Django-environ

django-environ allows you to use Twelve-factor methodology to configure your Django application with environment variables.

  import environ
    env = environ.Env(
        # set casting, default value
        DEBUG=(bool, False)
    )
    # reading .env file
    environ.Env.read_env()
    
    # False if not in os.environ
    DEBUG = env('DEBUG')
    
    # Raises django's ImproperlyConfigured exception if SECRET_KEY not in os.environ
    SECRET_KEY = env('SECRET_KEY')
    
    # Parse database connection url strings like psql://user:[email protected]:8458/db
    DATABASES = {
        # read os.environ['DATABASE_URL'] and raises ImproperlyConfigured exception if not found
        'default': env.db(),
        # read os.environ['SQLITE_URL']
        'extra': env.db('SQLITE_URL', default='sqlite:////tmp/my-tmp-sqlite.db')
    }
    
    CACHES = {
        # read os.environ['CACHE_URL'] and raises ImproperlyConfigured exception if not found
        'default': env.cache(),
        # read os.environ['REDIS_URL']
        'redis': env.cache('REDIS_URL')
    }

See the similar code, without django-environ.

     _ _                                              _
    | (_)                                            (_)
  __| |_  __ _ _ __   __ _  ___ ______ ___ _ ____   ___ _ __ ___  _ __
 / _` | |/ _` | '_ \ / _` |/ _ \______/ _ \ '_ \ \ / / | '__/ _ \| '_ \
| (_| | | (_| | | | | (_| | (_) |    |  __/ | | \ V /| | | | (_) | | | |
 \__,_| |\__,_|_| |_|\__, |\___/      \___|_| |_|\_/ |_|_|  \___/|_| |_|
     _/ |             __/ |
    |__/             |___/

The idea of this package is to unify a lot of packages that make the same stuff: Take a string from os.environ, parse and cast it to some of useful python typed variables. To do that and to use the 12factor approach, some connection strings are expressed as url, so this package can parse it and return a urllib.parse.ParseResult. These strings from os.environ are loaded from a .env file and filled in os.environ with setdefault method, to avoid to overwrite the real environ. A similar approach is used in Two Scoops of Django book and explained in 12factor-django article.

Using django-environ you can stop to make a lot of unversioned settings_*.py to configure your app. See cookiecutter-django for a concrete example on using with a django project.

Feature Support

  • Fast and easy multi environment for deploy
  • Fill os.environ with .env file variables
  • Variables casting (see supported_types below)
  • Url variables exploded to django specific package settings

Django-environ officially supports Django 1.11, 2.2 and 3.0.

Installation

$ pip install django-environ

NOTE: No need to add it to INSTALLED_APPS.

Then create a .env file:

DEBUG=on
SECRET_KEY=your-secret-key
DATABASE_URL=psql://user:[email protected]:8458/database
SQLITE_URL=sqlite:///my-local-sqlite.db
CACHE_URL=memcache://127.0.0.1:11211,127.0.0.1:11212,127.0.0.1:11213
REDIS_URL=rediscache://127.0.0.1:6379/1?client_class=django_redis.client.DefaultClient&password=ungithubbed-secret

And use it with settings.py above. Don't forget to add .env in your .gitignore (tip: add .env.example with a template of your variables).

Documentation

Documentation is available at RTFD.

Supported types

  • str
  • bool
  • int
  • float
  • json
  • list (FOO=a,b,c)
  • tuple (FOO=(a,b,c))
  • dict (BAR=key=val,foo=bar) #environ.Env(BAR=(dict, {}))
  • dict (BAR=key=val;foo=1.1;baz=True) #environ.Env(BAR=(dict(value=unicode, cast=dict(foo=float,baz=bool)), {}))
  • url
  • path (environ.Path)
  • db_url
    • PostgreSQL: postgres://, pgsql://, psql:// or postgresql://
    • PostGIS: postgis://
    • MySQL: mysql:// or mysql2://
    • MySQL for GeoDjango: mysqlgis://
    • Mysql Connector Python from Oracle: mysql-connector://
    • SQLITE: sqlite://
    • SQLITE with SPATIALITE for GeoDjango: spatialite://
    • Oracle: oracle://
    • MSSQL: mssql://
    • PyODBC: pyodbc://
    • Redshift: redshift://
    • LDAP: ldap://
  • cache_url
    • Database: dbcache://
    • Dummy: dummycache://
    • File: filecache://
    • Memory: locmemcache://
    • Memcached: memcache://
    • Python memory: pymemcache://
    • Redis: rediscache://, redis://, or rediss://
  • search_url
    • ElasticSearch: elasticsearch://
    • Solr: solr://
    • Whoosh: whoosh://
    • Xapian: xapian://
    • Simple cache: simple://
  • email_url
    • SMTP: smtp://
    • SMTP+SSL: smtp+ssl://
    • SMTP+TLS: smtp+tls://
    • Console mail: consolemail://
    • File mail: filemail://
    • LocMem mail: memorymail://
    • Dummy mail: dummymail://

Tips

Using unsafe characters in URLs

In order to use unsafe characters you have to encode with urllib.parse.encode before you set into .env file.

DATABASE_URL=mysql://user:%[email protected]:3306/dbname

See https://perishablepress.com/stop-using-unsafe-characters-in-urls/ for reference.

Smart Casting

django-environ has a "Smart-casting" enabled by default, if you don't provide a cast type, it will be detected from default type. This could raise side effects (see #192). To disable it use env.smart_caset = False. New major release will disable it as default.

Multiple redis cache locations

For redis cache, multiple master/slave or shard locations can be configured as follows:

CACHE_URL='rediscache://master:6379,slave1:6379,slave2:6379/1'

Email settings

In order to set email configuration for django you can use this code:

EMAIL_CONFIG = env.email_url(
    'EMAIL_URL', default='smtp://user:password@localhost:25')

vars().update(EMAIL_CONFIG)

SQLite urls

SQLite connects to file based databases. The same URL format is used, omitting the hostname, and using the "file" portion as the filename of the database. This has the effect of four slashes being present for an absolute

file path: sqlite:////full/path/to/your/database/file.sqlite.

Nested lists

Some settings such as Django's ADMINS make use of nested lists. You can use something like this to handle similar cases.

# DJANGO_ADMINS=John:[email protected],Jane:[email protected]
ADMINS = [x.split(':') for x in env.list('DJANGO_ADMINS')]

# or use more specific function

from email.utils import getaddresses

# DJANGO_ADMINS=Full Name <[email protected]>,[email protected]
ADMINS = getaddresses([env('DJANGO_ADMINS')])

Multiline value

You can set a multiline variable value:

# MULTILINE_TEXT=Hello\\nWorld
>>> print env.str('MULTILINE_TEXT', multiline=True)
Hello
World

Proxy value

You can set a value prefixed by $ to use as a proxy to another variable value:

# BAR=FOO
# PROXY=$BAR
>>> print env.str('PROXY')
FOO

Multiple env files

It is possible to have multiple env files and select one using environment variables.

env = environ.Env()
env.read_env(env.str('ENV_PATH', '.env'))

Now ENV_PATH=other-env ./manage.py runserver uses other-env while ./manage.py runserver uses .env.

Tests

$ git clone [email protected]:joke2k/django-environ.git
$ cd django-environ/
$ python setup.py test

GitHub

https://github.com/joke2k/django-environ