Systemd is a software application that provides an array of system components for Linux operating systems. It is the first service to initialize the boot sequence. This always runs with pid 1. This also helps use to manage system and application service on our Linux operating system.
We can also run any custom script as systemd service. It helps the script to start on system boot. This can be helpful for you to run any script which required to run at boot time only or to run always.
In our previous tutorial we have provides you instructions to run a Python script using Systemd. This tutorial coverts to run a shell script as Systemd service.
Step 1 – Create a Shell Script
First of all, create a sample shell script to run always until the system is running. We will use bash while loop to run infinitely.
sudo nano /usr/bin/script.sh
Add the following sample script.
1 2 3 4 5 6 7 | #!/bin/bash while true do // Your statements goes here sleep 10 done |
Save script and set execute permission.
sudo chmod +x /usr/bin/script.sh
To run a script once during system boot time doesn’t required any infinite loop. Instead of the above script, you can use your shell script to run as Systemd service.
Step 2 – Create A SystemD File
Next, create a service file for the systemd on your system. This file must have .service extension and saved under the under /lib/systemd/system/ directory
sudo nano /lib/systemd/system/shellscript.service
Now, add the following content and update the script filename and location. You can also change the description of the service.
[Unit] Description=My Shell Script [Service] ExecStart=/usr/bin/script.sh [Install] WantedBy=multi-user.target
Save the file and close it.
Step 3 – Enable New Service
Your system service has been added to your service. Let’s reload the systemctl daemon to read new file. You need to reload this deamon each time after making any changes in in .service file.
sudo systemctl daemon-reload
Now enable the service to start on system boot, also start the service using the following commands.
sudo systemctl enable shellscript.servicesudo systemctl start shellscript.service
Finally verify the script is up and running as a systemd service.
sudo systemctl status shellscript.service
Output looks like below:
Conclusion
This tutorial helped you to configure a shell script as systemd service.
5 Comments
This is useful material but you should place locally added services in /etc/systemd/system/
Other paths will work but the /usr/lib (or /lib) on is for the distribution package manager
https://www.freedesktop.org/software/systemd/man/systemd.unit.html#Unit%20File%20Load%20Path
A minor detail but it’s always good to be as correct as possible when teaching other people.
Thanks you for this great tutorial
Thanks for the steps.. it really helped
can we write a shell script which automatically copies the information to the service file (shellscript.service ) automatically when we run the .sh file instead of us entering it manually ?
of course you can. but this isn’t a bash tutorial