAddress, writer io.Writer, applyChanges bool) (err error) {
+	if !applyChanges {
+		fmt.Fprintf(writer, "Would ask volume server %s to leave (dry-run)\n", volumeServer)
+		return nil
+	}
 	return operation.WithVolumeServerClient(false, volumeServer, grpcDialOption, func(volumeServerClient volume_server_pb.VolumeServerClient) error {
 		_, leaveErr := volumeServerClient.VolumeServerLeave(context.Background(), &volume_server_pb.VolumeServerLeaveRequest{})
 		if leaveErr != nil {