Re: Bug: machine id is never generated

[Henning Schild <henning.schild@siemens.com>]

Am Thu, 21 Jul 2022 17:41:07 +0200
schrieb "Moessbauer, Felix (T CED SES-DE)"
<felix.moessbauer@siemens.com>:

> Hi,
> 
> when booting plain ISAR images (with Debian11), the "/etc/machine-id"
> is never generated. This breaks a couple of services that depend on
> having the id. An example is the systemd-networkd with DHCP, leading
> to error messages like this one (and breaking networking):
> 
> systemd-networkd[277]: enp8s0: DHCP6 CLIENT: Failed to set
> identifier: No such file or directory

Seems that can also cause issues for NetworkManager where one can loose
the network when a lease expires and a renew is due. I hope that
https://github.com/ilbers/isar/commit/693d76b8c06af fixed that but just
drop the error message here for completeness.

NetworkManager[526]: <error> [1665061214.9410] /etc/machine-id: no
valid machine-id. Use fake one based on secret-key: ...

Henning

> The error can manually be fixed by running
> "systemd-machine-id-setup", but this obviously does not work in
> embedded scenarios.
> 
> The root cause could be that /etc is read-only mounted when the
> first-boot-complete.target is reached. At least the logs indicate
> this:
> 
> journalctl --grep machine --no-pager
> -- Journal begins at Thu 2022-07-21 15:07:21 UTC, ends at Thu
> 2022-07-21 15:35:20 UTC. -- Jul 21 15:07:21 test-image systemd[1]:
> System cannot boot: Missing /etc/machine-id and /etc is mounted
> read-only. Jul 21 15:07:21 test-image systemd[1]: 1) /etc/machine-id
> exists and is populated. Jul 21 15:07:21 test-image systemd[1]: 2)
> /etc/machine-id exists and is empty. Jul 21 15:07:21 test-image
> systemd[1]: 3) /etc/machine-id is missing and /etc is writable. Jul
> 21 15:07:24 test-image systemd[1]: Condition check resulted in Commit
> a transient machine-id on disk being skipped.
> 
> Maybe Quirin knows more, as he implemented the postproc removal in
> 8b5e3f9. IIRC Jan also mentioned something that "rw" has to be added
> to the kernel cmdline, but this looks like a workaround as well. For
> the sake of completeness:
> 
> cat /proc/cmdline
> initrd=\initrd.img-5.10.0-16-amd64 LABEL=Boot
> root=PARTUUID=9ad286e9-8df8-42c2-ac7d-0f2d7387d03d rootwait
> console=tty0 console=ttyS0,115200
> 
> IMO this is a pretty critical bug as it affects a ton of images.
> 
> Best regards,
> Felix
> 
> --
> Siemens AG, Linux Expert Center
> Otto-Hahn-Ring 6, 81739 München, Germany
>