Remove dangling volumes

[ymilki]

Sometimes volumes are left behind from docker-compose. docker volume ls -f dangling=true lists them all. These volumes aren't removed by dcgc because they aren't associated with any containers or images. They are left in /var/lib/docker/volumes indefinitely until removed.

[dnephin]

LGTM

[ymilki]

The only filter for volume deletion is dangling=True. docker volume inspect only provides the keys Name, Driver, Mountpoint, Label.

I suspect we may want either an exclude list or filters on Labels and Names (labels=null, name='^[a-z0-9]{64}$' perhaps) because volumes can be attached to containers.

[Bert-R]

I tried running Custodian with the new --dangling-volumes flag, like this:

docker run -i --rm -v /var/run/docker.sock:/var/run/docker.sock yelp/docker-custodian dcgc --dangling-volumes --max-container-age ...

But that causes the following error:

Getting all containers
Found 11 containers
Getting all containers
Found 11 containers
Getting all images
Found 33 images
Getting dangling volumes
Traceback (most recent call last):
  File "/usr/bin/dcgc", line 9, in <module>
    load_entry_point('docker-custodian==0.7.0', 'console_scripts', 'dcgc')()
  File "/code/docker_custodian/docker_gc.py", line 222, in main
    cleanup_volumes(client, args.dry_run)
  File "/code/docker_custodian/docker_gc.py", line 163, in cleanup_volumes
    dangling_volumes = get_dangling_volumes(client)
  File "/code/docker_custodian/docker_gc.py", line 80, in get_dangling_volumes
    log.info("Found %s dangling volumes", len(volumes))
TypeError: object of type 'NoneType' has no len()

Is it me? Or should I log an issue?

[dnephin]

It sounds like it found no dangling volumes. Please open an issue about it.

[Bert-R]

Done. See #41