Creating/Installing Custom Feature with config properties

[constv]

Hi,

I am creating a custom feature that includes my custom bundles, as well as the necessary dependency bundles and features. My feature is configured to pull my bundles from a Maven repository.  So far, everything is clear. However, as most applications, my bundles rely on configuration files: myapp.cfg, as well as a number of configuration properties files that I need to be deployed under etc/conf.   One of my build artifacts is a distribution package that, in addition to the bundle jars contains the /conf directory with the properties files my application needs to have externalized. Until now, during the development and testing, I used that distro artifact to manually drop the bundle jars into <karaf-home>/deploy, and the /conf folder - into <karaf-home>/etc directory.

Question: Is there a way to install externalized configuration files automatically as part of the feature, in the same way the bundles and dependencies are installed, when I run the "features:install " command?  I couldn't find any examples. Or do they have to always be copied manually into /etc?

Thanks,

Constantine

[ffang]

Hi,

Yeah, you can specify configuration with your feature descriptor, here is an example

<feature name="http" description="Implementation of the OSGi HTTP service" version="2.3.0" resolver="(obr)">
          <config name="org.ops4j.pax.web">
            org.osgi.service.http.port=8181
            javax.servlet.context.tempdir=...
            org.ops4j.pax.web.config.file=...
        </config>
        <feature version="[7.0,8.0)">jetty</feature>
        <bundle start-level="30">mvn:org.ops4j.pax.web/pax-web-api/1.1.3</bundle>
        <bundle start-level="30">mvn:org.ops4j.pax.web/pax-web-spi/1.1.3</bundle>
        <bundle start-level="30">mvn:org.ops4j.pax.web/pax-web-runtime/1.1.3</bundle>
        <bundle start-level="30">mvn:org.ops4j.pax.web/pax-web-jetty/1.1.3</bundle>
    </feature>

Freeman

[constv]

Freeman, thank you. This example shows how to specify actual properties and have them placed in a .cfg file. That's great. The legacy application I have ported to OSGi uses a number of other .properties and XML files that should remain externalized. All those files are distributed in a single /conf folder, and I need that folder to be deployed, for example, as a subdirectory under <karaf-home>/etc (or anywhere else.) I understand that the only way to do that would be by dropping that subdirectory manually to the desired location. Correct?

[ffang]

Hi,

You can do something like

<feature name="..." description="..." version="..." resolver="(obr)">
        <configfile finalname="/etc/whatever">mvn:your_configuration_file</configfile>
...
</feature>

Freeman

[constv]

Thank you!

[constv]

Hi Freeman,

I have realized that installing this "config" feature does not replace the .cfg file if the file already exists in the /etc directory. If I remove the file first and then install the feature, the file is picked up in the Maven repository and installed. Otherwise the old/outdated file remains intact. Is there a way to enforce Karaf to replace the file each time "feature:install" is executed for the "configfile" feature?

Thanks,

Constantine

[constv]

Added a follow-up question, see above...

[ffang]

Hi,

Yes, you can add

override="true" attribute

for configfile tag

Freeman

[constv]

Thank you! Is there a complete reference guide available somewhere where things like that are documented?

The most painful thing about OSGi and Karaf to me has been the lack of consistent and consolidated documentation. Some topics are well documented, but many useful details are either missing or very hard to find.

[davsclaus]

Yes I agree. Both the Karaf and Aries team should focus IMHO on improving and documenting. And have some more examples, FAQ, etc.

And do not tell users to read the entire OSGi spec as thats massive.

There is also this new OSGi book but albeit a bit short on 60+ pages

http://www.packtpub.com/open-services-gateway-initiative-starter/book

And Fuse ESB Enterprise has some OSGi docs at

http://fusesource.com/products/fuse-esb-enterprise/#documentation