This script will run Robo 3T (robomongo) with MongoDB and then it will close MongoDB if you close robo 3t

MongoWithRobo3t.sh

#!/bin/zsh

#mongodb data directory - change this to your desired location - and check for write permissions
DIRECTORY=~/.local/share/mongodb

#create directories if not exist
mkdir -p "$DIRECTORY/data"
mkdir -p "$DIRECTORY/log"

#create empty log file if not exist
if [ ! -e "$DIRECTORY/log/mongodb.log" ] ; then
    touch "$DIRECTORY/log/mongodb.log"
fi 

#run mongo db if not running - then I close it when you close robo3t
DidIRunMongodb=false
if [[ ! $(pgrep mongo) ]] ; then
    DidIRunMongodb=true
    mongod --dbpath "$DIRECTORY/data" --logpath "$DIRECTORY/log/mongodb.log" &
fi 

#run robo3t 
/opt/Robo3T/bin/robo3t

#kill mongodb if is running by this script
if [[ $(pgrep mongo) ]] ; then
    if [ "$DidIRunMongodb" = true ] ; then
        kill -9 $(<"$DIRECTORY/data/mongod.lock")
    fi
fi 

#mongo & robo3t are now closed - bye :)
exit

this script is ready for execution .
don't forget to apply modification to meet your needs.
this method is great if you use MongoDB & Robo 3t on your development environment.
you can also use this script as a desktop file in your linux desktop.
I hope this helps someone else!