Distributed OSGi

The Apache CXF Distributed OSGi subproject provides the Reference Implementation of the Distribution Provider component of the OSGi Remote Services Specification (Chapter 13 in the OSGi 4.2 Compendium Specification).
It implements the Remote Services functionality using Web Services, leveraging SOAP over HTTP and exposing the Service over a WSDL contract. Starting from version 1.1, Java interfaces can also be exposed and consumed as RESTful JAX-RS services.

The 1.2 version of this project is also the Reference Implementation of the OSGi Remote Service Admin specification, chapter 122 in the OSGi 4.2 Enterprise Specification).

This page is about getting started and the demos, further links:

Getting Started

To get started, get yourself a CXF-DOSGi distribution. The following distributions are available:

Multi Bundle Distribution: This distribution is a zip file containing the Distributed OSGi bundles, as well as all their dependencies.
Single Bundle Distribution: This is a convenience distribution of a single bundle that embeds all the dependencies.

Which distribution to take? That depends on what you are doing. The single-bundle distribution is a really convenient way of getting started as it provides all of Distributed OSGi plus its dependencies in one.
The multi-bundle distribution is obviously a little more work to install, but the fine-grained bundles do have an extra benefit: they allow sharing. So if your application depends on one or more of the library bundles, it can use them from the multi-bundle distribution. Similarly, the multi-bundle distribution makes it possible to update the dependency bundles - if compatible - without having to replace the Distributed OSGi bundles.

Get a distribution by:

Downloading a built distribution. See the DOSGi Releases page.
Alternatively, built the distribution yourself. See the DOSGi Build page.

Setting up your OSGi container

Setting up the single-bundle distribution is really simple, see below. For instructions on setting up the multi-bundle distribution see the Multi Bundle Setup page.

Prerequisites for the single-bundle distribution:

The single-bundle distribution requires some of the interfaces of the OSGi compendium specification. These are provided with the Equinox and Felix OSGi distributions, but not installed by default.

Setting up Felix

The compendium interfaces can be downloaded from the following various places, the easiest is probably from Maven Central, for example:
"g! install http://repo1.maven.org/maven2/org/osgi/org.osgi.compendium/4.2.0/org.osgi.compendium-4.2.0.jar".
(Note: this step is not required for DOSGI RI 1.3)

To set up Felix you can follow these steps:
Verified with: Felix 4.0.2 and DOSGI RI 1.3

../felix-4.0.2> java -jar bin/felix.jar

Welcome to Apache Felix Gogo
g! start http://www.apache.org/dist/cxf/dosgi/1.3/cxf-dosgi-ri-singlebundle-distribution-1.3.jar
... some log messages may appear...
g! lb
    0|Active     |    0|org.apache.felix.framework (4.0.2)
    1|Active     |    1|org.apache.felix.bundlerepository (1.6.6)
    2|Active     |    1|org.apache.felix.gogo.command (0.12.0)
    3|Active     |    1|org.apache.felix.gogo.runtime (0.10.0)
    4|Active     |    1|org.apache.felix.gogo.shell (0.10.0)
    5|Active     |    1|cxf-dosgi-ri-singlebundle-distribution (1.3.0)

However, you can also change the conf/config.properties file to automatically load these bundles. This approach is described in the Multi Bundle Setup page.

Setting up Equinox

The compendium interfaces are part of the Equinox/Eclipse distribution and can be found in a file called plugins/org.eclipse.osgi.services_3.2.0.v20090520-1800.jar (the timestamp could vary), for example:
"osgi> install file:plugins/org.eclipse.osgi.services_3.2.100.v20100503.jar"
(Note: this step is not required for DOSGI RI 1.3)

To set up Equinox you can follow these steps:
Verified with: Eclipse 3.6.2

.../eclipse> java -jar plugins/org.eclipse.osgi_3.6.2.R36x_v20110210.jar -console

osgi> install http://www.apache.org/dist/cxf/dosgi/1.3/cxf-dosgi-ri-singlebundle-distribution-1.3.jar
Bundle id is 1

osgi> start 1
... some log messages may appear...
osgi> ss

Framework is launched.

id      State       Bundle
0       ACTIVE      org.eclipse.osgi_3.6.2.R36x_v20110210
1       ACTIVE      cxf-dosgi-ri-singlebundle-distribution_1.3.0

However, you can also create a config.ini file to automatically load these bundles. This approach is described in the Multi Bundle Setup page.

Using Equinox from within the Eclipse IDE

This option is really handy for debugging. Verified with: Eclipse 3.5M4
Setting up Eclipse for Running and Debugging Distributed OSGi

Setting up CXF/DOSGi Discovery

See the DOSGi Discovery page and the DOSGi Discovery Demo page.

The Samples

The samples directory contains these sample projects:

Sample	Description	Doc Page
greeter	a very simple demo of a Greeter OSGi Service exposed remotely and a Consumer invoking on it.	Walkthrough of the Greeter Demo
greeter_rest	a very simple demo of a Greeter OSGi Service exposed remotely as a RESTful service and a Consumer invoking on it. Virtually identical to a greeter sample	Walkthrough of the Greeter Demo
spring_dm	a demo created using Spring-DM. Rather than invoking on the OSGi API's directly, the Spring-DM demo shows how you can use Spring to configure your beans as OSGi Services and similarly how to use Spring-DM to invoke a (remote) OSGi Service.	DOSGi Spring-DM Demo page
ds	this demo shows how Distributed OSGi can be used with OSGi Declarative Services (DS).	DOSGi DS Demo page
discovery	this demo shows how to use Distributed OSGi with a dynamic Discovery system such as the one based on Zookeeper that comes with CXF/DOSGi.	DOSGi Discovery Demo page
iPOJO	this demo shows how Distributed OSGi can be used with iPOJO	DOSGi iPOJO Demo page

The samples can be installed directly from the maven release repository (as described in the demo documentation pages), but you can also build them yourself.
To build the samples from source:

simply check out the DOSGi trunk from SVN (http://svn.apache.org/repos/asf/cxf/dosgi/trunk)
go into the samples directory
and build them using mvn install

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