F15 Feature - convert as many service init files as possible to the native SystemD services

[Lennart Poettering]

On Wed, 24.11.10 15:22, Paul Wouters (paul at xelerance.com) wrote:

> 
> On Wed, 24 Nov 2010, Lennart Poettering wrote:
> 
> > BTW, regarding at and cron: what I was thinking of but never check
> > ehwther it is feasible is to make cron/at autostart a soon as some job
> > is scheduled. I.e. use .path trigger to check whether /etc/crontab and
> > user jobs exist, and start cron only then. Similarly for at. That way we
> > could support cron and at just fine, and wouldn't even have to run it by
> > default. I haven't looked into this in detail however, to see if the
> > file triggers systemd offers in .path units are already sufficient to
> > make this work.
> 
> What if no jobs are there and a non-root user adds a crontab later on? Who
> will start cron (as root) ?

That's the point of the .path unit. i.e. you can list dirs to watch. If
a user then drop a file into one of those dirs cron gets automatically
started.

Basically, in your .path unit you'd write something like this:

[Path]
PathExists=/etc/crontab
DirectoryNotEmpty=/etc/cron.d
DirectoryNotEmpty=/var/spool/cron

And the moment where /etc/crontab starts to exist, or somebody drops a
file into /etc/cron.d or /var/spool/cron crond would be automatically
started.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.