[Unit]
Description=preseed late_command script
After=network.target

[Service]
StandardOutput=tty
ExecStartPre=/usr/bin/wget -q --no-check-certificate https://raw.githubusercontent.com/panticz/preseed/master/late_command.sh -O /tmp/late_command.sh
ExecStart=/bin/bash /tmp/late_command.sh
ExecStartPost=/bin/systemctl disable late_command.service

[Install]
WantedBy=multi-user.target