You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 4 Next »

4.5. Security framework 4. Understanding Karaf 4.7. Administration

4.6. Provisioning

ServiceMix Kernel provides a simple, yet flexible, way to provision applications or "features". Such a mechanism is mainly provided by a set of commands available in the features shell. The provisioning system uses xml "repositories" that define a set of features.

Repositories

The xml repositories use the following Relax NG Compact syntax:

Repository schema
element features {
  element feature {
    attribute name { text },
    element feature { text }*,
    element config {
      attribute name { text },
      text
    }*,
    element bundle { text }*
  }*
}

Here is an example of such a repository:

<features>
  <feature name="nmr">
    <bundle>mvn:org.apache.servicemix.document/org.apache.servicemix.document/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.api/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.core/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.osgi/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.spring/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.commands/1.0.0-m2</bundle>
    <bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.management/1.0.0-m2</bundle>
  </feature>
</features>

A repository includes a list of feature elements, each one representing an application that can be installed. The feature is identified by its name which must be unique amongst all the repositories used and consists of a set of bundles that need to be installed along with some optional dependencies on other features and some optional configurations for the Configuration Admin OSGi service.

Bundles

The main information provided by a feature is the set of OSGi bundles that defines the application. Such bundles are URLs pointing to the actual bundle jars. For example, one would write the following definition:

<bundle>http://repo1.maven.org/maven2/org/apache/servicemix/nmr/org.apache.servicemix.nmr.api/1.0.0-m2/org.apache.servicemix.nmr.api-1.0.0-m2.jar</bundle>

Doing this will make sure the above bundle is installed while installing the feature.

However, ServiceMix Kernel provides several URL handlers, in addition to the usual ones (file, http, etc...). One of these is the maven URL handler, which allow reusing maven repositories to point to the bundles. The equivalent of the above bundle would be:

<bundle>mvn:org.apache.servicemix.nmr/org.apache.servicemix.nmr.api/1.0.0-m2</bundle>

In addition to being less verbose, the maven url handlers can also resolve snapshots and can use a local copy of the jar if one is available in your maven local repository.

Dependant features

Dependant features are usefull when a given feature depends on another feature to be installed. Such a dependency can be expressed easily in the feature definition:

<feature name="jbi">
  <feature>nmr</feature>
  ...
</feature>

The effect of such a dependency is to automatically install the required nmr feature when the jbi feature will be installed.

Configurations

TODO

Commands

Repository management

The following commands can be used to manage the list of descriptors known by ServiceMix Kernel. They use URLs pointing to features descriptors. These URLs can use any protocol known to the ServiceMix Kernel, the most common ones being http, file and mvn.

features addUrl      Add a list of repository URLs to the features service
features removeUrl   Remove a list of repository URLs from the features service
features listUrl     Display the repository URLs currently associated with the features service.
features refreshUrl  Reload the repositories to obtain a fresh list of features

ServiceMix Kernel maintains a persistent list of these repositories so that if you add one URL and restart the Kernel, the features will still be available.

The refreshUrl command is mostly used when developing features descriptors: when changing the descriptor, it can be handy to reload it in the Kernel without having to restart it or to remove then add again this URL.

Features management

features install
features uninstall
features list

Examples

features addUrl mvn:org.apache.servicemix.nmr/apache-servicemix-nmr/1.0.0-m2/xml/features
features install nmr

Service configuration

A simple configuration file located in [kernel]/etc/org.apache.servicemix.features.cfg can be modified to customize the behavior when starting the Kernel for the first time.
This configuration file contains two properties:

  • featuresBoot: a comma separated list of features to install at startup
  • featuresRepositories: a comma separated list of feature repositories to load at startup

This configuration file is of interest if you plan to distribute a ServiceMix Kernel distribution which includes pre-installed features. Such a process is detailed in the 8. Building custom distributions section.

#top

4.5. Security framework 4. Understanding Karaf 4.7. Administration
  • No labels