I\'m using boot2docker on OS X and cloned the following repo:
https://github.com/enokd/docker-node-hello
It basically has a Dockerfile and a very simple express
Concerning shared folders with VirtualBox, please check out:
boot2docker together with VirtualBox Guest Additions
How to mount /Users into boot2docker
https://medium.com/boot2docker-lightweight-linux-for-docker/boot2docker-together-with-virtualbox-guest-additions-da1e3ab2465c
tl;dr Build your own custom boot2docker.iso with VirtualBox Guest Additions (see link) or download http://static.dockerfiles.io/boot2docker-v1.1.0-virtualbox-guest-additions-v4.3.12.iso and save it to ~/.boot2docker/boot2docker.iso.
EDIT: updated link to boot2docker v1.1.0