1 файл
const es = require('elasticsearch');
const esClient = new es.Client({
    host: 'localhost:9200',
    log: 'trace'
});
const search = function search(index, body) {
    return esClient.search({index: index, body: body});
};

module.exports = search;
2 файл
let body = {
            query: {
                match_all:
                    {output}
            }
        };
        search('SAP', body)
            .then(results => {
                console.log(`found ${results.hits.total} items in ${results.took}ms`);
              console.log(`returned article titles:`);
                results.hits.hits.forEach((hit, index) => console.log(`\t${body.from + ++index} - ${hit._source.title}`));
            })
            .catch(console.error);