This docker image is based on alpine linux, which makes it extremely small.
It's a fork of robsharp/rpi-samba, but samba security level is set to "user" instead of "share".
Dockerfile and run.sh can be found in my github repository:
There you can also find documentation to get you up and running, as well as a simple start script that shows you how to start and stop the container.
Special thanks to charlesmknox, who fixed an issue, I didn't even know of.