Merge properties files with grails config in runtime

configMerge.groovy

//Merges Properties file with config grails
Properties properties = new Properties()
//Lets say we have file in web-app/settings/setting.properties folder
File propertiesFile = grailsApplication.mainContext.getResource("settings/settings.properties").file
propertiesFile.withInputStream {
    properties.load(it)
}
ConfigSlurper cs = new ConfigSlurper()
ConfigObject co = cs.parse(properties)

//Merges only the settings we need. leaves everything else intact
grailsApplication.config.merge(co)