groups:
  - name: base-alerts
    rules:
      - alert: InstanceDown
        expr: up == 0
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: "{{ $labels.instance }} down"
          description: "{{ $labels.job }} on {{ $labels.instance }} is not responding"

      - alert: HighCPU
        expr: (1 - avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m]))) > 0.90
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "High CPU on {{ $labels.instance }}"
          description: "CPU usage > 90% for 10m"

      - alert: HighMemory
        expr: (1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) > 0.90
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "High memory on {{ $labels.instance }}"
          description: "Memory usage > 90% for 10m"

      - alert: DiskFull
        expr: (node_filesystem_avail_bytes{fstype!~"tmpfs|overlay"} / node_filesystem_size_bytes{fstype!~"tmpfs|overlay"}) < 0.10
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "Disk low on {{ $labels.instance }}"
          description: "<10% free on {{ $labels.mountpoint }}"

      - alert: DiskUsageHigh
        expr: (1 - (node_filesystem_avail_bytes{mountpoint="/",fstype!~"tmpfs|overlay"} / node_filesystem_size_bytes{mountpoint="/",fstype!~"tmpfs|overlay"})) > 0.85
        for: 15m
        labels:
          severity: warning
        annotations:
          summary: "Disk usage >85% on {{ $labels.instance }}"
          description: "Root filesystem usage above 85%"

      - alert: MemAvailableLow
        expr: (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes) < 0.08
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "Low available memory on {{ $labels.instance }}"
          description: "MemAvailable < 8%"