How to serve different config settings in flask app to uwsgi using create_app?

问题

In my Flask application's config.py i have LocalConfig and ProdConfig and latter is to be used in production, once app is deployed.

Now i'm using uWsgi to serve app to Nginx and here the myapp.wsgi i have created.

from myapp import create_app
from myapp.config import ProdConfig

app = create_app(config=ProdConfig)

and in one of other app.py create_app is defined as:

def create_app(config=None, app_name=None, blueprints=None):

    # some code
    app = Flask(app_name, instance_path=INSTANCE_FOLDER_PATH, instance_relative_config=True)
    configure_app(app, config)
    # some other code

    return app

def configure_app(app, config=None):
    """Different ways of configurations."""

    app.config.from_object(LocalConfig)
    app.config.from_pyfile('production.cfg', silent=True)

    if config:
        app.config.from_object(config)

I want to know, will it properly with uWSGI? Will uWSGI be able to applying the ProdConfig successfully?

Or is it better to use Environment Variables to distinguish between different config settings? Like if os.environ.get('PROD', True): #do something?

Which way is better? Flask's create_app() one or the env variable one? Any other suitable approach?

回答1:

A common way of doing this is storing the configurations in a dictionary.

class Config:
     ALL_CAPS_CONFIG = 'SOME VALUE'

class DevConfig(Config):
    pass

class TestConfig(Config):
    pass

class ProdConfig(Config):
    pass

configs = {
  'dev'  : DevConfig,
  'test' : TestConfig,
  'prod' : ProdConfig,
  'default' : ProdConfig
  }

And then where you actually create your app, you'd do something like this::

from config import configs
import os

evn = os.environ.get('MY_FLASK_APP_ENV', 'default')

create_app(config=configs[evn])

That way you can easily switch between the environments by changing a variable in your shell.

回答2:

It is actually much nicer to point an environment variable to a completely separate config.py file. Personally I have a config.py file that contains my base and development settings, then another config.py for my production configuration, the location of which is specified from an environment variable.

I would recommend that you look at the Flask Configuration documentation, as it does a good job at explaining how the configuration files should be setup.

来源：https://stackoverflow.com/questions/25745390/how-to-serve-different-config-settings-in-flask-app-to-uwsgi-using-create-app

标签

python

nginx

Flask

uwsgi