sudo apt-get install x11vnc

    x11vnc -storepasswd

    x11vnc -auth guess -once -loop -noxdamage -repeat -rfbauth ~/.vnc/passwd -rfbport 5900 -shared -ncache

    cp ~/.vnc/passwd /etc/x11vnc.pass

    /lib/systemd/system/x11vnc.service

    [Unit]
    Description=Start x11vnc at startup.
    After=multi-user.target
    [Service]
    Type=simple
    ExecStart=/usr/bin/x11vnc -auth guess -forever -loop -noxdamage -repeat -rfbauth /etc/x11vnc.pass -rfbport 5900 -shared -o /var/log/x11vnc.log
    [Install]
    WantedBy=multi-user.target

    systemctl daemon-reload

    systemctl enable x11vnc.service

    systemctl start x11vnc.service