Kubernetes is deprecating Docker support, but don’t worry, Kubernetes will still run images built by Docker.
CNCF ambassador Kat Cosgrove provides an explainer thread on Twitter and summarizes the situation like this: “From Kubernetes v1.20, you will receive a deprecation warning for Docker. After that, you will need to use a different container runtime” such as containerd or CRI-O.
Kohei Ota provides additional container runtime info on Dev.to, noting that “Docker does not support Kubernetes Runtime API called CRI (Container Runtime Interface) and Kubernetes people have been using a bridge service called "dockershim." It converts Docker API and CRI, but it will no longer be provided from Kubernetes side within a few minor releases.