Ini Cfg Demo

Example of project with two levels of configuration files:

• LEVEL 1: read the configuration from the sources/application's folder (virtualenv)
• LEVEL 2: read the configuration from the user HOME

Python project structure

According to the reference [Packaging and Distributing Projects](https://packaging.python.org/distributing/) a (modern) Python project should have the following structure. In the package directory, I add a __main__.py for the main entry pointand a IniCfgDemo.ini for configuration.

Here is the structure:

python-ini-cfg-demo/
+-- MANIFEST.in
+-- README.rst
+-- setup.py
+-- setup.cfg
    src/
    \-- ini_cfg_demo/
        +-- __init__.py
        +-- __main__.py
        \-- IniCfgDemo.ini

Project's configuration

You must add a package_data entry in you setup.py to include "IniCfgDemo.ini" in your Source Distribution.

For exemple, here is a small setup.py:

from distutils.core import setup

from setuptools import find_packages

setup(
    name='my_app',
    version='0.1.0',
    url="http://url/to/your/project",
    author="My NAME",
    author_email="[email protected]",
    packages=find_packages("src"),
    package_dir={'': 'src'},
    package_data={
        'ini_cfg_demo': ['IniCfgDemo.ini'],
    },
)

For backward compatibility with Python 2.6, you also need a MANIFEST.in file.

For instance, we can include all *.ini files:

include src/ini_cfg_demo/*.ini

To check your configuration, run the following command:

python setup.py sdist

Default configuration for logging

The IniCfgDemo.ini store the default configuration for logging:

[formatters]
keys=default

[formatter_default]
format=%(asctime)s:%(levelname)s:%(message)s
class=logging.Formatter

[handlers]
keys=console

[handler_console]
class=logging.StreamHandler
formatter=default
args=tuple()

[loggers]
keys=root

[logger_root]
level=DEBUG
formatter=default
handlers=console

It has only one logger (the root logger), with default handlers and formatters.

Main application

The __main__.py is the entry point of the application.

Here is the source code of __main__.py:

# -*- coding: utf-8 -*-
import logging.config
import os.path

import sys

WIN = sys.platform.startswith('win')


def _posixify(name):
    return '-'.join(name.split()).lower()


def get_app_dir(app_name, roaming=True, force_posix=False):
    if WIN:
        key = roaming and 'APPDATA' or 'LOCALAPPDATA'
        folder = os.environ.get(key)
        if folder is None:
            folder = os.path.expanduser('~')
        return os.path.join(folder, app_name)
    if force_posix:
        return os.path.join(os.path.expanduser('~/.' + _posixify(app_name)))
    if sys.platform == 'darwin':
        return os.path.join(os.path.expanduser(
            '~/Library/Application Support'), app_name)
    return os.path.join(
        os.environ.get('XDG_CONFIG_HOME', os.path.expanduser('~/.config')),
        _posixify(app_name))


def run_ini_cfg_demo():
    # LEVEL 1: read the configuration from the sources/application's folder (virtualenv)
    ini1_path = os.path.join(os.path.dirname(__file__), "IniCfgDemo.ini")
    logging.config.fileConfig(ini1_path)
    logging.info("Starting...")

    # LEVEL 2: read the configuration from the user HOME
    ini2_path = get_app_dir("IniCfgDemo")
    logging.debug('Reading configuration from "{ini2_path}...'.format(ini2_path=ini2_path))
    try:
        logging.config.fileConfig(ini2_path)
    except KeyError:
        logging.warning('Bad or missing logging configuration in "{ini2_path}...'.format(ini2_path=ini2_path))

    logging.info("Running...")


if __name__ == '__main__':
    run_ini_cfg_demo()

You can add this entry point in your setup.py, like this:

entry_points={
    'console_scripts': [
        'ini_cfg_demo = ini_cfg_demo.__main__:run_ini_cfg_demo',
    ],
},

To test the entry point, you can install it with pip:

pip install -e .

Then you can test your application:

ini_cfg_demo

2016-07-16 15:47:35,613:INFO:Starting...
2016-07-16 15:47:35,613:DEBUG:Reading configuration from "/Users/my_name/Library/Application Support/IniCfgDemo...
2016-07-16 15:47:35,613:WARNING:Bad or missing logging configuration in "/Users/my_name/Library/Application Support/IniCfgDemo...
2016-07-16 15:47:35,613:INFO:Running...

Note: the ``ini_cfg_demo`` was launched in a Mac OSX.

Her it is.