LaunchdAutostart

Starting up a Daemon/Agent on OSX boot/login

This simple recipe, will give some clues on how to have your favorite app/daemon/software automatically started with your OSX session or boot.

OSX uses Launchd to manage daemons. You can define new jobs that can:

• run as a user only for a given user
• run as a user a system wide available daemon/app
• run as root a system wide daemon/app

This current recipe works for a daemon that will be owned by the user logged in, and made available to all users.

Property List

The job is described as a property list. A very simple one that calls a Python script would be:

<?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>Label</key>
	<string>xx.mydomain.mydaemon</string>
	<key>ProgramArguments</key>
	<array>
		<string>/path/to/my.py</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
</dict>
</plist>

Pay attention to the following parameters:

• <string>xx.mydomain.mydaemon</string>: unique name of your job
• <string>/path/to/my.py</string>: points to your daemon/software (make it available system wide, ie /Applications or /usr/bin)
• <key>RunAtLoad</key>: autostart when users login

install your job

• Copy the above in a file called xx.mydomain.mydaemon.plist and save it under /Library/LaunchAgents
• Reboot
• If my.py is a daemon (or simply running in loop) it should be visible in the process list and owned by your user. You can check that with the following command:

ps aux | grep my.py

Troubeshooting

You can always manually start/stop/control your job using the command-line launchd application, just open a terminal and type launchctl, then help.

References

• http://developer.apple.com/macosx/launchd.html
• http://en.wikipedia.org/wiki/Launchd