Re: [PATCH 3/3] image-postproc-extension: add removal of machine-id

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

Am Tue, 28 May 2019 10:58:14 +0200
schrieb "[ext] claudius.heine.ext@siemens.com"
<claudius.heine.ext@siemens.com>:

> From: Claudius Heine <ch@denx.de>
> 
> The machine-id(5) should contain a unique id of the machine, but since
> this file is created by the systemd postinst script, every machine
> using the same image would have the same id.
> 
> The file is removed in a postprocessing step and will be regenerated
> by systemd on the first boot.

Systemd is not the only officially supported init system on Debian. And
i disagree with anyone claiming that it is OK to assume that in Isar ;).

I just did a little test and the outcome means we need more research.

In stretch with sysvinit-core in IMAGE_PREINSTALL there will be no
machine-id. So it is OK to rm -f, where the f is important.

In buster there is one, no clue where it comes from ... But that is
not magically recreated at first boot. Meaning we might have deleted an
important file without a plan to bring it back.

Question is, is it important at all for !systemd. If not at all, who
created and and why? Btw ... my gentoo laptop also has one, and i would
never install systemd. Maybe udev ...

Henning

> Signed-off-by: Claudius Heine <ch@denx.de>
> ---
>  meta/classes/image-postproc-extension.bbclass | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/meta/classes/image-postproc-extension.bbclass
> b/meta/classes/image-postproc-extension.bbclass index
> 625ba7d..495eae6 100644 ---
> a/meta/classes/image-postproc-extension.bbclass +++
> b/meta/classes/image-postproc-extension.bbclass @@ -26,8 +26,7 @@
> update_etc_os_release() { fi
>  }
>  
> -ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_configure
> image_postprocess_mark" -
> +ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_configure"
>  image_postprocess_configure() {
>      # Configure root filesystem
>      if [ -n "${DISTRO_CONFIG_SCRIPT}" ]; then
> @@ -39,8 +38,16 @@ image_postprocess_configure() {
>     fi
>  }
>  
> +ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_mark"
> +
>  image_postprocess_mark() {
>      BUILD_ID=$(get_build_id)
>      update_etc_os_release \
>          --build-id "${BUILD_ID}" --variant "${DESCRIPTION}"
>  }
> +
> +ROOTFS_POSTPROCESS_COMMAND =+ "image_postprocess_machine_id"
> +image_postprocess_machine_id() {
> +    # systemd(1) takes care of recreating the machine-id on first
> boot
> +    sudo rm -f '${IMAGE_ROOTFS}/etc/machine-id'
> +}