add prometheus exporter rom borg_exporter.sh

borg_exporter.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+ENVFIILE=/etc/prometheus/node_exporter/borg_exporter.env
+[[ -f "$ENVFIILE" ]] && source "$ENVFIILE"
+
+REPO_BASE=${REPO_BASE:-/home/backup/borg}
+TEXTFILE_COLLECTOR_DIR=${TEXTFILE_COLLECTOR_DIR:-/var/lib/node_exporter/}
+
+PROM_FILE=$TEXTFILE_COLLECTOR_DIR/backup.prom
+TMP_FILE=$PROM_FILE.$$
+
+mapfile -t REPOS < <(find $REPO_BASE -type d -name data -print0 | xargs --null -n1 dirname)
+
+for repository in "${REPOS[@]}" ; do
+  echo "# $repository"
+  hostname=${HOSTNAMES[$repository]:-$repository}
+  if [[ "$hostname" == "$repository" ]] ; then
+    hostname=${hostname/"${REPO_BASE}/"//}
+    hostname=${hostname/"/backup"//}
+  fi
+  index_base="$repository/index"
+  age_seconds="$(( $(date +%s) - $(date +%s -r "$index_base".*) ))"
+  size="$(du -s "$repository" | cut -d/  -f1)"
+  echo backup_age_time_seconds\{host=\""$hostname"\", repository=\""$repository"\"\} "$age_seconds"
+  echo backup_size_bytes\{host=\""$hostname"\", repository=\""$repository"\"\} "$size"
+done >> $TMP_FILE
+
+mv $TMP_FILE $PROM_FILE