[systemd-devel] Question about systemd-firstboot

[Zbigniew Jędrzejewski-Szmek]

On Thu, Mar 09, 2017 at 10:48:03AM +0100, Francis Moreau wrote:
> Hello,
> 
> I'm puzzled about systemd-firstboot service.
> 
> In my understanding this service is ran only during the firstboot. The
> firstboot condition is detected with the presence of /etc/machine-id
> file.
> 
> If this file is not present then it's assumed to be a first boot and
> systemd-firstboot.service is ran and will create the machine-id file.
> 
> Now the thing is that I dont see how systemd-firstboot.service can
> have a chance to be started because if /etc/machine-id is missing the
> whole boot is failing due to journald requiring /etc/machine-id.
> 
> Could anybody give me some clues ?

machine_id_setup() is called from main(). So pid1 should set up
/etc/machine-id if possible (/etc is wriable) before it starts the
firstboot services.

Zbyszek