added cluster identifier support

lib/layouts.js

@@ -145,7 +145,7 @@ function messagePassThroughLayout (loggingEvent) {
  */
 function patternLayout (pattern, tokens) {
   var TTCC_CONVERSION_PATTERN  = "%r %p %c - %m%n";
-  var regex = /%(-?[0-9]+)?(\.?[0-9]+)?([\[\]cdhmnprzx%])(\{([^\}]+)\})?|([^%]+)/;
+  var regex = /%(-?[0-9]+)?(\.?[0-9]+)?([\[\]cdhmnprzxy%])(\{([^\}]+)\})?|([^%]+)/;
   
   pattern = pattern || TTCC_CONVERSION_PATTERN;
 
@@ -212,8 +212,25 @@ function patternLayout (pattern, tokens) {
     return '%';
   }
 
-  function pid() {
-    return process.pid;
+  function pid(loggingEvent) {
+    if (loggingEvent.pid) {
+      return loggingEvent.pid;
+    } else {
+      return process.pid;
+    }
+  }
+  
+  function clusterInfo(loggingEvent, specifier) {
+    if (loggingEvent.cluster && specifier) {
+      return specifier
+        .replace('%m', loggingEvent.cluster.master)
+        .replace('%w', loggingEvent.cluster.worker)
+        .replace('%i', loggingEvent.cluster.workerId);
+    } else if (loggingEvent.cluster) {
+      return loggingEvent.cluster.worker+'@'+loggingEvent.cluster.master;
+    } else {
+      return pid();
+    }
   }
 
   function userDefined(loggingEvent, specifier) {
@@ -237,6 +254,7 @@ function patternLayout (pattern, tokens) {
     'r': startTime,
     '[': startColour,
     ']': endColour,
+    'y': clusterInfo,
     'z': pid,
     '%': percent,
     'x': userDefined