Create a Systemd service in Linux

Most of us are familier with applications in Windows like Word, Notepad etc. To use a Word application, it is not enough to install it. After the installation, we open (start) a Word application, use it and then later close it. Similarly, in Linux, we can treat similar applications like services. We can do several operations like start, status, restart and stop etc.

Let us create a simple service.

a) Create a script (bash)

Open terminal and create a script named hello.sh

vim hello.sh

Now, let’s create a bash file which prints some text. ( under /home/user/test )

#!/bin/bash
while :
do
    echo "test service.. mike testing"
    sleep 10
done

Give executable permission to this file

chmod +x /home/user/test/hello.sh

b) Create a service file

Under /etc/systemd/system/ , create a service file

vim hello.service

We have 3 sections when creating a service file

 1) Unit 2) Service 3) Install. For now, we shall just go with the mandatory one.

[Service]
ExecStart=/home/pi/test/hello.sh

c) Do operations on that service: start, status, stop

To start the service

sudo systemctl start hello

To check status

sudo systemctl status hello

To stop service

sudo systemctl stop hello

Add more stuff to the service file

[Unit]
Description=My first service to test

[Service]
ExecStart=/home/pi/test/printname.sh
Restart=always
WorkingDirectory=/home/pi/test
User=pi
Group=pi

[Install]
WantedBy=multi-user.target

Here, we are providing following:

Giving a discription to our service file

Specifying our working directory

Specifying user and group name etc.