diskimage-builder/diskimage_builder/elements/rpm-distro/cleanup.d/99-selinux-fixfiles-restore
Olivier Bourdon 7566819139 Fix CentOS image build failure when dib runs on system where audit disabled
Without this fix, building a CentOS image on Ubuntu where audit=0 is passed
as a kernel boot parameter will lead to the following error:
disk-image-create centos7 dhcp-all-interfaces cloud-init-nocloud \
    devuser yum epel baremetal
... dib-run-parts Running tmpdir/hooks/cleanup.d/99-selinux-fixfiles-restore
... Error connecting to audit system.

Change-Id: I229d9b72f88bffddca42da57f01c27e902427071
2018-09-04 08:23:02 +02:00

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#!/bin/bash
if [ ${DIB_DEBUG_TRACE:-1} -gt 0 ]; then
set -x
fi
set -eu
set -o pipefail
# parser isn't smart enough to figure out \
# dib-lint: disable=safe_sudo
# Here be dragons ... a previous dragon slayer helpfully pointed out in
# http://www.spinics.net/lists/selinux/msg17379.html
#
# Not all of the contexts defined by the offline system's
# file_contexts may be valid under the policy of the host on which
# you are running (e.g. if they run different distributions or even
# different releases of the same distribution), which will normally
# prevent setting those contexts (the kernel won't recognize them).
# If you have this issue, you'll need to run setfiles as root in a
# special domain, setfiles_mac_t, that is allowed to set contexts
# unknown to the host policy, and likely chrooted so that it doesn't
# ask the kernel whether the contexts are valid via
# /sys/fs/selinux/context. That is how livecd-creator supported
# creating images for other releases.
# One issue you might see without fixing selinux file labels is sshd
# will run in the kernel_t domain instead of the sshd_t domain, making
# ssh connections fail with "Unable to get valid context for <user>"
# error message. Other failures will occur too.
# XXX: is it really valid to build rpm-distros without this?
if [[ ! -f ${TARGET_ROOT}/etc/selinux/targeted/contexts/files/file_contexts ]]; then
echo "No selinux policy found in chroot, skipping..."
exit 0
fi
if [[ ! -x ${TARGET_ROOT}/usr/sbin/setfiles ]]; then
echo "Can not find setfiles in chroot!"
exit 1
fi
# If we're on a selinux system, enable permissive mode for
# setfiles_mac_t so we can relabel within the chroot without concern
# for whatever policy is in the host kernel. We will run under
# "runcon" to specifically allow this
_runcon=""
if [[ -d /sys/fs/selinux ]]; then
sudo semanage permissive -a setfiles_mac_t
_runcon="runcon -t setfiles_mac_t -- "
fi
# setfiles in > Fedora 26 added this flag:
# do not read /proc/mounts to obtain a list of
# non-seclabel mounts to be excluded from relabeling
# checks. Setting this option is useful where there is
# a non-seclabel fs mounted with a seclabel fs
# this describes our situation of being on a loopback device on
# an ubuntu system, say. See also
# https://bugzilla.redhat.com/show_bug.cgi?id=1472709
_dash_m=""
if [[ $DISTRO_NAME == "fedora" && $DIB_RELEASE -ge 26 ]]; then
_dash_m+="-m"
fi
IFS='|' read -ra SPLIT_MOUNTS <<< "$DIB_MOUNTPOINTS"
for MOUNTPOINT in "${SPLIT_MOUNTS[@]}"; do
if [ "${MOUNTPOINT}" != "/tmp/in_target.d" ] && [ "${MOUNTPOINT}" != "/dev" ] && [ "${MOUNTPOINT}" != "/boot/efi" ]; then
if ! pgrep kauditd >/dev/null; then
echo "*** kauditd not found, suggesting auditing support is disabled in the host kernel. setfiles will fail without this, please enable and rebuild"
exit 1
fi
sudo ${_runcon} chroot ${TARGET_ROOT} \
/usr/sbin/setfiles -F ${_dash_m} \
/etc/selinux/targeted/contexts/files/file_contexts ${MOUNTPOINT}
fi
done