I would like to control the on-board PWR/ACT LEDs on the Raspberry Pi 4 from inside my app container.
Running the container as privileged and writing to
/sys/class/leds/led[0,1]/trigger works, but the Balena supervisor also sometimes sets the state of the ACT LED as per troubleshooting, for example when internet connectivity is lost.
As per this thread and this related documentation it is possible to manually edit
/etc/resin-supervisor/supervisor.conf and set
LED_FILE=/dev/null which stops the supervisor interfering with my own control of the ACT LED. However I have only edited that file manually via
balena ssh for testing and it feels like I am changing an internal file in an unsupported way.
What is the ‘correct’ or more maintainable way to make this change across my fleet?