RE: [PATCH v2 1/1] fix on-first-boot for systemd >= 247

["Moessbauer, Felix" <felix.moessbauer@siemens.com>]

FYI: We have a confirmation from systemd devs, that using "uninitialized" is the correct strategy.
They also mention what to consider when using ConditionFirstBoot=.
For technical details, see [1]

The GH issue is really worth a read 😉

Felix

[1] https://github.com/systemd/systemd/issues/14131#issuecomment-1194015162

> -----Original Message-----
> From: Moessbauer, Felix (T CED SES-DE) <felix.moessbauer@siemens.com>
> Sent: Monday, July 25, 2022 11:09 PM
> To: isar-users@googlegroups.com
> Cc: Schmidl, Tobias (T CED SES-DE) <tobiasschmidl@siemens.com>; Schild,
> Henning (T CED SES-DE) <henning.schild@siemens.com>; Kiszka, Jan (T CED)
> <jan.kiszka@siemens.com>; Moessbauer, Felix (T CED SES-DE)
> <felix.moessbauer@siemens.com>
> Subject: [PATCH v2 1/1] fix on-first-boot for systemd >= 247
> 
> This patch fixes the bug that /etc/machine-id is never generated when
> running from within an initrd with an ro rootfs.
> 
> In this case, the magic value "uninitialized" has to be used instead of deleting
> the file.
> 
> Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
> ---
>  meta/classes/image-postproc-extension.bbclass | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/meta/classes/image-postproc-extension.bbclass
> b/meta/classes/image-postproc-extension.bbclass
> index 0c412c0d..f9e26c1e 100644
> --- a/meta/classes/image-postproc-extension.bbclass
> +++ b/meta/classes/image-postproc-extension.bbclass
> @@ -56,8 +56,15 @@ image_postprocess_mark() {
> ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_machine_id"
>  image_postprocess_machine_id() {
>      # systemd(1) takes care of recreating the machine-id on first boot
> +    # for systemd < v247, remove the file, else set to uninitialized
> +    # (required if initramfs with ro root is used)
> +    SYSTEMD_VERSION=$( sudo chroot ${IMAGE_ROOTFS} dpkg-query --
> showformat='${source:Upstream-Version}' --show systemd || echo "0" )
> +    if dpkg --compare-versions "$SYSTEMD_VERSION" "lt" "247"; then
> +        sudo rm -f '${IMAGE_ROOTFS}/etc/machine-id'
> +    else
> +        echo "uninitialized" | sudo tee '${IMAGE_ROOTFS}/etc/machine-id'
> +    fi
>      sudo rm -f '${IMAGE_ROOTFS}/var/lib/dbus/machine-id'
> -    sudo rm -f '${IMAGE_ROOTFS}/etc/machine-id'
>  }
> 
>  ROOTFS_POSTPROCESS_COMMAND =+
> "image_postprocess_sshd_key_regen"
> --
> 2.30.2