Create A Service to Run Jar File In Background As System Service on AWS EC2

 

Prerequisite:

1. Java should already have
2. Open and connect AWS ec2 instance using terminal
3. Reach out root folder where the domain is pointing out for me it’s /var/www/HTML/
4. Take pull the latest Spring Boot code from git https://bitbucket.org/***
5. MVN clean install – this will convert java code with all its dependencies in a jar file

   (SUDO) java -jar target/YOUR_FILE_NAME.jar (target is a folder on root)

Problem: We found a challenge while running java -jar *.jar on AWS ec2 instance in the background

Solution:  Create a system service to run the Jar file in the background Linux

Ubuntu/Linux has an in-built mechanism to create custom services and enable them to start on system boot time and start/stop them as a service.

Create a bash script to run jar file Linux:

Replace the customservicename with your own service name

1. Create a vi or nano file under /usr/local/bin/ by running the following commandeg: sudo vi /usr/local/bin/customservicename.shThis will open a file with the name customservicename.sh.

2. Paste the following Code in opened sh.
   In the below code replace the customservicename with your own service name,
   JAR_FILE_PATH(Absolute Path to your jar File), and choose a PID_NAME_PATH(just replace CUSTOM_SERVICE_NAME to your customservicename keeping -PID at the end ) for the file you are going to use to store your service ID.

The only changes needed are to the first 3 variables.

#!/bin/sh

CUSTOM_SERVICE_NAME=customservicename

JAR_FILE_PATH=/var/www/html/target/YourJavaApplication.jar

PID_NAME_PATH=/tmp/customservicename-pid

case $1 in

start)

echo "Starting $CUSTOM_SERVICE_NAME ..."

if [ ! -f $PID_NAME_PATH ]; then

nohup java -jar $JAR_FILE_PATH /tmp 2>> /dev/null >>/dev/null & echo $! > $PID_NAME_PATH

echo "$CUSTOM_SERVICE_NAME started ..."

else

echo "$CUSTOM_SERVICE_NAME is already running ..."

fi

;;

stop)

if [ -f $PID_NAME_PATH ]; then

PID=$(cat $PID_NAME_PATH);

echo "$CUSTOM_SERVICE_NAME stopping ..."

kill $PID;

echo "$CUSTOM_SERVICE_NAME stopped ..."

rm $PID_NAME_PATH

else

echo "$CUSTOM_SERVICE_NAME is not running ..."

fi

;;

restart)

if [ -f $PID_NAME_PATH ]; then

PID=$(cat $PID_NAME_PATH);

echo "$CUSTOM_SERVICE_NAME stopping ...";

kill $PID;

echo "$CUSTOM_SERVICE_NAME stopped ...";

rm $PID_NAME_PATH

echo "$CUSTOM_SERVICE_NAME starting ..."

nohup java -jar $JAR_FILE_PATH /tmp 2>> /dev/null >> /dev/null & echo $! > $PID_NAME_PATH

echo "$CUSTOM_SERVICE_NAME started ..."

else

echo "$CUSTOM_SERVICE_NAME is not running ..."

fi

;;

esac

1. 3. Write and quit the above file by pressing the ESC button then:wq! and give execution permissions :eg: sudo chmod +x /usr/local/bin/customservicename.sh

Read Also:- Setting Up Jenkins on Amazon EC2 Ubuntu Instance

Use The Following Commands to Test Whether Java Application Is Working:

/usr/local/bin/./customservicename.sh start

/usr/local/bin/./customservicename.sh stop

/usr/local/bin/./customservicename.sh start

/usr/local/bin/./customservicename.sh restart

 

If all the above commands do not give an error then we move forward to create a service

1. Create a file under /etc/system/system/ with nano or vi and paste the example script below.

        Eg. sudo vi /etc/systemd/system/customservicename.service

2. Insert the following code in customservicename:
   [Unit]

   Description = My Java Service

   After network.target = customservicename.service

   [Service]

   Type = forking

   Restart=always

   RestartSec=1

   SuccessExitStatus=143

   ExecStart = /usr/local/bin/customservicename.sh start

   ExecStop = /usr/local/bin/customservicename.sh stop

   ExecReload = /usr/local/bin/customservicename.sh reload

   [Install]

   WantedBy=multi-user.target

    

3. Write and quit this file by pressing the ESC button then:wq!
   Now Service is all set up.

You can enable/start/stop your Java Application as a Service using the following commands:

sudo systemctl daemon-reload

sudo systemctl enable customservicename

sudo systemctl start customservicename

sudo systemctl stop customservicename

 

This should get Java Application up and running in the background as a System Service.

Original Source:- https://www.devstringx.com/run-jar-file-in-background-on-aws-ec2