Introduction

A Liquibase bundle that contains extensions from Everit so that Liquibase can be used in an OSGi environmnent. When this bundle is used, no other jar of Liquibase should be dropped into the OSGi container.

Inclusion of changeLog from other bundles

One enhancement of this bundle is that in XML changeLog format it is possible to address changeLogs from other bundles.

To be able to use the OSGi include element, the OSGiResourceAccessor class has to be instantiated and passed to the Liquibase object. By default, resources will be searched in the bundle containing the changeLog file. However, it is possible to prefix the file path with an "eosgi:" prefix. In that case, the parser will search for Bundle wires based on a special capability and if it finds an appropriate wire, a bundle switch will be carried out during the parsing process. For example, let`s see a case where an include tag is defined in the following way:

<include file="eosgi:myApp" />

In this case, the current bundle containing this snippet has to be wired to another bundle based on the following capability:

liquibase.schema;name=myApp;resource=/pathToChangelogFile

Additional filters may be defined in include tags like this:

<include file="eosgi:myApp;filter:=(version>=2)" />

In this case, the provider bundle will contain something like this in the MANIFEST file:

Provide-Capability: liquibase.schema;name=myApp;resource=/path;version=3 

Furthermore, the bundle that contains the inclusion must contain a requirement:

Require-Capability: liquibase.schema;filter:=(name=myApp)

Please note, that the resource attribute on the provider side is always required! The parser will search for the changelog file based on that attribute.

Future plans

In the future, it is possible that there will be a maven plugin that automatically generates Require-Capability entries in MANIFEST if it finds a changelog file in the bundle.