configFileProvider([configFile(fileId: 'known_hosts', variable: 'KNOWN_HOSTS')]) {
  sh 'su -c "mkdir -p /root/.ssh" && su -c "chmod 700 /root/.ssh"'
  sh 'su -c "cp ${KNOWN_HOSTS} /root/.ssh/known_hosts" && su -c "chmod 644 /root/.ssh/known_hosts"'
}