#!/usr/bin/env bash

stat=/proc/mdstat

if [ ! -e "$stat" ]; then
  echo "WARNING: $stat does not exist"
  exit 1
fi

if [ ! -r "$stat" ]; then
  echo "WARNING: cannot read $stat"
  exit 1
fi

count=$(grep ^md -c "$stat")

if [ "$count" -eq 0 ]; then
  echo 'WARNING: no arrays found.'
  exit 1
elif [ "$count" -eq 1 ]; then
  out="Linux Software RAID: $count array"
else
  out="Linux Software RAID: $count arrays"
fi

degrated=$(grep -c '\[.*_.*\]' "$stat")
recovering=$(awk '/recovery/ {print $4}' "$stat")
resyncing=$(awk '/resync/ {print $4}' "$stat")

if [ -n "$recovering" ]; then
  out="$out, recovering: $recovering"
elif [ -n "$resyncing" ]; then
  out="$out, resyncing: $resyncing"
elif [ "$degrated" -gt 0 ]; then
  out="$out, degrated: $degrated"
fi

if [ "$degrated" -gt 0 ]; then
  echo "CRITICAL: $out."
  exit 2
fi

if [ -n "$recovering$resyncing" ]; then
  echo "WARNING: $out."
  exit 1
fi

echo "OK: $out."
exit 0