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

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

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
> > split it up so we can discuss the issues with dev and sys while
> > already merging the rest.  
> 
> 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 ...

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"  
> >   
>