[Aside] Rocket, App Container Spec, and CoreOS with Alex Polvi

Listened to a good episode of The Changelog podcast today. It’s about two months old – an interview with Alex Polvi, CEO of CoreOS.

CoreOS recently launched an alternative to the Docker container platform, called Rocket. It’s not a fork of Docker, it’s something new. The announcement got a lot of hype including some comments by the creator of Docker. In this podcast Alex talks on why he and Brandon (co-founder of CoreOS) created CoreOS – their focus was on security and an OS that automatically updated itself, for this they wanted all the applications and its dependencies to be in packages of its own independent of the core OS, Docker containers fit the bill, and so CoreOS decided to use Docker containers as the only applications it would run with CoreOS itself being a core OS that automatically updated. If they hadn’t come across Docker they might have invented something of their own.

CoreOS was happy with Docker but Docker now has plans of its own – not bad per se, just that they don’t fit with what CoreOS wanted from Docker. CoreOS was expecting Docker containers as a “component” to be still available, with new features from Docker added on to this base component, but Docker seems to be modifying the container approach itself to suit their needs. So CoreOS can’t use Docker containers the way they want to.

Added to that Docker is poor on security. The Docker daemon runs as root and listens on HTTP. Poor security practice. Downloads aren’t verified. There’s no standard defining what containers are. And there’s no way of easily discovering Docker containers. (So that’s three issues – (1) poor security, (2) no standard, and (3) poor discoverability). Rocket aims to fix these, and be a component (following the Unix philosophy of simple components that do one thing and do it well, working together to form something bigger). They don’t view Docker as a competition, as in their eyes Docker has now moved on to a lot more things.

I haven’t used Docker, CoreOS, or Rocket, but I am aware of them and read whatever I come across. This was an interesting podcast – thought I should point to it in case anyone else finds it interesting. Cheers!