Flask-Env

.. image:: https://badge.fury.io/py/Flask-Env.svg :target: https://badge.fury.io/py/Flask-Env .. image:: https://travis-ci.org/brettlangdon/flask-env.svg?branch=master :target: https://travis-ci.org/brettlangdon/flask-env

Easily set Flask <http://flask.pocoo.org/>_ settings from environment variables.

The reason for using :code:flask-env is to be able to follow the 12-factor app <http://12factor.net/>_ suggestions for configuring your application.

With :code:flask-env you can define your default configuration options in code and very easily override via environment variables.

Installation

.. code:: bash

   pip install Flask-Env


Usage
~~~~~

With :code:`flask-env` you will define your configuration as an object and load it into your Flask application via `app.config.from_object <http://flask.pocoo.org/docs/0.11/api/#flask.Config.from_object>`_ method.

Python 2
--------

.. code:: python

   from flask import Flask
   from flask_env import MetaFlaskEnv


   class Configuration(object):
       __metaclass__ = MetaFlaskEnv

       DEBUG = False
       PORT = 5000


   app = Flask(__name__)
   app.config.from_object(Configuration)


Python 3
--------

.. code:: python

   from flask import Flask
   from flask_env import MetaFlaskEnv


   class Configuration(metaclass=MetaFlaskEnv):
       DEBUG = False
       PORT = 5000


   app = Flask(__name__)
   app.config.from_object(Configuration)


Overriding environment variables
--------------------------------

.. code:: bash

    # Export environment variable for shell session
    export DEBUG=true

    # Set explicitly for a specific command execution
    PORT=8000 python app.py


Configuring flask-env

:code:flask-env offers two configuration options to determine how/which environment variables are loaded.

ENV_PREFIX Only consider environment variables that start with this prefix. The prefix will be removed from the environment variable name when setting in the configuration. (default: :code:'', example: :code:ENV_PREFIX = 'MYAPP_')

ENV_LOAD_ALL Whether or not to load all environment variables for the configuration object. When :code:False only settings predefined on the configuration object are loaded, all others are ignored. When :code:True all environment variables defined in :code:os.environ will get loaded into your configuration object. (default :code:False)

Setting configuration values

You can set the :code:flask-env configuration settings directly on your Flask configuration object.

.. code:: python

from flask_env import MetaFlaskEnv

class Configuration(metaclass=MetaFlaskEnv): ENV_PREFIX = 'MYAPP_' ENV_LOAD_ALL = False