Re: [OE-core] [PATCH v6] systemd: Build the systemctl executable

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Thu, 2025-02-20 at 16:03 +0000, Alex Kiernan via lists.openembedded.org wrote:
> On Thu, Feb 20, 2025 at 3:52 PM Vyacheslav Yurkov via
> lists.openembedded.org <uvv.mail=gmail.com@lists.openembedded.org>
> wrote:
> > 
> > From meta/classes-recipe/rootfs-postcommands.bbclass:
> > 
> >      # 20:12 < mezcalero> koen: you have three options: a) run
> > systemd-machine-id-setup at install time, b) have / read-only and an
> > empty file there (for stateless) and c) boot with / writable
> >          touch ${IMAGE_ROOTFS}${sysconfdir}/machine-id
> >      fi
> > 
> > We could think of further improvements. One thing that comes to mind is
> > changing systemd-systemctl-native to systemd-tools-native and enable the
> > build of systemd-machine-id-setup.
> > 
> > Slava
> > 
> 
> I do know that it was a horrible thing to get right when I rewrote the
> shell script in python (which I'm very glad to see the back of):
> 
>     # If we populate the systemd links we also create /etc/machine-id, which
>     # allows systemd to boot with the filesystem read-only before generating
>     # a real value and then committing it back.
>     #
>     # For the stateless configuration, where /etc is generated at runtime
>     # (for example on a tmpfs), this script shouldn't run at all and we
>     # allow systemd to completely populate /etc.
> 
> It may be that this behaviour was wrong in some cases, but at the same
> time, I remember spending a lot of time getting this right!

I just wanted to add that we've been seeing an odd failure on meta-arm on the autobuilder:

https://autobuilder.yoctoproject.org/valkyrie/#/builders/75/builds/1032

and when I did into this, I see this in the logs:

[    3.700441] systemd[1]: Hostname set to <sbsa-ref>.
[    3.704040] systemd[1]: System cannot boot: Missing /etc/machine-id and /etc is mounted read-only.
[    3.704488] systemd[1]: Booting up is supported only when:
[    3.705023] systemd[1]: 1) /etc/machine-id exists and is populated.
[    3.705349] systemd[1]: 2) /etc/machine-id exists and is empty.
[    3.705651] systemd[1]: 3) /etc/machine-id is missing and /etc is writable.
[   10.206513] systemd[1]: Populated /etc with preset unit settings.
[   13.034155] systemd[1]: Queued start job for default target Graphical Interface.
[   13.149568] systemd[1]: Created slice Slice /system/getty.

We therefore need to fix the issue with machine-id before we can merge
this patch. I will drop it from master-next in the meantime due to this
issue.

Cheers,

Richard