RPM macros question

[Paul Howarth]

On Thu, 02 Aug 2012 12:41:49 -0600
Dmitry Makovey <dmitry at athabascau.ca> wrote:
> I'm working on bringing pgpool-II packages
> (postgresql-pgpool-II-3.1.2-1) from Fedora over to RHEL6. I've
> already "hacked" Fedora version to play nice with RHEL (removing
> systemd references and supplanting systemd unit with init script). I
> have also conditionalized it to build either one depending on whether
> systemd is to be used or not using the 
> 
> %if %{systemd_enabled}
> ...
> %else
> ...
> %endif
> 
> blocks. However I can't quite figure out an optimal way of
> determining which platform package is being compiled for (in other
> words: how to set up systemd_enabled macro automatically rather than
> rely on manual setup). I'm sure people on this list came across this
> problem more than once, and I would like to know what's the standard
> way of resolving it. What I'm trying to achieve is to get one SPEC
> for both Fedora and RHEL. Am I attacking this problem the wrong way?

I don't think there's a standard for this, but an approach I've used
with success is to test for the existence of the /run/lock directory:

# If directory /run/lock exists, do a systemd-based build; otherwise,a sysvinit-based build
%global use_systemd %([ -d /run/lock ] && echo 1 || echo 0)

Cheers, Paul.