What is the current recommendation when creating a cluster? (VM)

Rancher 2.x
#1

According to the docs, k3s is the latest distribution and the recommended one, when used with rancher.

However, when looking at the “create cluster options” in rancher, there is an option of which docker version to use.

Then I just read this topic:
Docker support deprecated

Rancher doesn’t care what CRI is used below a cluster when managing resources inside it. RKE2 and k3s both already use containerd.

Then I don´t understand why (as per node requerements) I should install docker on my nodes?

Obviously there is something I can not comprehend. The more docs I read, the more confused I get.

I would appreciate it if someone would tell me how to achieve:

Set up a HA cluster, with 3 master nodes(ctrl Plane - etcd - agent) - with embedded etcd -
Cluster should be setup and managed from within rancherUI,

  • on nodes where docker is not installed, and never will be installed.

Happy new year!

#2

I’ve also been trying to understand what the statement “docker support deprecated” so this is my latest attempt. If you search for Docker Engine Release notes, they say that the latest version of docker is now split into separate packages; for example, on Ubuntu, docker-ce, docker-cli, and containerd. In other words, docker installation now requires the runtime to be installed separately; I guess this gives users the chance to install a runtime of their choice. So I think as long as you install the latest docker packages for your system then you should be okay. Maybe for a Kubernetes node, installing packages such as the docker CLI are optional now.

Going back to your first point, I’m not sure what you mean by “k3s is the latest distribution”. Where do you see that claim? Per my understanding, it’s a k8s that’s lighter on resource requirements. My understanding is that for a production cluster, you can use either rancher (which is run as a docker container and provides a web UI) or RKE (which is a command-line tool). I use RKE to create my cluster. I’ve also used rancher to connect to the cluster for the dashboard experience. I suppose you could run k3s and manage that with rancher as well.

I hope I got some points correct!

#3

Thank you for reply, and clarifying about the runtime…

As the rancher train moving FFWD, I might have confused some docs, here and there. All I know is k3s is newer than RKE, and k3s uses containerd, and doesn´t need docker to run.
Sure RKE is the way to go if you want to create clusters from within Rancher server, as k3s isn´t supported - yet!

However! I just managed to import my k3s cluster into my rancher server - FINALLY… I had issues for days, and days… untill I finally reloaded my firewall… (no comment)

Have a nice one.
Cheers