eos-config-journal

#!/bin/bash -e
# Copyright (C) 2018 Endless Technologies, Inc.
# Licensed under the GPLv2

parentdir=/var/log
# if this dir exists, the journal will be persistently stored to it
JOURNALDIR=$parentdir/journal
blockerfile=$parentdir/.no_journal_on_fragile_storage
cmdname=${0##*/}

# get the device which will hold the journal
device=$(df --output=source $parentdir | tail -n 1)

# will contain non-empty string if this device is an MMC or SD device (both of
# which are susceptible to damage with excessive writing)
subsystem=$(lsblk --noheading -o SUBSYSTEMS --inverse "$device" | grep '^block:mmc' \
    || true)

if [ "x$subsystem" != "x" ]; then
    echo "$cmdname: not enabling persistent journal: non-durable storage" \
        "(MMC or SD)"
    touch $blockerfile
    exit 0
fi

if [ -e $blockerfile ]; then
    echo "$cmdname: not enabling persistent journal: $blockerfile exists"
    exit 0
fi

if [ ! -d $JOURNALDIR ]; then
    echo "$cmdname: enabling persistent journal on durable storage"
    mkdir $JOURNALDIR
    systemd-tmpfiles --create --prefix $JOURNALDIR
fi