Let’s say you have a flask app and you want to create an Ubuntu service for this app. This way, the service will restart whenever the server restarts or the service fails. Here is a sample flask app on /home/user/server.py:

#!/usr/bin/python
from flask import Flask, request
app = Flask(__name__)
@app.route('/', methods=['GET'])
def index():
    return "Hello world"

if __name__ == '__main__':
   app.run(host="0.0.0.0", port=31013)

We have to write the following service configuration in /etc/init/flask.conf:

description "flask"
start on stopped rc RUNLEVEL=[2345]
respawn
exec python /home/user/server.py

Try sudo service flask start. If you receive any error, you may have to create an additional file /lib/systemd/system/flask.service

[Unit]
Description=Flask web server

[Install]
WantedBy=multi-user.target

[Service]
User=root
Group=root
PermissionsStartOnly=true
ExecStart=/home/user/server.py
TimeoutSec=600
Restart=on-failure
RuntimeDirectoryMode=755

You now can sudo service flask start/stop/status.

Follow @aladagemre