Collects checkins from scripts (e.g. backups), and provides status endpoints returning OKAY if checkin happened within the last N hours, which you can monitor via updown.io or similar.
Install: go install github.com/andreyvit/watchdogd@latest
Run: watchdogd -f /var/lib/watchdogd.json -t SECRET -l :8080
Checkin: curl -X POST -H 'Authentication: Bearer SECRET' http://127.0.0.1:8080/backups-24h
Set up monitoring to match OKAY on this URL: http://127.0.0.1:8080/backups-24h
Note that keys must end with -99h, -99m or -99s suffixes, where 99 is the number of hours, minutes or seconds to consider the checkin fresh.
View all keys: http://127.0.0.1:8080/