Install k3s on the RaspberryPi 4

In this tutorial we will install one node kubernetes cluster using the k3s distribution on the raspberry pi 4.

Pre Checks

Ensure that cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory is in /boot/cmdline.txt:

$ cat /boot/cmdline.txt
console=serial0,115200 console=tty1 root=PARTUUID=738a4d67-02 rootfstype=ext4 elevator=deadline rootwait cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory  

Install k3s

Install k3s with:

$ curl -sfL | sh -

Once the installation is done, make the config readable by the pi user:

$ sudo chown pi:pi /etc/rancher/k3s/k3s.yaml

Interact with Kubernetes

Test your setup, to interact with kubernetes:

$ kubectl get nodes
rpi-06   Ready    master   18h   v1.18.2+k3s1  

If you want to use the kubernetes outside the cluster, you need to replace the localhost ip in the kubecontext: /etc/rancher/k3s/k3s.yaml:

$ cat /etc/rancher/k3s/k3s.yaml | sed "s/$(ifconfig eth0 | grep -w 'inet' | awk '{print $2}')/g" > /tmp/kubeconfig

Now outside the cluster copy the contents from the raspberry pi /tmp/kubeconfig to ~/.kube/config then run:

$ export KUBECONFIG=~/.kube/config

Then you will be able to access kubernetes outside the cluster.