PREIN

/bin/sh

getent group return >/dev/null || groupadd -r return
getent passwd return >/dev/null || \
    useradd -r -g return -d / -s /sbin/nologin \
    -c "reTurn TURN server" return

PREUN

/bin/sh

if [ $1 -eq 0 ] ; then 
        # Package removal, not upgrade 
        systemctl --no-reload disable resiprocate-turn-server.service > /dev/null 2>&1 || : 
        systemctl stop resiprocate-turn-server.service > /dev/null 2>&1 || : 
fi

POSTIN

/bin/sh

if [ $1 -eq 1 ] ; then 
        # Initial installation 
        systemctl preset resiprocate-turn-server.service >/dev/null 2>&1 || : 
fi

POSTUN

/bin/sh

systemctl daemon-reload >/dev/null 2>&1 || : 
if [ $1 -ge 1 ] ; then 
        # Package upgrade, not uninstall 
        systemctl try-restart resiprocate-turn-server.service >/dev/null 2>&1 || : 
fi