[CentOS] systemd private tmp dirs

[Matthew Miller]

On Wed, Apr 15, 2015 at 04:15:23PM -0500, Les Mikesell wrote:
> > Why does this directory have to be /tmp rather than a specific
> > directory belonging to twiki?
> Twiki is a perl web application run under apache.  It doesn't have its
> own uid.  It doesn't 'have' to be anywhere in particular but that is
> the way it was written and thus has very confusing results when trying
> to move it to CentOS 7.  Is there some generic approach to fixing this
> kind of breakage (that is, to make it work and not confusing, not to
> say it was broken as designed)?    To function as a backup, it
> probably shouldn't default to being in the same directory as the files
> it backs up.

There are two (sane) options, I think.

The first, and I think the best, is to configure twiki to share files
in some specific location rather than /tmp. It doesn't have to be the
same directory as the files being backed up — maybe something under
/var/lib/twiki (or /var/local/twiki).

If the twiki backup plugin didn't allow this to be configured, I would
argue that it _is_ broken by design. But a quick Google search leads me
to <http://twiki.org/cgi-bin/view/Plugins/BackupRestorePlugin>, which
shows that it is indeed configurable, so I'm just going to call it a
questionable default. :)

If you want to keep that default, though, the second approach would be
to configure Apache to not use a private namespace, which I don't
recommend because you lose the security benefit. To do that, put

[Service]
PrivateTmp=false

in /etc/systemd/system/httpd.service (which may not exist).

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