How to Run Script at Startup Automatically in Linux

Running scripts automatically at startup can streamline tasks like launching applications, managing services, or performing system maintenance. This guide provides step-by-step instructions for setting up startup scripts on Ubuntu, CentOS, and Debian.

Why Run Scripts at Startup on Linux?

Automating scripts to execute during system startup can:

• Run background processes automatically without manual intervention.
• Automate system maintenance tasks like backups, updates, and monitoring.
• Ensure critical services start on boot to maintain uptime and reliability.

Different Linux distributions provide various ways to execute startup scripts. Below, we cover the most effective methods for Ubuntu, CentOS, and Debian.

Run a Script at Startup on Ubuntu Using systemd

Ubuntu uses systemd, a modern service manager that provides a reliable way to run scripts at startup. This method is preferred because it offers fine-grained control over startup processes, ensuring your script runs after the necessary system services are available. In this guide, we’ll walk through creating a startup script, configuring it as a systemd service, and enabling it to run automatically when Ubuntu boots. Let’s begin…

Step 1: Create the Startup Script

First, save your script in a safe directory and make it executable.

# Navigate to the desired script directory
cd /usr/local/bin/

# Create the script file
sudo nano my_startup_script.sh

Add the following content inside the script file:

#!/bin/bash
echo "Script is running on startup" >> /var/log/startup_script.log

Make the script executable:

sudo chmod +x /usr/local/bin/my_startup_script.sh

Step 2: Create a systemd Service File

Systemd services need a configuration file in /etc/systemd/system/.

# Open a new service file
sudo nano /etc/systemd/system/my_startup_service.service

Add the following configuration:

[Unit]
Description=My Custom Startup Script  # Description of the service
After=network.target  # Ensures network is available before running the script

[Service]
ExecStart=/usr/local/bin/my_startup_script.sh  # Path to the script
Type=simple  # Runs the script as a simple process
RemainAfterExit=yes  # Keeps the service active even after script execution

[Install]
WantedBy=multi-user.target  # Ensures it starts in multi-user mode

Step 3: Enable and Start the systemd Service

Reload systemd so it recognizes the new service:

sudo systemctl daemon-reload

Enable the service to start on boot:

sudo systemctl enable my_startup_service.service

Start the service immediately:

sudo systemctl start my_startup_service.service

Check the status to confirm the service is running:

sudo systemctl status my_startup_service.service

Now, your script runs automatically every time Ubuntu boots. 🚀

Run a Script at Boot on CentOS Using Cron @reboot

Step 1: Create the Script

First, create the script in a safe directory:

# Navigate to the script directory
cd /usr/local/bin/

# Create the script file
sudo nano my_startup_script.sh

Add the script content:

#!/bin/bash
echo "CentOS startup script executed" >> /var/log/startup_script.log

Make the script executable:

sudo chmod +x /usr/local/bin/my_startup_script.sh

Step 2: Add the Script to Cron Jobs

Edit the cron table for the current user:

crontab -e

Add this line at the end:

@reboot /usr/local/bin/my_startup_script.sh

Save and exit.

To verify if the job is scheduled, run:

crontab -l

Now, your script executes automatically on CentOS startup. 🎯

Run a Script at Startup on Debian Using rc.local

Debian-based systems traditionally use the rc.local file to execute scripts at boot. While this method is considered legacy, it remains a quick and effective way to automate startup tasks. In this section, we’ll guide you through creating a startup script, adding it to rc.local, and ensuring it runs automatically when Debian starts.

Step 1: Create Your Script

Create the script file:

sudo nano /usr/local/bin/my_startup_script.sh

Add this content:

#!/bin/bash
echo "Debian startup script executed" >> /var/log/startup_script.log

Make it executable:

sudo chmod +x /usr/local/bin/my_startup_script.sh

Step 2: Edit the rc.local File

Open the rc.local file:

sudo nano /etc/rc.local

Add the script execution command before exit 0:

/usr/local/bin/my_startup_script.sh
exit 0  # Ensures the script runs before the system exits the boot process

Save and exit.

Step 3: Ensure rc.local is Executable

Set executable permissions:

sudo chmod +x /etc/rc.local

All done, now you can automate scripts at start-up on Debian Linux.

Tips for Running Linux Startup Scripts Successfully

• Test Before Rebooting: Execute your script manually to confirm it works as intended.
• Use Logging: Redirect output to a log file for troubleshooting: /usr/local/bin/my_startup_script.sh >> /var/log/my_script.log 2>&1
• Check Permissions: Ensure your script has the necessary permissions and ownership, especially when accessing sensitive files or directories.

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