github.com/ethanhsieh/snapd@v0.0.0-20210615102523-3db9b8e4edc5/packaging/ubuntu-16.04/snapd.postinst

#!/bin/sh

set -e

# "powerpc" is not supported unfortunately, do nothing here# 
if [ "$DPKG_MAINTSCRIPT_ARCH" = powerpc ]; then
    exit 0
fi

case "$1" in
    configure)
        # ensure /var/lib/snapd/lib/gl is cleared
        if dpkg --compare-versions "$2" lt-nl "2.0.7"; then
            ldconfig
        fi

        # Ensure that we undo the damage done by the snap.mount unit that was present
        # in snapd 2.31.
        #
        # We found that update scripts make systemd stop inactive mount units and this
        # in turn stops all the units that depend on it so when the snap.mount unit is
        # stopped all the per-snap mount units gets stopped along with them.  The 2.31
        # release was only out briefly in xenial-proposed and bionic but to keep the
        # affected users safe let's start all the per-snap mount units so that snaps no
        # longer appear as broken after update.
        if dpkg --compare-versions "$2" ge-nl "2.31" && \
                dpkg --compare-versions "$2" lt-nl "2.32"; then
            units=$(systemctl list-unit-files --full | grep '^snap[-.]' | cut -f1 -d ' ' | grep -vF snap.mount.service || true)
            mounts=$(echo "$units" | grep '^snap[-.].*\.mount$' || true)
            for unit in $mounts; do
                # ensure its really a snap mount unit or systemd unit
                if ! grep -q 'What=/var/lib/snapd/snaps/' "/etc/systemd/system/$unit" && ! grep -q 'X-Snappy=yes' "/etc/systemd/system/$unit"; then
                    echo "Skipping non-snapd systemd unit $unit"
                    continue
                fi

                echo "Starting $unit"
                deb-systemd-invoke start "$unit" || true
            done
        fi

        # In commit 0dce4704a5d (2017-03-28, snapd v2.23.6) we renamed
        # /etc/apparmor.d/usr.lib.snap-confine to usr.lib.snap-confine.real
        # to fix LP: #1673247 - however some people (developers?) still have
        # the old usr.lib.snap-confine file. This seems to be loaded instead
        # of the correct usr.lib.snap-confine.real profile. To fix this we
        # use the rather blunt approach to rename the file forcefully.
        if test -f /etc/apparmor.d/usr.lib.snapd.snap-confine && test -f /etc/apparmor.d/usr.lib.snapd.snap-confine.real; then
            mv /etc/apparmor.d/usr.lib.snapd.snap-confine /etc/apparmor.d/usr.lib.snapd.snap-confine.dpkg-bak
        fi

        # Ensure that the void directory has correct permissions.
        chmod 111 /var/lib/snapd/void

        # Ubuntu 20.04 had a incorrect seed directory during development.
        #
        # This was causing hangs in the postinst when systemctl tries to
        # start snapd.seeded.service which will wait for snapd to finish
        # seeding (which will never happen because seeding is broken).
        # See LP: 1868706
        # This snippet detect this incorrect seed and disables it.
        if [ -e /var/lib/snapd/seed/seed.yaml ] && [ "$(snap debug state --is-seeded /var/lib/snapd/state.json)" = "false" ]; then
            if ! snap debug validate-seed /var/lib/snapd/seed/seed.yaml; then
                echo "Found incorrect seed, disabling it"
                mv /var/lib/snapd/seed /var/lib/snapd/seed.disabled
            fi
        fi

        # ensure "snap userd" is restarted
        if dpkg --compare-versions "$2" lt-nl "2.45.2"; then
            pkill -f "snap userd" || true
        fi
esac

#DEBHELPER#