If you have Steam Guard enabled, which let's face it: most of us do, you will need to do a few things differently.
1. Run the container with both `-i` (`stdin_open: true` in Compose) and `-t` (`tty: true` in Compose) arguments, which effectively allows for direct interaction
2. Be ready to attach to the container as soon as you launch it, as you will need to relatively quickly be able to provide the authentication code (eg. `docker attach starbound-server`, enter the auth code and detach by pressing `CTRL-p` followed by `CTRL-q`)
3. This should now keep you logged in, at least until the authentication token expires, at which point you can simply do these steps again
NOTE: At some point we may make a less tedious workaround for this, such as a web interface which can be used to securely manage the Steam session, credentials and Steam Guard authentication codes.