cluster: print more clear warning when scale in with --force (#1477)

pkg/cluster/manager/scale_in.go

@@ -48,21 +48,24 @@ func (m *Manager) ScaleIn(
 		nodes []string = gOpt.Nodes
 	)
 	if !skipConfirm {
-		if err := cliutil.PromptForConfirmOrAbortError(
-			"This operation will delete the %s nodes in `%s` and all their data.\nDo you want to continue? [y/N]:",
-			strings.Join(nodes, ","),
-			color.HiYellowString(name)); err != nil {
-			return err
-		}
-
 		if force {
 			if err := cliutil.PromptForConfirmOrAbortError(
-				"Forcing scale in is unsafe and may result in data lost for stateful components.\nDo you want to continue? [y/N]:",
+				color.HiRedString("Forcing scale in is unsafe and may result in data loss for stateful components.\n"+
+					"The process is irreversible and could NOT be cancelled.\n") +
+					"Only use `--force` when some of the servers are already permanently offline.\n" +
+					"Are you sure to continue? [y/N]:",
 			); err != nil {
 				return err
 			}
 		}
 
+		if err := cliutil.PromptForConfirmOrAbortError(
+			"This operation will delete the %s nodes in `%s` and all their data.\nDo you want to continue? [y/N]:",
+			strings.Join(nodes, ","),
+			color.HiYellowString(name)); err != nil {
+			return err
+		}
+
 		log.Infof("Scale-in nodes...")
 	}