You don't have to use one or the other. Docker is more about shipping around images that can be used to start containers. How you configure the image is up to

You don't have to use one or the other. Docker is more about shipping around images that can be used to start containers. How you configure the image is up to you, but Docker provides a "Dockerfile" that can configure images with bash commands. You can call Chef / Puppet / Ansible from the Dockerfile to configure the image. Once the image is created you can send it out to any machine that has docker installed and start it up.