# =============================================================================
# Prometheus Alerting Rules for Longhorn
# =============================================================================
# =============================================================================
# Prometheus Alerting Rules for Longhorn
# Excludes prometheus-data PVC since it's designed to run at ~95% capacity
# =============================================================================
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-rules
  namespace: mon-system
  labels:
    app: prometheus
data:
  longhorn-alerts.yml: |
    groups:
      - name: longhorn-volume-alerts
        rules:
          # Critical: Volume at 95% capacity (excluding prometheus-data)
          - alert: LonghornVolumeSpaceCritical
            expr: |
              (
                (avg by (volume) (longhorn_volume_actual_size_bytes{volume!="pvc-81912547-5a18-4410-ac27-9c15251483a8"}))
                / 
                (avg by (volume) (longhorn_volume_capacity_bytes{volume!="pvc-81912547-5a18-4410-ac27-9c15251483a8"}))
              ) * 100 > 95
            for: 5m
            labels:
              severity: critical
            annotations:
              summary: "Longhorn volume {{ $labels.volume }} is critically full"
              description: "Volume {{ $labels.volume }} is at {{ printf \"%.1f\" $value }}% capacity. Immediate action required."
          # Warning: Volume at 85% capacity (excluding prometheus-data)  
          - alert: LonghornVolumeSpaceWarning
            expr: |
              (
                (avg by (volume) (longhorn_volume_actual_size_bytes{volume!="pvc-81912547-5a18-4410-ac27-9c15251483a8"}))
                / 
                (avg by (volume) (longhorn_volume_capacity_bytes{volume!="pvc-81912547-5a18-4410-ac27-9c15251483a8"}))
              ) * 100 > 85
            for: 10m
            labels:
              severity: warning
            annotations:
              summary: "Longhorn volume {{ $labels.volume }} is running low on space"
              description: "Volume {{ $labels.volume }} is at {{ printf \"%.1f\" $value }}% capacity. Consider expanding or cleaning up."
          # Volume degraded
          - alert: LonghornVolumeDegraded
            expr: longhorn_volume_robustness != 1
            for: 5m
            labels:
              severity: warning
            annotations:
              summary: "Longhorn volume {{ $labels.volume }} is degraded"
              description: "Volume {{ $labels.volume }} robustness is not healthy. Check replica status."

          # Node storage pressure
          - alert: LonghornNodeStoragePressure
            expr: |
              (
                longhorn_node_storage_usage_bytes 
                / 
                longhorn_node_storage_capacity_bytes
              ) * 100 > 90
            for: 10m
            labels:
              severity: warning
            annotations:
              summary: "Longhorn node {{ $labels.node }} storage pressure"
              description: "Node {{ $labels.node }} disk usage is at {{ printf \"%.1f\" $value }}%."