check_zookeeper

#!/bin/bash
#
# Author: Bart Janssens
# Email:  bjanssens@inuits.eu
# Date:   Wed Jun 10 2016
#
# Requires the nmap-ncat and bc packages to work
#
showhelp () {
cat <<eof

  Check to monitor the zookeeper instance. Checks if it is reachable,
  if it's reporting 'imok' and if the amount of connections isn't above the given values.

 Parameters:
   --host|-h            : The host to try and connect to, defaults to localhost.
   --port|-p            : The port to try and connect to, default to 2181.
   --warning|-w         : The warning threashold, defaults to 250.
   --critical|-c        : The critical threashold, defaults to 300.

 Example usage:
 ./check_zookeeper --host localhost --port 2181 --warning 250 --critical 300

eof
  exit 3
}

params () {
  if [ -z $host ]; then host='localhost'; fi
  if [ -z $port ]; then port='2181'; fi
  if [ -z $connections_warning ]; then connections_warning='250'; fi
  if [ -z $connections_critical ]; then connections_critical='300'; fi
}

check_reachable () {
  echo 'ruok' | nc $host $port 1>/dev/null && nc_status=$?
  if [ ! $nc_status -eq '0' ]
  then
    message="Unknown: Unable to complete nc command"
    exitstatus=3
    quit
  fi
}

check_alive () {
  status=$( echo ruok | nc $host $port )
  if [ ! $status == 'imok' ]
  then
    message="Critical: Zookeeper reporting status: $status"
    exitstatus=2
    quit
  fi
}

get_srvr () {
  srvr=$( echo srvr | nc $host $port )
}

check_connections () {
  current_connections=$( echo "$srvr" | grep -i connections | cut -d ' ' -f 2 )
  if [ ! -z $current_connections ]
  then
    if (( ${current_connections} < ${connections_critical} ))
    then
      if (( ${current_connections} < ${connections_warning} ))
      then
        message="Ok: Amount of connections is currently: $current_connections"
        exitstatus=0
        quit
      else
        message="Warning: Amount of connections is currently: $current_connections"
        exitstatus=1
        quit
      fi
    else
      message="Critical: Amount of connections is currently: $current_connections"
      exitstatus=2
      quit
    fi
  else
    message="Warning: Zookeeper reporting status: $status, but failed to get the connections"
    exitstatus=1
    quit
  fi
}

quit () {
  echo "$message" && exit $exitstatus
}

# start the case-ing
while test -n "$1"
do
  case "$1" in
    --help|-h)
      showhelp
      ;;
    --port|-p)
      shift
      port=$1
      shift
      ;;
    --host|-h)
      shift
      host=$1
      shift
      ;;
    --warning|-w)
      shift
      connections_warning=$1
      shift
      ;;
    --critical|-c)
      shift
      connections_critical=$1
      shift
      ;;
    *)
      showhelp
      ;;
  esac
done

params
check_reachable
check_alive
get_srvr
check_connections