OSGi spec R8 and Blueprint in Karaf

[Jan Fetyko <ja...@gmail.com>]

Dear Karaf team,

I'm wondering if anybody has an idea what will happen to Blueprint support
in Karaf when it moves to support OSGi spec version 8, which as far as I
can tell, has the Blueprint spec removed.

A related question is, why was that spec even removed ? There is no mention
of its removal anywhere that I can find, but it is for sure not there.

Anybody have any insight or thoughts about the above concerns ?

Thank you,

Jan

Re: OSGi spec R8 and Blueprint in Karaf

[David Bosschaert <da...@gmail.com>]

Hi Jan,

While Blueprint was removed from the overall OSGi R8 Compendium spec
document this doesn't mean the spec doesn't exist any more it's still part
of the OSGi R7 Compendium spec:
https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.blueprint.html

Main reason why it was removed was that nobody was helping to maintain this
specification and that as it was, the Blueprint spec contains some
decisions that over time have turned out to not be ideal (for example the
Service Damping that Blueprint has turned out to be counter productive in
large systems).
If someone starts maintaining Blueprint to fix its issues, it might come
back into the set of OSGi specs in the future.

Having said that, OSGi is not about implementing everything at once, but
more aimed at 'implement just what you need'. Additionally, OSGi specs are
versioned, and in many cases mixing specs implementation of R8 Compendium
can perfectly well be combined with older specs implementations.
So in short, if you need Blueprint you can just pick up an implementation
that supports the existing R7 specs and you should be able to combine it
with newer specs implementations from R8.
If you need _improvements_ to Blueprint, then someone needs to jump in and
start maintaining it: https://github.com/osgi/osgi (the OSGi spec process
is now at Eclipse, that link should get you started).

Best regards,

David

On Sun, 20 Mar 2022 at 16:10, Jan Fetyko <ja...@gmail.com> wrote:

> Dear Karaf team,
>
> I'm wondering if anybody has an idea what will happen to Blueprint support
> in Karaf when it moves to support OSGi spec version 8, which as far as I
> can tell, has the Blueprint spec removed.
>
> A related question is, why was that spec even removed ? There is no mention
> of its removal anywhere that I can find, but it is for sure not there.
>
> Anybody have any insight or thoughts about the above concerns ?
>
> Thank you,
>
> Jan
>