[HEADS-UP] systemd for F14 - the next steps

[Lennart Poettering]

On Wed, 21.07.10 20:08, Toshio Kuratomi (a.badger at gmail.com) wrote:

> > - If you want to enable and possibly start a service from the %post of
> >   an RPM then use the "systemd-install enable" command, which will
> >   create a few symlinks as listed in the [Install] section of the unit
> >   file. On top of that you may also pass --realize=... to the command,
> >   which allows you to not only enable the unit for the next boot, but
> >   also have the changes take effect immediately: i.e. --realize=reload
> >   is the very least you should use, which simply makes systemd aware of
> >   the changed symlinks. Then, at time of %preun you should use
> >   --realize=yes which makes sure the daemon is stopped in
> >   deinstallation. For a few daemons it makes sense to restart them if
> >   they are running already during upgrade. Use --realize=minimal for
> >   those. For even others (usually very low-level ones) it might even
> >   make sense to start them right-away after installation, even if they
> >   were not running before. For those use --realize=maybe. But which
> >   option you use really depends on the package. Most packages
> >   should probably stick to --realize=yes on %preun and --realize=reload
> >   in %post. Suggested .spec file fragments you find in the daemon(7) man
> >   page.
> > 
> Normally, we don't want a service to be started just because the package has
> been installed:
> 

Yepp, which is why I said "very low-level ones", i.e. as low-level as
for example udev, which you really want to be running.

> https://fedoraproject.org/wiki/Packaging/SysVInitScript.
> 
> This is the current recommended scriptlets:
> 
> %post
> # This adds the proper /etc/rc*.d links for the script
> /sbin/chkconfig --add <script>
> 
> %preun
> if [ $1 = 0 ] ; then
>     /sbin/service <script> stop >/dev/null 2>&1
>     /sbin/chkconfig --del <script>
> fi
> 
> %postun
> if [ "$1" -ge "1" ] ; then
>     /sbin/service <script> condrestart >/dev/null 2>&1 || :
> fi
> 
> 
> I think I've got the %preun translated correctly but I'm not sure about
> either the %post or %postun::
> 
> %post
> # Don't need a %post as systemd automatically knows about the defaults?

It is needed:

if [ $1 -eq 1 ] ; then
        # For new installations, hook unit file into the appropriate places via symlinks
        /usr/bin/systemd-install enable --realize=reload %{unit name}.service > /dev/null 2>&1 || :
else
        # For old installations, just reload the configuration, don't change symlinks
        /bin/bin/systemd-install realize --realize=reload %{unit name}.service > /dev/null 2>&1 || :
fi        

> 
> %preun
> if [ $1 = 0 ] ; then
>     /usr/bin/systemd-install disable %{unit name}.service --realize=disable > /dev/null 2>&1 || :
> fi

Almost:

if [ $1 -eq 0 ] ; then
        /usr/bin/systemd-install disable --realize=yes %{unit name}.service > /dev/null 2>&1 || :
fi

> %postun
> if [ "$1" -ge "1" ] ; then
>     # Can't figure out how to do a conditional restart here.  Help?
> fi

If you want to restart the service on upgrade I'd do that in %post. It
should be sufficient to replace --realize=reload by --realize=minimal
which will restart the unit if it is running, and only then.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.