I am yet to understand what docker brings to nova, what the existing lxc driver couldn't do.. It seems like an abstraction layer which is hidden by nova.. therefore no new gain?
Remember, Docker is primarily a container format, not a virtualization platform. Supporting Docker in your own virtualization platform means letting people plug in their pre-made Docker-compatible containers have have them Just Work.
So, I'm not sure either, but I think the AUFS addition makes images easier to sync between machines?
That is, say I start with an Ubuntu image. Then I run an application on it on a Docker cloud. Then I install Python 3.0 and NumPy on it and take a snapshot. And then I want to run the new app with these libraries. I think when you deploy, or when images are being sync'd to machines, they can use the differential compression based on AUFS snapshots. So instead of transferring 300 MB, maybe you will only transfer 30 MB.
That would seem logical based on what I've read. But I have never actually gotten Docker to work, so I don't know. Would appreciate any comments on this.
Hey, sorry to hear that you didn't get docker to work! If you want to try again, feel free to come by our irc channel, #docker on freenode. The people there are very nice and will be happy to help you out.
Yup; there are lots of Docker images available at http://index.docker.io/; and more interesting features are on the way (trusted images, automated builds...)
Also, the Docker workflow is appealing to (at least) some people; this helps them to integrate Docker and OpenStack together.
