Bug#717388: Volunteers needed to work on enabling persistent journal

[Josh Triplett]

On Thu, Feb 15, 2018 at 06:16:20PM +0100, Andreas Henriksson wrote:
> On Thu, Feb 15, 2018 at 09:07:21AM -0800, Josh Triplett wrote:
> > On Thu, Feb 15, 2018 at 05:14:03PM +0100, Andreas Henriksson wrote:
> [...]
> > > - (How to handle updates? Consensus seemed to be towards no change on
> > >    updates.)
> > 
> > I'm interested in helping with this.
> > 
> > I think we should *always* provide /var/log/journal, and continue to
> > configure systemd to not use the persistent journal by default rather
> > than autodetecting via the existence of /var/log/journal; that way, we
> [...]
> 
> Interesting proposal, but how do we handle upgrades in this case?
> 
> I'm thinking about the (possibly small) group of people who has
> manually uninstalled (r)syslog and created the directory according
> to /usr/share/doc/systemd/README.Debian.gz instructions (and rely on
> autodetection). Maybe a NEWS.Debian entry is enough to tell them
> they now need to install the package that enables persistant journal,
> but at the same time there will be those who do not pay enough attention
> and ends up with no logging what so ever after an upgrade which makes
> me a bit worried....

How about this:

systemd-journal-transient ships
/usr/lib/systemd/journald.conf.d/transient.conf which explcitly disables
the persistent jorunal by setting Storage=volatile.

systemd-journal-persistent ships
/usr/lib/systemd/journald.conf.d/persistent.conf which explicitly
enables the persistent journal by setting Storage=persistent.

systemd-journal-syslog Depends on systemd-journal-persistent |
systemd-journal-transient (so that you *can* still explicitly choose to
have syslog with transient-only storage, useful for some systems such as
those with no persistent storage at all) and Conflicts/Provides
system-log-daemon.

default-system-log-daemon would depend on rsyslog for now, and in the
future, it could start depending on systemd-journal-syslog instead. (Or
we could handle it as a virtual package, though that could make upgrades
harder.)