TIL: Docker | Prune Only Unnamed Volumes

Story

I was trying to do some cleanup of space for docker and needed to prune my unnamed volumes names.

Question

How to prune all unnamed docker volumes?

Answer

Use --filter option. From docs:

By default, all unused volumes are removed. You can limit the scope using
the --filter flag. For instance, the following command only removes
volumes which are not labelled with the keep label:

$ docker volume prune --filter "label!=keep" 

But to create correct filter first we need to inspect volumes to find what labels and other parameters are present for them

$ docker volume inspect project_volume [ { "CreatedAt": "2021-09-30T11:35:55Z", "Driver": "local", "Labels": { "com.docker.compose.project": "project", "com.docker.compose.version": "2.0.0", "com.docker.compose.volume": "project_volume" }, "Mountpoint": "/var/lib/docker/volumes/project_project_data/_data", "Name": "project_project_data", "Options": null, "Scope": "local" } ] 

So we could filter our volumes like this

$ docker volume prune --filter 'label!=com.docker.compose.project' 

Note negative filtering does not work for docker volume ls for some reason.

$ docker volume ls --filter 'label!=com.docker.compose.project' Error response from daemon: Invalid filter 'label!' 

Links

• https://docs.docker.com/engine/reference/commandline/volume_inspect/
• https://docs.docker.com/config/pruning/#prune-volumes