How to run gunicorn inside python not as a command line?

Question

I have a flask application.

I run it in production with this command:

python -m gunicorn -w 1 -b 0.0.0.0:5000 "path.to.wsgi:return_app()"

Instead, I want to run it inside a my_file.py

I need a function to run and it should accept the app object and port binding and number of workers

How can I do that?

I need something like this psudo code:

import gunicorn

app = return_app()

gunicorn(workers=1, ip="0.0.0.0", port=5000, app=app)

the most important part to me is the app=app part

the main point is that I want to use the app object as an instance of Flask(). I want to directly give app object to gunicorn not throough addressing it in a string

What I have tried: I have opened gunicorn library main.py file

from gunicorn.app.wsgiapp import run
run()

to see how it works but could not figure it out

def run():
    """\
    The ``gunicorn`` command line runner for launching Gunicorn with
    generic WSGI applications.
    """
    from gunicorn.app.wsgiapp import WSGIApplication
    WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()

Answer 1

insert the following inside your my_file.py

from subprocess import run
run("gunicorn -w 1 -b 0.0.0.0:5000 'path.to.wsgi:return_app()'".split(' '))

Answer 2

Something like this works for me. First I instantiate the BaseApplication class. It has a run() method. The details are on how to create a custom application in gunicorn documentation.

if platform.uname().system.lower()=='linux':
    print("Detected Linux, Preparing gunicorn")        
    import gunicorn.app.base
    class StandaloneApplication(gunicorn.app.base.BaseApplication):

        def __init__(self, app, options=None):
            self.options = options or {}
            self.application = app
            super().__init__()

        def load_config(self):
            config = {key: value for key, value in self.options.items()
                    if key in self.cfg.settings and value is not None}
            for key, value in config.items():
                self.cfg.set(key.lower(), value)

        def load(self):
            return self.application

if __name__ == "__main__":
    # Use a debugging session in port 5001    
    if platform.uname().system.lower()=='linux':
        print("Detected Linux, Running Gunicorn")
        options = {
            'bind': '%s:%s' % ('0.0.0.0', '5001'),
            'workers': number_of_workers(),
            # 'threads': number_of_workers(),
            'timeout': 120,
        }
        initialize()
        StandaloneApplication(app, options).run()
    else:
        print("Detected non Linux, Running in pure Flask")
        initialize()
        app.run(debug=True, host=socket.gethostbyname(socket.gethostname()), port=5001)