Add alert rules to prometheus for minio.

kubernetes/apps/monitoring/kube-prometheus-stack/app/kustomization.yaml

@@ -7,3 +7,4 @@ resources:
   - ./externalsecret.yaml
   - ./helmrelease.yaml
   - ./scrapeconfigs
+  - ./prometheusrules

kubernetes/apps/monitoring/kube-prometheus-stack/app/prometheusrules/kustomization.yaml

@@ -0,0 +1,7 @@
+---
+# yaml-language-server: $schema=https://json.schemastore.org/kustomization
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: monitoring
+resources:
+  - ./minio.yaml

kubernetes/apps/monitoring/kube-prometheus-stack/app/prometheusrules/minio.yaml

@@ -0,0 +1,31 @@
+---
+# yaml-language-server: $schema=https://kubernetes-schemas.devbu.io/monitoring.coreos.com/prometheusrule_v1.json
+apiVersion: monitoring.coreos.com/v1
+kind: PrometheusRule
+metadata:
+  name: miscellaneous-rules
+  namespace: monitoring
+  labels:
+    prometheus: k8s
+    role: alert-rules
+spec:
+  groups:
+    - name: minio-alerts
+      rules:
+        - alert: NodesOffline
+          expr: avg_over_time(minio_cluster_nodes_offline_total{job="minio-job"}[5m]) > 0
+          for: 10m
+          labels:
+            severity: warn
+          annotations:
+            summary: "Node down in MinIO deployment"
+            description: "Node(s) in cluster {{ $labels.instance }} offline for more than 5 minutes"
+
+        - alert: DisksOffline
+          expr: avg_over_time(minio_cluster_disk_offline_total{job="minio-job"}[5m]) > 0
+          for: 10m
+          labels:
+            severity: warn
+          annotations:
+            summary: "Disks down in MinIO deployment"
+            description: "Disks(s) in cluster {{ $labels.instance }} offline for more than 5 minutes"