Config::Model 0.603 review

Config::Model provides a framework to help in validating the semantic content of configuration data. Config::Model can also be use

License: LGPL (GNU Lesser General Public License) File size: 0K Developer: Dominique Dumont

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Config::Model provides a framework to help in validating the semantic content of configuration data.

Config::Model can also be used to provide a semantic check of options of a complex program like mplayer or transcode.

How does this work ?

Using this project, a typical configuration validation tool will be made of 3 parts :

- The user interface
- The validation engine which is in charge of validating all the configuration information provided by the user.
- The storage facility that store the configuration information

Don't we already have some configuration validation tools ?

You're probably thinking of tools like webmin. Yes, these tools exist and work fine, but they have their set of drawbacks.

Usually, the validation of configuration data is done with a script which performs semantic validation and often ends up being quite complex (e.g. 2500 lines for Debian's xserver-xorg.config script which handles xorg.conf file).

In most cases, the configuration model is expressed in instructions (whatever programming language is used) and interspersed with a lot of processing to handle the actual configuration data.

What's the advantage of this project ?

The Config::Model projects provide a way to get a validation engine where the configuration model is completely separated from the actual processing instruction.

The configuration model is expressed in a declarative form (i.e. a Perl data structure) which is always easier to maintain than a lot of code.

The declaration specifies:

the structure of the configuration data (which can be queried by generic user interfaces)
the properties of each element (boundaries, check, integer or string, enum like type ...)
the default values of parameters (if any)
mandatory parameters
the targeted audience (intermediate, advance, master)
on-line help (for ach parameter or value of parameter)
the level of expertise of each parameter (to hide expert parameters from newbie eyes)

So, in the end:

maintenance and evolution of the configuration content is easier
user will see a *common* interface for *all* programs using this project.
user will not see advanced parameters
upgrade of configuration data is easier and sanity check is performed
audit of configuration is possible to check what was modified by the user compat

What's New in This Release:
modifications required by the Xorg model I'm working on
changed 'element_class' parameter or hash and list to 'cargo_class' to make model declaration more consistent.
bug fix
doc update