Docker Machine - Rancher k3s

This sets up a single-node Kubernetes installation, using regular Boot2Docker ISO.

Tested with k3s version: v1.17.0+k3s.1 featuring kubernetes version: v1.17.0

Written by Anders Björklund (@afbjorklund)

External URLs

Use k3s-download to get the binaries, and k3s-install to install into a machine.

See https://github.com/rancher/k3s

Requirements

It is possible to install using 1 vCPU / 1G RAM, but 2 vCPU / 2G RAM is recommended.

The total installation is as small as 400M, even after expanding the 40M k3s install.

Containerd

There is an embedded containerd with k3s, but we are going to use docker-machine.

Use containerd as included with Docker, after enabling cri-containerd plugin.

{ "cri-containerd": true }

The plugin is included with the standard install, but it is disabled by default.

disabled_plugins = ["cri"]

We then configure k3s and crictl to use the remote endpoint of this containerd:

unix:///var/run/docker/containerd/containerd.sock

See https://github.com/containerd/containerd

Flannel

There is an embedded flannel with k3s, but for some reason it doesn't work.

So we install the regular flannel CNI networking, using the kubeadm instructions:

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#pod-network

See https://github.com/coreos/flannel