execute Python file on Systemstart

Question

I want to run a simple python script like:

import webbrowser
webbrowser.open('http://google.com/', new=2)

when the startup progress of my RPI 4 is finished. I tried something like "[How to run a script after bootup on RPi 4/Raspbian 10 (buster)"

I don't know why but it won't work for me if I change the ExecStart line into

ExecStart=python /home/pi/Desktop/startupBrowser.py 

Did I miss anything?

Answer 1

As you wrote in a comment you only want to start the web browser. Wrap it into a python script isn't needed. That's only an additional layer of execution and waste of resources. Just start the browser direct. Because we need a graphical environment try this service:

rpi ~$ sudo systemctl --force --full edit run-browser.service

In the empty editor insert these statements, save them and quit the editor:

[Unit]
Description=Run web browser
After=graphical.target

[Service]
User=pi
WorkingDirectory=/home/pi
Environment=DISPLAY=:0
ExecStart=/usr/bin/chromium-browser http://google.com

[Install]
WantedBy=graphical.target

Enable the new service and reboot:

rpi ~$ sudo systemctl enable run-browser.service
rpi ~$ sudo systemctl reboot

If you want to run a python script then first you should use python3 instead of python. The latter uses deprecated python2 and has no support since 2020-01-01 anymore. Then make sure that the script is running on the commandline with user pi. If it works then you can change ExecStart to something like:

ExecStart=/usr/bin/python3 /home/pi/my-script.py

Answer 2

You are not allowed to use commands in systemd services.:

The command to execute must be an absolute path name. Source: systemd.service

---

You should add the exact path of the command. You can find that by this command:

which python

You would get the output as it:

/usr/bin/python

Finally, use the output of which command to your systemd service.

---

It should be something like this:

ExecStart=/usr/bin/python /home/pi/Desktop/startupBrowser.py

---

How to simply create a systemd service?

Create a file:

nano /etc/systemd/system/startupbrowser.service  

Put all lines below there:

[Unit]
Description=startupbrowser service

[Service]
ExecStart=/usr/bin/python /home/pi/Desktop/startupBrowser.py
StandardOutput=syslog
StandardError=syslog
Restart=on-failure

User=root
Group=root
SyslogIdentifier=startupbrowser

[Install]
WantedBy=multi-user.target  

Save the file and reload the daemon:

sudo systemctl daemon-reload

Test that is your code is running:

sudo service startupbrowser start

Check the log by:

journalctl -f -u startupbrowser.service

It will give you the real-time log of your python code to troubleshoot what's going on.

If everything was good as you intended, run this command to enable is as a startup service:

sudo systemctl enable startupbrowser.service