+1000 for removing the existing region support I added before the subsystems
spec was ready.
I don't understand why you want to do the rest. Could you elaborate on what
your proposal does that can't be done with spec subsystems? Also, what tooling
is missing for spec subsystems?
I always thought that when the subsystems spec was ready karat would drop its
proprietary features.
thanks
david jencks
On Apr 17, 2014, at 12:56 AM, Guillaume Nodet <gno...@apache.org> wrote:
> Reminder: region is a concept which allows partitioning the OSGi framework
> between multiple defined regions and control the visibility of bundles,
> packages and services while crossing regions. This allow the same bundle
> to be deployed in two different regions if the regions can't see each other
> (that's simplifying a bit, but you get the idea).
>
> Unless I'm wrong, support for regions in Karaf 3.x is very limited and
> while we have a few commands to view and operate on regions. Currently,
> the region where a feature is deployed has to be written in the feature
> descriptor (which makes deploying the same feature in 2 different regions
> quite difficult) and there's no option for sharing policies between regions.
>
> I've recently added support for Aries Subsystems in master. While
> Subsystems could theoretically fulfil our needs, we still have the same
> problems than with applications: i.e. it's totally unmanageable without
> tooling.
>
> What I'd like to do, is get rid of the current region support to have the
> feature service more aware of regions. The idea is to have the following:
> * a "root" region
> * multiple user created child regions for isolation (import everything
> from the parent, but share nothing) as a tree
> Those regions are organized in a tree:
> root
> root/container1
> root/container2
> root/container2/spring2
> root/container2/spring3
>
> When installing / uninstalling features, the user will have to provide the
> region path in which the new features should be added or removed.
>
> By default, features would be flattened, i.e, bundles are deployed directly
> in the region, however, features can specify a custom sharing policy so
> that the internal (services and packages) is hidden and not visible outside
> of the region. For example, the aries-proxy could be defined with the
> following:
>
> <feature name="aries-proxy" description="Aries Proxy"
> version="${project.version}">
> <bundle dependency="true"
> start-level="20">mvn:org.ow2.asm/asm-all/${asm.version}</bundle>
> <bundle dependency="true"
> start-level="20">mvn:org.apache.aries/org.apache.aries.util/${aries.util.version}</bundle>
> <bundle
> start-level="20">mvn:org.apache.aries.proxy/org.apache.aries.proxy.api/${aries.proxy.api.version}</bundle>
> <bundle
> start-level="20">mvn:org.apache.aries.proxy/org.apache.aries.proxy.impl/${aries.proxy.version}</bundle>
> <capability>
>
> service-reference;effective:=active;objectClass=org.apache.aries.proxy.ProxyManager
> </capability>
> <scoping>
> <export namespace="osgi.service">
> (objectClass=org.apache.aries.proxy.ProxyManager)
> </export>
> <export namespace="osgi.wiring.package">
>
> (|(osgi.wiring.package=org.apache.aries.proxy)(osgi.wiring.package=org.apache.aries.proxy.*))
> </export>
> <import namespace="org.eclipse.equinox.allow.all">
> (|(!(all=*))(all=*))
> </import>
> </scoping>
> </feature>
>
> The <scoping> element defines a custom policy. In the above case, the only
> thing exported from the region is the org.apache.aries.proxy.* packages
> and the org.apache.aries.proxy.ProxyManager service. The region imports
> everything.
> This is really just an example and while the syntax is what i'm
> experimenting with now, the idea is to simplify it so that the user would
> write "package", "service", "all" and with dedicated elements to help.
>
> Those scoped features will also create regions automatically, so that the
> above when deployed into root/apps1 would create a child region
> /root/apps1/aries-proxy-4.0.0-SNAPSHOT.
>
> The features service will be responsible for computing the regions and
> which and where bundles need to be deployed using the OSGi resolver.
>
> Anyway, I'm still experimenting, but I wanted to give a heads up on this
> point.
>
> Cheers,
> Guillaume Nodet
