Re: [PATCH] expand-on-first-boot: Add support for devicemapper

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

Am Thu, 21 Apr 2022 19:43:47 +0200
schrieb Henning Schild <henning.schild@siemens.com>:

> I learned yesterday about systemd-repart
> https://www.freedesktop.org/software/systemd/man/systemd-repart.service.html

This currently needs >= bookworm to even start playing with systemd >=
250.1-2

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=976959

So maybe a little too early for isar, but still something we could look
into.

systemd-growfs is also available in older versions, but that just deals
with the filesystem, not with the partition table.

Henning

> We should look at this and how mkosi puts/uses it for debian.
> 
> Not a review, just a generic remark that there might be more powerful
> and ready to use tools out there. At some point i will play with this
> and see if it can replace expand-on-first-boot, i bet we will soon
> hear the first btrfs stories ... and maybe luks.
> 
> I know people do that with isar and their own funny scripting which
> can not be found upstream.
> 
> Am Thu, 21 Apr 2022 19:10:44 +0200
> schrieb Jan Kiszka <jan.kiszka@siemens.com>:
> 
> > From: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > When the rootfs is inside a devicemapper volume, e.g. dm-verity, the
> > script so far fails to identify the boot device. This adds at least
> > basic support for that case (single level, single slave). Once there
> > is a good example for more complex setups, this could be taken into
> > account as well.
> > 
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > ---
> >  .../expand-on-first-boot/files/expand-last-partition.sh    | 7
> > ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git
> > a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> > b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> > index 7175dfd3..bb371e9f 100755 ---
> > a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> > +++
> > b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
> > @@ -10,8 +10,13 @@ set -e ROOT_DEV="$(findmnt / -o source -n)"
> > -BOOT_DEV="$(echo "${ROOT_DEV}" | sed 's/p\?[0-9]*$//')"
> > +ROOT_DEV_NAME=${ROOT_DEV##*/}
> > +ROOT_DEV_SLAVE=$(ls -d /sys/block/${ROOT_DEV_NAME}/slaves/*  
> > 2>/dev/null | head -1) +if [ -n ${ROOT_DEV_SLAVE} ]; then  
> > +	ROOT_DEV=/dev/${ROOT_DEV_SLAVE##*/}
> > +fi
> >  
> > +BOOT_DEV="$(echo "${ROOT_DEV}" | sed 's/p\?[0-9]*$//')"  
> 
> Please add a wks and switch at least one CI target. In case wic can
> not generate that dm-verity ... NACK, or provide the wic plugin as
> well.
> 
> Henning
> 
> >  if [ "${ROOT_DEV}" = "${BOOT_DEV}" ]; then
> >  	echo "Boot device equals root device - no partitioning
> > found" >&2 exit 1  
>