Loki alerts (#218)

Co-authored-by: Samuel Berthe <dev@samuel-berthe.fr>

README.md

@@ -72,6 +72,8 @@ Collection available here: **[https://awesome-prometheus-alerts.grep.to](https:/
 #### Other
 
 - [Thanos](https://awesome-prometheus-alerts.grep.to/rules#thanos)
+- [Loki](https://awesome-prometheus-alerts.grep.to/rules#loki)
+- [Cortex](https://awesome-prometheus-alerts.grep.to/rules#cortex)
 
 ## 🤝 Contributing
 

_data/rules.yml

@@ -2001,3 +2001,29 @@ groups:
                 description: Thanos compaction has not run in 24 hours.
                 query: '(time() - thanos_objstore_bucket_last_successful_upload_time) > 24*60*60'
                 severity: critical
+      - name: Loki
+        exporters:
+          - rules:
+              - name: Loki process too many restarts
+                description: A loki process had too many restarts (target {{ $labels.instance }})
+                query: changes(process_start_time_seconds{job=~"loki"}[15m]) > 2
+                severity: warning
+      - name: Cortex
+        exporters:
+          - rules:
+              - name: Cortex ruler configuration reload failure
+                description: Cortex ruler configuration reload failure (instance {{ $labels.instance }})
+                query: cortex_ruler_config_last_reload_successful != 1
+                severity: warning
+              - name: Cortex not connected to Alertmanager
+                description: Cortex not connected to Alertmanager (instance {{ $labels.instance }})
+                query: cortex_prometheus_notifications_alertmanagers_discovered < 1
+                severity: critical
+              - name: Cortex notification are being dropped
+                description: Cortex notification are being dropped due to errors (instance {{ $labels.instance }})
+                query: rate(cortex_prometheus_notifications_dropped_total[5m]) > 0
+                severity: critical
+              - name: Cortex notification error
+                description: Cortex is failing when sengin alert notifications (instance {{ $labels.instance }})
+                query: rate(cortex_prometheus_notifications_errors_total[5m]) > 0
+                severity: critical