runenv

Wrapper to run programs with modified environment variables loaded from given file. You can use runenv to manage your app settings using 12-factor principles.

You can use same environment file with runenv and with docker using env-file parameter

Features

CLI:

  • command-line tool to load environment variables from given file

Python API:

  • load variables from a file (.env or passed filename)
  • load only variables with given prefix
  • prefix can be stripped during load
  • detect whether environment was loaded by runenv CLI
  • force load even if runenv CLI was used
  • search_parent option which allows to look for env_file in parent dirs

Installation

In order to install use pip

$ pip install -U runenv

Usage

Run from shell

$ runenv env.development ./manage.py runserver

example env.development file

BASE_URL=http://127.0.0.1:8000
DATABASE_URI=postgres://postgres:password@localhost/dbname
SECRET_KEY=y7W8pbRcuPuAmgTHsJtEpKocb7XPcV0u

# email settings
EMAIL_HOST=smtp.mandrillapp.com
EMAIL_PORT=587
EMAIL_HOST_USER=someuser
EMAIL_HOST_PASSWORD=hardpassword
EMAIL_FROM=dev@local.host
EMAIL_USE_TLS=1

Python API

load_env(env_file=’.env’, prefix=None, strip_prefix=True, force=False, search_parent=0)

Loads environment from given env_file` (default .env).

Options:

option default description
env_file .env relative or absolute path to file with environment variables
prefix None prefix to match variables e.g. APP_
strip_prefix True should the prefix be stripped during loa
force False load env_file, even though runenv CLI command was used
search_parent 0 To what level traverse parents in search of file

If prefix option is provided only variables starting with it will be loaded to environment, with their keys stripped of that prefix. To preserve prefix, you can set strip_prefix to False.

Example

$ echo 'APP_SECRET_KEY=bzemAG0xfdMgFrHBT3tJBbiYIoY6EeAj' > .env

$ python
>>> import os
>>> from runenv import load_env
>>> load_env(prefix='APP_')
>>> 'APP_SECRET_KEY' in os.environ
False
>>> 'SECRET_KEY' in os.environ
True
>>> load_env(prefix='APP_', strip_prefix=False)
>>> 'APP_SECRET_KEY' in os.environ
True

Notice: Environment will not be loaded if command was fired by runenv wrapper, unless you set the force parameter to True

load_env does not load variables when wrapper runenv is used. Also _RUNENV_WRAPPED is set to 1

Example

$ echo 'APP_SECRET_KEY=bzemAG0xfdMgFrHBT3tJBbiYIoY6EeAj' > .env

$ python
>>> import os
>>> from runenv import load_env
>>> os.environ['_RUNENV_WRAPPED'] = '1'
>>> load_env()
>>> 'APP_SECRET_KEY' in os.environ
False
>>> load_env(force=True)
>>> 'APP_SECRET_KEY' in os.environ
True

Django/Flask integration

To use load_env with Django or Flask, put the followin in manage.py and wsgi.py

from runenv import load_env
load_env()

Similar projects