Hi Grzegorz, Sorry about the delay in getting back to you.
I realise your concerns about sci's from different webapps interfering with each other. However the SCI mechanism appears to be the way that the other web technologies, such as JAXRS and SpringMVC have a chance to detect and influence the creation of the servlet. Given that ServiceLoader architecture is being used, is it unreasonable that all possible instances for the SCI get asked to look at the bundle and initialize the context is appropriate? If not, then we need another way to extend the WebExtender with other web frameworks, allowing them to get involved with servlet creation. Which does not include altering the webapp in some OSGI specific way. Cheers Paul On 30 Oct 2020, 08:46, at 08:46, Grzegorz Grzybek <[email protected]> wrote: >Hello > >czw., 29 paź 2020 o 19:50 Matt Pavlovich <[email protected]> napisał(a): > >> Paul-- >> >> You might checkout a BundleTracker. A BundleTracker is ensured to >get a >> callback for every bundle, regardless as to when your bundle started. >With >> a BundleListener, there is a race condition that you may not be >activated >> before some bundles that you care about. >> > >It's not about bundle tracker or listener. Whiteboard implementation >uses >such tracker to ensure that when a bundle is gone, all associated >contexts >and web elements should be deregistered. >It's more about which bundles should be scanned for >ServletContainerInitializers. imagine you install two "sets" of bundles >(e.g., Karaf features) - you don't want SCIs from one feature (web >application) to be used in another feature/web application... > >regards >Grzegorz Grzybek > > >> >> ref: >> >https://docs.osgi.org/specification/osgi.core/7.0.0/util.tracker.html#d0e52020 >> >> -Matt >> >> On Thursday, October 29, 2020 at 1:17:19 PM UTC-5 >[email protected] >> wrote: >> >>> >>> Thanks Grzegorz. I know what you mean about doing my "normal job", >I >>> also have be careful as to what can be shared to the community. >>> >>> I realise that the ServiceLoader is a bit of a problem and I've >already >>> had to alter other standard services to be bundle-aware. Which is >why I >>> think implementing a Bundle Listener could be a better approach for >the >>> SCI's. >>> >>> I'm out of the office for a couple of weeks so I'm going to look >>> prototyping a solution when I get back. >>> >>> Cheers >>> Paul >>> On 29 Oct 2020, at 13:28, Grzegorz Grzybek <[email protected]> >wrote: >>> >>>> Hello >>>> >>>> You're generally right. I'm working on Pax Web 8 improvements >(actual, >>>> full implementation of OSGi CMPN R6+ Whiteboard specification + >HttpService >>>> specification + Web Applications Specification) and I tackled the >problem >>>> of ServletContainerInitializers. >>>> >>>> The problem is that OSGi CMPN spec doesn't mention SCIs at all, >only Web >>>> Applications Specification generally assumes that "web bundle" >should be >>>> processed ("extended") by the implementation which involves web.xml >parsing >>>> + fragments parsing + (possibly) "classpath scanning". See for >example: >>>> >>>> A WAB can optionally contain a web.xml resource to specify >additional >>>>> configuration. This web.xml must be found with the Bundle >*findEntries* >>>>> method at the path WEB-INF/web.xml. The findEntries method >includes >>>>> fragments, allowing the web.xml to be provided by a fragment. >>>>> >>>> >>>> So here there's nothing about "scanning other bundles" not referred >>>> through "fragment" relationship. >>>> >>>> Also: >>>> >>>> Unlike a WAR, a WAB is not constrained to package classes and code >>>>> resources in the WEB-INF/classes directory or dependent JARs in >>>>> WEB-INF/lib/ only. These entries can be packaged in any way that's >valid >>>>> for an OSGi bundle as long as such directories and JARs are part >of bundle >>>>> class path as set with the Bundle-ClassPath header and any >attached >>>>> fragments. JARs that are specified in the Bundle-ClassPath header >are >>>>> treated like JARs in the WEB-INF/lib/ directory of the Servlet >>>>> specification. Similarly, any directory that is part of the >>>>> Bundle-ClassPath header is treated like WEB-INF/classes directory >of the >>>>> Servlet specification. >>>>> >>>> >>>> So again - you can "bring" additional libraries to your "bundle >>>> classpath" by referring them in "Bundle-ClassPath" header. No >scanning of >>>> everything (that's for example tracked by BundleListener). >>>> >>>> And about java.util.ServiceLoader (which should in theory be a >>>> suggestion to how ServletContainerInitializer "services" are >found), >>>> "java.util.ServiceLoader#load(java.lang.Class<S>, >java.lang.ClassLoader)" >>>> method simply uses the passed classLoader and the other "load()" >version >>>> uses TCCL. Neither of these methods scan ALL classloaders (all >bundles in >>>> OSGi). >>>> >>>> In Pax Web 8 I'm definitely going to solve this problem - for now, >a >>>> bundle that registered "a context" >>>> (org.osgi.service.http.context.ServletContextHelper) is an "entry >point" to >>>> classLoader "mesh" where all are checked for SCIs. >>>> >>>> My Pax Web 8 refactoring is taking its shape at >>>> https://github.com/ops4j/org.ops4j.pax.web/tree/master-improvements >>>> branch, but I have to do my normal job a bit ;) So please be >patient. >>>> >>>> regards >>>> Grzegorz Grzybek >>>> >>>> >>>> czw., 29 paź 2020 o 14:13 'paul stanley' via OPS4J < >>>> [email protected]> napisał(a): >>>> >>>>> Hello. >>>>> >>>>> I'm tracing this through to try and understand why Jersey Servlet >>>>> Initializer is not invoked for a pure Jaxrs applications running >in Karaf >>>>> 4.3.0. >>>>> >>>>> It appears the way that the ServletContainerInitializerScanner in >the >>>>> pax-web-api has a fundamental design flaw when it searches >bundles for >>>>> instances of the /META-INF/services/ >ServletContainerInitializerScanner >>>>> file. Namely that it only searches dependent bundles of the one >that is >>>>> being initialised. As the implementation of any service is meant >to be >>>>> hidden by the API, it means that you will never be able to >initialise any >>>>> web servlet. As such the pax-jetty-web adds the bodge of >wiring-in itself >>>>> to all web-context so its contextInitializer code can be >discovered, but no >>>>> other implementations. >>>>> >>>>> Rather than performing a bundle scan each time, surely jetty >should be >>>>> implementing the bundle listener pattern and have the set of >servlet >>>>> initializers that are available in the platform? Or am I missing >something? >>>>> >>>>> Cheers, >>>>> >>>>> Paul >>>>> >>>>> -- >>>>> -- >>>>> ------------------ >>>>> OPS4J - http://www.ops4j.org - [email protected] >>>>> >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "OPS4J" group. >>>>> To unsubscribe from this group and stop receiving emails from it, >send >>>>> an email to [email protected]. >>>>> To view this discussion on the web visit >>>>> >https://groups.google.com/d/msgid/ops4j/e9d0b4ab-33d7-4895-8a0f-e6d55e3e3b43n%40googlegroups.com >>>>> ><https://groups.google.com/d/msgid/ops4j/e9d0b4ab-33d7-4895-8a0f-e6d55e3e3b43n%40googlegroups.com?utm_medium=email&utm_source=footer>. >>>>> >>>>> >>>> -- >>>> -- >>>> ------------------ >>>> OPS4J - http://www.ops4j.org - [email protected] >>>> >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "OPS4J" group. >>>> To unsubscribe from this group and stop receiving emails from it, >send >>>> an email to [email protected]. >>>> >>> To view this discussion on the web visit >>>> >https://groups.google.com/d/msgid/ops4j/CAAdXmhqcqH3h1bhJhYLb1%2B08u3dcSzFE%2BEYpe%2B62O7CbmMZHGQ%40mail.gmail.com >>>> ><https://groups.google.com/d/msgid/ops4j/CAAdXmhqcqH3h1bhJhYLb1%2B08u3dcSzFE%2BEYpe%2B62O7CbmMZHGQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. >>>> >>>> >>> -- >> -- >> ------------------ >> OPS4J - http://www.ops4j.org - [email protected] >> >> --- >> You received this message because you are subscribed to the Google >Groups >> "OPS4J" group. >> To unsubscribe from this group and stop receiving emails from it, >send an >> email to [email protected]. >> To view this discussion on the web visit >> >https://groups.google.com/d/msgid/ops4j/a2363134-86ad-40e9-869b-36885ac68083n%40googlegroups.com >> ><https://groups.google.com/d/msgid/ops4j/a2363134-86ad-40e9-869b-36885ac68083n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > >-- >-- >------------------ >OPS4J - http://www.ops4j.org - [email protected] > >--- >You received this message because you are subscribed to the Google >Groups "OPS4J" group. >To unsubscribe from this group and stop receiving emails from it, send >an email to [email protected]. >To view this discussion on the web visit >https://groups.google.com/d/msgid/ops4j/CAAdXmhpRfntRwzx2oykWjf56AJtWPH2nFD59dfLBFWLO5NpCJA%40mail.gmail.com. -- -- ------------------ OPS4J - http://www.ops4j.org - [email protected] --- You received this message because you are subscribed to the Google Groups "OPS4J" group. 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