Re: [PATCH] isar: Clean mount point on bitbake exit

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

Am Fri, 9 Feb 2018 16:08:01 +0300
schrieb Alexander Smirnov <asmirnov@ilbers.de>:

> On 02/09/2018 03:41 PM, Jan Kiszka wrote:
> > On 2018-02-09 13:40, Henning Schild wrote:  
> >> Am Fri, 9 Feb 2018 13:35:15 +0100
> >> schrieb Jan Kiszka <jan.kiszka@siemens.com>:
> >>  
> >>> On 2018-02-09 13:33, [ext] Henning Schild wrote:  
> >>>> Hi,
> >>>>
> >>>> this patch is causing problems when building in a docker
> >>>> container, because sysfs can only be mounted ro. (Subject:
> >>>> current next bash in buildchroot problem)
> >>>> Now we could discuss whether we should relax the security of our
> >>>> containers even more, or whether Isar should care about that
> >>>> use-case.
> >>>>
> >>>> But this patch actually does several things at a time, it
> >>>> changes >>>> the way we mount and adds three new mounts. I would
> >>>> suggest to  
> 
> Actually not. It adds the only one new mount for sysfs. /proc was 
> mounted inside do_build, /dev was mounted inside configscript.sh, so 
> this is a kind of consolidation of these calls in one place.

Ok, in that case sys should be in a separate patch.

> I have no case for sysfs, so probably we could drop it for now.
> Please let me know ASAP because I'm going to release v0.4.

I brought up sysfs as part of a "complete" chroot. If we do not have a
real case for it yet, and it hurts us in some docker-corner-case ...
leave it out for now.

As a general advice for the release. Most Isar-users probably consume
git anyways. And turning next directly into a release sounds like a bad
idea. I would first update master and wait some time until you get
bug-reports for your new master.
But hey, it is just a tag for people that like tarballs, might as well
leave some bugs in there ;).

> >>>> split it up so we can discuss the issues with dev and sys while
> >>>> already merging the rest.  
> 
> There is no official Docker support in Isar, so until there will be a 
> document which specifies the container configuration, it really would
> be inefficient to block contributions. We can't support everything
> everywhere.

Fair enough, but i can assure you that a lot of people build Isar
images in docker. I could even name the container for that etc. And
until that becomes an official feature we can still try and make sure
we do not break it.

Henning

> >>>
> >>> I think (didn't check if there was an update of next this
> >>> morning) it works for me - in Docker. How are you starting the
> >>> container?  
> >>
> >> docker run -e USER_ID=$(id -u) --rm -t -i --cap-add=SYS_ADMIN
> >> --cap-add=MKNOD --device $(/sbin/losetup -f) -e ... proxy stuff ...
> >>  
> 
> Do you have instructions how to build Isar in container, so at least
> I could be able to reproduce the issue?
> 
> Alex
> 
> 
> > Try adding --privileged - that's needed for binfmt anyway.
> > 
> > Jan
> >   
> >> inside my sysfs is ro, a bind-mount of sysfs is ro and a "mount -t
> >> sysfs ..." will be ro. Maybe i could add a "-o rw" to the mount
> >> but for now i just reverted the two patches that deal with
> >> mounting.
> >>
> >> Might also be a difference in our host systems.
> >>
> >> Henning
> >>  
> >>> Jan
> >>>  
> >>>>
> >>>> Henning
> >>>>
> >>>> Am Tue, 6 Feb 2018 22:55:16 +0300
> >>>> schrieb Alexander Smirnov <asmirnov@ilbers.de>:
> >>>>      
> >>>>> 8<--
> >>>>>
> >>>>> That's it! Branch 'asmirnov/devel', please test and enjoy :-)
> >>>>>
> >>>>> 8<--
> >>>>>
> >>>>> Now each multiconfig has registered handler for BuildCompleted
> >>>>> event (see class 'isar-event.bbclass'). Moreover, the
> >>>>> '/proc/mounts' file contains all the active mounts. In addition,
> >>>>> from event handler we could derive all the variables like
> >>>>> ${TMPDIR}, ${DISTRO} etc. So it's possible to find all the
> >>>>> active mounts for current multiconfig and clean them.
> >>>>>
> >>>>> NOTE: if build is interrupted by double ^C, some mount points
> >>>>> could stay uncleaned. This is caused by remaining processes
> >>>>> started by bitbake, for example:
> >>>>>   - 'chroot build.sh ...'
> >>>>>   - 'multistrap ...'
> >>>>>
> >>>>> So please be careful when interrupting build.
> >>>>>
> >>>>> Signed-off-by: Alexander Smirnov <asmirnov@ilbers.de>
> >>>>> ---
> >>>>>   meta-isar/recipes-core/images/isar-image-base.bb   | 11
> >>>>> ++++------ meta/classes/dpkg-base.bbclass                     |
> >>>>> 12 ++++-------
> >>>>> meta/classes/isar-events.bbclass                   | 15
> >>>>> +++++++++++---
> >>>>> meta/recipes-devtools/buildchroot/buildchroot.bb   | 24
> >>>>> +++++++++------------- .../buildchroot/files/configscript.sh |
> >>>>> 4 ---- .../buildchroot/files/download_dev-random          | 13
> >>>>> ------------ 6 files changed, 30 insertions(+), 49 deletions(-)
> >>>>> delete mode 100644
> >>>>> meta/recipes-devtools/buildchroot/files/download_dev-random
> >>>>>
> >>>>> diff --git a/meta-isar/recipes-core/images/isar-image-base.bb
> >>>>> b/meta-isar/recipes-core/images/isar-image-base.bb index
> >>>>> e359ac3..8ddbabb 100644 ---
> >>>>> a/meta-isar/recipes-core/images/isar-image-base.bb +++
> >>>>> b/meta-isar/recipes-core/images/isar-image-base.bb @@ -55,14
> >>>>> +55,10 @@ do_rootfs() { -e
> >>>>> 's|##ISAR_DISTRO_SUITE##|${DEBDISTRONAME}|g' \
> >>>>> "${WORKDIR}/multistrap.conf.in" > "${WORKDIR}/multistrap.conf"
> >>>>> +    # Do not use bitbake flag [dirs] here because this folder
> >>>>> should have
> >>>>> +    # specific ownership.
> >>>>>       [ ! -d ${IMAGE_ROOTFS}/proc ] && sudo install -d -o 0 -g
> >>>>> 0 -m 555 ${IMAGE_ROOTFS}/proc sudo mount -t proc none
> >>>>> ${IMAGE_ROOTFS}/proc
> >>>>> -    _do_rootfs_cleanup() {
> >>>>> -        ret=$?
> >>>>> -        sudo umount ${IMAGE_ROOTFS}/proc 2>/dev/null || true
> >>>>> -        (exit $ret) || bb_exit_handler
> >>>>> -    }
> >>>>> -    trap '_do_rootfs_cleanup' EXIT
> >>>>>   
> >>>>>       # Create root filesystem. We must use sudo -E here to
> >>>>> preserve the environment # because of proxy settings
> >>>>> @@ -72,5 +68,6 @@ do_rootfs() {
> >>>>>       sudo chroot ${IMAGE_ROOTFS} /${DISTRO_CONFIG_SCRIPT}
> >>>>> ${MACHINE_SERIAL} ${BAUDRATE_TTY} \ ${ROOTFS_DEV}
> >>>>>       sudo rm "${IMAGE_ROOTFS}/${DISTRO_CONFIG_SCRIPT}"
> >>>>> -    _do_rootfs_cleanup
> >>>>> +
> >>>>> +    sudo umount ${IMAGE_ROOTFS}/proc 2>/dev/null || true
> >>>>>   }
> >>>>> diff --git a/meta/classes/dpkg-base.bbclass
> >>>>> b/meta/classes/dpkg-base.bbclass index 5d5a924..a34c21f 100644
> >>>>> --- a/meta/classes/dpkg-base.bbclass
> >>>>> +++ b/meta/classes/dpkg-base.bbclass
> >>>>> @@ -20,15 +20,11 @@ dpkg_runbuild() {
> >>>>>   do_build() {
> >>>>>       mkdir -p ${BUILDROOT}
> >>>>>       sudo mount --bind ${WORKDIR} ${BUILDROOT}
> >>>>> -    _do_build_cleanup() {
> >>>>> -        ret=$?
> >>>>> -        sudo umount ${BUILDROOT} 2>/dev/null || true
> >>>>> -        sudo rmdir ${BUILDROOT} 2>/dev/null || true
> >>>>> -        (exit $ret) || bb_exit_handler
> >>>>> -    }
> >>>>> -    trap '_do_build_cleanup' EXIT
> >>>>> +
> >>>>>       dpkg_runbuild
> >>>>> -    _do_build_cleanup
> >>>>> +
> >>>>> +    sudo umount ${BUILDROOT} 2>/dev/null || true
> >>>>> +    sudo rmdir ${BUILDROOT} 2>/dev/null || true
> >>>>>   }
> >>>>>   
> >>>>>   # Install package to Isar-apt
> >>>>> diff --git a/meta/classes/isar-events.bbclass
> >>>>> b/meta/classes/isar-events.bbclass index 55fc106..ae0f791 100644
> >>>>> --- a/meta/classes/isar-events.bbclass
> >>>>> +++ b/meta/classes/isar-events.bbclass
> >>>>> @@ -11,10 +11,19 @@ python isar_handler () {
> >>>>>       devnull = open(os.devnull, 'w')
> >>>>>   
> >>>>>       if isinstance(e, bb.event.BuildCompleted):
> >>>>> -        bchroot = d.getVar('BUILDCHROOT_DIR', True)
> >>>>> +        tmpdir = d.getVar('TMPDIR', True)
> >>>>> +        distro = d.getVar('DISTRO', True)
> >>>>> +        arch = d.getVar('DISTRO_ARCH', True)
> >>>>>   
> >>>>> -        # Clean up buildchroot
> >>>>> -        subprocess.call('/usr/bin/sudo /bin/umount ' + bchroot
> >>>>> + '/isar-apt || /bin/true', stdout=devnull, stderr=devnull,
> >>>>> shell=True)
> >>>>> +        w = tmpdir + '/work/' + distro + '-' + arch
> >>>>> +
> >>>>> +        # '/proc/mounts' contains all the active mounts, so
> >>>>> knowing 'w' we
> >>>>> +        # could get the list of mounts for the specific
> >>>>> multiconfig and
> >>>>> +        # clean them.
> >>>>> +        with open('/proc/mounts', 'rU') as f:
> >>>>> +            for line in f:
> >>>>> +                if w in line:
> >>>>> +                    subprocess.call('sudo umount -f ' +
> >>>>> line.split()[1], stdout=devnull, stderr=devnull, shell=True)
> >>>>>       devnull.close()
> >>>>>   }
> >>>>> diff --git a/meta/recipes-devtools/buildchroot/buildchroot.bb
> >>>>> b/meta/recipes-devtools/buildchroot/buildchroot.bb index
> >>>>> 304c67e..df9df19 100644 ---
> >>>>> a/meta/recipes-devtools/buildchroot/buildchroot.bb +++
> >>>>> b/meta/recipes-devtools/buildchroot/buildchroot.bb @@ -12,7
> >>>>> +12,6 @@ FILESPATH =.
> >>>>> "${LAYERDIR_core}/recipes-devtools/buildchroot/files:" SRC_URI =
> >>>>> "file://multistrap.conf.in \ file://configscript.sh \
> >>>>> file://setup.sh \
> >>>>> -           file://download_dev-random \
> >>>>>              file://build.sh"
> >>>>>   PV = "1.0"
> >>>>>   
> >>>>> @@ -32,8 +31,10 @@ BUILDCHROOT_PREINSTALL ?= "gcc \
> >>>>>   WORKDIR = "${TMPDIR}/work/${DISTRO}-${DISTRO_ARCH}/${PN}"
> >>>>>   
> >>>>>   do_build[stamp-extra-info] = "${DISTRO}-${DISTRO_ARCH}"
> >>>>> -do_build[dirs] = "${WORKDIR}/hooks_multistrap \
> >>>>> -                  ${BUILDCHROOT_DIR}/isar-apt"
> >>>>> +do_build[dirs] = "${BUILDCHROOT_DIR}/isar-apt \
> >>>>> +                  ${BUILDCHROOT_DIR}/dev \
> >>>>> +                  ${BUILDCHROOT_DIR}/proc \
> >>>>> +                  ${BUILDCHROOT_DIR}/sys"
> >>>>>   do_build[depends] = "isar-apt:do_cache_config"
> >>>>>   
> >>>>>   do_build() {
> >>>>> @@ -41,7 +42,6 @@ do_build() {
> >>>>>   
> >>>>>       chmod +x "${WORKDIR}/setup.sh"
> >>>>>       chmod +x "${WORKDIR}/configscript.sh"
> >>>>> -    install -m 755 "${WORKDIR}/download_dev-random"
> >>>>> "${WORKDIR}/hooks_multistrap/"
> >>>>>       # Multistrap accepts only relative path in configuration
> >>>>> files, so get it: cd ${TOPDIR}
> >>>>> @@ -60,15 +60,6 @@ do_build() {
> >>>>>           -e
> >>>>> 's|##DIR_HOOKS##|./'"$WORKDIR_REL"'/hooks_multistrap|g' \
> >>>>> "${WORKDIR}/multistrap.conf.in" > "${WORKDIR}/multistrap.conf"
> >>>>> -    [ ! -d ${BUILDCHROOT_DIR}/proc ] && install -d -m 555
> >>>>> ${BUILDCHROOT_DIR}/proc
> >>>>> -    sudo mount -t proc none ${BUILDCHROOT_DIR}/proc
> >>>>> -    _do_build_cleanup() {
> >>>>> -        ret=$?
> >>>>> -        sudo umount ${BUILDCHROOT_DIR}/proc 2>/dev/null || true
> >>>>> -        (exit $ret) || bb_exit_handler
> >>>>> -    }
> >>>>> -    trap '_do_build_cleanup' EXIT
> >>>>> -
> >>>>>       do_setup_mounts
> >>>>>   
> >>>>>       # Create root filesystem
> >>>>> @@ -79,7 +70,6 @@ do_build() {
> >>>>>   
> >>>>>       # Configure root filesystem
> >>>>>       sudo chroot ${BUILDCHROOT_DIR} /configscript.sh
> >>>>> -    _do_build_cleanup
> >>>>>   
> >>>>>       do_cleanup_mounts
> >>>>>   }
> >>>>> @@ -96,10 +86,16 @@ do_setup_mounts[stamp-extra-info] =
> >>>>> "${DISTRO}-${DISTRO_ARCH}"
> >>>>>   do_setup_mounts() {
> >>>>>       sudo mount --bind ${DEPLOY_DIR_APT}/${DISTRO}
> >>>>> ${BUILDCHROOT_DIR}/isar-apt
> >>>>> +    sudo mount --bind /dev ${BUILDCHROOT_DIR}/dev
> >>>>> +    sudo mount -t proc none ${BUILDCHROOT_DIR}/proc
> >>>>> +    sudo mount -t sysfs none ${BUILDCHROOT_DIR}/sys
> >>>>>   }
> >>>>>   
> >>>>>   addtask setup_mounts after do_build
> >>>>>   
> >>>>>   do_cleanup_mounts() {
> >>>>>       sudo umount ${BUILDCHROOT_DIR}/isar-apt 2>/dev/null ||
> >>>>> true
> >>>>> +    sudo umount ${BUILDCHROOT_DIR}/dev 2>/dev/null || true
> >>>>> +    sudo umount ${BUILDCHROOT_DIR}/proc 2>/dev/null || true
> >>>>> +    sudo umount ${BUILDCHROOT_DIR}/sys 2>/dev/null || true
> >>>>>   }
> >>>>> diff --git
> >>>>> a/meta/recipes-devtools/buildchroot/files/configscript.sh
> >>>>> b/meta/recipes-devtools/buildchroot/files/configscript.sh index
> >>>>> 9813c9a..524e50c 100644 ---
> >>>>> a/meta/recipes-devtools/buildchroot/files/configscript.sh +++
> >>>>> b/meta/recipes-devtools/buildchroot/files/configscript.sh @@
> >>>>> -39,10 +39,6 @@ export LC_ALL=C LANGUAGE=C LANG=C #run pre
> >>>>> installation script /var/lib/dpkg/info/dash.preinst install
> >>>>> -# apt-get http method, gpg require /dev/null
> >>>>> -mount -t devtmpfs -o mode=0755,nosuid devtmpfs /dev
> >>>>> -
> >>>>>   #configuring packages
> >>>>>   dpkg --configure -a
> >>>>>   apt-get update
> >>>>> -umount /dev
> >>>>> diff --git
> >>>>> a/meta/recipes-devtools/buildchroot/files/download_dev-random
> >>>>> b/meta/recipes-devtools/buildchroot/files/download_dev-random
> >>>>> deleted file mode 100644 index 5b5b96b..0000000 ---
> >>>>> a/meta/recipes-devtools/buildchroot/files/download_dev-random
> >>>>> +++ /dev/null @@ -1,13 +0,0 @@
> >>>>> -#!/bin/sh
> >>>>> -
> >>>>> -set -e
> >>>>> -
> >>>>> -readonly ROOTFS="$1"
> >>>>> -
> >>>>> -mknod "${ROOTFS}/dev/random" c 1 8
> >>>>> -chmod 640 "${ROOTFS}/dev/random"
> >>>>> -chown 0:0 "${ROOTFS}/dev/random"
> >>>>> -
> >>>>> -mknod "${ROOTFS}/dev/urandom" c 1 9
> >>>>> -chmod 640 "${ROOTFS}/dev/urandom"
> >>>>> -chown 0:0 "${ROOTFS}/dev/urandom"  
> >>>>      
> >>>  
> >>  
> >   
>