[CentOS] systemd private tmp dirs

Wed Apr 15 23:48:09 UTC 2015
Matthew Miller <mattdm at mattdm.org>

On Wed, Apr 15, 2015 at 05:31:52PM -0500, Les Mikesell wrote:
> Thanks - I can see how those would work once you understand what is
> broken on the target system and why, but is there a way that programs
> 'should' be written to run with/without systemd?   That just happened
> to be the first thing I've tried to move over that wasn't already
> packaged and adapted - I expect to hit many more.

This isn't really a systemd thing. It's a standard Linux kernel
feature, which could also be enabled with (for example) pam_namespace.
Systemd happens to make it easy, so we started enabling it for services
which would benefit on Fedora, and that was inherited into RHEL and
CentOS. See the change page for this
<https://fedoraproject.org/wiki/Features/ServicesPrivateTmp>.

If you're really interested in learning every possible thing about
systemd, you could of course go through the author's blog post series
"systemd for administrators" — see
<http://0pointer.de/blog/projects/systemd-for-admins-1.html>. It's
pretty useful. 

Or, if you're mostly interested in packaging something up to run in a
nice way in the Fedora/RHEL/CentOS-ecosystem, the Fedora packaging
guidelines for systemd might help; those are at 
<http://fedoraproject.org/wiki/Packaging:Systemd>. I notice that
private temp dirs aren't mentioned there (not a bad thing to add,
really) but you'll find some other advice that might be helpful. (Take
a look at private devices and networking for a related issue.)


-- 
Matthew Miller
<mattdm at fedoraproject.org>
Fedora Project Leader