Re: OSGi Manifests in Maven JARs

[Jason van Zyl]

On 29 Jun 06, at 11:51 PM 29 Jun 06, Niclas Hedhman wrote:
On Thursday 29 June 2006 23:38, Jason van Zyl wrote:

I took a quick look at the OSGi plugin that you guys have and I
quickly tried to hack it up so that the standard Maven Jar plugin
used some of the logic to add the appropriate manifest entries.

Thanks for the interest. _I_ am not entirely sure what you are  
actually trying
to achieve and what the request really is.


It's not really a request, it's an offer being made after chatting  
with Richard.

Out of all the code for the plugin, very little is duplicated work,  
although
there are a couple of lines.


You're basically doing what the JAR plugin is doing. You should be  
able to easily extend the JAR plugin to add bits and pieces to the  
resultant JAR.

More important issue, IMHO, is the general <configuration> tag for  
plugins,
which can't at all be decoupled from the <plugin> declaration. Many  
OSGi
projects consists of a lot of bundles, and having a lot of  
duplication of
both the plugin declaration as well as common manifest entries  
makes each
bundle's pom fairly extensive, even if it doesn't really need to be.

I forked[1] the Maven OSGi plugin to allow me to put these entries as
<properties> entries in the pom instead, which made the project  
poms very
nimble. That change has not made it into the Felix version.

What would be cool is a 'extension' mechanism for the configuration  
section of
a plugin. Not sure how it should look like, but where it is  
possible to
override configuration elements of the parent pom's plugin  
declaration with
additional or new values, and without deeply nested XML elements.


Ok, these are all things that can be done in the future. My  
suggestion as a first step is something would place information in  
standard JARs that will be useful for OSGi users. So we're talking  
zero configuration on the part of the typical user and OSGi folks get  
a non-optimal set of entries in the manifest. So in this first step  
let's take commons-logging for example: the commons-logging people  
won't know anything about OSGi but some basic OSGi manifest entries  
will be placed in the JAR in the hopes that the commons-logging JAR  
doesn't have to be repackaged for use with an OSGi environment.

So this is just a first simple step to try and help OSGi leverage  
anything that is built with Maven. Once that is done we can work on  
the configuration bits that people might use to take full advantage  
of OSGi features and there are a couple people here at ApacheCon like  
the Jetty folks who would like to try the extended features to make a  
Jetty bundle. But simple steps first :-)

Jason.


Cheers
Niclas

[1] Source is available at;
    https://scm.ops4j.org/repos/ops4j/projects/pax/maven/osgi-bundle/


Jason van Zyl
[EMAIL PROTECTED]