As of Rancher v2.6, you can create RKE2 clusters (it’s in tech preview as of v2.6.4) and what Rancher will do is give you a curl command to run in the same way RKE1 gives you that docker run command.
Now if you don’t want to use Rancher, you’ll need to look at tools like puppet, chef, or ansible to manage to bootstrap the cluster and join nodes. But personally, I use my script rke2-up to handle this process for my RKE2 clusters.
The key item to understand about RKE2 is designed to manage itself. This means you don’t need an outside tool (like RKE) to upgrade your cluster or join/remove nodes. The RKE2 binary and the controllers in the cluster should handle that all for you.