elasticsearch.js

var elasticsearch = require('elasticsearch');
var client = new elasticsearch.Client({
    host: 'localhost:9200',
    log: 'trace'
});
client.count({
    index: 'logstash-2015.06.22',
    body: {
        query: {
            filtered: {
                filter: {
                    terms: {
                        foo: ['bar']
                    }
                }
            }
        }
    }
}, function(err, response) {
    console.log(err, response)
});