task.yaml

summary: check that the core and kernel snaps roll back correctly after a failed upgrade

systems: [ubuntu-core-16-*]

details: |
    This test ensures that the system can survive to a failed upgrade of a fundamental
    snap, rolling back to the last good known version.

    The logic common to all the scenarios unpacks the target snap, injects the failure,
    repacks and installs it. Then it checks that all is set for installed the snap with
    the failure and executes a reboot. The test checks that after the reboot (in fact two
    reboots, one for trying the upgrade and another for rolling back) the installed
    fundamental snap is the good one and the boot environment variables are correctly set.

environment:
    INJECT_FAILURE/rclocalcrash: inject_rclocalcrash_failure
    INJECT_FAILURE/emptysystemd: inject_emptysystemd_failure
    # FIXME: disabled until we find what to do!
    # fails with:  ERROR cannot replace signed kernel snap with an unasserted one
    #INJECT_FAILURE/emptyinitrd: inject_emptyinitrd_failure
    TARGET_SNAP/rclocalcrash: core
    TARGET_SNAP/emptysystemd: core
    #TARGET_SNAP/emptyinitrd: kernel
    BUILD_DIR: /home/tmp

prepare: |
    mkdir -p $BUILD_DIR

restore: |
    rm -f failing.snap failBoot currentBoot prevBoot
    rm -rf $BUILD_DIR

    # FIXME: remove the unset when we reset properly snap_try_{core,kernel} on rollback
    . $TESTSLIB/boot.sh
    bootenv_unset snap_try_core
    bootenv_unset snap_try_kernel

debug: |
    . $TESTSLIB/boot.sh
    bootenv
    snap list
    snap changes

execute: |
    inject_rclocalcrash_failure(){
        chmod a+x $BUILD_DIR/unpack/etc/rc.local
        cat <<EOF > $BUILD_DIR/unpack/etc/rc.local
    #!bin/sh
    printf c > /proc/sysrq-trigger
    EOF
    }

    inject_emptysystemd_failure(){
        truncate -s 0 $BUILD_DIR/unpack/lib/systemd/systemd
    }

    inject_emptyinitrd_failure(){
        truncate -s 0 $BUILD_DIR/unpack/initrd.img
    }

    . $TESTSLIB/names.sh
    . $TESTSLIB/boot.sh
    if [ "$TARGET_SNAP" = kernel ]; then
        TARGET_SNAP_NAME=$kernel_name
    else
        TARGET_SNAP_NAME=core
    fi

    if [ "$SPREAD_REBOOT" = 0 ]; then
        # first pass, save current target snap revision
        snap list | awk "/^${TARGET_SNAP_NAME} / {print(\$3)}" > prevBoot

        # unpack current target snap
        unsquashfs -d $BUILD_DIR/unpack /var/lib/snapd/snaps/${TARGET_SNAP_NAME}_$(cat prevBoot).snap

        # set failure condition
        eval ${INJECT_FAILURE}

        # repack new target snap
        snap pack $BUILD_DIR/unpack && mv ${TARGET_SNAP_NAME}_*.snap failing.snap

        # install new target snap
        chg_id=$(snap install --dangerous failing.snap --no-wait)

        while ! snap change ${chg_id}|grep -q "^Done.*Make snap.*available to the system" ; do sleep 1 ; done

        # check boot env vars
        snap list | awk "/^${TARGET_SNAP_NAME} / {print(\$3)}" > failBoot
        test "$(bootenv snap_${TARGET_SNAP})" = "${TARGET_SNAP_NAME}_$(cat prevBoot).snap"
        test "$(bootenv snap_try_${TARGET_SNAP})" = "${TARGET_SNAP_NAME}_$(cat failBoot).snap"

        REBOOT
    fi

    # after rollback, we have the original target snap for a while
    # wait until the kernel and core snap revisions are in place
    while true ; do
        current=$(snap list | awk "/^${TARGET_SNAP_NAME} / {print(\$3)}")
        if [ "$current" = "$(cat prevBoot)" ] ; then
            break
        fi
        sleep 1
    done

    # and the boot env vars are correctly set
    echo "Waiting for snapd to clean snap_mode"
    while [ "$(bootenv snap_mode)" != "" ]; do
        sleep 1
    done

    test "$(bootenv snap_${TARGET_SNAP})" = "${TARGET_SNAP_NAME}_$(cat prevBoot).snap"
    # FIXME: reenable the last check when we reset properly snap_try_{core,kernel} on rollback
    # test "$(bootenv snap_try_${TARGET_SNAP})" = ""