In order to understand a bit more about cloud technologies I'm trying to create a Kubernetes High Availability Cluster using 6 Raspberry Pi 3's. The goal is 3 stacked masters and 3 workers.

I've followed the instructions at: https://kubernetes.io/docs/setup/independent/high-availability/ but whenever I include:

api:
  controlPlaneEndpoint: "master"

in the kubeadm-config.yaml I end up in a situation where CoreDNS services aren't deployed:

root@master-1:~# kubectl get pods --all-namespaces
NAMESPACE     NAME                               READY     STATUS    RESTARTS   AGE
kube-system   etcd-master-1                      1/1       Running   0          39m
kube-system   kube-apiserver-master-1            1/1       Running   0          39m
kube-system   kube-controller-manager-master-1   1/1       Running   0          39m
kube-system   kube-scheduler-master-1            1/1       Running   0          38m

The deployment is installed, but for some reason it's not activated when I use the controlPlaneEndpoint directive.

root@master-1:~# kubectl get deployments -n kube-system
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
coredns   2         0         0            0           41m

It's like it's not even trying.

If I exclude the controlPlaneEndpoint directive from kubeadm-conf.yaml its deployed correctly but then I cannot add the other masters without errors from kube-controller-manager and kube-scheduler

root@master-1:~# kubectl logs -n kube-system kube-controller-manager-master-2
invalid configuration: no configuration has been provided
root@master-1:~# kubectl logs -n kube-system kube-scheduler-master-2
invalid configuration: no configuration has been provided

I would expect CoreDNS to become 'Pending' until a CNI plugin has been installed.

This is driving me nuts. It feels like it's so close to working!

Any pointers are welcome.

Thanks,

// Fredrik