Davanum Srinivas wrote:
Folks,
Any interest in support for RFC 124, "A Component Model for OSGi"?
http://www.osgi.org/download/osgi-4.2-early-draft.pdf
This is in addition to typical J2EE artifacts that we already support.
thanks,
dims
Time, I think, to give this thread a kick.
There are lots of different aspects to this, so I think we should first
make an attempt at deciding what the target goal is here. RFC 124 (aka,
the "blueprint service") is inherently an OSGi thing, so first we need
to address what it means to add OSGi to Geronimo. And, I think, in
general, this really means "OSGi as a Geronimo application programming
model".
This can have multiple meanings. One approach, already under discussion
in the "Whence Geronimo kernel?" thread would be rearchitect the
Geronimo kernel around OSGi bundles and the OSGi classloading model. In
this mode, an application model should be fairly simple to add, though
there may be some issues of bridging between the OSGi "bundle world" and
the JEE programming model. Additions like the blueprint service might
be directly usable within the Geronimo kernel for assembly and injection.
Another approach would be to add an OSGi application container to
Geronimo. This would allow OSGi/blueprint-based applications to be
hosted on Geronimo, and there may be some Geronimo services that get
exposed to the apps, but the apps run in their own separate environment.
The container approach is, I believe, probably the easier path, but we I
think we lose a lot of the advantages of the OSGi model in other
places. Also, OSGi is working on a number of additional RFCs that will
add different JEE concepts to the platform. I'd hate to think that
Geronimo might need to maintain two versions of each of these pieces,
one for the OSGi container and one for the non-OSGi world.
Anyway, I think regardless of the implementation approach, we need to
start discussing this in terms of "what does it mean to host an OSGi
application on Geronimo?". Here are a few questions that immediately
come to mind:
1. How are applications deployed? Is there some higher-level
deployment model than the bundle level?
2. What services are available Geronimo application environment?
Blueprint is certainly one service, what others do we need?
3. How is the config-admin service managed? Do we need Geronimo
console access and editting of config admin properties?
4. Are there any bridges from the OSGi world to the JEE world? For
example, is is possible to export service registry instances to JNDI?
I think this is a good starting point for discussing ideas....I'm sure
there are additional questions that will come up in the discussions.
Rick
