容器基本操作

容器基本操作主要是 ctr image 命令，查看命令帮助：

[root@localhost ~]# ctr containers -h
NAME:
   ctr containers - Manage containers

USAGE:
   ctr containers command [command options] [arguments...]

COMMANDS:
   create                   Create container
   delete, del, remove, rm  Delete one or more existing containers
   info                     Get info about a container
   list, ls                 List containers
   label                    Set and clear labels for a container
   checkpoint               Checkpoint a container
   restore                  Restore a container from checkpoint

OPTIONS:
   --help, -h  show help