post_install() {
    check_hostid
    run_depmod
}

post_remove() {
    run_depmod
}

post_upgrade() {
    check_hostid
    run_depmod
}

check_hostid() {
    # Check /etc/hostid to see if it set to the sentinel value, see
    # https://wiki.archlinux.org/index.php/ZFS for more information.
    HOSTID=$(hostid)
    if [ "0x${HOSTID}" == "0xffffffff" ]; then
        # Generate a new hostid
        : >/etc/hostid
        HOSTID=$(hostid)
        # hostid is 4 byte little endian
        printf $(echo -n $HOSTID | sed 's/\(..\)\(..\)\(..\)\(..\)/\x\4\x\3\x\2\x\1/') >/etc/hostid
    fi
}

run_depmod() {
    echo ">>> Updating SPL module dependencies"
    depmod -a 4.6.3-1-ARCH
}