code: func buildSecureBootstrapKubeConfig(endpoint string, caCert []byte, clustername string) *clientcmdapi.Config {
  	controlPlaneEndpoint := fmt.Sprintf("https://%s", endpoint)
  	bootstrapConfig := kubeconfigutil.CreateBasic(controlPlaneEndpoint, clustername, BootstrapUser, caCert)
  	return bootstrapConfig
  }
docs: // buildSecureBootstrapKubeConfig makes a kubeconfig object that connects securely to the API Server for bootstrapping purposes (validating with the specified CA)