Jeff Martin nodeselector

🔄 Hackathon '26: Automating Fleet Reboots with Temporal

Our management hosts have never been systematically rebooted. Some have been up for months — running vulnerable kernel versions the entire time. A security exception gave us about a year to fix it, and the interim plan was a manual weekly reboot process (#7655) — open a spreadsheet, pick some hosts, SSH in, cross your fingers, reboot, wait, check if they come back, file an issue if they don't. Repeat. For hundreds of hosts. Every week.

We wanted to kill that toil. So for the hackathon, we built it.

The Demo

Imagine a grid of colored squares — each one a management host. Green means healthy, orange means it's been up too long and needs a reboot. You click "start" on a Temporal schedule, and watch.

Simulator limitations

Simulator performance does not correlate to device performance in a meaningful way. If you want to test performance of an app as it behaves on your users' devices, you must test on a real device. When I say simulator performance in the rest of this document, I mean the performance of the simulator itself, not the performance of the app running in the simulator.

Hello World

open -a Simulator --args -CurrentDeviceUDID 5FCE6A79-78EF-497A-8329-99D9755C8559

Code Signing

Terms

Bundle ID

https://developer.apple.com/documentation/bundleresources/information_property_list/cfbundleidentifier

A string used to uniquely identify an app.
By convention, it's a reverse-DNS style string.
Must be globally unique.

	#!/bin/bash

	# A cleaner alternative to this approach, but which requires a restart, is to populate TCC's SiteOverrides.plist inside
	# the TCC app support directory with the following:
	# <?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>Services</key>
	# <dict>