docker-utils

Some simple utilities to manage Docker environments.

purge_docker_volumes

Something I learned after quite a bit of Docker use and running out of space in the /var/lib/docker filesystem is that docker rm by default does not remove the associated "vfs" volumes created via the Dockerfile's VOLUME declaration.

For example,

$ docker inspect -f "{{.Volumes}}" 9a8e6969eced
map[/conf:/var/lib/docker/vfs/dir/77de7629c684968f98848372db3c490b28a0a22b94227ad7a8fc6cc55c55e16c /data:/var/lib/docker/vfs/dir/dde88b9a0d615ed1b411c142916f92cd5b5b4f829ad97f2e56d786db739bd83c]
$ sudo ls /var/lib/docker/vfs/dir/77de7629c684968f98848372db3c490b28a0a22b94227ad7a8fc6cc55c55e16c
elasticsearch.yml  logging.yml

Now, let's remove that container

$ docker rm 9a8e6969eced
9a8e6969eced
$ sudo ls /var/lib/docker/vfs/dir/77de7629c684968f98848372db3c490b28a0a22b94227ad7a8fc6cc55c55e16c
elasticsearch.yml  logging.yml

Ohh, it's still there. That's great if I wanted to get at the content later, but not if I have burned through containers without knowing they had VOLUMEs.

Safely purge these stale volumes by using:

$ sudo ~/go/bin/purge_docker_volumes
DELETING /var/lib/docker/vfs/dir/dde88b9a0d615ed1b411c142916f92cd5b5b4f829ad97f2e56d786db739bd83c
DELETING /var/lib/docker/vfs/dir/77de7629c684968f98848372db3c490b28a0a22b94227ad7a8fc6cc55c55e16c

And it's safe to re-run it:

$ sudo ~/go/bin/purge_docker_volumes
Congrats, nothing to purge

Building

Get it and install it:

$ go get github.com/itzg/docker-utils/purge_docker_volumes
$ go install github.com/itzg/docker-utils/purge_docker_volumes

and it run it from your $GOPATH/bin