prometheus: Add monitoring and alert for orphan and foreign packages

Closes: #332

Signed-off-by: Leonidas Spyropoulos <artafinde@gmail.com>

roles/prometheus/files/node.rules.yml

@@ -221,6 +221,24 @@ groups:
         annotations:
           description: 'host {{ $labels.instance }} has vulnerable date packages'
           summary: '{{ $labels.instance }} has {{ $value }} vulnerable packages'
+      - alert: pacman_orphans
+        expr: pacman_orphans > 0
+        for: 15m
+        labels:
+          severity: warning
+          service: pacman
+        annotations:
+          description: 'host {{ $labels.instance }} has orphan packages'
+          summary: '{{ $labels.instance }} has {{ $value }} orphan packages'
+      - alert: pacman_foreigns
+        expr: pacman_foreigns > 0
+        for: 15m
+        labels:
+          severity: warning
+          service: pacman
+        annotations:
+          description: 'host {{ $labels.instance }} has foreigns packages'
+          summary: '{{ $labels.instance }} has {{ $value }} foreigns packages'
 
   - name: btrfs
     interval: 2m

roles/prometheus_exporters/files/arch-textcollector.sh

@@ -18,6 +18,8 @@ trap "rm -f $TMP_FILE" EXIT
 
 updates=$(/usr/bin/checkupdates | wc -l)
 secupdates=$(/usr/bin/arch-audit -u | wc -l)
+orphans=$(/usr/bin/pacman -Qdtq | wc -l)
+foreigns=$(/usr/bin/pacman -Qmq | wc -l)
 
 echo "# HELP pacman_updates_pending number of pending updates from pacman" >> $TMP_FILE
 echo "# TYPE pacman_updates_pending gauge" >> $TMP_FILE
@@ -27,4 +29,12 @@ echo "# HELP pacman_security_updates_pending number of pending updates from pacm
 echo "# TYPE pacman_security_updates_pending gauge" >> $TMP_FILE
 echo "pacman_security_updates_pending $secupdates" >> $TMP_FILE
 
+echo "# HELP pacman_orphans number of orphan packages from pacman" >> $TMP_FILE
+echo "# TYPE pacman_orphans gauge" >> $TMP_FILE
+echo "pacman_orphans $orphans" >> $TMP_FILE
+
+echo "# HELP pacman_foreigns number of foreign packages from pacman" >> $TMP_FILE
+echo "# TYPE pacman_foreigns gauge" >> $TMP_FILE
+echo "pacman_foreigns $foreigns" >> $TMP_FILE
+
 mv -f $TMP_FILE $PROM_FILE