[FIXED] How to deploy a flask application with a config file?

Issue

I have a flask application and I use a config file with some sensitive information. I was wondering how to deploy my application with the config file without releasing the sensitive information it holds.

Solution

TLDR; Create a class to hold your config secrets, store the actual secrets in environment variables on your host machine, and read in the environment variables in your app.

Detailed implementation below.

This is my folder structure:

api
|_cofig
  |_config.py
|_app.py

Then inside of my app.py, which actually starts my Flask application, it looks roughly like this (I've excluded everything that doesn't matter).

from config.config import config
def create_app(app_environment=None):
    if app_environment is None:
        app = Flask(__name__)
        app.config.from_object(config[os.getenv('FLASK_ENV', 'dev')])
    else:
        app = Flask(__name__)
        app.config.from_object(config[app_environment])

if __name__ == "__main__":
    app = create_app(os.getenv('FLASK_ENV', 'dev'))
    app.run()

This allows you to dynamically specify an app environment. For example, you can pass the app environment by setting an environment variable and reading it in before you call create_app(). This is extremely useful if you containerize your Flask app using Docker or some other virtualization tool.

Lastly, my config.py file looks like this. You would change the attributes in each of my environment configs to your secrets.

import os

class ProdConfig:
    # Database configuration
    API_TOKEN = os.environ.get('PROD_MARKET_STACK_API_KEY_SECRET')


class DevConfig:
    # Database configuration
    API_TOKEN = os.environ.get('API_KEY_SECRET')

class TestConfig:
    # Database configuration
    API_TOKEN = os.environ.get('MARKET_STACK_API_KEY')

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

Further, you would access your config secrets throughout any modules in your Flask application via...

from flask import current_app
current_app.config['API_TOKEN']`

Answered By - dporth