NewCheckEtcdPhase is a hidden phase that runs after the control-plane-prepare and before the bootstrap-kubelet phase that ensures etcd is healthy.

NewControlPlanePreparePhase creates a kubeadm workflow phase that implements the preparation of the node to serve a control plane.

NewKubeletStartPhase creates a kubeadm workflow phase that start kubelet on a node.

NewPreflightPhase creates a kubeadm workflow phase that implements preflight checks for a new node join.