OSGi integration for camunda BPM platform

camunda BPM community extension providing support for camunda BPM platform inside OSGi containers

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: camunda BPM Platform OSGi
Bundle-SymbolicName: org.camunda.bpm.extension.osgi
Bundle-Version: 
Export-Package: [...]
Import-Package: [...]

Project structure

Every module is supposed to fullfil a single purpose and to be used independently of the others. Three modules are an exception from this rule, namely

• camunda-bpm-karaf-assembly, which is used to provide a Karaf distribution that you can download here
• camunda-bpm-osgi-itest, which contains all the integration tests
• camunda-bpm-osgi, which contains some core components and is the only one required by all the modules

Get started

Part 1 starting the camunda BPM OSGi bundle

Before you start you have to install all the required bundles into your OSGi runtime. To see a list of the required bundles you can take a look at the Apache Karaf feature.xml. It contains a list of the required dependencies and a list containing all the optional dependencies, too.

After you've done that you can drop the camunda-bpm-osgi bundle into the runtime. It should then move to the resolved state and you could start it.

If you prefer to use Apache Karaf as your runtime you can use the feature.xml directly. The guide can be found here.

Part 2 creating a process engine

After you successfully deployed the camunda BPM OSGi bundle your next step is to create a ProcessEngine.

Using the ProcessEngineFactory

To help a little bit with the creating of a process engine you can use the ProcessEngineFactory class. You'll have to pass a ProcessEngineConfiguration object and the current bundle to it by calling the setBundle() and setProcessEngineConfiguration() methods. Finally you'll have to call init(). After that you may call getObject() to get a reference to the process engine. Please be aware that the order is mandatory or else getObject() will return null.

Please note also, that the process engine won't be exported automatically. If you want to share it, you can do that by yourself.

If you want to use a special ELResolver (see part 4) you'll have to use the ProcessEngineFactoryWithELResolver.

Using Blueprint

See camunda BPM OSGi - Blueprint Wrapper

Old school

If you wanna stay old school and use core OSGi you can do that, too. Import the package org.camunda.bpm.engine and org.camunda.bpm.engine.impl.cfg and instantiate your own StandaloneProcessEngineConfiguration.

Using the ProcessApplication API

See camunda BPMN OSGi - Process Application Integration

Using the ConfigurationAdmin service

See camunda BPM OSGi ConfigAdmin.

Part 3 Deploying process definitions

After you created a ProcessEngine you can start to deploy process definitions. The following steps only work when you exported a ProcessEngine as OSGi service.

Inside a bundle

When you deploy a bundle containing a process definition the process can be automatically added to the ProcessEngine. For the process definition to be found, you'll have to do one of the following things:

• place it in the OSGI-INF/processes/ directory
• set the "Process-Definitions" header in the MANIFEST.MF and let it point to a file or directory

If you reference any JavaDelegates or ActivityBehaviors from within your process defniition please take a look at Part 4

ProcessApplication API

See camunda BPMN OSGi - Process Application Integration

Part 4 Referencing inside processes

With the BlueprintELResolver

See camunda BPM OSGi - Blueprint Wrapper

With the OSGiELResolver

The OSGiELResolver uses a three step resolution to match expressions with classes

Step 1

The first step uses the LDAP filter property. You have to export a service with the filter property "processExpression=". The OSGiELResolver then matches the expression with the filter.

Step 2

If the LDAP search doesn't suceed the ELResolver will search the Service Registry for JavaDelegates. Then the class name will be compared to the expression. The comparison is similiar to the default CDI bean names. That means the expression has to match the class name starting with a lowercase character, e.g. org.foo.bar.MyClass would match "${myClass}".

Step 3

The third steps works likes the second one, only that it searches for exported ActivityBehaviours.

ProcessApplication API

See camunda BPMN OSGi - Process Application Integration

OSGi Event Bridge

See camunda BPM OSGi - Eventing API.

Resources

• Issue Tracker
• Contributing

Roadmap

a short list of things that yet need to be done (until we organize it elsewhere ;) )

todo

• camunda webapp WAB (cockpit, tasklist, admin)
• create example for configuring engine using PAX-CDI

done

• QA, integration tests (resolve engine-bundle)
• example for configuring engine using Blueprint

Maintainers:

• @rbraeunlich

License

Apache License, Version 2.0