#!/bin/bash 

rm -f /var/lib/prometheus/node-exporter/certs.prom

for f in /etc/certs/*; do
	snapshot_timestamp=$(openssl x509 -noout -enddate -in $f/cert.pem | cut -d= -f2)
	snapshot_secs=$(date --date "$snapshot_timestamp" +%s)
	now=$(date +%s)
	delta=$((snapshot_secs - now))
	name=$(echo $f | cut -d/ -f4)
	printf 'certificate_validity{label="%s"} %s\n' $name $delta >> /var/lib/prometheus/node-exporter/certs.prom
done