[systemd-devel] How to run *ctl command using systemd-nspawn

[Lennart Poettering]

On Wed, 17.04.13 17:09, Lennart Poettering (lennart at poettering.net) wrote:

> 
> On Tue, 16.04.13 09:11, Koen Kooi (koen at dominion.thruhere.net) wrote:
> 
> > Hi,
> > 
> > To help with flashing the onboard eMMC of a 100000 boards I'm using systemd-nspawn to run package postinstall scripts that generate UUIDs and some other things and it's working great for that! Every board now has a unique value in /etc/machine-id instead it being empty and systemd randomizing it on startup.
> > 
> > What doesn't work however is something like this:
> > 
> > 	systemd-nspawn -D ${PART2MOUNT} /usr/bin/timedatectl set-timezone Europe/Paris
> > 
> > or this:
> > 
> > 	systemd-nspawn -D ${PART2MOUNT} /usr/bin/hostnamectl set-hostname BeagleBoneBlack
> > 
> > I know I can run the lowlevel 'ln -sf <zoneinfo> /etc/timezone' or echo the name into /etc/hostname, but I'd like to use the *ctl commands because they work and have error handling built-in. 
> > it looks like I would need -b to get the *ctl commands to work, but -b
> > doesn't support running single commands and exiting.
> 
> timedatectl is just a frontend to timedated. So, without running
> timedated inside of the container this is not going to be easy to do.

Ah, I missed that you'd actually be OK with booting up the whole thing
for this command... You'd just need a nice way to run something after
boot-up is complete, and that immeidately shuts down the container
afterwards, right?

Hmm, here's an idea:

we could add a generator to systemd which looks for "systemd.run=" or so
on the kernel cmdline and simply generates throw-away unit files from
that, that runs the specified command(s) and triggers a shutdown
afterwards... Would that work for you?

i.e. you'd then call:

systemd-nspawn -bD /srv/foobar \
               systemd.run='/usr/bin/timedatectl set-timezone Europe/Paris' \
               systemd.run='/usr/bin/timedatectl set-hostname BeagleBoneBlack'

and so on...

I think that would be reasonably pretty?

Lennart

-- 
Lennart Poettering - Red Hat, Inc.