Custom labels with dockerspawner

Hi !

is it possible to add custom labels to the containers spawned by dockerspawner ?

My use case is that I have an external Traefik proxy that I would like to use instead of the standard ConfigurableHTTPProxy.
Traefik is configured with its docker provider for automatic configuration discovery, but I would need to add a couple of custom lables to the spawned containers so that routing is done correctly.

Yes, I am aware of the traefik-proxy project, but as my Traefik install is running in a dedicated container (not in the same container that JupyterHub is running in), I would need an KV store (etcd or consul) to implement it. I would like to prevent this additional component if at all possible, so doing it via docker labels seems to be the best way to implement it.

Thanks for any advice