Support different kubernetes version

[gianarb]

In theory you can specify the Kubernetes version you want your cluster to run.

I am saying in theory because right now we do not support that. I feel like this
is in some way related to #118 but not sure yet.

As you can see from cluster-template.yaml you can specify the kubernetes version

apiVersion: cluster.x-k8s.io/v1alpha3
kind: MachineDeployment
metadata:
  name: ${CLUSTER_NAME}-worker-a
  labels:
    cluster.x-k8s.io/cluster-name: ${CLUSTER_NAME}
    pool: worker-a
spec:
  replicas: ${WORKER_MACHINE_COUNT}
  clusterName: ${CLUSTER_NAME}
  selector:
    matchLabels:
      cluster.x-k8s.io/cluster-name: ${CLUSTER_NAME}
      pool: worker-a
  template:
    metadata:
      labels:
        cluster.x-k8s.io/cluster-name: ${CLUSTER_NAME}
        pool: worker-a
    spec:
      version: ${KUBERNETES_VERSION}
      clusterName: ${CLUSTER_NAME}
      bootstrap:
        configRef:
          name: ${CLUSTER_NAME}-worker-a
          apiVersion: bootstrap.cluster.x-k8s.io/v1alpha3
          kind: KubeadmConfigTemplate
      infrastructureRef:
        name: ${CLUSTER_NAME}-worker-a
        apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
        kind: PacketMachineTemplate

We have to dig into it to see how the other cluster-api-providers implemented
this feature.

[gianarb]

This is what I have to do:

kubeadm init --kubernetes-version=x.y

At least as a first step, this does not work if the kubeadm version does not support the required Kubernetes version

[gianarb]

This is a no-issue. I was using a Machine type for the control plane because of #3 and #47 . Now that I am fixing them and I am working with KubeadmControlPlane everything is working just fine 👍