On Monday 19 October 2015 15:40:31 David Bosschaert wrote: > Hi Oliver, Hi David,
> On 19 October 2015 at 15:21, Oliver Lietz <[email protected]> wrote: > >> While doing that, if you think of changes that need to be made to our > >> other launchers (Karaf, Crankstart) to support subsystems it would be > >> nice to list them somewhere, jira tickets maybe. > > > > It should be sufficient to install the subsystems feature from the > > enterprise features repository in Karaf. > > > > David, can you outline some use cases? > > > > I think there will be some limitations for applications because of > > isolation, e.g. picking up services from scripts in the repository. > > OSGi Subsystems are defined in the OSGi Subsystem spec (chapter 134 of > the Enterprise spec [1]). In short, there are currently 3 types of > subsystems: > 1. Features - all bundles in these are shared as if they were > installed normally. Feature subsystems are effectively just a > deployment vehicle that make it easy to deploy an application built up > of a lot of bundles. > 2. Applications - this type of subsystem isolates the bundles inside > the subsystem to not export any packages or services outside of it. > 3. Composites - these have configurable isolation. This means that you > can export/import some packages or some services but not all. What is > precisely exported or imported is configured explicitly. > So depending on what you want to do, you pick the subsystem type that > fits :) If Sling needs to see your service then an application > subsystem is probably not good, because it doesn't export the service, > but a composite subsystem might be useful if you don't want to leak > any internal services to the outside... I'm aware of these different types thanks to your blog posts and presentations on this topic 8D. But I think we should give Sling's users some hints with examples when to use which type (in Sling's context). Our documentation has much room for improvements and my intention is to gather information to provide better documentation at least for new stuff coming. Regards, O. > Cheers, > > David > > [1] http://www.osgi.org/Download/Release6
