Learn what the deprecation of Docker as a container runtime means for you and how to ensure a pain-free transition.

Kubernetes 1.20 was released last week. This version contains a number of amazing enhancements including graceful node shutdown, more visibility into resource requests, and snapshotting volumes.

But the change generating the most buzz is the deprecation of Docker as a container runtime.

Much of the discussion revolves around a misunderstanding of what the Docker deprecation entails and how it affects both Kubernetes administrators and application developers.

Let’s dive into what this deprecation means for you and how you can use chaos engineering to ensure a smooth transition off of the Docker runtime.

Docker Isn’t Just a Container Runtime

They say that naming things is one of the hardest things in technology, and this is certainly true with Docker. Often when discussing Docker, there’s some confusion around whether this refers to the container images or the application that runs those containers. The Kubernetes deprecation is for the application that runs your containers.

But don’t worry, this doesn’t mean your Kubernetes cluster will stop running your Docker containers!

Docker, like most applications, is actually a collection of smaller applications. There are sub-applications for the UI, an API, and many other things, including the container runtime. In 2016, Docker spun off its container runtime into a new, more modular runtime project called containerd. Containerd is fully supported by Kubernetes, so your Docker containers are also fully supported by Kubernetes.

The piece that’s being deprecated is the support for all of the other sub-applications that come along with Docker. Supporting all of those pieces required an integration layer called dockershim that required additional work to maintain — work that is largely unnecessary because most Kubernetes users only needed containerd and not the extra Docker features. Deprecating this feature will actually reduce the workload on the Kubernetes maintainers and make Kubernetes less complex.

#docker #kubernetes #chaos engineering #docker and kubernetes