Flask - Dev and Prod Configuration Setup

.env

# Sensible defaults for development

CONFIGURATION_SETUP=config.DevelopmentConfig
HOST_SERVER=test
HOST_SERVER_URL="https://placeholder_for_test.com"
SECRET_KEY="1234"

config.py

from os import environ


class Config(object):
    """Base config"""

    SECRET_KEY = environ.get("SECRET_KEY") or "top-secret"
    HOST_SERVER = environ.get("HOST_SERVER")
    HOST_SERVER_URL = environ.get("HOST_SERVER_URL")


class ProductionConfig(Config):
    FLASK_ENV = "production"
    DEBUG = False
    TESTING = False


class DevelopmentConfig(Config):
    ENV = "dev"
    FLASK_ENV = "development"
    DEBUG = True
    TESTING = True

main.py

from flask import Flask
from os import environ

app = Flask(__name__)
environment_configuration = environ.get(
    "CONFIGURATION_SETUP", "config.ProductionConfig"
)
app.config.from_object(environment_configuration)

@app.route("/env")
def env():
    return f"FLASK_ENV = { app.config['FLASK_ENV']} | ENV = { app.config['ENV']} | SECRET = { app.config['SECRET_KEY']} | SERVER_URL= { app.config['HOST_SERVER_URL']}"