musette

musette enables application configuration by providing a proxy to os.environ which allows:

• type-casting of environment values
• updating the environment via plaintext key-value properties files
• shell-style interpolation

musette is a direct fork of django-environ with significant changes. Although it is intended for Django settings configuration it does not actually require Django itself.

The original module (django-environ) was a merge of:

• envparse
• honcho
• dj-database-url
• dj-search-url
• dj-config-url
• django-cache-url

Basic usage

from musette import environ

environ.read('env.properties')

DEBUG = environ.bool("DEBUG")

Django Settings

This is your settings.py file before you have installed musette:

DEBUG = True
TEMPLATE_DEBUG = DEBUG

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'database',
        'USER': 'user',
        'PASSWORD': 'githubbedpassword',
        'HOST': '127.0.0.1',
        'PORT': '8458',
    }
    'extra': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': 'database.sqlite'
    }
}

SECRET_KEY = 'notsecret'

CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
        'LOCATION': [
            '127.0.0.1:11211', '127.0.0.1:11212', '127.0.0.1:11213',
        ]
    },
    'redis': {
        'BACKEND': 'redis_cache.cache.RedisCache',
        'LOCATION': '127.0.0.1:6379:1',
        'OPTIONS': {
            'CLIENT_CLASS': 'redis_cache.client.DefaultClient',
            'PASSWORD': 'redis-githubbed-password',
        }
    }
}

After:

from musette import Environment

env = Environment(DEBUG=(bool, False),)
env.read('env.properties')

DEBUG = env('DEBUG') # False if not in os.environ
TEMPLATE_DEBUG = DEBUG

DATABASES = {
    'default': env.db(),
    'extra': env.db('SQLITE_URL', default='sqlite:////tmp/my-tmp-sqlite.db')
}

SECRET_KEY = env('SECRET_KEY')

CACHES = {
    'default': env.cache(),
    'redis': env.cache('REDIS_URL')
}

Properties Files

A properties or "env" file is plain text file containing one or more key := value or key = value lines, where values may optionally refer to other environment values via shell-style variables:

that := something
this := ${that}

How to install

$ pip install musette

How to use

There is an Environment class and a convenient instance of that class called environ:

>>> from musette import Environment
>>> env = Environment(
        DEBUG=(bool, False),
    )
>>> env('DEBUG')
False
>>> env('DEBUG', default=True)
True

>>> open('.myenv', 'a').write('DEBUG=on\n')
>>> env.read('.myenv')
>>> env('DEBUG')
True

>>> open('.myenv', 'a').write('INT_VAR=1010\n')
>>> env.read('.myenv')
>>> env.int('INT_VAR'), env.str('INT_VAR')
1010, '1010'

>>> open('.myenv', 'a').write('DATABASE_URL=sqlite:///my-local-sqlite.db\n')
>>> env.read('.myenv')
>>> env.db()
{'ENGINE': 'django.db.backends.sqlite3', 'NAME': 'my-local-sqlite.db', 'HOST': '', 'USER': '', 'PASSWORD': '', 'PORT': ''}

Environment by default provides an effective proxy to the os.environ data dictionary, but you can pass in any other dict instead:

>>> from musette import Environment
>>> _environ = {}
>>> env = Environment(_environ, DEBUG=True)
>>> _environ['DEBUG']
True

If you are neither passing in a configuration dict or any schema values then you can just use the environ instance:

>>> import os
>>> from musette import environ
>>> set(os.environ.keys()) == set(environ.keys())
True

Supported Types

• str
• bool
• int
• float
• json
• list (FOO=a,b,c)
• dict (BAR=key=val;foo=bar)
• url

• 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://
  • 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://
  • Simple cache: simple://

• email_url

  • SMTP: smtp://
  • SMTPS: smtps://
  • Console mail: consolemail://
  • File mail: filemail://
  • LocMem mail: memorymail://
  • Dummy mail: dummymail://

Tests

$ git clone git@github.com:averagehuman/musette.git
$ cd musette
$ python setup.py test