inotifywait-based change generator for use with apps/files scan api

oc-watch.sh

#!/bin/bash

# inotify-based file watcher, to be used in combination with a patched files app
# command which supports the scanSingle/scanBatch api
#
# run as any user; make sure user can modify the PID file

TIMEOUT=60

OC_ROOT=/var/www/owncloud
OC_ADMIN_USER="admin"
OC_ADMIN_PASS="zooperzeekret"
OC_ROOT_PATH="https://www.example.org/owncloud"
PID=/var/run/oc-watch.pid

echo $$ > $PID

LOGDIR=$(mktemp -qd /tmp/oc-watch.XXXXXX)


LOG=$LOGDIR/log
QUEUE=$LOGDIR/queue
ACT=$LOGDIR/act
mkfifo $LOGDIR/fifo

> $LOG
> $QUEUE
> $ACT

# mounts and mountpoints (see mount.json in OC data root)
# every mount has a mountpoint for every user. Only one user
# needs to be given for each storage_id, which does not matter.

mounts=(/export/books)
mountpoints=(/frank/files/Library)

delay=$TIMEOUT

check_sanity () {
        if [ ${#mounts[*]} -ne ${#mountpoints[*]} ]; then
                echo please specify exactly one mountpoint per mount!
                echo "  ${#mounts[*]} mounts: ${mounts[*]}"
                echo "  ${#mountpoints[*]} mountpoints: ${mountpoints[*]}"
                exit
        fi
}

make_sed_script () {
        for j in $(seq 0 $((${#mounts[*]}-1)));do
                echo -n "s@^${mounts[$j]}@${mountpoints[$j]}@;"
        done
}

on_exit () {
        [ -n "$COPROC_PID" ] && kill $COPROC_PID
        rm $LOG
        rm $QUEUE
        rm $ACT
        rm $LOGDIR/fifo
        rmdir $LOGDIR
        rm $PID
}

oc_scan () {
        curl -s -d @${ACT} -u ${OC_ADMIN_USER}:"${OC_ADMIN_PASS}" -H "Content-Type:application/json" ${OC_ROOT_PATH}/index.php/apps/files/api/v1/scan
}

trap on_exit EXIT

check_sanity

sed_script=$(make_sed_script)

coproc inotifywait -sqmr -e CREATE,DELETE,MOVE --format '%w%f' ${mounts[*]} >> $LOG

# occ needs to be executed from the OC_ROOT directory
cd $OC_ROOT

# sleep for (TIMEOUT - runtime previous scan (0 if result is negative)),
# pause inotifywait, copy contents of log to queue, empty log,
# unpause inotifywait. Sort/uniq queue, translate mounts
# to mountpoints, wrap results in json and feed them to OC
# through curl

while :;do
        sleep $delay
        kill -STOP $COPROC_PID
        cp $LOG $QUEUE
        > $LOG
        kill -CONT $COPROC_PID

        start_time=$(date +%s)

        declare -a paths

        sort $QUEUE|uniq > $LOGDIR/fifo &

        while IFS= read -r f; do
                IFS= paths+=($(echo "$f"|sed -e "$sed_script"))
        done < $LOGDIR/fifo

        if [ ${#paths[*]} -gt 0 ]; then
                printf -v expanded_paths "%s\n" "${paths[@]}"
                jq -n --arg ARR "$expanded_paths" '{ path_list: $ARR | rtrimstr("\n") | split("\n")  }' > $ACT
                oc_scan $ACT 2>&1 > /dev/null
        fi

        stop_time=$(date +%s)
        run_time=$(($stop_time-$start_time))
        if [ "$run_time" -ge "$TIMEOUT" ]; then
                delay=0
        else
                delay=$(($TIMEOUT-$run_time))
        fi

        unset paths

        > $QUEUE
        > $ACT
done

Edited script to make it space-in-filename-proof... (added IFS= before 'paths+=($(echo "$f"|sed -e "$sed_script"))')

That's a great solution for reliable syncing of files which are modified outside the scope of ownCloud, e.g. via a Samba share. That you very much! I've found it useful to include modified files to the watch criteria, line 74:
coproc inotifywait -sqmr -e CREATE,DELETE,MOVE,MODIFY --format '%w%f' ${mounts[*]} >> $LOG