Docker’s very own Jérôme Petazzoni presented at March’s London Docker Meetup with the attendance figures of a small conference with a deep dive, nay, not so deep dive into Docker storage drivers since the temperamental French DevOps dude who will replace anyone that annoys him with a very small shell script was only given twenty minutes to talk rather than the pre agreed forty five. Hence .Zip.
In between the blah blah blah Petazzoni gives a brief history of copy and write also explaining how it is not moving, for example, an entire 10GB image but rather more like being able to refer to the copy of a book with notes made. When you see a section that is of interest, then you get a Xerox copy of the entire section of the book you are interested in, far more efficient.
Petazzoni is always really good at contextualising what he talks about and with Docker Storage Drivers gives the history of dotCloud’s (Docker’s previous incarnation) advanced multilayered file unification system, “when we released the first version of Docker we had AUFS and it wasn’t such a big deal because AUFS ships not with the normal kernel but with the kernel of Debian and Ubuntu and we love Debian and Ubuntu so we didn’t care, some people using other distros like CentOS, Fedora etc were very unhappy about this and said, Docker is great but why can’t I have Docker on my distro? Just use a custom kernel. But we don’t want to use a custom kernel, we want to use our precious Red Hat approved kernel. Well, you’re out of luck, buddy.”
When Red Hat became Docker fans they then starting giving device mapper thin snapshot support for Docker so that Docker would then work in Red Hat.
Terry Dhariwal also gave a talk on running distributed NoSQL on Clocker as well as Luke Marsden and Ilya Dmitrichenko talking about Powerstrip which is implemented as a configurable, pluggable HTTP proxy for the Docker API allowing you to plug multiple Docker extension prototypes into the same Docker daemon.
