Linux - How to create systemd systemdaemon background linux

Systemd is the init system used by many modern Linux distributions to manage system processes and services. Creating a systemd service allows you to run background tasks, manage system daemons, and ensure that your services start automatically at boot. In this guide, we’ll walk through the steps to create a systemd service, specifically using an example of a Metabase daemon. Follow these steps to set up your own systemd service:

Step 1: Locate User-Defined Services

Systemd services are typically stored in specific directories based on their scope. For user-defined services, you’ll usually work within /etc/systemd/system/ on Ubuntu. This directory is where you should place your custom service files.

cd /etc/systemd/system/

Step 2: Create Your Service File

Using your preferred text editor, create a new service file. You can name this file anything you like, but it must end with .service. For example, let’s name it metabase.service.

sudo nano whatever_you_want.service

Step 3: Define Your Service Configuration

Add the following template to your service file. This configuration is designed for a hypothetical Metabase daemon, but you can customize it for any service you need.

[Unit]
Description=Metabase Daemon

[Service]
PIDFile=/var/tmp/metabase.pid
WorkingDirectory=/usr/local/bin/metabase/
User=ubuntu
Group=ubuntu

# Run command here
ExecStart=/usr/bin/java -jar -Xmx512m /usr/local/bin/metabase/metabase.jar

Restart=on-failure
RestartSec=30
PrivateTmp=true

StandardOutput=metabase
StandardError=metabase_err
SyslogIdentifier=metabase

[Install]
WantedBy=multi-user.target

Explanation:

Step 4: Manage Your Service

Once you’ve created and saved your service file, you need to reload systemd to recognize your new service and then manage it using systemctl.

Start the Service:

sudo systemctl start whatever_you_want.service

Enable Auto-Start at Boot:

sudo systemctl enable whatever_you_want.service

Disable Auto-Start:

sudo systemctl disable whatever_you_want.service

Stop the Service:

sudo systemctl stop whatever_you_want.service

Restart the Service:

sudo systemctl restart whatever_you_want.service

View Service Logs:

journalctl -e -u whatever_you_want.service

This command shows the most recent log entries for your service, which is useful for troubleshooting and monitoring.

Conclusion

Creating and managing a systemd service on Linux is a powerful way to handle background tasks and system daemons. By following these steps, you can easily set up your services to run automatically at boot and manage them with simple commands. Whether you’re running a web application, a background process, or any other service, systemd provides the tools you need to keep things running smoothly and efficiently.