Kubernetes Introduction: Docker vs Containerd

Kubernetes (also written as k8s) is an advanced container management and orchestration platform. It sits above the container management engine, which provides command interfaces for running containers and managing them. Docker is one example of a container management engine; Containerd is another. In fact, Docker is more of a hybrid, providing enhancements and programming interface to the Containerd engine it actually uses under the hood. As k8s sits above Containerd and Docker, it is required to install a container management engine when installing k8s.

In the past Docker directly developed a shim that would interface between itself and k8s, but has since ceased development on it. This produced blog posts announcing that k8s could no longer support Docker. However, development for the shim was picked up by Mirantis. It can found hosted on Github: cri-dockerd