PREIN
/bin/sh
getent group docker > /dev/null || /usr/sbin/groupadd -r docker
exit 0
PREUN
/bin/sh
if [ $1 -eq 0 ] ; then
# Package removal, not upgrade
systemctl --no-reload disable docker > /dev/null 2>&1 || :
systemctl stop docker > /dev/null 2>&1 || :
fi
POSTIN
/bin/sh
if [ $1 -eq 1 ] ; then
# Initial installation
systemctl preset docker >/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 docker >/dev/null 2>&1 || :
fi