Issue with External monitor returning value

I am attempting to write an external monitor to determine which of our three databases is the "master." We need to first ssh to the server and then run a command. This command should return either a 'true' or 'fals'

#!/bin/sh

# Name of the pidfile

pidfile="/var/run/$MONITOR_NAME.$1..$2.pid"

# Send signal to the process group to kill our former self and any children 

# as external monitors are run with SIGHUP blocked

if [ -f $pidfile ]

then

  kill -9 -`cat $pidfile` > /dev/null 2>&1

fi

echo "$$" > $pidfile

# Remove the IPv6/IPv4 compatibility prefix 

node_ip=`echo $1 | sed 's/::ffff://'`

/bin/expect<<EOF

  log_file -noappend /var/tmp/mongo_status.log

  spawn /bin/ssh svc_f5_mongo@10.xx.yy.zz

  sleep 1;

  expect "password:"

  send "***********"

  expect "svc_f5"

  send "/bin/mongo -u ******** -p ******** --authenticationDatabase admin --eval 'printjson(db.isMaster())'|grep 'ismaster' | cut -c15-18\r"

  sleep 4

  send "exit\r"

EOF

status=$?

echo "$status"

if [ $status -eq 0 ]

then

# Remove the pidfile before the script echoes anything to stdout and is killed by bigd    

  rm -f $pidfile

  echo "up"

fi

# Remove the pidfile before the script ends

rm -f $pidfile

I have been unable to determine the the value from expect.

Any suggestions would be most appreciated.

Thank you