How to run your Java / Spring Boot App / Jar / WAR as Systemd Service on Linux

This article walks you through the process of deploying Java JAR or WARpackage file on linux operating system as systemd service. Please note that we will discuss the generic method of JAR / WAR deployment regardless of the underlaying framework or programming language available on JVM stack, so this guide is applicable to deployment of artifacts produced with frameworks like Spring, Spring Boot, Grails and Dropwizard and languages including Java , Scalaand Kotlin.

What is Systemd?

Systemd is a system and service manager for Linux operating systems

In Linux operating systems, Systemd is used to manage system and services. Systemd uses configuration files known as systemd unit files to create a linux daemon. Some of common systemd unit types include.

• Service Unit : A unit file (with .service file extension) used to create system service.
• Automount Unit : A unit file (with .automount file extension) used to create auto-mount point.
• Timer Unit : A unit file (with .timer file extension) used to create systemd timer.
• Socket Unit : A unit file (with .socket file extension) used to create a socket.

Java Spring Boot App as Systemd Service

With some high level overview of systemd, let’s start our journey of deploying a Java Spring Boot app as systemd service. We will start by creating  deployment directory structure.

Deployment directory structure

We will put our binaries (JAR / WAR) in /usr/local/bin directory.

sudo cp myapp.jar /usr/local/bin 

We will place our configuration files under /etc/ directory, let’s create configuration directory for our app.

sudo mkdir /etc/myapp

Environment file for systemd service

We can set environment variables for systemd service unit using Environmentconfiguration option. To avoid lengthy list of environment variables within service unit file, we can store all the environment variables in a separate environment filethat can be pointed using EnvironmentFile directive in service unit file. The key advantage of using environment file is dynamic injection of configuration without having to run daemon-reload command. Let’s create the environment file for our service with the service configuration directory /etc/myapp.

sudo nano /etc/myapp/environmentfile

Copy following contents into newly created environment file.

ROOT_DIR=/usr/local/bin
EXEC_JAR="myapp.jar"
JAVA_OPTS="-Xmx128m"
WEB_SERVER_PORT="8088"
USER="myapp"

Creating the system group and user for systemd service

In this section we will create system user to run our systemd service.

1. Create myapp system group. sudo groupadd --system myapp
2. Create myapp system user with nologin shell and add it to myapp system group created in previous step. sudo useradd -s /sbin/nologin --system -g myapp myapp Creating the systemd service unit file for Java / Spring Boot App

In this section we will create the systemd service unit file for our Java Spring Boot App.

1. Create the myapp.service file as following. sudo nano /etc/systemd/system/myapp.service
2. Copy following contents to newly created myapp.servicefile, save file (Ctrl + O) and exit the nano editor (Ctrl + X). [Unit] Description=My Java Spring Boot App Documentation=https://www.sma.im After=network.target [Service] EnvironmentFile=/etc/myapp/environmentfile Type=simple User=myapp WorkingDirectory=/usr/local/bin ExecStart=/usr/bin/java $JAVA_OPTS -jar $EXEC_JAR StandardOutput=journal StandardError=journal SyslogIdentifier=myapp SuccessExitStatus=143 TimeoutStopSec=10 Restart=on-failure RestartSec=60 [Install] WantedBy=multi-user.target

Load service and configure it to start on boot

Run the systemctl daemon-reload command to reload systemd manager configuration, this is soft reload otherwise we will need to restart the system to get our newly cerated systemd service recognized by systemd. sudo systemctl daemon-reload

We can use systemctl enable command to enable our service for auto start on system boot.

```
sudo systemctl enable myapp.service
```

Staring and Stopping our Systemd service

We can start myapp service using service command as following.

sudo service myapp start

Run following command to stop myapp service.

sudo service myapp stop

Check current status of myapp service

We can check current status of myapp service using status option of servicecommand.

sudo service myapp status

Viewing logs of our Java Spring Boot App

StandardOutput=journal and StandardError=journaloptions in our service unit file will enable us to view logs emitted by our program myapp using journalctl command as following.

journalctl -u myapp.service 

That’s it, hope you enjoyed it. You like this article, have any questions or suggestions please let us know in the comments section.

Thanks and Happy Learning!