Node Exporter Reboot Watcher

Little daemon watching for presence or absence of a sentinel file, updating a Node Exporter Textfile Collector compatible file accordingly.

Useful to export a reboot_required metric on debian-ish systems via Node Exporter's Textfile Collector, exposing the presence (or absence) of the /var/run/reboot-required file.

Usage

Configure Node Exporter to monitor a folder for files with additional metrics to expose (e.g node_exporter --collector.textfile.directory /var/lib/node_exporter). Let reboot_watcher run alongside to watch for the sentinel file.

Make sure the user you run the daemon with has write permissions for the promfile, and read permission for the sentinel file location.

Example

The generated file will look something like this

node_reboot_required 1

CLI options

Option	Description	Default
-sentinel	path of file to watch	/var/run/reboot-required
-promfile	path of file to update	/var/lib/node_exporter/reboot.prom
-metric	name of the metric to use	node_reboot_required
-help	show help