getent group lightdm > /dev/null 2>&1 || groupadd -g 620 lightdm
getent passwd lightdm > /dev/null 2>&1 || useradd -c 'Light Display Manager' -u 620 -g lightdm -d /var/lib/lightdm -s /usr/bin/nologin lightdm
passwd -l lightdm > /dev/null