22 Mar
2010
22 Mar
'10
9:53 a.m.
Hi,
I'd like to propose a small variation which is to consider WEB-INF/* properties as
default values and all the other location are overrides.
Thus to summarize:
Use Cases:
UC1: Easy install: no need to explode the XAR to install XWiki. See also the comment about
xwiki on http://java.dzone.com/articles/file-system-storage-and
UC2: Easy upgrade: no need to take care about saving the configuration so that it's
not overwritten by an upgrade
UC3: Should be possible to have multiple installs on the same machine and running at the
same time
UC4: Should be possible to control the location of the configuration files for our
automated functional tests (so that we control the configuration used)
UC5: Make XWiki work without configuration files
Implementation:
0) Read the default properties from xwiki.cfg and xwiki.properties and the steps below (1)
to 4)) will override these default values, so that users only need to define properties
they want to override. Note that ideally we would do the same with hibernate.cfg.xml but
it's harder to implement since it means merging an XML file.
1) Look for a system property (e.g. xwiki.config.dir) defining a directory location and if
defined look for the files in it using File IO (I know it's not JEE kosher but
it's acceptable IMO, especially since it won't break and we'll fallback in
case of problem). Could be relative or absolute.
2) If not found, look for a JNDI property that gives the location of the config directory
3) If not found, look for config files in [user.home]/.xwiki
wdyt?
Thanks
-Vincent
On Mar 19, 2010, at 6:08 PM, Vincent Massol wrote:
Hi devs,
I've been wanting to make it easy to upgrade XWiki from one version to another for
some time (I'm not talking about XAR upgrade here, that's the extension manager).
I'm talking about XWiki configuration files.
Here are the use cases I'd like to solve:
UC1: Easy install: no need to explode the XAR to install XWiki. See also the comment
about xwiki on http://java.dzone.com/articles/file-system-storage-and
UC2: Easy upgrade: no need to take care about saving the configuration so that it's
not overwritten by an upgrade
UC3: Should be possible to have multiple installs on the same machine and running at the
same time
UC4: Should be possible to control the location of the configuration files for our
automated functional tests (so that we control the configuration used)
The configuration files I'm talking about are:
* xwiki.cfg
* hibernate.cfg.xml
* xwiki.properties
Proposed Solution:
===============
1) Look for a system property (e.g. xwiki.config.dir) defining a directory location and
if defined look for the files in it using File IO (I know it's not JEE kosher but
it's acceptable IMO). Could be relative or absolute.
2) If not found, look for a JNDI property that gives the location of the config
directory
3) If not found, look for config files in [user.home]/.xwiki
4) If not found, emit an error explaining how to configure xwiki
1) solves UC3 and UC4
2) solves UC3
3) solves UC1 and UC2
Note
====
I'm not suggesting any backward compatibility here since it's a new way of
configuring XWiki. It means upgraders will need to read the release notes/doc to
understand how to configure XWiki.
If really needed, we could devise a backward compat strategy, but I'm not sure we
absolutely need that.
WDYT?
Thanks
-Vincent