How to run script on startup on Ubuntu 22.04 Jammy Jellyfish Server/Desktop

The purpose of this article is to configure a script such as a Bash script or Python script to run upon system startup in Ubuntu 22.04 Jammy Jellyfish Server/Desktop.

In this tutorial you will learn:

  • How to create Systemd service unit
  • How to create a simple disk space check script
  • How to set permissions to Systemd service unit file
  • How to set script permissions
  • How to enable Systemd service unit to run at the system startup
How to run script on startup on Ubuntu 22.04 Jammy Jellyfish Server/Desktop
How to run script on startup on Ubuntu 22.04 Jammy Jellyfish Server/Desktop
Software Requirements and Linux Command Line Conventions
Category Requirements, Conventions or Software Version Used
System Ubuntu 22.04 Jammy Jellyfish
Software N/A
Other Privileged access to your Linux system as root or via the sudo command.
Conventions # – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command
$ – requires given linux commands to be executed as a regular non-privileged user

How to run script on startup on Ubuntu 22.04 step by step instructions



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The Ubuntu 22.04 is based on Systemd hence the simplest and recommended way to run a script on startup is to create a Systemd service file and execute any script such as bash, python etc, via this service during the system boot.

The below steps will show you to run an example bash script which reports disk space usage of the /home directory and saves the report in the /root directory every time the Ubuntu 22.04 system boots.

  1. First, create a Systemd service file as in an example below. We will store this file as /etc/systemd/system/disk-space-check.service.
    [Unit]
    After=network.target
    
    [Service]
    ExecStart=/usr/local/bin/disk-space-check.sh
    
    [Install]
    WantedBy=default.target

    After: Instructs systemd on when the script should be run. In our case the script will run after network connection. Other example could be mysql.target etc.
    ExecStart: This field provides a full path to the actual script to be executed on startup
    WantedBy: Into what boot target the systemd unit should be installed

    NOTE
    For more information on how to create Systemd service unit execute the man systemd.unit command.
  2. Create a script to be executed on Ubuntu system startup. As specified in the above Step 1, the path and the name of the new script in our example will be /usr/local/bin/disk-space-check.sh.

    The below is an example of such script:

    #!/bin/bash
    
    date > /root/disk_space_report.txt
    du -sh /home/ >> /root/disk_space_report.txt
  3. Set appropriate permissions for both, the Systemd service unit and script:
    $ sudo chmod 744 /usr/local/bin/disk-space-check.sh
    $ sudo chmod 664 /etc/systemd/system/disk-space-check.service
    
  4. Next, enable the service unit:
    $ sudo systemctl daemon-reload
    $ sudo systemctl enable disk-space-check.service
    
  5. Now you are ready to reboot your system. Once the system boots you should see the following file containing disk space usage within your /root directory:
    $ sudo ls /root/
    disk_space_report.txt
    

Closing Thoughts




In this tutorial, we saw how to configure Ubuntu 22.04 to run a script upon each system startup. This is a handy feature for system administrators to implement in order to make sure a Bash or Python script is executed every time Ubuntu loads in from a system reboot.