OSGi Metadata for Plain Maven Projects

The tycho-wrap-plugin is different from most other Tycho plugins: it does not need the Tycho build extension and works with ordinary Maven projects (packaging jar). It is meant for library authors who build without Eclipse/Tycho but want to provide good OSGi metadata, or who want to make sure it stays usable, without being OSGi experts.

Goal	Purpose
`tycho-wrap:verify`	Checks that the manifest of the project artifact can be resolved in OSGi
`tycho-wrap:wrap`	Creates an additional OSGi flavor of an existing jar using bnd

Verifying the generated manifest

Many projects generate a MANIFEST.MF (e.g. with bnd-maven-plugin or maven-bundle-plugin) but have no way to know if the result is usable. Full integration tests are expensive to maintain, the verify goal fills the gap:

Bundle-SymbolicName and Bundle-Version are present and valid
every non-optional Import-Package can be satisfied by the JVM or by a dependency of the project
imports only provided by dependencies that are not OSGi bundles are reported

<plugin>
    <groupId>org.eclipse.tycho</groupId>
    <artifactId>tycho-wrap-plugin</artifactId>
    <version>${tycho-version}</version>
    <executions>
        <execution>
            <goals>
                <goal>verify</goal>
            </goals>
        </execution>
    </executions>
</plugin>

The goal runs in the verify phase, so the project artifact must already contain the manifest. Each problem is reported with a hint how to fix it. If a problem can not be fixed right now, it can be ignored so the build is never blocked completely:

<configuration>
    <ignored>
        <ignore>Import-Package: x.y.z</ignore>
    </ignored>
</configuration>

Use the exact requirement text from the error message as ignore entry.

Providing an OSGi flavor of an existing artifact

The wrap goal applies bnd instructions (from bnd.bnd or the <bnd> configuration) to an existing jar and attaches the result with the classifier bundle. Projects can thereby offer a plain and an OSGi-fied artifact, without changing how their main artifact is built.