Now batch service is linked to express app in order to make it accesible from main app module to expose drain mechanism

app.js

@@ -97,3 +97,16 @@ process.on('SIGHUP', function() {
         console.log('Log files reloaded');
     });
 });
+
+process.on('SIGTERM', function () {
+    app.batch.stop();
+    app.batch.drain(function (err) {
+        if (err) {
+            console.log('Exit with error');
+            return process.exit(1);
+        }
+
+        console.log('Exit gracefully');
+        process.exit(0);
+    });
+});

app/app.js

@@ -39,7 +39,7 @@ var CacheStatusController = require('./controllers/cache_status_controller');
 var HealthCheckController = require('./controllers/health_check_controller');
 var VersionController = require('./controllers/version_controller');
 
-var batch = require('../batch');
+var batchFactory = require('../batch');
 
 process.env.PGAPPNAME = process.env.PGAPPNAME || 'cartodb_sqlapi';
 
@@ -206,7 +206,8 @@ function App() {
     var isBatchProcess = process.argv.indexOf('--no-batch') === -1;
 
     if (global.settings.environment !== 'test' && isBatchProcess) {
-        batch(metadataBackend).start();
+        app.batch = batchFactory(metadataBackend);
+        app.batch.start();
     }
 
     return app;

batch/batch.js

@@ -15,21 +15,7 @@ function Batch(jobSubscriber, jobQueuePool, jobRunner, jobCanceller) {
 util.inherits(Batch, EventEmitter);
 
 Batch.prototype.start = function () {
-    var self = this;
     this._subscribe();
-
-    process.on('SIGTERM', function () {
-        self.stop();
-        self.drain(function (err) {
-            if (err) {
-                console.log('Exit with error');
-                return process.exit(1);
-            }
-
-            console.log('Exit gracefully');
-            process.exit(0);
-        });
-    });
 };
 
 Batch.prototype._subscribe = function () {