winston-elastic.JS

const winston = require('winston');
const Elasticsearch = require('winston-elasticsearch');
 
const esTransportOpts = {
  level: 'info'
};

const logger = winston.createLogger({
  level: 'info',
  format: winston.format.json(),
  transports: [
    new winston.transports.File({ filename: "logfile.log", level: 'error' }), //save errors on file
    new Elasticsearch(esTransportOpts) //everything info and above goes to elastic
  ]
});
 
if (process.env.NODE_ENV !== 'production') {
  logger.add(new winston.transports.Console({ //we also log to console if we're not in production
    format: winston.format.simple()
  }));
}