OSGi dependency issue - need help in deploying maven bundle to OSGi contain

[wl880504]

I want to deploy a mavenized project floodlight to Fuse esb OSGi container. Here is what I did so far:

1. Download maven project:

    git clone https://github.com/oshothebig/floodlight.git

2. go to download project floder:

    cd floodlight

    git checkout -b maven origin/maven

    mvn install

3. work with eclipse

    mvn eclipse:eclipse

4. import this maven project

    eclipse - import - existing maven projects - choose floodlight

5. Create the FloodlightLaunch target:

    Click Run->Run Configurations

    Right Click Java Application->New

      Name: FloodlightLaunch

      Project: floodlight

      Main: net.floodlightcontroller.core.Main

    Click Apply

    run - maven install -> got floodglight.jar in target folder

6.  deploy floodlight.jar to osgi container

     the floodlight project has many dependency. In the referenced library, there are 28 jar files. So I copy each of them from .m2 repository to Fuse deploy folder (/opt/Fuse-ESB/deploy). Then I got dependency resolution issues among these dependencies, for example:

Unable to start bundle 386: Uses constraint violation. Unable to resolve bundle revision slf4j.api [386.0 because it exports package 'org.slf4j.spi' and is also exposed to it from bundle revision org.ops4j.pax.logging.pax-logging-api [4.0 via the following dependency chain:

slf4j.api [386.0

import: (&(osgi.wiring.package=org.slf4j.impl)(version>=1.6.0))

export: osgi.wiring.package=org.slf4j.impl; uses:=org.slf4j.spi

ch.qos.logback.classic [385.0

import: (&(osgi.wiring.package=org.slf4j.spi)(version>=1.6.0))

export: osgi.wiring.package=org.slf4j.spi

org.ops4j.pax.logging.pax-logging-api [4.0

org.ops4j.pax.logging.pax-logging-api is a service bundle in karaf. slf4j.api and ch.qos.logback.classic are floodlight dependencies I put in the deploy folder. Can anyone help me with this?

[ffang]

Hi,

You need ensure all dependencies are already OSGi bundles, if not, OSGi-fy it first.

And the slf4j stuff already answered you in another thread.

http://fusesource.com/forums/thread.jspa?threadID=4676

Freeman

[wl880504]

Thanks Freeman.

Now I am thinking of another way to do it. The Floodlight.jar generated in the Maven target works good before deploying to Fuse esb. All its dependencies are stored in .m2 repository. So when I try to deploy it by:

osgi:install file:Dir/to/floodlight.jar

Is there a way to specify each location of its dependencies? Like:

osgi:install file:Dir/to/floodlight.jar /home/usr/.m2/org/apache/dependency1 /home/usr/.m2/org/google/dependency2

So Fuse esb can search its dependencies in .m2 repository instead of asking me to deploy each dependency to Fuse esb.

[ffang]

Hi,

You do need deploy each bundle into FUSE ESB anyway, though FUSE ESB will look for those bundles from your maven local repo.

You can use features.xml which help to make it easier for you.

Freeman

[wl880504]

Hi Freeman,

I am thinking another tricky:

Suppose the Floodlight.jar bundle has two dependencies: A and B. I copy A and B from .m2 repository to Floodlight/lib folder. Then in eclipse Floodlight/lib folder right click on A -> Build Path -> Add to Build Path and the same to B. Then in Floodlight pom.xml, delete  A and b. Run mvn install to create floodlight.jar bundle in target folder.

Next deploy floodlight.jar bundle to Fuse esb container. At this time, A and B are already included in floodlight.jar, so I do not need to deploy the dependency A and B to Fuse esb.

What do you think?

[ffang]

Hi,

No, embed lib isn't good practice in OSGi world, you should install bundles separately.

Freeman

[wl880504]

Hi Freeman,

If you have time, can you help me deploy this maven project floodlight to osgi container? I struggled for two weeks, but still failed.

These days, I have tried to use <embed-dependency> with maven-bundle-plugin. This generates a single bundle with all dependencies included. When I deploy it to OSGi, got error: unresolved constraint - missing requirement

Or can you give me your email? I can send some experiments documents to you to have a look.

Thanks

[ffang]

Hi,

If you have fuse subscription, I suggest you contact us through that channel.

Freeman

[wl880504]

Right now I dont have one. Do I need to pay for this service?

[davsclaus]

Hi

Have you tried deploying your project with FAB

http://www.davsclaus.com/2012/08/osgi-deployment-made-easy-with-fab.html

FAB is designed to take out the OSGi deployment pain, and just develop your project as a plain maven project.

Though there may be some edge-cases where FAB also comes short. As at the end its all running in the OSGi container (there is no escape from OSGi).

I suggest to take a look at those links form the blog post above. Otherwise you can spend weeks and weeks trying to get your project working as a pure OSGi, and that is really hard. Its not you, its really IMHO the OSGi deployment model that is way way to complicated for the common man. In advanced use-cases it rocks, but for the average projects people do, its way to complicated currently. Notice that this last paragraph is my own opinion!

[wl880504]

I did not give a try with FAB. I am really exhausted with handling maven project with osgi container. I hope this FAB can help me.

[davsclaus]

An alternative is to deploy your project as a WAR (eg web archive) as that is supported as well in Fuse ESB. Then you do not need to fight the OSGi dependency battle. Though as a WAR its an isolated deployment unit.

For example the Servlet Tomcat example from Apache Camel is a WAR, and is deployable in Fuse ESB

http://camel.apache.org/servlet-tomcat-example.html

Though if you use the shell to deploy you need to use the war url handler

https://access.redhat.com/knowledge/docs/en-US/Fuse_ESB_Enterprise/7.1/html/Deploying_into_the_Container/files/UrlHandlers-War.html