groups:

- name: NodeExporter

  rules:

    - alert: HostUnderUtilizedOfMemory
      expr: 'node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes * 100 > 80'
      for: 7d
      labels:
        severity: info
      annotations:
        summary: Host memory is under utilized (instance {{ $labels.instance }})
        description: "Node memory is not fully used (> 80% free) for 1 week. Consider reducing memory space.\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    - alert: HostUnderUtilizedCpuLoad
      expr: '100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[2m])) * 100) < 20'
      for: 7d
      labels:
        severity: info
      annotations:
        summary: Host CPU load is under utilized (instance {{ $labels.instance }})
        description: "CPU load is < 20% for 1 week. Consider reducing the number of CPUs.\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"

    - alert: HostLotsOfFreeDiskSpace
      expr: '(node_filesystem_avail_bytes * 100) / node_filesystem_size_bytes > 80 and ON (instance, device, mountpoint) node_filesystem_readonly == 0'
      for: 7d
      labels:
        severity: info
      annotations:
        summary: Host lots of free disk space (instance {{ $labels.instance }})
        description: "Disk space is not fully used (> 80% free) for 1 week. Consider reducing disk space.\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}"