If you wish to try out this plug-in against a running Jenkins image you can do this:
export JENKINS_CONTAINER=`docker ps | grep jenkins | { read first rest ; echo $first ; }`
mvn install
docker cp target/openshift-jenkins-sync-plugin.hpi $JENKINS_CONTAINER:/var/jenkins_home/plugins
Then you need to go into jenkins and reload the configuration which can be done via the Reload Configuration from disk option here: http://jenkins.vagrant.f8/manage
curl -X POST http://jenkins.vagrant.f8/safeRestart