You can do read the properties
file as below:
plugins {
def props = new Properties()
new File("grails-app/conf/config.properties").withReader{
props.load(it)
}
def slurp = new ConfigSlurper().parse(props)
build ":tomcat:$slurp.grails.tomcat.version"
}
I do not see a value out of it if you only have that single entry to use from the properties file. I would rather have that config defined in Config.groovy
.