[memracom]

What I like about Docker is that if I have a production server build based on Centos 6.4 and use Docker to install tools x, y and z, then I can easily and quickly build a VM on my desktop with Virtualbox, install the base Centos 6.4, and run the Docker builds for tools x, y, and z. At that point I have a dev environment that is as close as you can reasonably get to the production server. This means that there will be fewer integration issues in QA and fewer release issues down the road. That is what Docker buys you. Anyone who has worked with Solaris containers will argue that there is fundamentally no difference, and they would be right. In addition, you could skip Docker and just use build scripts written in bash and get the same results, and that is also true. Docker is a small incremental improvement over these earlier solutions, but what matters is not size, but that it does improve the situation. The Dockerfile is cleaner and clearer than a bash script. The registry is already built for you https://github.com/dotcloud/docker-registry and the learning curve for new people is much reduced http://docs.docker.io/en/latest/

These are worthwhile improvements.