Clor 0.4.0

Application configuration via Python logging.config

Clor

Clor is a tiny wrapper around logging configuration system [1], which allows its reuse for general application configuration. The name was coined this way: “configurator” → “c10r” → “clor”.

Usage

Normally there’s a configuration module (e.g. envconf.py), or a YAML file. Here is a CherryPy example:

base = {
  'global' : {
    'server.socket_host' : '127.0.0.1',
    'server.socket_port' : 8080,
    'server.thread_pool' : 8
  },
  'app' : {
    'api' : {
      '/' : {
        'request.dispatch' : {
          '()' : 'cherrypy._cpdispatch.MethodDispatcher'
        }
      }
    }
  }
}

production = (base, {
  'global' : {
    'server.socket_host' : '0.0.0.0',
    'server.thread_pool' : 16,
    'tools.auth_basic.on'            : True,
    'tools.auth_basic.realm'         : 'App',
    'tools.auth_basic.checkpassword' : 'ext://someapp.password.checker'
  },
})

development = (base, {
  'global' : {
    'server.thread_pool' : None,
  },
  'app' : {
    'api' : {
      '/' : {
        'tools.response_headers.on'      : True,
        'tools.response_headers.headers' : [('Access-Control-Allow-Origin', '*')]
      }
    },
    'api2' : 'cfg://app.api'
  }
})

A few observations:

• Nest dictionaries are merged recursively

• logging’s ext pseudo-protocols

• logging’s cfg pseudo-protocols

• logging’s instantiation with () key

• Keys having None value are removed

Then in your bootstrapping code you can do:

import clor

from . import envconf


config = clor.configure(*getattr(envconf, 'production'))

cherrypy.config.update(config)
cherrypy.tree.mount(ApiApplication(), '/api', config['app']['api'])

[1]

https://docs.python.org/3/library/logging.config.html