These scripts generate machine readable tool installer metadata. You need Groovy 2.0 or later to run them. You can add new one by doing monkey-see monkey-do. Any one of these scripts are individually runnable, for example:
groovy -Dgrape.config=./grapeConfig.xml ./lib/runner.groovy mongodb.groovy
If you need to "only" sign the JSON files (after an update center certificate renewal for instance):
mkdir -p ./target/
rsync -av "${source}/*.json" ./target/
export JENKINS_SIGNER="-key path/to/uc-cert.key -certificate path/to/uc-cert.cert -root-certificate path/to/uc-root-ca.crt"
groovy -Dgrape.config=./grapeConfig.xml ./lib/runner.groovy ./lib/signer.groovy
# You can find the signed files in ./target/*.html