How to change Grails server port ?

In your web application, edit conf/BuildConfig.groovy file and add the port number like the following :

grails.server.port.http = 8090

For example :

grails.project.dependency.resolution = {
    // inherit Grails' default dependencies
    inherits("global") {
        // specify dependency exclusions here; for example, uncomment this to disable ehcache:
        // excludes 'ehcache'
        grails.server.port.http = 8090
    }
    log "error" // log level of Ivy resolver, either 'error', 'warn', 'info', 'debug' or 'verbose'
    checksums true // Whether to verify checksums on resolve
    legacyResolve true // whether to do a secondary resolve on plugin installation, not advised but here for backwards compatibility

This tips come from http://stackoverflow.com/questions/10955899/how-to-change-grails-localhost-port