Kata Containers


I recently looked into Kata Containers, it’s interesting to see what they are for.

Container-based technologies are amazing and eased the evolution of a lot of interesting stuff. We’ll not talk about it here!

One popular simplification is that containers fit in a lot of places where some years ago you would have probably used a virtual machine, where:

  • containers are much faster to spin up and shut down;
  • virtual machines allow a better isolation of workloads.

The goal of Kata Containers is to try to keep the isolation provided by the virtual machines, while still benefitting of way faster start-up times.

I think that the definition given at the beginning of this video is extremely helpful:

What are Kata Containers?

You’re taking your container and we’re looking to add an extra layer of isolation. So we’re not saying that containers are terrible, it’s just we think that defence at depth makes a lot of sense, depending on your security profile. So what we do on a per-container basis, or per-Pod if you’re in the Kubernetes space, is launch a lightweight virtual machine and inside of that instantiate your container, and the rest of it is just us doing plumbing so that way it’s not a lot of overhead for you and that just works.

One interesting aspect of Kata Containers is that the machinery to bring them up closely mimics that of spinning up containers as done by runc. This means that - from what I understood - it provides a drop-in replacement for runc and also that all higher level machinery - notably, kubernetes - should just work.

Want to know more?

There’s a lot to read around about Kata Containers. An interesting article, providing a view about the history of the project, is this: Kata Containers: Secure, Lightweight Virtual Machines for Container Environments.

Happy reading!

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