Grails Restclient. Elastic Search with authentication for ElasticSearch HQ

gistfile1.groovy

        withRest(uri: 'https://esh01.elasticsearchhq.com:9200) {
            handler.success = { resp, results ->
                return results
            }

            handler.failure = { resp ->
                log.error "Unexpected failure: ${resp.statusLine}"
                return false;
            }
            def response = post(
                    path: indexname + '/_search',
                    body: queryObj,
                    headers: ['Authorization': "Basic " + this.encodeAuth(username, password) + "=="],
                    requestContentType: JSON
            )
        }


    public String encodeAuth(username, password) {
        def authC = username + ':' + password
        def bytes = authC.bytes
        return bytes.encodeBase64().toString();
    }

Nice gist! Where in the grails project should I put this code? I have an ElasticSearch instance running aside from my Grails project. I want make my grails app be the only one to be ale to athenticate and get info (search, index) from my ElasticSearch. Any clue? Thank you very much :)