Apparently the ATO requires an hourly timesheet to prove you were working from home at any given time.
Anyway I thought I'd automate it: ping my work laptop from my home server and if it's online then I'm working from home. Easy!
Caveats
- Macbooks respond to pings even when they're asleep. Disable this in System Preferences > Energy Saver > Power Adapter > Wake for Wi-Fi network access. This will shut down the network interface ~1 minute after the Mac sleeps.
- I'm running this on my Docker host because it's simple enough, however I can't resolve local names from inside