haufe.hrs.configuration 0.4.0

A central configuration service for Zope 2/3-based applications based on a pseudo-hierarchical INI-file format with model support for defining the configuration schema

Introduction

haufe.hrs.configuration provides a central configuration service for Zope-based application with a pseudo-hierarchical configuration mechanism.

Features

• configurations based on INI files

• configurations are pseudo-hierarchical (section names can be dotted-names (like ‘cms.somepath’, ‘foo.bat.something.else’)

• all valid configuration options are defined through a model (an INI-style file defining sections, their options, their types and default values). The model is used for performing type-checking and providing defaults

• models and configuration files can be loaded all-in-one or incremental into the configuration service

• optional supervision of changes to the configuration file (a change of a configuration file can trigger an immediate reload of the configuration)

• very simple API

• ZCML directives for defining the location of models and configuration files

• integrates easily with Zope 2 and Zope 3

• can be used outside Zope (pure Python applications) - the package has only a minor number of dependencies to other zope.* packages

• good test coverage

Defining a model

A model definition may look like this:

[cms]
HRSCheckoutPath=string,default=42
HRSCheckoutURL=string
HRSImportPath=string
HRSImportClientPath=string
HRSPreviewPath=string
HRSPreviewClientPath=string
CvtSGMLtoRtfPath=string
CvtSGMLtoRtfMaxWait=int
ADB2StartURLbase=string
ADB2Version=int
ToolboxStartURLbase=string
NormenDBStartURLbase=string
VADBStartURLbase=string
LauflistenStartURL=string
HRS2UIStartURLbase=string
MedienStartURLbase=string

[cms.db]
datenbank1=
datenbank2=
datenbank3=

You see that the syntax is pretty simple. The syntax is always:

<optionname> = <type>, [default=<default-value>]

<optionname> is mandatory. <type> defaults to ‘string’ and can be omitted (other types are ‘int’, ‘list’, ‘float’, ‘complex’). The ‘=’ is mandatory (otherwise Python’s configuration parser will spit out an error. An optional default can be defined (otherwise None will be used).

A related configuration file may look like this:

[cms]
HRSCheckout = /foo/bar
adb2version = 44
hrscheckoutpath = 12
port = 22


[toolbox]
partition_id = Toolbox
nginx_baseurl = http://weiss.nix.de/

For values of the configuration are accessible through dotted-names like:

cms.ADB2Version
CMS.HRSCheckoutURL
cms.db.datenbank

Usage

From Python:

from haufe.hrs.configuration import ConfigurationService

service = ConfigurationService(watch=True)
service.registerModel('example/model')
service.loadConfiguration('example/sample_config/all-in-one.ini')
print service.getConfigurations()
print service.get('cms.ADB2Version')
print service.get('datenbank', prefix='cms.db')

ZCML integration

haufe.hrs.configuration provides two ZCML directives hrs:registerConfigurationModel and hrs:registerConfiguration:

<configure xmlns="http://namespaces.zope.org/zope"
           xmlns:hrs="http://namespaces.haufe.de/hrs">

  <hrs:registerConfigurationModel
      configuration="haufe/hrs/configuration/tests/model"
  />

  <hrs:registerConfiguration
      configuration="haufe/hrs/configuration/tests/example-config.ini"
  />

</configure>

Credits

The implementation is based on the cfgparse module by Dann Gass

Author

haufe.hrs.configuration was written by Andreas Jung for Haufe Mediengruppe, Freiburg, Germany and ZOPYX Ltd. & Co. KG, Tuebingen, Germany.

License

haufe.hrs.configuration is licensed under the Zope Public License 2.1. See the included ZPL.txt file.

Contact

ZOPYX Ltd. & Co. KG

Andreas Jung

Charlottenstr. 37/1

D-72070 Tuebingen, Germany

E-mail: info at zopyx dot com

Web: http://www.zopyx.com

Changelog

0.4.0 (2008-11-03)

• first public release

• updated documentation and tests

• some internal cleanup in order to fix race-conditions

0.3.0 (2008-11-02)

• added pyinotify dependency

• watching configuration file changes

• sending ConfigurationChangedEvent upon reload()

0.2.0 (2008-11-01)

• added service implementation

• added zcml implementation

• more tests

0.1.0 (2008-10-31)

• Initial release