Probo.ci is an open source continuous integration and quality assurance tool that lets you build branches and pull requests inside docker containers, reports back on the progress of each step, and then keeps the environment around and gives you a link so that you can go and preview the work in a shared space.
Probo has a Service Oriented Architecture so to get the full picture have a look at all of the projects in the Probo Organization. This project currently contains the Container Manager (which provides a high level interface to docker) and the Github Handler (responsible for receiving data from and sending data to github). In the long term these services will be factored out into their own projects and this project will be a packaging project making it easy to install compatible versions of all of the individual services.
See the Quickstart guide for how to get up and running with your own instance of Probo
The code uses generators and requires node io.js or node 4.x+.