How to Run a Script as a Service in Raspberry Pi - Raspbian Jessie

By: Diego Acuña

Original Article: http://www.diegoacuna.me/how-to-run-a-script-as-a-service-in-raspberry-pi-raspbian-jessie/

A pretty common task when using this device, is to run some script (for example a python script) as a service in the operating system so it can start on boot, stop and restart using systemctl and more. In this post I'm going to explain how to set a little script as a service using Raspbian Jessie in a Raspberry Pi.

Example Python Script

First of all, we are going to write a small python script which print "Hello World" every 60 seconds. This is going to be our service script (hello_world.py):

#!/usr/bin/python

from time import sleep

try:
    while True:
        print "Hello World"
        sleep(60)
except KeyboardInterrupt, e:
    logging.info("Stopping...")

You can execute it by python hello_world.py. If you get boring reading so many hello worlds, press Ctrl+C (or Cmd+C on OSX) to stop it. Save this file as hello_world.py in your home folder (home/pi/).

Service for the Script

Now we're going to define the service to run this script:

cd /lib/systemd/system/
sudo nano hello.service

The service definition must be on the /lib/systemd/system folder. Our service is going to be called "hello.service":

[Unit]
Description=Hello World
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/python /home/pi/hello_world.py
Restart=on-abort

[Install]
WantedBy=multi-user.target

Here we are creating a very simple service that runs our hello_world script and if by any means is aborted is going to be restarted automatically. You can check more on service's options in the next wiki: https://wiki.archlinux.org/index.php/systemd.

Now that we have our service we need to activate it:

sudo chmod 644 /lib/systemd/system/hello.service
chmod +x /home/pi/hello_world.py
sudo systemctl daemon-reload
sudo systemctl enable hello.service
sudo systemctl start hello.service

Service Tasks

For every change that we do on the /lib/systemd/system folder we need to execute a daemon-reload (third line of previous code). If we want to check the status of our service, you can execute:

sudo systemctl status hello.service

In general:

Check status

sudo systemctl status hello.service

Start service

sudo systemctl start hello.service

Stop service

sudo systemctl stop hello.service

Check service's log

sudo journalctl -f -u hello.service

emxsys/raspberry_pi_script_as_service.md