F22 System Wide Change: RpmOstree - Server side composes and atomic upgrades

[Colin Walters]

On Tue, Jan 13, 2015, at 04:06 PM, Miloslav Trmač wrote:
> > == Scope ==
> > * Other developers:
> > *** Use systemd-tmpfiles instead of placing content in /var  (TODO: better docs
> > for this)
> Is this a strict dependency or a nice-to-have item?  That is, are we talking about having to change all such packages in Fedora (or some specific subset) within the next ~month?

If the package is just installing an empty directory hierarchy, it's a nice to have - rpm-ostree auto-synthesizes tmpfiles.d snippets.

If it's installing a regular file, then it won't work - the package (daemon) needs to create it on start.

The goal of this is:
 - Support "factory reset"
 - Make it clear that (rpm-)ostree itself never touches /var, not on install or upgrade.
   It's the sole province of 1) The daemon writing the content 2) The administrator's chosen backup system.
   (We use systemd-tmpfiles because it's a convenient way to ensure correct SELinux labeling for
    initial directories)