F23 System Wide Change: SELinux policy store migration

[Colin Walters]

On Thu, Jun 11, 2015, at 06:51 AM, Jan Kurik wrote:
> = Proposed System Wide Change: SELinux policy store migration =
> https://fedoraproject.org/wiki/Changes/SELinuxPolicyStoreMigration
> 
> Change owner(s):
> * Petr Lautrbach <plautrba at redhat dot com>
> * Miroslav Grepl <mgrepl at redhat dot com>
> 
> The newest SELinux userspace project release 2015-02-02 includes a change of the location of the SELinux policy store, which defaults to /var/lib/selinux/. 

This will need to support having an empty /var on boot in order to be compatible
with both rpm-ostree and the systemd factory reset work.  For most of user space,
the simplest implementation of this is to just have a systemd-tmpfiles unit that
copies data on startup.  But policy is currently loaded very early after switch root.  This
will require that /var be mounted too.

It will also mean rpm-ostree rollbacks by default won't affect the selinux policy, which is
a major and unfortunate change.

The listed benefit is:

 -moving the policy store out of /etc
    user could easily get back Factory setup by removing a directory out of /etc 

Note that OSTree provides that today - all the /etc defaults are copied into
/usr/etc, so at any point you can easily reset things.  (This is different from
the systemd effort for an empty /etc).

It seems far simpler to just keep things in /etc, but teach the tools to read
/usr.  Then *only if* I create a custom local policy, my changes are tracked
in /etc, and the local compiled policy file lives there too.