How can I change the host and port that the flask command uses?

I want to change the host and port that my app runs on. I set host and port in app.run, but the flask run command still runs on the default 127.0.0.1:8000. How can I change the host and port that the flask command uses?

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=3000)

set FLASK_APP=onlinegame
set FLASK_DEBUG=true
python -m flask run

Answer

The flask command is separate from the flask.run method. It doesn’t see the app or its configuration. To change the host and port, pass them as options to the command.

flask run -h localhost -p 3000

Pass --help for the full list of options.

Setting the SERVER_NAME config will not affect the command either, as the command can’t see the app’s config.

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Never expose the dev server to the outside (such as binding to 0.0.0.0). Use a production WSGI server such as uWSGI or Gunicorn.

gunicorn -w 2 -b 0.0.0.0:3000 myapp:app