launchd testbench

gistfile1.sh

#!/bin/bash

# Findings:
#
#   StartOnMount=true will cause the job to start when anything is
#   mounted even if other conditions, e.g. QueueDirectories, say the
#   job should not run
#
#   The StartInterval timer begins ticking at the moment the plist is
#   loaded.  If QueueDirectories is preventing the job from running,
#   but the queue becomes available, the job will only be started 
#   at the next StartInterval boundary.
#
#   If something else causes the job to run (e.g. StartOnMount) and
#   the StartInterval timer expires while the job is running, it
#   will start again immediately.

set -e

TOP=/tmp/scratch
JOB=mac.test
# TEMP_PLIST=$TOP/$JOB.plist
PLIST=$TOP/$JOB.plist #/Library/LaunchDaemons/$JOB.plist
LOG=$TOP/test.log
IMG=$TOP/news.sparseimage
MNT=$TOP/news
QUEUE=$TOP/news/leaf.node

function msg() {
    date "+%H:%M:%S \"$@\""
}    

function msgn() {
    msg "$@" | tr '\n' ' '
}    

function load() {
    msgn 'loading plist...'
    sudo launchctl load $PLIST
    echo 'Done.'
}

function unload() {
    msgn 'unloading plist...'
    sudo launchctl unload $PLIST
    echo 'Done.'
}

function mount() {
    msgn 'mounting image...'
    mkdir -p $MNT
    sudo chown -R _news $MNT
    sudo hdiutil attach -quiet -nobrowse -notremovable -noautofsck -owners on -mountpoint $MNT $IMG
    echo 'Done.'
}

function unmount() {
    msgn 'unmounting image...'
    sudo umount $MNT > /dev/null 2>&1
    echo 'Done.'
}

#
# Clean up anything left over from a previous run
#
( ( unload ; unmount ; sudo rm -rf $TOP ) || True ) > /dev/null 2>&1

# create the log file
mkdir -p $TOP
touch $LOG
sudo chown _news $LOG


# prepare a sparse image
msgn 'preparing images...'
hdiutil create -quiet -fs HFS+ -size 1M -type SPARSE -volname news $IMG
mount > /dev/null
sudo chown -R _news $MNT/
sudo -u _news mkdir $QUEUE
sudo -u _news touch $QUEUE/foo
unmount > /dev/null


echo 'Done.'

cat > $PLIST<<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
        <dict>
                <key>UserName</key>          <string>_news</string>
                <key>Label</key>             <string>$JOB</string>
                <key>StartInterval</key>  <integer>18</integer>

                <key>ProgramArguments</key>
                <array>
                        <string>/bin/bash</string>
                        <string>-c</string>
<string>
date +&quot;%H:%M:%S ------------------------&quot;
for i in &#123;1..12&#125; ; do 
  date +&quot;%H:%M:%S%t&lt;\$i&gt;&quot;
  sleep 1
done
date +&quot;%H:%M:%S ==========================&quot;
</string>
                </array>

                <key>QueueDirectories</key>
                <array>
                        <string>$QUEUE</string>
                </array>

                <key>StandardOutPath</key>  <string>$LOG</string>
                <key>StandardErrorPath</key> <string>$LOG</string>
        </dict>
</plist>
EOF

sudo chown root $PLIST

msg "Starting log monitor"
tail -f "$LOG"&
MONITOR=$!

load
msg "...pause to prove launchd isn't starting us up without queue mounted..."
sleep 5
msg '** mounting with plist loaded'
mount
sleep 50
unload
unmount

msg "...pause..."
sleep 5


msg '** loading with queue mounted'
mount
load
sleep 5
unload
unmount


echo 


msg "Stopping log monitor"
kill $MONITOR