Thanks, if we "stay" at build time, we can always find workaround (fragment, wrap/uber bundle, ...). Not sure we have a lot of use cases for the "runtime" approach though.
Regards JB On 19/03/2019 13:51, Grzegorz Grzybek wrote: > Thank you very much for constructive feedback. > > Fragment bundle for servlet-api fixes my problem with "[3.1,4)" import > range perfectly. > I'll keep the "bundle processor" mechanism in local branch - maybe there'll > come some useful scenarios for it? > > regards > Grzegorz Grzybek > > > wt., 19 mar 2019 o 13:42 Jean-Baptiste Onofré <j...@nanthrax.net> napisał(a): > >> Hi Stephan, >> >> that's what I meant by different between wrap and feature processing. >> >> At least, it requires a good documentation and should be considered as >> "last chance action" ;) >> >> A fragment could work, but also a dedicated "wrapper" bundle (as we do >> for other spec), but that's at build time. Greg is proposing "runtime". >> >> Regards >> JB >> >> On 19/03/2019 11:30, Siano, Stephan wrote: >>> Hi Jean-Baptiste, >>> >>> What Grzegorz is proposing looks to me like some magic behind-the-scenes >> automatic wrap for all kind of installed bundles. >>> >>> I am not sure if this is really such a good idea. If it works, it can >> make things work that do not work without some significant effort like >> manually wrapping all bundles that reference the servlet API. If there are >> issues, you will have a situation, which is extremely hard to analyze with >> having bundles wiring to other bundles they are not supposed to be wiring >> according to their manifest. >>> >>> Even if that works with servlet API 4.0 for some reason, once that >> mechanism is there, it will likely be used for other packages, and once you >> have defined changes to several packages which cause the auto-wrap of >> dozens of bundles, I really think that it will be very difficult to >> understand the wiring afterwards. >>> >>> Therefore IMHO the least ugly workaround for this issue would be to >> create a fragment bundle for the servlet-api bundle that exports the >> packages with some lower version number (e.g. 3.2) that is only installed >> if it's really necessary. Over time the developers of the bundles >> referencing the servlet API hopefully asses whether their bundle also works >> with the servlet 4.0 API and adapt their import ranges accordingly (so the >> fragment can go away eventually). >>> >>> Best regards >>> Stephan >>> >>> -----Original Message----- >>> From: Jean-Baptiste Onofré <j...@nanthrax.net> >>> Sent: Dienstag, 19. März 2019 10:24 >>> To: dev@karaf.apache.org >>> Subject: Re: Idea - how to override bundle headers without wrap: >>> >>> Hi Grzegorz >>> >>> I think what you are proposing is at different level than wrap. >>> >>> wrap is more for single jar (and works "outside" of Karaf) whereas your >>> proposal is at feature level. >>> >>> It makes sense but we have to keep it simple and clear (in term of >>> documentation). I think we should improve the feature processing >>> documentation: in which case should I use it, and how to use it. >>> >>> But overall +1 to me. >>> >>> Regards >>> JB >>> >>> On 19/03/2019 08:26, Grzegorz Grzybek wrote: >>>> Hello >>>> >>>> I was thinking about one scenario. In my custom distro, I'm using >> pax-web >>>> 7.3.3 (tech preview >>>> <https://groups.google.com/d/msg/ops4j/JP5L63Qh4u8/nPG1LN4HAAAJ>) which >>>> uses Undertow 2, Tomcat 9 and Servlet API 4. >>>> >>>> The "problem" is that maven-bundle-plugin, by default (and correctly) >>>> generates import ranges according to pom dependencies. So if pom has >>>> javax.servlet-api-3.1.0 dep, generated Import-Package header will have >>>> (correctly) "[3.1,4.0)" range which is the most natural range according >> to >>>> semantic versioning. >>>> >>>> The problem is that with some deps (and servlet-api used in >>>> "@org.osgi.annotation.versioning.ConsumerType" mode is such dependency) >>>> you're safe to use newer version of the API. >>>> >>>> There were different approaches to this problem, see for example: >>>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=385806 where bundles >> either >>>> export packages in many versions or export lower version than one >> matching >>>> directly JavaEE specification. For example, >>>> geronimo-servlet_3.0_spec-1.0.jar exports javax.servlet package with >>>> version 2.6 and 3.0. >>>> >>>> What I did (locally) is a little enhancement to new >> override&blacklisting >>>> mechanism configured in etc/org.apache.karaf.features.xml. I added this >>>> section for example: >>>> >>>> <bundleProcessing> >>>> <bundle location="mvn:org.eclipse.jetty*/*"> >>>> <add header="Processed-By" value="Karaf Bundle Processor" /> >>>> <clause header="Import-Package" name="javax.servlet" >>>> value='javax.servlet;version="[3.1.0,5)"' /> >>>> <clause header="Import-Package" name="javax.servlet.annotation" >>>> value='javax.servlet.annotation;version="[3.1.0,5)"' /> >>>> <clause header="Import-Package" name="javax.servlet.descriptor" >>>> value='javax.servlet.descriptor;version="[3.1.0,5)"' /> >>>> <clause header="Import-Package" name="javax.servlet.http" >>>> value='javax.servlet.http;version="[3.1.0,5)"' /> >>>> </bundle> >>>> </bundleProcessing> >>>> >>>> My goal was to be able to install for example "camel-websocket" feature >>>> which uses jetty which (at version 9.4) requires servlet API 3.1. >>>> >>>> FeaturesProcessor (the one that currently can override URIs of bundles >> or >>>> entire feature, blacklist features, bundle and repository URIs, has >>>> (locally in my branch) ability to transform a bundle when matching some >>>> criteria. >>>> >>>> In the above example, I can override all jetty bundles, so each >> *individual >>>> clause* (unlike with wrap: where you work at header level) can be >> changed. >>>> I can add full headers, remove headers, modify headers or modify >> individual >>>> clauses. >>>> >>>> For example, to install jetty-util bundle, I had to wrap: it with: >>>> >>>> >> wrap:mvn:org.eclipse.jetty/jetty-util/9.4.12.v20180830$overwrite=merge&Import-Package=javax.imageio,javax.naming,javax.naming.ldap,javax.net.ssl,javax.security.auth.x500,javax.xml.parsers,org.slf4j.*;resolution:=optional;version="[1.7.25,2)",javax.servlet.*;version="[3.1,5)" >>>> >>>> remembering to preserve existing Import-Package clauses. >>>> >>>> With XML configuration I can focus only on fixing javax.servlet.* import >>>> clauses. >>>> >>>> The transformed (repackaging + manifest change) bundles are stored in >> (by >>>> default) ${karaf.data}/repository-bpr (bpr = bundle processing) >> directory, >>>> which is also explicitly prepended to >>>> org.ops4j.pax.url.mvn.defaultRepositories option used by maven resolver >>>> used by features service. >>>> >>>> Fitting into existing features processor mechanism, this change is >> actually >>>> not that big. I see nice potential in it, but I'd very like to get your >>>> opinion on it - maybe additional ideas? Or problems with current idea? >>>> >>>> best regards >>>> Grzegorz Grzybek >>>> >>> >> >> -- >> 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