Reading Metadata values in Grails scripts

After reading the useful post by Kevin Gill on adding build numbers to the grails build: Adding Auto Incrementing Build Number to a Grails Application

I began to wonder how to attach the build number to the project war file. Turns out the solution was simpler than I had thought.

grails.project.war.file = "target/${appName}-${appVersion}-${grails.util.Metadata.current.'app.buildNumber'.toInteger()+1}.war"