I've been using Racher products for a long time now - I really liked their original product Rancher 1.0, which was an alternative to Kubernetes, started before Kubernetes was fully obviously the winning solution.
More recently, it's so good to have a simple way of turning up a new kubernetes cluster, without having to worry too much about things. I know there's a few alternatives, especially on Ubuntu like MicroK8s, but k3s is very simple, even on something like a Raspberry PI.
To run it, it's a simple as this:
curl -sfL https://get.k3s.io | sh -
# Check for Ready node, takes ~30 seconds
sudo k3s kubectl get node
The great thing about it you really don't have to worry about getting it all working, especially on a single node solution, which is a good way to test out