Creating a Raspberry Pi Kubernetes cluster is straight forward, however it becomes more complicated when you want to mix and match kubernetes nodes of different CPU architectures.
I recently deployed a new Kubernetes cluster in my home lab which initially consisted of two Ubuntu nodes running kubeadm and are VMs on VMware ESXi. Last night I tried to add a Raspberry Pi and ran into a couple of issues which I resolved and describe further down to save you some time.
kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-raspberry-01 Ready 4h v1.11.2 192.168.1.216 Raspbian GNU/Linux 9 (stretch) 4.14.62-v7+ docker://18.6.1
k8s-ubuntu-01 Ready master 5d v1.11.2 192.168.1.127 Ubuntu 18.04.1 LTS 4.15.0-33-generic docker://18.6.1
k8s-ubuntu-02 Ready 5d v1.11.2 192.168.1.156 Ubuntu 18.04.1 LTS 4.15.0-33-generic docker://18.6.1