#!/usr/bin/env bash

hostname=`hostname`
emaildomain=''
alertemail=''
mailgunapikey=''

# max capacity % before getting capacity alert
maxCapacity=80

# age of scrub (in seconds) before getting scrub alert
scrubExpire=1209600

function email {
  curl -s --user "api:${mailgunapikey}" \
    https://api.mailgun.net/v3/${emaildomain}/messages \
    -F from="zfs alerts <no-reply@${emaildomain}>" \
    -F to=${alertemail} \
    -F subject="$1" \
    -F text="$2"
  printf "\n"
}

currentDate=$(date +%s)
zfsVolumes=$(/sbin/zpool list -H -o name)
capacity=$(/sbin/zpool list -H -o capacity)
errors=$(/sbin/zpool status | grep ONLINE | grep -v state | awk '{print $3 $4 $5}' | grep -v 000)

for volume in ${zfsVolumes}
do
  condition=$(/sbin/zpool status ${volume} | egrep -i '(DEGRADED|FAULTED|OFFLINE|UNAVAIL|REMOVED|FAIL|DESTROYED|corrupt|cannot|unrecover)')
  if [ "${condition}" ]; then
    email "zfs alerts ${hostname} check condition of ${volume}" "${condition}"
  fi
done

capacityExceeded=false
for line in ${capacity//%/}
do
  if [ $line -ge $maxCapacity ]; then
    capacityExceeded=true
  fi
done

if [ "$capacityExceeded" = true ] ; then
  email "zfs alerts ${hostname} capacity exceeded" "${capacity}"
fi

if [ "${errors}" ]; then
  email "zfs alerts ${hostname} drive errors" "${errors}"
fi

for volume in ${zfsVolumes}
do
  if [ $(/sbin/zpool status $volume | egrep -c "none requested") -ge 1 ]; then
    echo "ERROR: You need to run \"zpool scrub $volume\" before this script can monitor the scrub expiration time."
    break
  fi
  if [ $(/sbin/zpool status $volume | egrep -c "scrub in progress|resilver") -ge 1 ]; then
    break
  fi

  ### FreeBSD with *nix supported date format
  #scrubRawDate=$(/sbin/zpool status $volume | grep scrub | awk '{print $15 $12 $13}')
  #scrubDate=$(date -j -f '%Y%b%e-%H%M%S' $scrubRawDate'-000000' +%s)

  ### Ubuntu with GNU supported date format
  scrubRawDate=$(/sbin/zpool status $volume | grep scrub | awk '{print $13" "$14" " $15" " $16" "$17}')
  scrubDate=$(date -d "$scrubRawDate" +%s)

  if [ $(($currentDate - $scrubDate)) -ge $scrubExpire ]; then
    email "zfs alerts ${hostname} volume needs scrub" "${volume} needs scrub"
  fi
done