Advice on running flask app ONLY locally forever

Question

I want to create web form that stays on forever on a single computer. Users can come to the computer fill out the form and submit it. After submitting, it will record the responses in an excel file and send emails. The next user can then come and fill out a new form automatically. I was planning on using Flask for this task since it is simple to create, but since I am not doing this on some production server, I will just have it running locally in development on the single computer.

I have never seen anyone do something like this with Flask so I was wondering if my idea is possible or if I should avoid it. I am also new to web development so I was wondering what problems there could be with keeping a flask application stay on 24/7 on a local development computer.

Thanks

Answer 1

There is nothing wrong with doing this in principle however, it is likely not the best solution for the time-to-reward payoff.

First, to answer your question, this could easily be done, even for a beginner, completing this in a few hours with minimal Python and HTML experience could definitely be done. Your app could crash in the background for many reasons (running out of space, bad memory addresses, etc) but most likely you will be fine.

As for specifically building it, it is all possible, there are libraries you can use to add the results to an excel file, or you can easily just append to a CSV (which is what I would recommend). Creating and sending an email, similarly is relatively simple, but again, doing it without python would be much easier.

If you are not set on flask/python, you could check out Google Forms but if you are set on python, or want to use it as a learning experience, it can definitely be done.

Answer 2

Yes, this could be done. It's very similar to the applications that run on the servers in data centers.

To keep the application running forever or restarting it after your system starts you'll need to use a system manager similar to systemd in Unix. You could use NSSM - the Non-Sucking Service Manager or Service Control to monitor your application and restart it if it crashes. This will also have to be enabled on startup.

Other than this, you could use Waitres to serve your Flask application. Waitress is a WSGI web server with which you can easily configure the number of threads and workers to enable serving multiple users at the same time.

In a production environment, it's always suggested to use a web server interface like Gunicorn or Waitress.

Answer 3

Your idea is possible and while there are many ways to do this kind of thing, what you are suggesting is not necessarily to be avoided.

All apps that run on a computer over a long period of time start a process and keep it going until closed. That is essentially what you are doing.

Having done this myself (and still currently doing it) at my business, I can say that it works great.

The only caveat is that to ensure that it will always be available, you need to have the process monitored by some tool to make sure that it gets restarted if it ever closes due to a variety of reasons.

In linux, supervisor is a great tool for doing that. In windows you could register it as a service. But you could also just create an easy way to restart and make it easy for the user to do so if it is down when they need it.