alert.rules

ALERT service_down
  IF up == 0
  ANNOTATIONS {
    summary = "Instance {{ $labels.instance }} is down",
  }

ALERT cpu_threshold_exceeded
  IF (100 * (1 - avg by(instance)(irate(node_cpu{job='node',mode='idle'}[5m])))) > THRESHOLD_CPU
  ANNOTATIONS {
    summary = "Instance {{ $labels.instance }} CPU usage is dangerously high",
    description = "This device's cpu usage has exceeded the threshold with a value of {{ $value }}.",
  }

ALERT mem_threshold_exceeded
  IF (node_memory_MemFree{job='node'} + node_memory_Cached{job='node'} + node_memory_Buffers{job='node'})/1000000 < THRESHOLD_MEM
  ANNOTATIONS {
    summary = "Instance {{ $labels.instance }} memory usage is dangerously high",
    description = "This device's memory usage has exceeded the threshold with a value of {{ $value }}.",
  }

ALERT filesystem_threshold_exceeded
  IF node_filesystem_avail{job='node',mountpoint='/'} / node_filesystem_size{job='node'} * 100 < THRESHOLD_FS
  ANNOTATIONS {
    summary = "Instance {{ $labels.instance }} filesystem usage is dangerously high",
    description = "This device's filesystem usage has exceeded the threshold with a value of {{ $value }}.",
  }