Re: [PATCH 2/9] images: new class wic-img for wic intregration

[Alexander Smirnov <asmirnov@ilbers.de>]

On 01/31/2018 12:41 PM, Henning Schild wrote:
> This patch integrates wic into the bitbake workflow, wic will be used
> for the imaging step, no need to call it manually.
> 
> The target of this patch is to work with an unmodified wic, that is why
> it contains a few wic-specifics, mostly taken from OE.
> 
> There is one major difference to OE, we assume that wic is run as root.
> And we smuggle in a wrapper that patches calls to an fsck that does not
> behave like the one on OE.
> 
> Issues:
>    - wic was never integrated
>    - you always had to build an ext4-img to create a wic image later
>    - there was never a way to control the size of wic disks/partition,
>      only directly in the wks
> 
> Impact:
>    The patch solves the Issues without changing the default behaviour of
>    Isar.
> 
> Signed-off-by: Henning Schild <henning.schild@siemens.com>
> ---
>   meta/classes/wic-img.bbclass | 64 ++++++++++++++++++++++++++++++++++++++++++++
>   scripts/wic_fakeroot         | 37 +++++++++++++++++++++++++
>   2 files changed, 101 insertions(+)
>   create mode 100644 meta/classes/wic-img.bbclass
>   create mode 100755 scripts/wic_fakeroot
> 
> diff --git a/meta/classes/wic-img.bbclass b/meta/classes/wic-img.bbclass
> new file mode 100644
> index 0000000..e8d2678
> --- /dev/null
> +++ b/meta/classes/wic-img.bbclass
> @@ -0,0 +1,64 @@
> +# This software is a part of ISAR.
> +# Copyright (C) 2018 Siemens AG
> +#
> +# this class is heavily inspired by OEs ./meta/classes/image_types_wic.bbclass
> +#
> +
> +WKS_FILE ?= "sdimage-efi"
> +
> +# TODO here we leak buildenv into the image
> +# this needs to come from buildchroot
> +# and the isar efi plugin has the same problem
> +# syslinux in debian has different folder structure, need to for those plugins
> +STAGING_DATADIR ?= "/usr/share/"
> +STAGING_LIBDIR ?= "/usr/lib/"
> +STAGING_DIR ?= "${TMPDIR}"
> +IMAGE_BASENAME ?= "multiconfig:${MACHINE}-${DISTRO}:${PN}"
> +FAKEROOTCMD ?= "wic_fakeroot"
> +RECIPE_SYSROOT_NATIVE ?= "/"
> +
> +do_wic_image[stamp-extra-info] = "${DISTRO}-${MACHINE}"
> +
> +WIC_CREATE_EXTRA_ARGS ?= ""
> +
> +WICVARS ?= "\
> +           BBLAYERS IMGDEPLOYDIR DEPLOY_DIR_IMAGE FAKEROOTCMD IMAGE_BASENAME IMAGE_BOOT_FILES \
> +           IMAGE_LINK_NAME IMAGE_ROOTFS INITRAMFS_FSTYPES INITRD INITRD_LIVE ISODIR RECIPE_SYSROOT_NATIVE \
> +           ROOTFS_SIZE STAGING_DATADIR STAGING_DIR STAGING_LIBDIR TARGET_SYS TRANSLATED_TARGET_ARCH"
> +
> +# Isar specific vars used in our plugins
> +WICVARS += "KERNEL_IMAGE INITRD_IMAGE DISTRO_ARCH"
> +
> +python do_rootfs_wicenv () {
> +    wicvars = d.getVar('WICVARS', True)
> +    if not wicvars:
> +        return
> +
> +    stdir = d.getVar('STAGING_DIR', True)
> +    outdir = os.path.join(stdir, d.getVar('MACHINE', True), 'imgdata')
> +    bb.utils.mkdirhier(outdir)
> +    basename = d.getVar('IMAGE_BASENAME', True)
> +    with open(os.path.join(outdir, basename) + '.env', 'w') as envf:
> +        for var in wicvars.split():
> +            value = d.getVar(var, True)
> +            if value:
> +                envf.write('%s="%s"\n' % (var, value.strip()))
> +
> +    # this part is stolen from OE ./meta/recipes-core/meta/wic-tools.bb
> +    with open(os.path.join(outdir, "wic-tools.env"), 'w') as envf:
> +        for var in ('RECIPE_SYSROOT_NATIVE', 'STAGING_DATADIR', 'STAGING_LIBDIR'):
> +            envf.write('%s="%s"\n' % (var, d.getVar(var, True).strip()))
> +
> +}
> +
> +addtask do_rootfs_wicenv after do_copy_boot_files before do_wic_image
> +do_rootfs_wicenv[vardeps] += "${WICVARS}"
> +do_rootfs_wicenv[prefuncs] = 'set_image_size'
> +
> +do_wic_image() {
> +    export BUILDDIR="${BUILDDIR}"
> +
> +    sudo -E PATH="$PATH:/builder/isar/bitbake/bin:/builder/isar/scripts" /builder/isar/scripts/wic create ${WKS_FILE} --vars "${STAGING_DIR}/${MACHINE}/imgdata/" -o ${DEPLOY_DIR_IMAGE} -e ${IMAGE_BASENAME} ${WIC_CREATE_EXTRA_ARGS}
> +}

How this hardcoded path intended to work?

Alex

> +
> +addtask wic_image before do_build after do_copy_boot_files
> diff --git a/scripts/wic_fakeroot b/scripts/wic_fakeroot
> new file mode 100755
> index 0000000..9e01c38
> --- /dev/null
> +++ b/scripts/wic_fakeroot
> @@ -0,0 +1,37 @@
> +#!/usr/bin/env python3
> +#
> +# wic needs a FAKEROOT cmd to run, the default is pseudo. In Isar we do/can not
> +# use pseudo. And we call wic as root to begin with, so this script could be a
> +# dummy doing nothing. It is almost a dummy ...
> +#
> +# If the fsck hack ever becomes obsolete, FAKEROOTCMD ?= "true;" can be used
> +#
> +# This software is a part of Isar.
> +# Copyright (C) 2018 Siemens AG
> +#
> +import os
> +import sys
> +import shutil
> +import subprocess
> +
> +args = sys.argv
> +args.pop(0)
> +cmd = args[0]
> +
> +# expect to be running as root
> +# we could loosen that and execv(sudo, args) but even some early
> +# "du"s fail, which do not use the fakeroot-wrapper
> +#  i.e. in wics partition.py the "du -ks" fails on
> +#    var/cache/apt/archives/partial
> +#    rootfs/root ...
> +assert 'root' == os.environ["USER"]
> +
> +# e2fsck <= 1.43.5 returns 1 on non-errors (stretch and before affected)
> +# treat 1 as safe ... the filesystem was successfully repaired and is OK
> +if cmd.startswith('fsck.'):
> +    ret = subprocess.call(args)
> +    if ret == 0 or ret == 1:
> +        sys.exit(0)
> +    sys.exit(ret)
> +
> +os.execv(shutil.which(cmd), args)
>