Pull Request to Add Standalone startup from command line?

[BenGalewsky]

Thank you so much for this Docker file! I was researching it for some applications I have. For me, it's much more useful for the docker image to create a non-root user and accept the setup key from the command line and mount a host volume to store and receive files.

I got all of that working in a fork of the repo and was wondering if you'd be interested in a PR back to your repo?

Please take a look at https://github.com/nds-org/gcp-docker/tree/command_line and see if this is of interest.