minimum linux daemon sample

gistfile1.txt

crontab -e: 
@reboot /bin/bash /project/folder/cronjob_starter.sh

with cronjob_starter.sh containing

#!/bin/bash

if [[  $(screen -ls | grep rabbitmq_daemon) ]]
        then
                echo "rabbitmq_daemon already running!"
                /bin/true
        else
                # echo " rabbitmq_daemon not running!"
                screen -S rabbitmq_daemon -dm
                # workaround for https://savannah.gnu.org/bugs/index.php?54164
                sleep 1
                screen -S rabbitmq_daemon -X stuff "cd /project/folder; bin/console rabbitmq:consumer messaging^M"
fi