I am not sure if I saw it HN recently, but there is an article by Phusion [1] talking about the init process and how to handle it with Docker. They have a base image, baseimage-docker [2], that is supposed to solve that problem.

[1]: https://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zomb... [2]: https://phusion.github.io/baseimage-docker/