This is cross posted from the fusesource forum and the servicemmix forum.
I can't get DOSGi working in FUSE. I'm trying to get CXF's DOSGi 1.1-SNAPSHOT with Zookeeper discovery onto FUSE 4.1.0.2. I'm also using Zookeepr 3.2.1.
Everything works perfectly on Felix 2.0.0. I just follow the instructions on the DOSGi Discovery page and then install the Discovery Demo bundles. For DOSGi, I just use the cxf-dosgi-ri-singlebundle-distribution-1.1-SNAPSHOT.jar for DSW and cxf-dosgi-ri-discovery-singlebundle-distribution-1.1-SNAPSHOT.jar for zookeepr discovery. Then when I start the sample bundles with the sample service impl on one machine, I see the node creation in zookeeper. Then I start the sample client on another machine and I see the output on the service machine. Works great. I do have an warning about an xml error being ignored because some XSD coudln't be found, but it doesn't seem to affect anything. Oh, I also have to install the OSGi compendium bundle first.
When I move to Fuse, I have no such luck. The OSGi compendium bundle comes with fuse, so no need to install that. I should just be able to install the dosgi-ri singlebundle, and the dosgi-ri-discovery single bundle, but that doesn't work. The dosgi-ri singlebundle has all kinds of overlapping bundles with servicemix. I get an error about port 8081? or whatever the osgi.http.service parameter is, being already in use. Apparently the dosgi-ri singlebundle comes with pax webservice, which reads the same property as the servicemix http service bundle that comes with servicemix. Thats when I switch to the cxf-dosgi-ri-multibundle-distribution-1.1-SNAPSHOT.zip and unzip it to take the parts I want. I take the dsw bundle out of the dosgi-ri multibundle and install that. No luck because of the jdom dependency. Then I install the jdom that comes in the ri multibundle, which works fine. Then go back to dsw, and that installs, so I think i'm getting somewhere. Time to go back and install the ri-discovery singlebundle. When I start that I get a pax logging service classcastexception saying it can't be cast to a osgi logservice or something. But thats just a logging error, and at the bottom it says it can't find the transport class for http://schemas.xmlsoap.org/soap/http. Ok, so logging is screwed up and I'm missing some transport class. Well, clearly this comes from not installing enough from the ri multibundle because it worked on felix. So what else in there is necessary. The cxf-minimal-bundle upon inspection has the missing class causing that last error. So I install that. Try to start the discovery bundle, but I end up with some kind of corbabroker exception. Wtf. Whose using corba in all of this? Then I go back and undo all of that and try to stick with the singlebundle distros of ri and ri-discovery, but just turn off the servicemix http service. That crashes servicemix and I can't restart it becauuse the cxf jbi components end up with an unsatisfied dependency. Odd. I'll just ignore that because I don't use those anyway, and try to start my samples. Can't start the samples because it says jetty can't start because the ports already in use. Doesn't make sense because I shutdown the servicemix http service already. Then I restart jetty. Works? Maybe. My service gets registered and I can browse to the wsdl using firefox, but no registration in zookeeper. Try to shutdown the ri-discovery bundle and restart it, but I get a nullpointerexception. Appparently the ri-discovery never actually started up due to one of the aforementioned errors. Then I started trying to take apart the ri-discovery singlebundle and pull out the internals. That didn't work because its all apparently necessary, even though theres some libs inside we could do without.
End of the story. Can't get it to work. Can anybody else get it to work? I just want to run the discovery samples in SMX4. I'm pretty sure its just a bundle conflict problem. Isn't this what OSGi is supposed to fix??? This is worse than just telling me what jars you depend on and making me setup my classpath. At least then I'd eventually get the thing running.
My next steps, I think, will be to try again with the ri-multibundle, just the dsw and jdom, plus the ri-discovery singlebundle. Then I'll try some of the cxf-fuse bundles or some of the cxf-rt bundles to get around the soap transport issue.
Edit notes: I need more than just showing the DOSGi bundles in an Active state. They don't actually do much until you try to expose a service through them. I do need to see multiple machines registering services with a zookeeper instance and other machines consuming those services -- just like the running DOSGi Discovery Sample.
I've been able to get cxf to expose the distributed service sample as a soap webservice by using the minimal cxf bundle mentioned by either removing parts of the original cxf bundles and restarting the jetty service, and then starting the sample service... or by installing the cxf minimal buundle, then starting my service, then immediately uninstalling the cxf minimal bundle, then restarting jetty... I think that was the order. Neither of these will work from a clean startup, and having to restart services as a procedure to get DOSGi working is just bad. I don't even know why installing then uninstalling would do anything -- it shouldn't be leaving any artifacts around.
First point, looking at the CXF DOSGi mega-bundle I think this is only for quick-n-dirty hacking in a bare OSGi runtime, basically the minimal environment provided by Equinox and Felix. It will not be intended for richer environments like FUSE or Servicemix as you will likely clash on services from the bundle and the platform, as you appear to have seen.
I was able to get Servicemix 4.0 to start cleanly (this is on Windows) and then I hot-deployed:
com.springsource.org.jdom-1.0.0.jar
cxf-bundle-minimal-2.2.1.jar
cxf-dosgi-ri-discovery-local-1.0.jar
cxf.dosgi-ri-dws.cxf-1.0.jar
Using the Servicemix console I listed all bundles and saw that all of the above were in the Active state (as expected). I listed the services and the 2 CXF DOSGi bundles were exporting services, so that appeared to have worked correctly. No errors were reported in the log.
How familiar are you with OSGi? Servicemix looks quite large and learning OSGi, Servicemix and CXF/DOSGi together isn't going to be easy (in my opinion).
The supplied console isn't great for the OSGi stuff and I'd suggest installing the Apache Felix console bundles for a web interface.
Related
I'm creating a Liferay 7.1 OSGi bundle, which has some external dependencies in it. In consideration of time, we opted to embed the external JAR in our OSGi Bundle. I've managed to create a bnd file, which includes all of the ElasticSearch dependencies, and put them on the bundle classpath. I've used the source-code from github (https://github.com/liferay/liferay-portal/blob/master/modules/apps/portal-search-elasticsearch6/portal-search-elasticsearch6-impl/build.gradle) and the bnd.bnd file, to check what's imported.
When activating the bundle, an exception is thrown:
The activate method has thrown an exception
java.util.ServiceConfigurationError: org.elasticsearch.common.xcontent.XContentBuilderExtension: Provider org.elasticsearch.common.xcontent.XContentElasticsearchExtension not a subtype
at java.util.ServiceLoader.fail(ServiceLoader.java:239)
at java.util.ServiceLoader.access$300(ServiceLoader.java:185)
at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:376)
at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
at org.elasticsearch.common.xcontent.XContentBuilder.<clinit>(XContentBuilder.java:118)
at org.elasticsearch.common.settings.Setting.arrayToParsableString(Setting.java:1257)
The XContentBuilderExtension is from the elasticsearch-x-content-6.5.0.jar,
the XContentElasticsearchExtension class, is included in the elasticsearch-6.5.0.jar. Both are Included Resources, and have been put on the classpath.
The Activate-method initializes a TransportClient in my other jar, hence it happens on activation ;).
Edit:
I've noticed that this error does NOT occur when installing this the first time, or when the portal restarts. So it only occurs when I uninstall and reinstall the bundle. (This is functionality I really prefer to have!). Maybe a stupid thought.. But could it be that there is some 'hanging thread'? That the bundle is not correctly installed, or that the TransportClient still is alive? I'm checking this out. Any hints are welcome!
Edit 2:
I'm fearing this is an incompatibility between SPI and OSGi? I've checked: The High Level Rest Client has the same issue. (But then with another Extension). I'm going to try the Low-Level Rest Client. This should work, as there are minimal dependencies, I'm guessing. I'm still very curious on why the incompatibility is there. I'm certainly no expert on OSGi, neither on SPI. (Time to learn new stuff!)
Seems like a case where OSGi uses your bundle to solve a dependency from another bundle, probably one that used your bundle to solve a package when the system started.
Looking at the symptoms: it does not occur when booting or restarts. Also it is not a subtype.
When OSGi uses that bundle to solve a dependency, it will keep a copy around, even when you remove it. When the bundle comes back a package that was previously used by another bundle may still be around and you can have the situation where a class used has two version of itself, from different classloaders, meaning they are not the same class and therefore, not a subtype.
Expose only the necessary to minimize the effects of this. Import only if needs importing. If you are using Liferay Gradle configuration to include the bundle inside, stop - it's a terrible way to include as it exposes a lot. If using the bnd file to include a resource and create an entry for the adicional classpath location, do not expose if not necessary. If you have several bundles using one as dependency, make sure about the version they use and if the exchange objects from the problematic class, if they do, than extra care is required.
PS: you can include attributes when exporting and/or importing in order to be more specific and avoid using packages from the wrong origin.
You can have 2 elastic search connections inside one Java app and Liferay is by default not exposing the connection that it holds.
A way around it is to rebuild the Liferay ES connector. It's not a big deal because you don't need to change the code only the OSGi descriptor to expose more services.
I did it in one POC project and worked fine. The tricky thing is to rebuild the Liferay jar but that was explained by Pettry by his google like search blog posts. https://community.liferay.com/blogs/-/blogs/creating-a-google-like-search (it is a series but it's kind of hard to navigate in the new Liferay blogs but Google will probably help) Either way it is all nicely documented here https://github.com/peerkar/liferay-gsearch
the only thing then what needs to be done is to add org.elasticsearch.* in the bnd.bnd file in the export section. You will then be able to work with the native elastic API.
I have quite a sophisticated OSGi application which uses Declarative Services and was designed to be deployed in Equinox. Now the task is to make this application be deployable in WAS 8.
The first try was quite pragmatic: I have deployed an EAR which has started basically the same Equinox and after some WAS class loading policy tweaks it has worked.
Now I want to go further: get rid of the Equinox runtime and deploy my bundles "natively" in WAS 8. So I have composed an EBA, consisting out of my business bundles, their dependencies and Equinox DS runtime. The EBA is deployed as an asset and integrated into a BLA. The application has even started and runs but the components are not initialized.
The point is that one has to start equinox.ds in front of the own business bundles (UPDATE: not a must, s. discussion below) in order to make DS do its job. But how do I tell the bundles which is to be started first within the deployed EBA? I need some analog of Equinox' config.ini file.
I know I can rewire my components with natively supported Blueprint, but frankly this is the last thing I'd like to do. It should be possible to make Equinox DS work, shouldn't it?
Another question is: how to get the OSGi console for one's own application deployed under WAS 8? I want to control my bundles but seems that there is no way to do it from the Management Console.
UPDATE
Thanks to BJ and Neil (s. discussion below), the question takes down to "How do I start a specific bundle in my own OSGi application deployed in WAS 8.0?"
To answer the OSGi console part of your question, a normal OSGi console won't work because the OSGi applications are managed in nested frameworks. WebSphere provides its own console which can navigate the nested applications: http://pic.dhe.ibm.com/infocenter/wasinfo/v8r0/index.jsp?topic=%2Fcom.ibm.websphere.osgi.nd.multiplatform.doc%2Ftopics%2Fta_admin_runtime_console.html
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.
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
I am planning to use osgi in a typical client-server (with swing gui) application. Hot deploying bundles to the server is made easy with fileinstall but now I am looking for something similar on the GUI.
The GUI is started with webstart but I want to update bundles without asking the user to close and restart.
I was planning to have a server side bundle which monitors a directory containing bundles, exposes the bundles over http and notifies the clients when something has changed. A client side bundle would listen for the notifications and do the bundle installs/updates using the methods on BundleContext and Bundle.
(Note: I already have an RMI like link between the server and clients which can be used for the notifications)
Is there anything which already does this or similar?
I would at least like to reuse fileinstall for the filesystem watching part but I don't want the GUI bundles started on the server.
P2 is a great provisioning system for OSGi based applications. Eclipse uses it, and there are a lot of uses even for non-OSGi applications. You should definitely have a look at it before you start building you own update system. You can also check Apache Ace.
The Fractal example for the Paremus Service Fabric may be instructive here ( https://docs.paremus.com/display/SF16/Demonstration ). In this example both Server and Client side OSGi bundles may be dynamically installed. RMI is also supported.
Regards
Richard