examples/grails3-multiple-datasources/grails-app/init/datasources/Application.groovy

package datasources

import grails.boot.GrailsApp
import grails.boot.config.GrailsAutoConfiguration
import groovy.transform.CompileStatic
import org.springframework.boot.autoconfigure.EnableAutoConfiguration
import org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration

//@EnableAutoConfiguration(exclude = DataSourceTransactionManagerAutoConfiguration)
@CompileStatic
class Application extends GrailsAutoConfiguration {
    static void main(String[] args) {
        GrailsApp.run(Application)
    }
}