TIL about launchd.plists

Running a background service on an Apple computer

I created a Django app that runs on my computer. Most of the time, I don’t really think about running it as a background service because it’s not a production application. But I decided recently that I actually wanted it to be a background service on my Apple computer. And even though I’m not sure this is the right way to do it, I’m here to tell you it works!

First, you create a .plist file, let’s call it com.vdavez.app.service.plist.

<?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">
		<string>Dave's Django App Agent</string>

The key things to pay attention to here are the ProgramArguments and the WorkingDirectory tags. Within ProgramArguments are the script you want to run (taking care to have the first string be an absolute path). Then, WorkingDirectory is where you want the script to run.

I’m using poetry to manage the virtual environment, so it’s just calling poetry run gunicorn myapp:app as if I were doing it in the appropriate directory.

Next, save this file in ~/Library/LaunchAgents, and run launchctl load com.vdavez.app.service.plist. Now, it just works!

Hope someone finds this useful background material. 🥁