* Kubelets using TLS bootstrapping (`--bootstrap-kubeconfig`) or certificate rotation (`--rotate-certificates`) store certificates in the directory specified by `--cert-dir`. The default location (`/var/run/kubernetes`) is automatically erased on reboot on some platforms, which can prevent the kubelet from authenticating to the API server after a reboot. Specifying a non-transient location, such as `--cert-dir=/var/lib/kubelet/pki`, is recommended.