A simple Logstash UDP logger for Winston.

LogstashUDP.js

// Really simple Winston Logstash UDP Logger

var dgram = require('dgram'),
    util = require('util'),
    os = require('os'),
    winston = require('winston');

var LogstashUDP = module.exports = function (options) {
  winston.Transport.call(this, options);
  options = options || {};

  this.name                = 'logstashUdp';
  this.localhost           = options.localhost || os.hostname();
  this.host                = options.host || '127.0.0.1';
  this.port                = options.port || 9999;
  this.application         = options.appName || process.title;
  this.pid                 = options.pid || process.pid;

  this.client = dgram.createSocket("udp4");
};


util.inherits(LogstashUDP, winston.Transport);

LogstashUDP.prototype.log = function (level, msg, meta, callback) {
  var self = this,
      meta = winston.clone(meta || {});

  if (self.silent) {
    return callback(null, true);
  }

  var logEntry = {
    "@message": msg,
    "@source_host": self.localhost,
    "@timestamp": new Date().toISOString(),
    "@fields": {
      "level": level,
      "pid": self.pid,
      "application": self.application
    }
  };

  for (prop in meta) { 
    if (meta.hasOwnProperty(prop)) logEntry["@fields"][prop] = meta[prop];
  }

  self.sendLog(JSON.stringify(logEntry), callback);
};


LogstashUDP.prototype.sendLog = function (message, callback) {
  var self = this;
  callback = callback || function () {};
  var buf = new Buffer(message)
  self.client.send(buf, 0, buf.length, self.port, self.host, callback);
};

udp.conf

input {
  udp {
    format => "json_event"
    port => 9999
    type=> "app"
  }
}