[Proposal] Separate xwiki configuration from the XWiki WAR

[Vincent Massol]

Hi,

For XWiki 1.1 I'd like to separate XWiki's configuration files from  
the generated WAR.

What I mean by configuration files: xwiki.cfg, hibernate.cfg.xml,  
xwiki.hbm, feeds.hbm and possibly some others.

Rationale:

1) It would be nice to release different already made configurations  
for XWiki: for HSQLDB, for MySQL, for Oracle, with a minimal list of  
plugins configured, with all plugins enabled, with virtual wiki set  
up, etc. It's going to be way better to release a single WAR that is  
the same for all configs and a set of config files separately. This  
also makes it much easier in the build process.

2) It's currently a little bit of a pain for users when they upgrade  
their xwiki installation to a newer version. They have to remember to  
save their config files, to unpack the XWiki WAR, modify the  
configuration files, etc. What if an upgrade was a simple as dropping  
the new WAR file in the webapps/ directory of your servlet container? :)

Thus I'd like to propose the following strategy:

* XWiki looks for where the config files are stored using the  
following algorithm:
   1) first it checks if a system property has been defined (say for  
example "xwiki.configuration.directory")
   1) if not, it checks if a location has been specified in the  
web.xml file (as an init parameter)
   2) if not found, it checks if the files can be found at the root  
of the classpath (e.g. "/xwiki.cfg")
* The standalone distribution contains an already configured  
directory structure which uses the system property strategy for  
finding the configuration directory.

<further future - but not too far as it's the best solution I think>
We should propose a configuration wizard application which is in  
charge of generating xwiki configuration files. I propose the  
following distribution channels:

- as a webapp wizard configured on xwiki.org. Users use forms to  
select what they want (which plugin, virtual wiki or not, etc). It  
generate the files that can be downloaded by the users. Actually this  
can even be implemented as a XWiki Application... ;-) Eating our dog  
food they said...

- as a webapp wizard released inside the default WAR and that is  
activated automatically if no configuration is found, i.e. the first  
time XWiki is started. This is really by far the best I believe.

</further future>

WDYT?

Thanks
-Vincent