python-envcfg 0.1.0

Accessing environment variables with a magic module.

Accessing environment variables with a magic module.

>>> import os
>>> from envcfg.raw.python import CONFIGURE_OPTS
>>>
>>> CONFIGURE_OPTS
'--enable-shared --enable-universalsdk=/ --with-universal-archs=intel'
>>> CONFIGURE_OPTS == os.environ['PYTHON_CONFIGURE_OPTS']
True

It works with many frameworks such as Django and Flask. Then you can store your config in the environment variables instead of framework-specific config files. It is recommended by 12-Factor.

Installation

$ pip install python-envcfg
$ pip freeze > requirements.txt  # http://nvie.com/posts/pin-your-packages/

Examples

Uses with Flask

1. Defines environment variables with a prefix:

   $ cat .env  # should not checked into VCS
   # values are valid JSON expressions
   MYAPP_DEBUG=true
   MYAPP_SECRET_KEY='"7950ad141c7e4b3990631fcdf9a1d909"'
   MYAPP_SQLALCHEMY_DATABASE_URI='"sqlite:///tmp/myapp.sqlite3"'

2. Creates Flask app and loads config from python-envcfg:

   $ cat myapp.py
   ...
   app = Flask(__name__)
   app.config.from_object('envcfg.json.myapp')  # MYAPP_ -> .myapp
   ...

3. Enters your app with those environment variables:

   $ (source .env && python myapp.py)

Uses with Django

1. Creates a django project and moves all sensitive config items into the environment variables:

   $ cat djapp/settings.py  # codebase-scope config
   ...
   INSTALLED_APPS = (
       'django.contrib.admin',
   )
   ...
   
   $ cat .env  # environment-scope config, should not checked into VCS
   # values are valid JSON expressions
   DJAPP_SECRET_KEY='"wo9g2o#jws=u"'
   DJAPP_DEBUG=true
   DJAPP_TEMPLATE_DEBUG=true

2. Adds importing statements in the end of settings.py module:

   $ tail -n 2 djapp/settings.py
   # importing all config items stored in the environment variables
   from envcfg.json.djapp import *  # noqa

3. Runs your Django app with environment variables:

   $ (source .env && python manage.py runserver)

Works on Projects

In development, we can work with per-project environments but no more typing source foo/bar.

I recommend to put your project-specified environment variables in {PROJECT_ROOT}/.env and mark the .env as ignored in your VCS. For example, you can write /.env in .gitignore if you are using Git, and put a .env.example as a copying template for new-cloned projects.

And then, you can use some utility such as honcho or autoenv to apply the .env automatically.

For honcho:

$ echo 'MYPROJECT_DEBUG=true' >> .env
$ echo 'web: python manage.py runserver' >> Procfile
$ honcho run python manage.py check-debug
True
$ honcho start web
Starting development server at http://127.0.0.1:5000/
...

For autoenv:

$ echo 'MYPROJECT_DEBUG=true' >> myproject/.env
$ cd myproject
$ python manage.py check-debug
True
$ python manage.py runserver
Starting development server at http://127.0.0.1:5000/
...

Issues

If you want to report bugs or request features, please create issues on GitHub Issues.