Kubeadm: during "init" an empty cgroupDriver value in the KubeletConfiguration is now always set to "systemd" unless the user is explicit about it. This requires existing machine setups to configure the container runtime to use the "systemd" driver. Documentation on this topic can be found here: https://kubernetes.io/docs/setup/production-environment/container-runtimes/. When upgrading existing clusters / nodes using "kubeadm upgrade" the old cgroupDriver value is preserved, but in 1.22 this change will...

```

- Kubernetes components no longer handle panics, and instead actively crash.  All Kubernetes components should be run by something that actively restarts them. This is true of the default setups, but those with custom environments may need to double-check (#28800, @lavalamp)
- kubelet now defaults to `--cloud-provider=auto-detect`, use `--cloud-provider=''` to preserve previous default of no cloud provider (#28258, @vishh)

- Kubeadm: Fixed a preflight check that could fail hostname construction in IPv6 setups. ([#134588](https://github.com/kubernetes/kubernetes/pull/134588), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth, Cloud Provider, Cluster Lifecycle and Testing]

- Kubeadm: fixes a preflight check that can fail hostname construction in IPV6 setups ([#134592](https://github.com/kubernetes/kubernetes/pull/134592), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth, Cloud Provider, Cluster Lifecycle and Testing]

### Other (Cleanup or Flake)

- Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Kubeadm: remove the "ephemeral_storage" request from the etcd static pod that kubeadm deploys on stacked etcd control plane nodes. This request has caused sporadic failures on some setups due to a problem in the kubelet with cadvisor and the LocalStorageCapacityIsolation feature gate. See this issue for more details: https://github.com/kubernetes/kubernetes/issues/99305 ([#102673](https://github.com/kubernetes/kubernetes/pull/102673),...

Kubeadm: Automate certificate copy between control planes in HA setups

- Joining control plane nodes to a HA cluster can now be simplified by enabling the optional automatic copy of certificates from an existing control plane node.

- Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

mkdir -p "$TFCI_OUTPUT_DIR"

# In addition to dumping all script output to the terminal, place it into
# $TFCI_OUTPUT_DIR/script.log
exec > >(tee "$TFCI_OUTPUT_DIR/script.log") 2>&1

# Setup tfrun, a helper function for executing steps that can either be run
# locally or run under Docker. setup_docker.sh, below, redefines it as "docker
# exec".
# Important: "tfrun foo | bar" is "( tfrun foo ) | bar", not "tfrun (foo | bar)".

- Kubeadm: fixes a preflight check that can fail hostname construction in IPV6 setups ([#134590](https://github.com/kubernetes/kubernetes/pull/134590), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth, Cloud Provider, Cluster Lifecycle and Testing]