删除所有未使用的对象
docker system prune会删除所有stopped状态的容器、dangling状态的image和无用网络。
$ docker system prune
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all dangling images
- all build cache
Are you sure you want to continue? [y/N]
-f (--force)可跳过提示。
-a (--all) 慎用，会删除dangling状态和unused状态的image（-a参数会额外清理所有未被容器使用的镜像）
$ 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]
--volumes 默认情况下，该命令不会删除未使用的卷以防止丢失重要数据，要删除所有未使用的卷，请传递--volumes选项：
$ docker system prune --volumes
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all volumes not used by at least one container
- all dangling images
- all build cache
Are you sure you want to continue? [y/N] y
清理所有stopped的容器
$ docker container prune
WARNING! This will remove all stopped containers.
Are you sure you want to continue? [y/N] y
停止并清理所有容器
$ docker container stop $(docker container ls -aq)
$ docker container rm $(docker container ls -aq)
清理dangling镜像
同一个tag多次docker build之后，前面的镜像会变成dangling状态，这些镜像清理是安全的。
$ docker image prune
WARNING! This will remove all dangling images.
Are you sure you want to continue? [y/N] y
清理所有unused镜像
慎用，-a参数会清理所有未被容器使用的镜像。
$ docker image prune -a
WARNING! This will remove all images without at least one container associated to them.
Are you sure you want to continue? [y/N] y
清理所有unused volumes
要删除所有未使用的卷，运行docker volume prune命令：
$ docker volume prune
WARNING! This will remove all local volumes not used by at least one container.
Are you sure you want to continue? [y/N]
清理所有unused network
要删除所有未使用的网络，运行docker network prune命令：
$ docker network prune
WARNING! This will remove all networks not used by at least one container.
Are you sure you want to continue? [y/N]