From b293ae32304cfb8503a153d5f5a58497311d0896 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Sat, 31 Dec 2022 15:41:07 +0000
Subject: [PATCH] Alert if the number of SNMP PDUs returned decreases

---
 .../prometheus/templates/default/alert_rules.yml.erb     | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/cookbooks/prometheus/templates/default/alert_rules.yml.erb b/cookbooks/prometheus/templates/default/alert_rules.yml.erb
index 6c8078e45..24a7a725f 100644
--- a/cookbooks/prometheus/templates/default/alert_rules.yml.erb
+++ b/cookbooks/prometheus/templates/default/alert_rules.yml.erb
@@ -570,6 +570,15 @@ groups:
           alertgroup: "{{ $labels.instance }}"
         annotations:
           percentage_used: "{{ $value | humanizePercentage }}"
+  - name: snmp
+    rules:
+      - alert: snmp pdus missing
+        expr: max_over_time(snmp_scrape_pdus_returned[1d]) - snmp_scrape_pdus_returned > 0
+        for: 15m
+        labels:
+          alertgroup: snmp
+        annotations:
+          missing_pdus: "{{ $value }}"
   - name: ssl
     rules:
       - alert: ssl certificate probe failed
-- 
2.39.5