Re: [PATCH 12/16] meta: Add expand-on-first-boot support package

[Jan Kiszka <jan.kiszka@siemens.com>]

On 13.09.18 11:30, Henning Schild wrote:
> Am Thu, 13 Sep 2018 10:33:59 +0200
> schrieb Jan Kiszka <jan.kiszka@siemens.com>:
> 
>> On 12.09.18 15:46, Henning Schild wrote:
>>> Am Tue, 11 Sep 2018 14:05:52 +0200
>>> schrieb "[ext] Jan Kiszka" <jan.kiszka@siemens.com>:
>>>   
>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>
>>>> When installed, this systemd service expands the last partition on
>>>> a the boot medium to the full size of that medium. It then
>>>> deactivates itself.
>>>>
>>>> Based on sysvinit version by Henning Schild.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>> ---
>>>>  .../expand-on-first-boot/expand-on-first-boot.bb   | 25
>>>> +++++++++++++++++ .../files/expand-last-partition.sh
>>>> | 31
>>>> ++++++++++++++++++++++ .../files/expand-on-first-boot.service
>>>> | 23
>>>> ++++++++++++++++ .../expand-on-first-boot/files/postinst
>>>> |  3 +++ 4 files changed, 82 insertions(+) create mode 100644
>>>> meta/recipes-support/expand-on-first-boot/expand-on-first-boot.bb
>>>> create mode 100644
>>>> meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
>>>> create mode 100644
>>>> meta/recipes-support/expand-on-first-boot/files/expand-on-first-boot.service
>>>> create mode 100644
>>>> meta/recipes-support/expand-on-first-boot/files/postinst
>>>>
>>>> diff --git
>>>> a/meta/recipes-support/expand-on-first-boot/expand-on-first-boot.bb
>>>> b/meta/recipes-support/expand-on-first-boot/expand-on-first-boot.bb
>>>> new file mode 100644 index 0000000..49d6c3b --- /dev/null
>>>> +++
>>>> b/meta/recipes-support/expand-on-first-boot/expand-on-first-boot.bb
>>>> @@ -0,0 +1,25 @@ +# Resize last partition to full medium size on
>>>> fist boot +#
>>>> +# This software is a part of ISAR.
>>>> +# Copyright (c) Siemens AG, 2018
>>>> +#
>>>> +# SPDX-License-Identifier: MIT
>>>> +
>>>> +inherit dpkg-raw
>>>> +
>>>> +DESCRIPTION = "This service grows the last partition to the full
>>>> medium during first boot" +
>>>> +DEBIAN_DEPENDS = "systemd, sed, grep, coreutils, mount, e2fsprogs,
>>>> util-linux" +
>>>> +SRC_URI = " \
>>>> +    file://expand-on-first-boot.service \
>>>> +    file://expand-last-partition.sh \
>>>> +    file://postinst"
>>>> +
>>>> +do_install() {
>>>> +    install -d -m 755 ${D}/lib/systemd/system
>>>> +    install -m 644 ${WORKDIR}/expand-on-first-boot.service
>>>> ${D}/lib/systemd/system/ +
>>>> +    install -d -m 755 ${D}/usr/share/expand-on-first-boot
>>>> +    install -m 755 ${WORKDIR}/expand-last-partition.sh
>>>> ${D}/usr/share/expand-on-first-boot/ +}
>>>> diff --git
>>>> a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
>>>> b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
>>>> new file mode 100644 index 0000000..913e63b --- /dev/null
>>>> +++
>>>> b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
>>>> @@ -0,0 +1,31 @@ +#!/bin/sh
>>>> +#
>>>> +# Resize last partition to full medium size
>>>> +#
>>>> +# This software is a part of ISAR.
>>>> +# Copyright (c) Siemens AG, 2018
>>>> +#
>>>> +# SPDX-License-Identifier: MIT
>>>> +
>>>> +set -e
>>>> +
>>>> +ROOT_DEV=$(findmnt / -o source -n)
>>>> +BOOT_DEV=$(echo ${ROOT_DEV} | sed 's/p\?[0-9]*$//')
>>>> +
>>>> +if [ "${ROOT_DEV}" = "${BOOT_DEV}" ]; then
>>>> +	echo "Boot device equals root device - no partitioning
>>>> found" >&2
>>>> +	exit 1
>>>> +fi
>>>> +
>>>> +LAST_PART=$(sfdisk -d ${BOOT_DEV} 2>/dev/null | tail -1 | cut -d
>>>> ' ' -f 1) +
>>>> +# Remove all hints to the current medium (last-lba) and last
>>>> partition size, +# then ask sfdisk to recreate the partitioning
>>>> +sfdisk -d ${BOOT_DEV} 2>/dev/null | grep -v last-lba | \
>>>> +	sed 's|\('${LAST_PART}' .*, \)size=[^,]*, |\1|' | \
>>>> +	sfdisk --force ${BOOT_DEV}
>>>> +
>>>> +# Inform the kernel about the partitioning change
>>>> +partx -u ${LAST_PART}
>>>> +
>>>> +resize2fs ${LAST_PART}
>>>> diff --git
>>>> a/meta/recipes-support/expand-on-first-boot/files/expand-on-first-boot.service
>>>> b/meta/recipes-support/expand-on-first-boot/files/expand-on-first-boot.service
>>>> new file mode 100644 index 0000000..cbe3857 --- /dev/null
>>>> +++
>>>> b/meta/recipes-support/expand-on-first-boot/files/expand-on-first-boot.service
>>>> @@ -0,0 +1,23 @@ +# This software is a part of ISAR.
>>>> +# Copyright (c) Siemens AG, 2018
>>>> +#
>>>> +# SPDX-License-Identifier: MIT
>>>> +
>>>> +[Unit]
>>>> +Description=Expand last partition
>>>> +DefaultDependencies=no
>>>> +Conflicts=shutdown.target
>>>> +After=systemd-remount-fs.service
>>>> +Before=sysinit.target shutdown.target
>>>> +ConditionPathIsReadWrite=/etc
>>>> +
>>>> +[Service]
>>>> +Type=oneshot
>>>> +RemainAfterExit=yes
>>>> +ExecStart=/usr/share/expand-on-first-boot/expand-last-partition.sh
>>>> +ExecStartPost=-/bin/systemctl disable
>>>> expand-on-first-boot.service  
>>>
>>> Ok, this seems to be how you try to make sure this is done only
>>> once at the first boot. Is this a hack or somehow documented in
>>> systemd? I just read something about "ConditionFirstBoot=" in
>>> systemd.  
>>
>> ConditionFirstBoot was my first try as well, but it does not work
>> here because - my guess, didn't analyze deeply - the debootstrap run
>> or the rootfs installation step count as such, and the condition is
>> false on FirstRealBoot.
> 
> I would suggest leaving a mark with "touch" from within the script and
> using "ConditionPathExists=!", calling systemd from systemd sounds like
> a bad idea. Unless that is the officialy documented way of doing such
> things.

I picked it up from the grub2-once service of my distro. Works without problems,
so I don't see a need to fall back to that inferior PathExists method.

Jan

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