django-environ: A Python repository from ciphernix

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:pass@127.0.0.1:8458/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')
}

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  __| |_  __ _ _ __   __ _  ___ ______ ___ _ ____   ___ _ __ ___  _ __
 / _` | |/ _` | '_ \ / _` |/ _ \______/ _ \ '_ \ \ / / | '__/ _ \| '_ \
| (_| | | (_| | | | | (_| | (_) |    |  __/ | | \ 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 1.8 ~ 2.0.

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://urser:un-githubbedpassword@127.0.0.1:8458/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://
- 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://
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:%23password@127.0.0.1:3306/dbname

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

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:john@admin.com,Jane:jane@admin.com
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-with-name@example.com>,anotheremailwithoutname@example.com
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 git@github.com:joke2k/django-environ.git
$ cd django-environ/
$ python setup.py test

How to Contribute

Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug. There is a Contributor Friendly tag for issues that should be ideal for people who are not very familiar with the codebase yet.
Fork the repository on GitHub to start making your changes to the develop branch (or branch off of it).
Write a test which shows that the bug was fixed or that the feature works as expected.
Send a pull request and bug the maintainer until it gets merged and published. :) Make sure to add yourself to Authors file.

ciphernix/django-environ