If we run : grails run-app
By default the grails will listen at port : 8080
We can change by default port by run this command :
grails run-app -Dserver.port=9000
This command will make the grails listen to the port 9000
Another way is by editing the BuildConfig.groovy
Add the following line :
grails.server.port.http = 9000
NB: I use grails 2.2.4