directory-size.sh

#!/bin/sh
#
# Expose directory usage metrics, passed as an argument.
#
# Usage: add this to crontab:
#
# */5 * * * * prometheus directory-size.sh /var/lib/prometheus | sponge /var/lib/node_exporter/directory_size.prom
#
# sed pattern taken from https://www.robustperception.io/monitoring-directory-sizes-with-the-textfile-collector/
#
# Author: Antoine Beaupré <anarcat@debian.org>
echo "# HELP node_directory_size_bytes Disk space used by some directories"
echo "# TYPE node_directory_size_bytes gauge"
du --block-size=1 --summarize "$@" \
  | sed -ne 's/\\/\\\\/;s/"/\\"/g;s/^\([0-9]\+\)\t\(.*\)$/node_directory_size_bytes{directory="\2"} \1/p'