Create a systemd daemon

Like it or hate it, you’ll find systemd on any modern linux system these days. This management subsystem is the newer replacement for the older init scripts-based systems.

In today’s article, I’m going to show you how to create a daemon that will sit under the management of systemd.

.service file

A service file instructs systemd how to interact with the deployed application. It’s referred to as the service unit configuration. The following is an example:

[Unit]
Description=My Service
After=network.target

[Service]
ExecStart=/usr/bin/my-service
Restart=on-failure

[Install]
WantedBy=multi-user.target

Installation

This file, once you’ve created it gets deployed to systemd with a cp. You also need to notify systemd.

sudo cp my-service.service /lib/systemd/system

sudo systemctl daemon-reload
sudo systemctl enable my-service

Interacting with the service

Once the service is in place, you can start to interact with the daemon using systemctl.

sudo systemctl start my-service
sudo systemctl status my-service

You can also get a hold of any log pushed out to the standard system file descriptors:

journalctl --unit my-service --follow

Removal

Once you no longer need your service, you can remove it simply my rm‘ing the .service file. Of course, you’ll need to disable your service first.

That’s it for creating a systemd service.