Composite repositories

As repositories continually grow in size they become harder to manage. The goal of composite repositories is to make this task easier by allowing site maintainers to have a parent repository which refers to multiple child repositories. Users are then able to reference the parent repository and the content of all the child repositories will be transparently available to them.

How it works

With the built-in repository types defined by p2, when a user connects to a server, p2 checks to see if there are any files that are recognized. In particular for metadata repositories it searches for a content.xml file or a content.jar and in the case of artifact repositories it looks for an artifacts.xml or artifacts.jar file.

So in order to create a composite repository, all one needs to do is create a new "index" file for the metadata and/or artifact repository and p2 will recognize that a composite repository has been defined and it will load it and its children. Composite repositories use a different index file name to help p2 recognize them as composite repositories.

Sample composite metadata repository

File: compositeContent.xml

<?xml version='1.0' encoding='UTF-8'?>
<?compositeMetadataRepository version='1.0.0'?>
<repository name='"Eclipse Project Test Site"'
    type='org.eclipse.equinox.internal.p2.metadata.repository.CompositeMetadataRepository'
    version='1.0.0'>
  <properties size='1'>
    <property name='p2.timestamp' value='1243822502499'/>
  </properties>
  <children size='2'>
    <child location='http://example.eclipse.org/childOne'/>
    <child location='http://example.eclipse.org/childTwo'/>
  </children>
</repository>

Sample composite artifact repository

File: compositeArtifacts.xml

<?xml version='1.0' encoding='UTF-8'?>
<?compositeArtifactRepository version='1.0.0'?>
<repository name='"Eclipse Project Test Site"'
    type='org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository' 
    version='1.0.0'>
  <properties size='1'>
    <property name='p2.timestamp' value='1243822502440'/>
  </properties>
  <children size='2'>
    <child location='http://example.eclipse.org/childOne'/>
    <child location='http://example.eclipse.org/childTwo'/>
  </children>
</repository>

Composite repositories as part of the build

In order to automate composite repository actions in release engineering builds, Ant tasks have been provided which can be called to create and modify composite repositories. The tasks are defined in the org.eclipse.equinox.p2.repository.tools bundle.

p2.composite.repository

Attributes

Sub-elements

Examples

Some example Ant tasks for composite repositories and further explanation can be found on the p2 Ant tasks page.