I am able to get OSGi blueprint to work in Karaf, but I don't understand how to do it in Apache Felix, or my question can be also defined as how can I use OSGi blueprint in plain OSGi?
I made an example here https://github.com/PhilAndrew/sbt-osgi-felix-akka-blueprint-camel using https://github.com/doolse/sbt-osgi-felix in which Akka is working but Blueprint and Camel not yet working.
This question may help Is Apache Aries running in Felix?
It's not starting Blueprint because your bundle's code doesn't actually rely on any of the classes in blueprint, so you either need to add "Require-Bundle" header to your manifest:
requireBundle := Seq("org.apache.aries.blueprint")
or add the bundles that needed to be started to the osgiDependencies of run:
osgiDependencies in run := bundleReqs("org.apache.aries.blueprint.core",
"org.apache.aries.proxy")
Apache Karaf also runs on felix. So for the most part you just need to install the correct bundles and maybe do the necessary system package exports if you hit package use constraint violations.
Check what karaf installs and try to do the same.
Related
I have embedded Apache Felix 5.0.0 in an application I'm building.
When installing the bundles to the Felix framework object, I have no way of setting the bundles start level from code, and I read everywhere that people do it by hand using Gogo, but because I'm going to automatically install and start the bundles, I'd like to be able to set the start level from my code.
How can I do that? I've read about some StartLevel class and such, but I have found no actual working code that shows how to use it to set the bundle start level.
I guess you have a Framework instance if you use embedded Felix. In this case I think the following could work:
Bundle bundle = framework.getBundleContext().installBundle(location);
BundleStartLevel bundleStartLevel = bundle.adapt(BundleStartLevel.class);
bundleStartLevel.setStartLevel(xxx);
I am trying to develop an application that can be configured by its users. I need the configuration to be done by installing/updating/stopping/uninstalling bundles. All this should be of course done dynamically during the run-time of the application.
I found a nice framework which is Apache Felix FileInstall that provides a directory in which it seems to add a bundle when you add the bundle file in the directory (update, and remove bundles similarly).
But I can see that this method does not work in my case. I need to have the bundles in the directory but to stop or even uninstall them by my application. And I want to install them when it is appropriate. This is how I am expecting the configuration of my application to be done.
Is what I am trying to achieve supported by Apache FileInstall? Am I making any wrong assumptions about this framework? What are other possible ways that would help me if Apache FileInstall is not enough? Thanks.
You don't need FileInstall for this, just use the OSGi APIs. You specifically mentioned installing, updating, stopping and uninstalling; these are supported with the following API calls respectively:
BundleContext.installBundle
Bundle.update
Bundle.stop
Bundle.uninstall
Incidentally these are exactly the same methods that are called by FileInstall to implements its directory-based bundle management.
I try to use the "Apache Felix" implementation of OSGi for my project, I launch the framework from the distributable jar (/bin /felix.jar). I have created simple example bundles to register or consume services in the registry.
I want to use a configuration management service so I installed the bundle "org.apache.felix.configadmin" felix in the framework, and then I do not know how and where to put the configuration file of another bundle, for example I want to install the bundle "org.apache.felix.http.jetty" and then I want to configure this bundle through the configAdmin, so how I rename my config file, and where to put it?
Another question, what is the difference between setting, for example, the property "org.osgi.service.http.port" of the jetty bundle using the framework properties(conf/config.properties) or configure it through the bundle of configuration admin service.
Best regards,
You probably also need the file-installer from felix for it to pick up the config files.
If you want to see a working example of this take a look at Apache Karaf. It's a OSGi Container with lots of nice preconfigured features. The config admin service works out of the box.
Normally you use the felix config admin service together with the felix fileinstall. So fileinstall takes care of the directory to be monitored for config files and hands over to config admin to make it available as configs in OSGi.
For a fully working example take a look at Apache Karaf. There you can see the configs you need for it to work together. You might also consider to simply install your own bundles into karaf as it makes managing the felix framework a lot easier.
We run Restlet 2.1 in an OSGi environment (Equinox) as bundle (ie. not as library within a bundle). The problem is that the Restlet Engine does not detect helpers (like converters) that are provided by Restlet extensions. Specifically, the EngineClassLoader#getResources() call does not return any result. The extensions are also deployed as OSGi bundles in the target platform.
Is automatic converter registration actually supposed to work within OSGi environments?
In fact, Restlet supports such feature thanks to a dedicated activator (see the Activator class in the package org.restlet.engine.internal).
This activator introspects bundles to find out the following things:
servers corresponding to registered servers
servers corresponding to registered clients
authenticators corresponding to registered clients
converters
Be aware that to use this feature, we must use the OSGi edition of Restlet since it's the only that has the MANIFEST file of the org.restlet bundle with the activator class specified. Otherwise you don't have to care about the bundle loading order...
Hope it helps you.
Thierry
Unless the Restlet-bundle explicitly imports the packages that contain the extensions (and I doubt it does, and it shouldn't), it wouldn't be able to load them, because bundles have isolated class-spaces.
A possible solution would be to provide the extensions as fragments attached to the Restlet-bundle. Thus, if you make it use the bundle-classloader (the documentation says this can be done by setting the Engines classloader), it would be able to load classes from the fragments.
Indeed it doesn't quite work for OSGi, as it depends on the ability to see the entire class space.
The way to do this in OSGi would be to use the service registry for the extensions, but that only works for OSGi aware libraries.
There is some help on the way: In the recently released OSGi 5 (Service Loader Mediator) there will be support to 'bridge' META-INF/services (I don't know if Restlet uses those, though) onto OSGi services, so 'legacy' libraries should work well within OSGi.
There is an implementation in Apache Aries called Spi-Fly. I looked at it briefly a while back. It might do the trick for you, it might not.
Is anyone using Karaf instead of Servicemix? If so, how did you come to this decision? I'm aware that Servicemix adds a layer of functionality around Karaf, just curious if Karaf is being used on its own and why...
We're using Karaf for a number of our applications. We were already using Camel (JMS and Esper) for integration between several different platforms (a JBoss 4.2 instance, a Tomcat and several Felix instances) and as this was working well there was little justification in migrating this too (which would have been cause to consider ServiceMix).
The only reason we have some Felix nodes, is that they're limited in use (on client desktops), rarely need/get updated and I wanted the smallest footprint for these nodes. For anything OSGi on the serverside we're using Karaf.
Karaf provides all of the features you'd expect and need for a production environment (see the apache-karaf tag's info). We do our development and testing against standard minimal framework (using pax-exam) but deploy to Karaf.
If you don't need an ESB, JCA, BPEL, etc but want a solid, tunable OSGi container, then Karaf on it's own is more than adequate. (And if you found yourself needing a limited subset of ServiceMix's functionality you can always install these in a Karaf instance).
You can also customise the Karaf distribution as part of a maven build - personally I like have the container as part of the application's build, as I can checkout, build and run the entire setup from the command line in minimal time.
Recently there's a clustering subproject of Karaf called Cellar using HazelCast, I not sure if this applies to ServiceMix too.
Karaf's life started as the ServiceMix core. Currently, ServiceMix is really a set of bundles that are deployed into a Karaf container. ServiceMix has a number of very handy bundles which do a lot of cool stuff that karaf doesn't. That said, the two primary reason for using ServiceMix is if you want:
1) an ESB,
2) NMR (a feature that allows you to community between bundles AND instances of Karaf).
This all said, the ServiceMix group is currently planning version 5, which will remove the ESB and NMR features and will be focused on being a management container for Camel. In ESB's a great deal of effort when into creating components that could be described using BPL (Business Process Language). However, the folks that wrote ServiceMix began to focus on the implementation of EIP's (Enterprise Integration Patterns) which largely does the same stuff as BPL, but does it in a more standardized and accepted manner. This work was done under the Camel project.
So, in short. If you are using ServiceMix 4+, you're also using Karaf. If you want a more robust integration environment, the environment of choice today (in the Apache/Felix world at least) is Karaf, Camel, and a few bundles from Servicemix.
Here's a little comparative illustration I made. Going from the simplest case (JVM with OSGi functions provided by Apache Felix at the bottom), to more complete/manageable OSGi functions (Apache Karaf in the middle), to enough functions to implement complete ESB instances (Apache ServiceMix at the top) (note that "an ESB" is not a product but a set of endpoints, routers, databases, ETL functions and whatnot configured together in a particular task-specific way).
Karaf does NOT come with CXF.
Its pure extracted kernel of ServiceMix. However, you can install CXF on Karaf as below.
karaf:root()> feature:repo:add cxf
Once the feature URL is added we can see the "provided" features by using the following command.
karaf:root()> feature:repo:feature:list | grep cxf
To install cxf fire the command below
karaf:root()> feature:install cxf