Hi,
unfortunately it’s not that easy to add custom jars to the classpath, since the app is packaged as a war. What you could do is to add your jar to the war file with the following commands:
# Copy the flowable-rest.war to an empty directory
mkdir working-directory
cd working-directory
cp /path/to/flowable-rest.war .
# Copy my-classes.jar to WEB-INF/lib/
mkdir -p WEB-INF/lib/
cp /path/to/my-classes.jar WEB-INF/lib/
# Add the my-classes lib to the war file
jar -uvf0 flowable-rest.war WEB-INF
# Remove the WEB-INF folder (important in case you would like to start it directly without the docker container)
rm -rf WEB-INF
# Start the flowable-rest application (or include it into the docker image)
java -jar flowable-rest.war