func CreateCertificateKey() (string, error)
CreateCertificateKey returns a cryptographically secure random key
func DownloadCerts(client clientset.Interface, cfg *kubeadmapi.InitConfiguration, key string) error
DownloadCerts downloads the certificates needed to join a new control plane.
func UploadCerts(client clientset.Interface, cfg *kubeadmapi.InitConfiguration, key string) error
UploadCerts save certs needs to join a new control-plane on kubeadm-certs sercret.