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.
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/).
Now we're going to define the service to run this script:
cd /lib/systemd/system/
sudo nano hello.serviceThe 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.serviceFor 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:
sudo systemctl status hello.service
sudo systemctl start hello.service
sudo systemctl stop hello.service
sudo journalctl -f -u hello.service