systemd/ddns.service

   1 [Unit]
   2 Description=Dynamic DNS updater
   3 Requires=network.target
   4 After=network.target
   5
   6 [Service]
   7 User=bind
   8 Type=simple
   9 PIDFile=/var/run/ddns.pid
  10 ExecStart=/usr/local/bin/ddns
  11 Restart=always
  12 RestartSec=30s
  13
  14 [Install]
  15 WantedBy=multi-user.target