You probably want to pass persistent volumes to the following directories:
Attach your music store anywhere, you can configure this in the web interface (http://$IP:9000).
docker run -d -P --net=host -v '/media/music:/media/music' -v '/media/prefs:var/lib
/squeezeboxserver/prefs' -v '/media/cache:var/lib
Also supports CMD of "shell" for a bash shell and "upgrade" to upgrade to the latest available version of Logitech Media Server 7.9.
It's currently using --host=net as I was seeing some trouble streaming to my software squeezeboxes from the Spotify official plugin, so this will hopefully change in future (following more testing)