RKE2, also known as RKE Government, is Rancher's next-generation Kubernetes distribution.
It is a fully conformant Kubernetes distribution that focuses on security and compliance within the U.S. Federal Government sector.
To meet these goals, RKE2 does the following:
RKE2 combines the best-of-both-worlds from the 1.x version of RKE (hereafter referred to as RKE1) and K3s.
From K3s, it inherits the usability, ease-of-operations, and deployment model.
From RKE1, it inherits close alignment with upstream Kubernetes. In places K3s has diverged from upstream Kubernetes in order to optimize for edge deployments, but RKE1 and RKE2 can stay closely aligned with upstream.
Importantly, RKE2 does not rely on Docker as RKE1 does. RKE1 leveraged Docker for deploying and managing the control plane components as well as the container runtime for Kubernetes. RKE2 launches control plane components as static pods, managed by the kubelet. The embedded container runtime is containerd.
https://docs.rke2.io/install/requirements
What this means is that RKE2 is, at its simplest, a single binary to be installed and configured on all nodes expected to participate in the Kubernetes cluster. Once started, RKE2 is then able to bootstrap and supervise role-appropriate agents per node while sourcing needed content from the network.