Add plumbing for Volume Labels

[s4ke]

We are building infrastructure for multitenancy around Docker Swarm using labels on objects - see https://github.com/neuroforgede/swarmgate

I would love for this volume plugin to set and get labels from the Hetzner API. This way I can properly use our multi-tenancy concept with the driver.

What do you think @costela ? Should be possible as far as I can tell.

https://github.com/moby/moby/blob/93fffa299c2cb23055bb54c380a02d53c9a7d525/daemon/cluster/executor/container/container.go#L444

https://github.com/moby/moby/blob/93fffa299c2cb23055bb54c380a02d53c9a7d525/volume/drivers/proxy.go#L26

[s4ke]

The go-plugin-helpers might not support it after all though?

https://github.com/docker/go-plugins-helpers/blob/6eecb7beb65124bb44a23848bb46e98b4f50ae18/volume/api.go#L83

[s4ke]

If the label stuff does not work, we could work around it for our usecase by making the label the volume driver sets configurable and just deploy the volume driver multiple times. Then we set the volume driver permissions accordingly. Label's would be much simpler and straightforward though.

Ah, I forgot, the driver supports prefixing anyways.

[s4ke]

closing this. we will be going down the route of prefixing.

[costela]

ok, good to know! Sorry I didn't get around to answering earlier 🙈

[s4ke]

https://docs.docker.com/reference/api/engine/version/v1.45/#tag/Volume/operation/VolumeCreate

The API lists it however. This is weird. I think prefixing is a viable workaround for now, but I think we should get the label support into the driver anyways. It can help for other topics as well to have volumes listed in Hetzner cloud.