This cookbook installs a Chef handler for blinking the LEDs on Raspberry Pi and other similar systems that expose control of their LEDs in Linux via
leds0 may be any number of LEDs). At the beginning of the Chef client run the LEDs blink a heartbeat pattern, at the end the LEDs are disabled. If the Chef client run fails the lights all stay on.
It's quite simple, but this is an exercise in writing and installing handlers through a cookbook.