2013/12/5 Daniel Kulp <dk...@apache.org> > > On Dec 5, 2013, at 11:03 AM, Achim Nierbeck <bcanh...@googlemail.com> > wrote: > > > Hi Johan, > > > > I'm fully with you for the client side I wouldn't walk that path for a > > Karaf without Blueprint. > > I just have the feeling that especially for the minimal bundle it could > be > > really helpful to start without > > blueprint. > > @Dan regarding minimal and blueprint, yes though I think since we'd still > > provide the blueprint feature it would be viable way of doing minimal > > without blueprint but the user who still needs it > > needs to depend on that blueprint feature. > > The issues is what to do about frameworks that need blueprint, but the > user may not. The user may not even know that Blueprint is needed. > Their app may be completely spring-dm based or something. However, if they > depend on CXF, they would also need blueprint or CXF won’t work (CXF uses > Blueprint in many places). (Yes, changing CXF to use DS or something is > certainly a possible enhancement, anyone want to tackle that?) > > Right now, there isn’t a “blueprint” feature that CXF can depend on. We > can add one for 3.1 or 4.0, but if CXF then depends on it, then it would no > longer load into any 2.3.x Karaf without also doing a 2.3.x release. > That’s mostly my point, removing something that is there by default in 2.3 > or 3.0 WILL have user impact. It’s not a major one, but it is something > that needs to be considered on how to manage it, particularly for > frameworks that tend to try and keep a range of compatible Karaf versions > supported. > > It could also be something like having a very small bundle listener or > bundle install hook or something in the core that when a bundle is loaded > (pre-resolve), if there is a "Bundle-Blueprint” manifest, it would > automatically start the blueprint feature. Might have some timing quirks > that would need to be worked out, but possibly doable. > > Instead of using a bundle listener which would only be called after installation, it may be easier to just improve the FeaturesService implementation to automatically add those requirements at runtime. In short, we could easily rewrite the FeaturesServiceImpl#resolve(Feature) method and hack what we need there: look at bundles and if they have a blueprint header, add all the blueprint bundles. This would be more robust than relying on a different bundle to kick in imho. In the same area, we could also get rid of the OBR resolver and build a new one using the real OSGi resolver, but that's a separate discussion I think.
> Dan > > > > > > > regards, Achim > > > > > > 2013/12/5 Johan Edstrom <seij...@gmail.com> > > > >> Looking out there, I've seen one customer using DS in the last 3 years > or > >> so. > >> TX, JPA, Spring migrations, Spring only, BP only - sure. > >> Not to mention NS Handlers and so on. > >> > >> It would make a "tiny" karaf viable, less deps and faster startup. > >> I doubt any developing user would (want to) be able to give up DI. > >> > >> /je > >> > >> On Dec 5, 2013, at 8:36 AM, Jean-Baptiste Onofré <j...@nanthrax.net> > wrote: > >> > >>> You are right, but we should be careful about the side effects, > overlap, > >> etc ;) > >>> > >>> On 12/05/2013 04:32 PM, Achim Nierbeck wrote: > >>>> As far as I understood the idea, it's > >>>> to use DS for Karaf itself, not to get rid of Blueprint. > >>>> Just so Karaf itself does have a smaller footprint. > >>>> @Ioannis did I get this right? > >>>> > >>>> regards, Achim > >>>> > >>>> > >>>> 2013/12/5 Jean-Baptiste Onofré <j...@nanthrax.net> > >>>> > >>>>> Good point Dan. > >>>>> > >>>>> I think you should not hurry about this. > >>>>> > >>>>> Ioannis did a good PoC, but I quickly discussed with him and his goal > >> is > >>>>> not to "force" the inclusion on Karaf 3.x. > >>>>> > >>>>> I think it makes more sense (and it's wise ;)), to act for a plan for > >>>>> Karaf 4.x. > >>>>> > >>>>> Regards > >>>>> JB > >>>>> > >>>>> > >>>>> On 12/05/2013 04:26 PM, Daniel Kulp wrote: > >>>>> > >>>>>> > >>>>>> On Dec 5, 2013, at 7:31 AM, Guillaume Nodet <gno...@apache.org> > >> wrote: > >>>>>> > >>>>>> I think that can be argued : it's a big internal change, but not > >> really a > >>>>>>> user-facing one. If the work is done in a compatible way (which I > >> think > >>>>>>> is > >>>>>>> doable and should be the goal), it can be done in a minor release, > >> as it > >>>>>>> would be almost transparent for the user: i.e. a user should still > be > >>>>>>> able > >>>>>>> to deploy his own application without any changes. So I don't > think > >> it > >>>>>>> requires a major version change. > >>>>>>> > >>>>>> > >>>>>> Well, there COULD be an impact…. Right now, some of the > features.xml > >>>>>> files out there just assume blueprint is available. For example, > >> CXF’s > >>>>>> just assumes blueprint is there. They don’t depend on any > >> “blueprint” > >>>>>> feature. Thus, an application (or CXF) that would deploy fine on > >> the > >>>>>> minimal container out of the box right now would not with 3.1 (or > >> whatever) > >>>>>> where blueprint isn’t there. > >>>>>> > >>>>>> We COULD adjust for this by adding a “blueprint” feature right now > >>>>>> (before 3.0 ships) that is relatively redundant with the “framework” > >>>>>> feature (or have framework depend on the new blueprint) that the > other > >>>>>> features.xml could start depending on. That could also be added > for > >> a > >>>>>> 2.3.x patch as well. > >>>>>> > >>>>>> > >>>>>> > >>>>>> Dan > >>>>>> > >>>>>> > >>>>>> > >>>>>> 2013/12/5 Jamie G. <jamie.goody...@gmail.com> > >>>>>>> > >>>>>>> Just wanted to contribute my 2 cents -- I'd look at a SCR Karaf for > >> 4.0 > >>>>>>>> - > >>>>>>>> removing Blueprint dependencies from the core is too major a > change > >> to > >>>>>>>> try > >>>>>>>> to introduce it to 2.3.x or 3.0 at this stage. > >>>>>>>> > >>>>>>>> --Jamie > >>>>>>>> > >>>>>>>> > >>>>>>>> On Thu, Dec 5, 2013 at 8:10 AM, Jean-Baptiste Onofré < > >> j...@nanthrax.net > >>>>>>>> > >>>>>>>>> wrote: > >>>>>>>>> > >>>>>>>> > >>>>>>>> I think we have to distinguish different things: > >>>>>>>>> - the learn curve and usage "outside" of Karaf for developers. > CDI > >> is > >>>>>>>>> > >>>>>>>> like > >>>>>>>> > >>>>>>>>> EJB, and other framework. > >>>>>>>>> - the usage of CDI "inside" an OSGi application or Karaf itself > >> (or for > >>>>>>>>> "native" OSGi applications). > >>>>>>>>> > >>>>>>>>> The fact that Karaf now supports CDI (via pax-cdi) is as good as > >>>>>>>>> supporting OpenEJB (in KarafEE), or Spring (in Karaf "natively"). > >>>>>>>>> > >>>>>>>>> I would not use OpenEJB in Karaf "itself", nor Spring, nor CDI. > >>>>>>>>> > >>>>>>>>> If a developer wants to create a "generic" application (that can > >> work > >>>>>>>>> in > >>>>>>>>> both OSGi or non-OSGi containers), CDI is good. > >>>>>>>>> If a developer want to create a native OSGi application, I would > >> use > >>>>>>>>> natively OSGi "specific" framework (like blueprint). > >>>>>>>>> > >>>>>>>>> My 0.02€ > >>>>>>>>> > >>>>>>>>> Regards > >>>>>>>>> JB > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> On 12/05/2013 12:06 PM, Christian Schneider wrote: > >>>>>>>>> > >>>>>>>>> Probably you are right. > >>>>>>>>>> > >>>>>>>>>> The reason why I came up with CDI is that it has the potential > to > >> be > >>>>>>>>>> the > >>>>>>>>>> core of user applications. > >>>>>>>>>> It is fully featured regarding web and persistence if you > include > >>>>>>>>>> other > >>>>>>>>>> JavaEE stuff and also defines a standardized extension > mechanism. > >>>>>>>>>> CDI is also well known to JavaEE developers. So my point is/was > >> that > >>>>>>>>>> CDI > >>>>>>>>>> may be the only thing a developer needs to learn regarding > >> dependency > >>>>>>>>>> injection. > >>>>>>>>>> > >>>>>>>>>> On the other hand a programmer of user applications running on > >> karaf > >>>>>>>>>> is > >>>>>>>>>> quite decoupled from the karaf services and commands. > >>>>>>>>>> So it is probably not necessary that he uses and understands the > >> karaf > >>>>>>>>>> internals. So from this perspective minimum footprint counts > more > >> than > >>>>>>>>>> having only one framework. So from this point of view DS really > is > >>>>>>>>>> better than CDI. > >>>>>>>>>> > >>>>>>>>>> Another argument supporting this is that while I see most > >> potential in > >>>>>>>>>> CDI to take over dependency injection in user space it is far > >> from the > >>>>>>>>>> only solution. So there will always be people who use something > >> else. > >>>>>>>>>> As > >>>>>>>>>> karaf needs to support a wide range of frameworks this also > >> speaks for > >>>>>>>>>> minimum footprint for karaf's internals. > >>>>>>>>>> > >>>>>>>>>> Christian > >>>>>>>>>> > >>>>>>>>>> On 05.12.2013 11:49, Guillaume Nodet wrote: > >>>>>>>>>> > >>>>>>>>>> 2013/12/5 Christian Schneider <ch...@die-schneider.net> > >>>>>>>>>>> > >>>>>>>>>>> Good idea to look into alternatives to blueprint. > >>>>>>>>>>> > >>>>>>>>>>>> > >>>>>>>>>>>> The big advantage I see for DS is that it is very light > weight. > >> I am > >>>>>>>>>>>> > >>>>>>>>>>> not > >>>>>>>> > >>>>>>>>> so sure about its long term future though. > >>>>>>>>>>>> I personally think the future of OSGi dependency injection is > >> CDI > >>>>>>>>>>>> like > >>>>>>>>>>>> pax-cdi + weld or openwebbeans. > >>>>>>>>>>>> Of course this is not really near term and far from being a > sure > >>>>>>>>>>>> bet. > >>>>>>>>>>>> Still I think if we switch the DI framework we should > >>>>>>>>>>>> also at least experiment with CDI. I am currently working on a > >> karaf > >>>>>>>>>>>> tutorial for CDI. The service injections already work very > well. > >>>>>>>>>>>> I am now looking into jpa support. > >>>>>>>>>>>> > >>>>>>>>>>>> I disagree. CDI will have the same problems as blueprint, > it's > >> an > >>>>>>>>>>>> > >>>>>>>>>>> application level injection framework, not focused *primarily* > on > >>>>>>>>>>> OSGi. > >>>>>>>>>>> The lifecycle of CDI beans has to be static, so you have to use > >>>>>>>>>>> > >>>>>>>>>> proxies. > >>>>>>>> > >>>>>>>>> Blueprint has the exact same problem where the beans lifecycle > is > >>>>>>>>>>> bound to > >>>>>>>>>>> the lifecycle of the container. On the opposite, DS has a > >> better > >>>>>>>>>>> lifecycle mechanism for beans which can naturally handle the > OSGi > >>>>>>>>>>> dynamism. > >>>>>>>>>>> > >>>>>>>>>>> And CDI would be even more heavyweight than blueprint, so I'd > >> rather > >>>>>>>>>>> stick > >>>>>>>>>>> with blueprint than switching to CDI, even if it were ready. > >>>>>>>>>>> The real benefit of DS is that it has been designed to handle > the > >>>>>>>>>>> OSGi > >>>>>>>>>>> dynamism, so it does less, but it does it better. > >>>>>>>>>>> > >>>>>>>>>>> > >>>>>>>>>>> In any case I think switching the DI framework should be > >> considered > >>>>>>>>>>> > >>>>>>>>>> for > >>>>>>>> > >>>>>>>>> karaf 4. So in this case we have a bit of time to experiment. > >>>>>>>>>>>> > >>>>>>>>>>>> Christian > >>>>>>>>>>>> > >>>>>>>>>>>> > >>>>>>>>>>>> On 04.12.2013 21:41, Ioannis Canellos wrote: > >>>>>>>>>>>> > >>>>>>>>>>>> For anyone curious on how Karaf without Blueprint would look > >> like, > >>>>>>>>>>>> > >>>>>>>>>>>>> here is a karaf branch that is free of blueprint: > >>>>>>>>>>>>> https://github.com/iocanel/karaf/tree/karaf-light (it's a > >> fork of > >>>>>>>>>>>>> > >>>>>>>>>>>> the > >>>>>>>> > >>>>>>>>> karat-2.3.x branch). > >>>>>>>>>>>>> > >>>>>>>>>>>>> It is actually a refactored karaf 2.3.x that removes > blueprint > >> from > >>>>>>>>>>>>> all modules (yet still provides blueprint as feaures). Karaf > >>>>>>>>>>>>> specific > >>>>>>>>>>>>> blueprint namespace handlers have moved to optional bundles > so > >> that > >>>>>>>>>>>>> they can still be used if needed. > >>>>>>>>>>>>> Blueprint has been replaced with Felix SCR (including the > shell > >>>>>>>>>>>>> commands). Moreover, misc refactorings on features and > startup > >>>>>>>>>>>>> > >>>>>>>>>>>> bundles > >>>>>>>> > >>>>>>>>> have been performed in order to reduce the size and the amount of > >>>>>>>>>>>>> bundles in the minimal distro. > >>>>>>>>>>>>> > >>>>>>>>>>>>> The result is a minimal distribution that starts 12 bundles > [1] > >>>>>>>>>>>>> (out > >>>>>>>>>>>>> of 37 which were part of karaf 2.3.3 minimal distro). 10 of > >> those > >>>>>>>>>>>>> bundle were blueprint bundles and the rest are extra noise. > >>>>>>>>>>>>> > >>>>>>>>>>>>> My motivation behind this refactoring was: > >>>>>>>>>>>>> i) I like declarative services more than blueprint. > >>>>>>>>>>>>> ii) I've been working on projects that are packaged inside > the > >>>>>>>>>>>>> karaf > >>>>>>>>>>>>> minimal distro which would benefit from a smaller size (e.g. > >>>>>>>>>>>>> jclouds-cli). > >>>>>>>>>>>>> iii) I wanted to make a karaf distro as flexible as possible. > >>>>>>>>>>>>> > >>>>>>>>>>>>> Please note that my main focus was the minimal distribution > and > >>>>>>>>>>>>> also > >>>>>>>>>>>>> this is not 100% polished. > >>>>>>>>>>>>> > >>>>>>>>>>>>> Enjoy! > >>>>>>>>>>>>> > >>>>>>>>>>>>> > >>>>>>>>>>>>> [1]: The bundle list of the minimal distro: > >>>>>>>>>>>>> > >>>>>>>>>>>>> ID State Level Name > >>>>>>>>>>>>> [ 0] [Active ] [ 0] System Bundle (4.0.3) > >>>>>>>>>>>>> [ 1] [Active ] [ 5] OPS4J Pax Url - mvn: (1.3.6) > >>>>>>>>>>>>> [ 2] [Active ] [ 5] OPS4J Pax Url - wrap: (1.3.6) > >>>>>>>>>>>>> [ 3] [Active ] [ 8] OPS4J Pax Logging - API (1.7.1) > >>>>>>>>>>>>> [ 4] [Active ] [ 8] OPS4J Pax Logging - Service > >> (1.7.1) > >>>>>>>>>>>>> [ 5] [Active ] [ 10] Apache Felix Configuration Admin > >>>>>>>>>>>>> Service > >>>>>>>>>>>>> (1.6.0) > >>>>>>>>>>>>> [ 6] [Active ] [ 11] Apache Felix File Install > (3.2.6) > >>>>>>>>>>>>> [ 7] [Active ] [ 13] Apache Felix Declarative > Services > >>>>>>>>>>>>> > >>>>>>>>>>>> (1.6.2) > >>>>>>>> > >>>>>>>>> [ 8] [Active ] [ 25] Apache Karaf :: Shell :: Console > >>>>>>>>>>>>> (2.3.4.SNAPSHOT) > >>>>>>>>>>>>> [ 9] [Active ] [ 30] Apache Karaf :: Features :: Core > >>>>>>>>>>>>> (2.3.4.SNAPSHOT) > >>>>>>>>>>>>> [ 10] [Active ] [ 30] Apache Karaf :: Features :: > >> Command > >>>>>>>>>>>>> (2.3.4.SNAPSHOT) > >>>>>>>>>>>>> [ 11] [Active ] [ 30] Apache Karaf :: Shell :: Log > >> Commands > >>>>>>>>>>>>> (2.3.4.SNAPSHOT) > >>>>>>>>>>>>> [ 12] [Active ] [ 30] Apache Karaf :: Shell :: OSGi > >> Commands > >>>>>>>>>>>>> (2.3.4.SNAPSHOT) > >>>>>>>>>>>>> > >>>>>>>>>>>>> > >>>>>>>>>>>>> -- > >>>>>>>>>>>>> > >>>>>>>>>>>> Christian Schneider > >>>>>>>>>>>> http://www.liquid-reality.de > >>>>>>>>>>>> > >>>>>>>>>>>> Open Source Architect > >>>>>>>>>>>> http://www.talend.com > >>>>>>>>>>>> > >>>>>>>>>>>> > >>>>>>>>>>>> > >>>>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> -- > >>>>>>>>> Jean-Baptiste Onofré > >>>>>>>>> jbono...@apache.org > >>>>>>>>> http://blog.nanthrax.net > >>>>>>>>> Talend - http://www.talend.com > >>>>>>>>> > >>>>>>>>> > >>>>>>>> > >>>>>> > >>>>> -- > >>>>> Jean-Baptiste Onofré > >>>>> jbono...@apache.org > >>>>> http://blog.nanthrax.net > >>>>> Talend - http://www.talend.com > >>>>> > >>>> > >>>> > >>>> > >>> > >>> -- > >>> Jean-Baptiste Onofré > >>> jbono...@apache.org > >>> http://blog.nanthrax.net > >>> Talend - http://www.talend.com > >> > >> > > > > > > -- > > > > Apache Karaf <http://karaf.apache.org/> Committer & PMC > > OPS4J Pax Web <http://wiki.ops4j.org/display/paxweb/Pax+Web/> Committer > & > > Project Lead > > OPS4J Pax for Vaadin <http://team.ops4j.org/wiki/display/PAXVAADIN/Home> > > Commiter & Project Lead > > blog <http://notizblog.nierbeck.de/> > > -- > Daniel Kulp > dk...@apache.org - http://dankulp.com/blog > Talend Community Coder - http://coders.talend.com > >
