Merge pull request jaakkos#46 from JeffAtDeere/extract_transformer

Extract a transformer method for finer control of the formats and fields sent to logstash

lib/default-transform.js

@@ -0,0 +1,13 @@
+var common = require('winston/lib/winston/common');
+
+module.exports = function (level, msg, meta, self) {
+    return common.log({
+        level: level,
+        message: msg,
+        node_name: self.node_name,
+        meta: meta,
+        timestamp: self.timestamp,
+        json: true,
+        label: self.label
+    });
+};

lib/winston-logstash.js

@@ -11,7 +11,7 @@ var net = require('net'),
     tls = require('tls'),
     fs = require('fs'),
     winston = require('winston'),
-    common = require('winston/lib/winston/common');
+    defaultTransform = require('./default-transform');
 
 var ECONNREFUSED_REGEXP = /ECONNREFUSED/;
 
@@ -50,6 +50,7 @@ var Logstash = exports.Logstash = function (options) {
   this.strip_colors        = options.strip_colors || false;
   this.label               = options.label || this.node_name;
   this.meta_defaults       = options.meta || {};
+  this.transform           = options.transform || defaultTransform;
 
   // We want to avoid copy-by-reference for meta defaults, so make sure it's a flat object.
   for (var property in this.meta_defaults) {
@@ -98,15 +99,7 @@ Logstash.prototype.log = function (level, msg, meta, callback) {
     }
   }
 
-  log_entry = common.log({
-    level: level,
-    message: msg,
-    node_name: this.node_name,
-    meta: meta,
-    timestamp: self.timestamp,
-    json: true,
-    label: this.label
-  });
+  log_entry = this.transform(level, msg, meta, self);
 
   if (!self.connected) {
     self.log_queue.push({