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Your Docker image might be broken without you knowing it

By Hongli Lai on February 18th, 2014

Docker is an awesome new technology for the creation of lightweight containers. It has many purposes and serves as a good building block for PaaS, application deployments, continuous integration systems and more. No wonder it’s becoming more and more popular every day.

However what a lot of people may not realize is that the operating system inside the container must be configured correctly, and that this is not easy to do. Unix has many strange corner cases that are hard to get right if you are not intimately familiar with the Unix system model. This can cause a lot of strange problems. In other words, your Docker image might be broken, without you knowing it.

To raise awareness about this problem, we’ve published a website which explains the problem in detail. It explains what exactly could be broken, why it’s broken that way, and what can be done to fix them.

And to make it easier for other Docker users to get things right, we’ve published a preconfigured image — baseimage-docker — which does get everything right. This potentially saves you a lot of time.

Learn the right way to build your Dockerfile.

One of the gripes we have with random Docker images on the Docker registry is that they’re often very poorly documented, and do not provide the original Dockerfile from which they’re created. With baseimage-docker, we’re breaking that tradition by providing excellent documentation and by making the entire build reproducible. The Dockerfile and all other sources are available at Github, for everyone to see and to modify.

Happy Docking!