# CGI

If all other deployment methods do not work, CGI will work for sure. CGI is supported by all major servers but usually has a less-than-optimal performance.

This is also the way you can use a Flask application on Google's App Engine, there however the execution does happen in a CGI-like environment. The application's performance is unaffected because of that.

Watch Out

Please make sure in advance that your app.run() call you might have in your application file, is inside an if __name__ == '__main__': or moved to a separate file. Just make sure it's not called because this will always start a local WSGI server which we do not want if we deploy that application to CGI / app engine.

## Creating a .cgi file

First you need to create the CGI application file. Let's call it yourapplication.cgi:

#!/usr/bin/python
from wsgiref.handlers import CGIHandler
from yourapplication import app

CGIHandler().run(app)


## Server Setup

Usually there are two ways to configure the server. Either just copy the .cgi into a cgi-bin (and use mod_rewrite or something similar to rewrite the URL) or let the server point to the file directly.

In Apache for example you can put a like like this into the config:

ScriptAlias /app /path/to/the/application.cgi