Merge pull request #21 from ph0bos/correlation-id

Add correlation header to responses

README.md

@@ -92,3 +92,4 @@ app.use(micro([options]));
 - `controllersPath`: `String` Path to load controllers. Defaults to `controllers`.
 - `monitorsPath`: `String` Path to load monitors. Defaults to `monitors`.
 - `partialResponseQuery`: `String` The query parameter to use for partial reponse. Defaults to `fields`.
+- `correlationHeaderName`: `String` The name of your correlation header. Defaults to `X-CorrelationID`.

index.js

@@ -45,16 +45,17 @@ var buildOptions = function(options) {
   var config = konfig({ path: options.configPath || process.cwd() + '/config' });
 
   // Default options
-  options.server               = options.server || { port: process.env.PORT };
-  options.debug                = options.debug || false;
-  options.discoverable         = options.discoverable || false;
-  options.monitorsPath         = options.monitorsPath || 'monitors';
-  options.controllersPath      = options.controllersPath || 'controllers';
-  options.callerPath           = path.dirname(caller(2));
-  options.serviceName          = pkgInfo.name;
-  options.serviceBasePath      = 'services';
-  options.zookeeper            = { connectionString: 'localhost:2181', retry: { count: 5 } };
-  options.partialResponseQuery = options.partialResponseQuery || 'fields';
+  options.server                = options.server || { port: process.env.PORT };
+  options.debug                 = options.debug || false;
+  options.discoverable          = options.discoverable || false;
+  options.monitorsPath          = options.monitorsPath || 'monitors';
+  options.controllersPath       = options.controllersPath || 'controllers';
+  options.callerPath            = path.dirname(caller(2));
+  options.serviceName           = pkgInfo.name;
+  options.serviceBasePath       = 'services';
+  options.zookeeper             = { connectionString: 'localhost:2181', retry: { count: 5 } };
+  options.partialResponseQuery  = options.partialResponseQuery || 'fields';
+  options.correlationHeaderName = options.correlationHeaderName || 'X-CorrelationID';
 
   // Return now if we have no config
   if (!config.app) {

lib/bootstrap.js

@@ -11,7 +11,8 @@ var cache      = require('express-cache-response-directive');
 var zoologist  = require('./zoologist');
 var log        = require('./logger');
 var partialRes = require('express-partial-response');
-var validator  = require('express-validator')
+var validator  = require('express-validator');
+var correlate  = require('./middleware/correlate');
 
 /**
  * Bootstrap the microservice.
@@ -26,6 +27,9 @@ module.exports = function (app, options) {
   // Enable CORS
   app.use(cors({ preflightContinue: true }));
 
+  // Correlation
+  app.use(correlate(options.headerName));
+
   // Setup Cache Control
   app.use(cache());
 

lib/middleware/correlate.js

@@ -0,0 +1,20 @@
+'use strict';
+
+var uuid = require('node-uuid');
+
+/**
+ * Correlation Header Middleware
+ *
+ * @param options
+ */
+module.exports = function (options) {
+  options = options || {};
+
+  var CORRELATION_ID_HEADER = options.correlationHeaderName || 'X-CorrelationID';
+
+  return function (req, res, next) {
+    var id = (req.header(CORRELATION_ID_HEADER)) ? req.header(CORRELATION_ID_HEADER) : uuid.v4();
+    res.header(CORRELATION_ID_HEADER, id);
+    next();
+  };
+};

package.json

@@ -1,6 +1,6 @@
 {
   "name": "express-microservice-starter",
-  "version": "0.5.15",
+  "version": "0.5.16",
   "description": "An express-based Node.js API bootstrapping module for microservices.",
   "main": "index.js",
   "scripts": {
@@ -37,6 +37,7 @@
     "express-validator": "^2.18.0",
     "ip": "^0.3.2",
     "konfig": "^0.2.1",
+    "node-uuid": "^1.4.7",
     "optional": "^0.1.3",
     "vitalsigns": "^0.4.3",
     "zoologist": "^0.4.14"