modconfig 1.2.1

Simple hierarchic configuration manager for apps

modconfig – Simple hierarchic configuration manager for apps

Motivation

Applications (especially web services) often require certain configuration options to depend on the environment an application runs in (development, testing, production, etc.). For instance, a database address config option may default to a local database server during development, a mock database server during testing, and yet another database server during production. It may also need to be customizable via an environment variable. modconfig approaches scenarios like this and, allows to specify default configuration options for various environments and optionally override them by custom environment variables.

modconfig uses python modules for keep the configuration options. You are not locked by format (json, yaml, ini) restrictions and able to use any python statements/modules to tune your configuration as a pro. It keeps the flexability and make your configuration very declarative without any magic.

Contents

• Motivation

• Requirements

• Installation

• Usage

  • Fallbacks

  • Enviroments

  • Custom Environment Variables

• Bug tracker

• Contributing

• License

Requirements

• python >= 3.6

Installation

modconfig should be installed using pip:

pip install modconfig

Usage

For example you have the structure in your app:

|- myapp/
|  |- __init__.py
|  |- config/
|  |  |- __init__.py
|  |  |- defaults.py
|  |  |- production.py
|  |  |- stage.py
|  |  |- tests.py
|  | ...

See https://github.com/klen/modconfig/tree/develop/example as a simple reference.

Initialize the config in your app and use it anywhere:

from modconfig import Config

cfg = Config(

 # instead an import path it could be the module itself
 'myapp.config.production',

 # Override any options
 ANY_OPTION1="VALUE", ANY_OPTION2="VALUE")

assert cfg.DATABASE
assert cfg.ANY_OPTION1

Fallbacks

If you provide a several modules, modconfig will be using the first available:

from modconfig import Config

cfg = Config('myapp.config.local', 'myapp.config.production', ANY_OPTION1="VALUE")

assert cfg.DATABASE
assert cfg.ANY_OPTION1

Enviroments

The module path may be set as ENV variable:

import os
from modconfig import Config

# Let's define an env var
os.environ['MODCONFIG'] = 'myapp.config.production'

cfg = Config('env:MODCONFIG', 'myapp.config.local')
assert cfg.DATABASE

Custom Environment Variables

Any option may be redifened with ENV variables. By default the modconfig tries to parse value as a JSON which allows us to set complex values (dict, list, etc). If value is not JSON it would be parsed as str.

Any ENV variables which names are not contained in source module would be ignored.

See https://github.com/klen/modconfig/tree/develop/tests.py for more examples.

Bug tracker

If you have any suggestions, bug reports or annoyances please report them to the issue tracker at https://github.com/klen/modconfig/issues

Contributing

Development of the project happens at: https://github.com/klen/modconfig

License

Licensed under a MIT license.