That looks good, thanks a lot.
Do you think this is something others are interested in?
Should I create a Jira + PR if it is working?
2017-02-06 9:21 GMT+01:00 Guillaume Nodet <gno...@apache.org>:
> The best option is to:
> * fix the system bundle capabilities
> * use a dependency feature as you did
>
> To fix the system bundle capabilities, depending on the framework used, you
> can do something along the following:
>
> org.osgi.framework.system.capabilities=\
> ...\
> ${${framework}-capabilities}
>
> felix-capabilities=
>
> equinox-capabilities=\
>
> osgi.service;effective:=active;objectClass=javax.xml.parsers.SAXParserFactory
>
> I haven't tested the above, but hopefully you'll get the idea. It's similar
> to what's done for the ${jre-${java.specification.version}}...
>
> 2017-02-06 9:16 GMT+01:00 Markus Rathgeb <maggu2...@gmail.com>:
>>
>> Hi Guillaume,
>> thank you for your reply.
>>
>> In this special case it is about an implementation for
>> "javax.xml.parsers.SAXParserFactory" and a service for that.
>> The bundle "org.eclipse.equinox.registry" (I need to use to satisfy
>> third party dependencies) is using a tracker to find an implementation
>> and prints errors to stdout if there is no one.
>> To prevent that messages on every Karaf start I would like to have
>> such a service in the Karaf instance.
>>
>> The Equinox OSGi framework provides that service itself. Without any
>> provide capability in its manifest.
>> The Apache Felix OSGi framework doesn't provide such a service.
>>
>> So, what are the options:
>>
>> add it to "org.osgi.framework.system.capabilities"
>> IMHO this will be not correct, because the service is present if
>> Equinox is used and not present if Felix is used.
>>
>> Use "conditionals" in a feature to install another bundle that
>> provides a "javax.xml.parsers.SAXParserFactory" service if Felix is
>> used (and so the conditional will skip the installation if Equinox is
>> used).
>> If my reading has been correct, conditionals could be used for
>> installed features and not for the special OSGi framework
>> implementation.
>>
>> I can install another bundle / feature that provides that service
>> implementation for both frameworks.
>> This is okay, but if it is not necessary...
>>
>> So, is there a simple method to leave it up to the user to switch
>> between "karaf.framework" Felix or Equinox and handle that in some
>> way, so another implementation is installed only if not Equinox is
>> choosen?
>>
>> Best regards,
>> Markus
>>
>> 2017-02-06 8:45 GMT+01:00 Guillaume Nodet <gno...@apache.org>:
>> > You can modify the etc/config.properties file, in particular the
>> > org.osgi.framework.system.capabilities
>> > configuration. If some service are provided by default by the framework
>> > and
>> > are missing,
>> > you may want to raise a JIRA issue and provide a patch / pull request.
>> >
>> > 2017-02-05 12:05 GMT+01:00 Markus Rathgeb <maggu2...@gmail.com>:
>> >>
>> >> Ah, okay, I assume it is caused by the missing
>> >> Provide-Capability of the Equinox bundle that it provides that service.
>> >> Could this information be added by some configuration file without
>> >> modify the Equinox bundle itself?
>> >>
>> >> 2017-02-05 11:49 GMT+01:00 Markus Rathgeb <maggu2...@gmail.com>:
>> >> > Hello,
>> >> >
>> >> > I thought I understand how the dependency flag is working for
>> >> > features
>> >> > and bundles, but at least it seems to be different.
>> >> > Perhaps someone could explain me the following scenario:
>> >> >
>> >> > Feature file:
>> >> > ===
>> >> > <?xml version="1.0" encoding="UTF-8"?>
>> >> > <features name="saxparserfactory"
>> >> > xmlns="http://karaf.apache.org/xmlns/features/v1.4.0";>
>> >> >
>> >> > <feature name="saxparserfactory" version="1.0-SNAPSHOT">
>> >> >
>> >> >
>> >> > <requirement>osgi.service;filter:="(objectClass=javax.xml.parsers.SAXParserFactory)";effective:=active</requirement>
>> >> > <feature dependency="true">jboss-xerces</feature>
>> >> > </feature>
>> >> >
>> >> > <feature name="jboss-xerces" description="JBoss Xerces"
>> >> > version="1.0-SNAPSHOT">
>> >> > <details>OSGi service for
>> >> > 'javax.xml.parsers.SAXParserFactory'</details>
>> >> >
>> >> > <!-- Maven repository:
>> >> > https://repository.jboss.org/nexus/content/repositories/releases/ -->
>> >> > <!-- <bundle
>> >> >
>> >> >
>> >> > start-level="30">mvn:org.jboss.osgi.xerces/jbosgi-xerces/3.1.0.Final</bundle>
>> >> > -->
>> >> > <bundle
>> >> >
>> >> > start-level="30">https://repository.jboss.org/nexus/content/repositories/releases/org/jboss/osgi/xerces/jbosgi-xerces/3.1.0.Final/jbosgi-xerces-3.1.0.Final.jar</bundle>
>> >> >
>> >> >
>> >> > <capability>osgi.service;objectClass=javax.xml.parsers.SAXParserFactory</capability>
>> >> >
>> >> > <bundle dependency="true"
>> >> > start-level="30">mvn:org.osgi/org.osgi.util.xml/1.0.1</bundle>
>> >> > <bundle dependency="true"
>> >> >
>> >> > start-level="8">mvn:org.ops4j.pax.logging/pax-logging-api/1.9.1</bundle>
>> >> > </feature>
>> >> >
>> >> > </features>
>> >> > ===
>> >> >
>> >> > I would expect if I install the feature "saxparserfactory" the
>> >> > feature
>> >> > jboss-xerces is installed only if the requirements are not already
>> >> > fulfilled.
>> >> > The only requirement the feature drops in should be to ensure that
>> >> > there is a SAXParserFactory service available.
>> >> > Should this be possible?
>> >> >
>> >> >
>> >> > Test
>> >> > ===
>> >> >
>> >> > I used the current Karaf 4.1.0 form the second voting round.
>> >> >
>> >> > Start a clean instance:
>> >> > $ bin/karaf clean
>> >> >
>> >> > As expected Apache Felix is the used OSGi framework
>> >> >
>> >> > karaf@root()> bundle:list -t 0 -s 0 | grep Active
>> >> > 0 │ Active │ 0 │ 5.6.1 │ org.apache.felix.framework
>> >> >
>> >> > I added the feature repository file.
>> >> >
>> >> > karaf@root()> feature:repo-add
>> >> > file:///home/maggu2810/tmp/saxparserfactory-feature.xml
>> >> > Adding feature url
>> >> > file:///home/maggu2810/tmp/saxparserfactory-feature.xml
>> >> >
>> >> > After that let's look if there is already a SAXParserFactory present:
>> >> >
>> >> > karaf@root()> service:list javax.xml.parsers.SAXParserFactory
>> >> >
>> >> > No output, so as expected, no service found.
>> >> >
>> >> > Check what will be done if the feature is installed:
>> >> >
>> >> > karaf@root()> feature:install -t -v saxparserfactory
>> >> > Adding features: saxparserfactory/[1.0.0.SNAPSHOT,1.0.0.SNAPSHOT]
>> >> > Changes to perform:
>> >> > Region: root
>> >> > Bundles to install:
>> >> >
>> >> >
>> >> > https://repository.jboss.org/nexus/content/repositories/releases/org/jboss/osgi/xerces/jbosgi-xerces/3.1.0.Final/jbosgi-xerces-3.1.0.Final.jar
>> >> > mvn:org.osgi/org.osgi.util.xml/1.0.1
>> >> >
>> >> > This is as I expect what should be done.
>> >> >
>> >> > Let's exit the Karaf container.
>> >> >
>> >> > karaf@root()> shutdown -f
>> >> >
>> >> >
>> >> >
>> >> > After that I used the Equinox framework
>> >> >
>> >> > $ echo 'karaf.framework=equinox' >> etc/custom.properties
>> >> >
>> >> > and started again a clean isntance.
>> >> >
>> >> > $ bin/karaf clean
>> >> >
>> >> > Ensure the feature repository is available:
>> >> >
>> >> > karaf@root()> feature:repo-add
>> >> > file:///home/maggu2810/tmp/saxparserfactory-feature.xml
>> >> > Adding feature url
>> >> > file:///home/maggu2810/tmp/saxparserfactory-feature.xml
>> >> >
>> >> > The Equinox OSGi framework bundle already provides a SAXParserFactory
>> >> > service.
>> >> >
>> >> > karaf@root()> service:list javax.xml.parsers.SAXParserFactory
>> >> > [javax.xml.parsers.SAXParserFactory]
>> >> > ------------------------------------
>> >> > service.pid =
>> >> > 0.org.eclipse.osgi.internal.framework.XMLParsingServiceFactory
>> >> > service.vendor = Eclipse.org - Equinox
>> >> > service.id = 20
>> >> > service.bundleid = 0
>> >> > service.scope = bundle
>> >> > Provided by :
>> >> > OSGi System Bundle (0)
>> >> >
>> >> > Now I would expect that the installation of the saxparserfactory
>> >> > feature will not trigger an installation of the jboss-xerces feature,
>> >> > because all requirements should be already satisfied.
>> >> > But it looks like:
>> >> >
>> >> > karaf@root()> feature:install -t -v saxparserfactory
>> >> > Adding features: saxparserfactory/[1.0.0.SNAPSHOT,1.0.0.SNAPSHOT]
>> >> > Changes to perform:
>> >> > Region: root
>> >> > Bundles to install:
>> >> >
>> >> >
>> >> > https://repository.jboss.org/nexus/content/repositories/releases/org/jboss/osgi/xerces/jbosgi-xerces/3.1.0.Final/jbosgi-xerces-3.1.0.Final.jar
>> >> > mvn:org.osgi/org.osgi.util.xml/1.0.1
>> >> >
>> >> > What am I doing wrong?
>> >> >
>> >> > Best regards,
>> >> > Markus Rathgeb
>> >
>> >
>> >
>> >
>> > --
>> > ------------------------
>> > Guillaume Nodet
>> >
>
>
>
>
> --
> ------------------------
> Guillaume Nodet
>
