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

[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.

Jan

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