清理未使用的docker镜像

查看docker资源使用情况

[root@ ~]# docker system df
TYPE TOTAL ACTIVE SIZE RECLAIMABLE
Images 26 9 4.152GB 3.316GB (79%)
Containers 20 16 0B 0B
Local Volumes 0 0 0B 0B
Build Cache 0 0 0B 0B

删除未使用的镜像

[root@host ~]# docker system prune -a
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all images without at least one container associated to them
- all build cache
Are you sure you want to continue? [y/N] n