[Issue #7] Add support for graceful shutdowns.

config/webcore.json

@@ -4,6 +4,8 @@
 
     "host": ["OPENSHIFT_NODEJS_IP", "VCAP_APP_HOST", "HOST", "IP"],
 
+    "shutdownTimeout": 30000,
+
     "globalAgent": {
         "maxSockets": 250
     },

index.js

@@ -108,7 +108,7 @@ var kraken = {
         }
 
         function bind(app) {
-            var deferred, server, ssl;
+            var deferred, server, ssl, httpServer;
 
             if (port === undefined) {
                 port = that.port;
@@ -138,7 +138,8 @@ var kraken = {
             server = ssl ? https.createServer(ssl, app) : http.createServer(app);
             server.once('listening', resolve);
             server.once('error', reject);
-            server.listen(port, host);
+            httpServer = server.listen(port, host);
+            app.set('kraken:server', httpServer);
 
             return deferred.promise;
         }

lib/appcore.js

@@ -163,7 +163,9 @@ var proto = {
         config = this._config.get('middleware');
         srcRoot = this._resolve(config.static.srcRoot);
         staticRoot = this._resolve(config.static.rootPath);
+        errorPages = config.errorPages || {};
 
+        app.use(kraken.shutdown(app, this._config, errorPages['503']));
         app.use(express.favicon());
         app.use(kraken.compiler(srcRoot, staticRoot, this._config, this._i18n));
         app.use(express.static(staticRoot));
@@ -197,7 +199,6 @@ var proto = {
             delegate.requestAfterRoute(app);
         }
 
-        errorPages = config.errorPages || {};
         app.use(kraken.fileNotFound(errorPages['404']));
         app.use(kraken.serverError(errorPages['500']));
         app.use(kraken.errorHandler(config.errorHandler));

lib/middleware/index.js

@@ -33,6 +33,8 @@ exports = module.exports = {
     // TODO: Add multipart support
     //multipart: require('./multipart'),
 
+    shutdown: require('./shutdown'),
+
     compiler: require('./compiler'),
 
     fileNotFound: error.fileNotFound,

lib/middleware/shutdown.js

@@ -0,0 +1,56 @@
+/***@@@ BEGIN LICENSE @@@***/
+/*───────────────────────────────────────────────────────────────────────────*\
+│  Copyright (C) 2013 eBay Software Foundation                                │
+│                                                                             │
+│hh ,'""`.                                                                    │
+│  / _  _ \  Licensed under the Apache License, Version 2.0 (the "License");  │
+│  |(@)(@)|  you may not use this file except in compliance with the License. │
+│  )  __  (  You may obtain a copy of the License at                          │
+│ /,'))((`.\                                                                  │
+│(( ((  )) ))    http://www.apache.org/licenses/LICENSE-2.0                   │
+│ `\ `)(' /'                                                                  │
+│                                                                             │
+│   Unless required by applicable law or agreed to in writing, software       │
+│   distributed under the License is distributed on an "AS IS" BASIS,         │
+│   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  │
+│   See the License for the specific language governing permissions and       │
+│   limitations under the License.                                            │
+\*───────────────────────────────────────────────────────────────────────────*/
+/***@@@ END LICENSE @@@***/
+'use strict';
+
+module.exports = function (app, config, template) {
+
+    var gracefulShutdown = function () {
+        var server, timeout;
+        config.set('kraken:state', 'disconnecting');
+
+        server = app.get('kraken:server');
+        // switch to kraken.close once it's implemented
+        server.close(function () {
+            process.exit();
+        });
+
+        timeout = config.get('shutdownTimeout');
+        setTimeout(function () {
+            process.exit(1);
+        }, timeout);
+    };
+
+    process.on('SIGTERM', gracefulShutdown);
+    process.on('SIGINT', gracefulShutdown);
+
+    return function (req, res, next) {
+        if (config.get('kraken:state') !== 'disconnecting') {
+            return next();
+        }
+        res.setHeader('Connection', 'close');
+        if (template && !req.xhr) {
+            res.status(503);
+            res.render(template);
+        } else {
+            res.send(503, 'Server is in the process of shutting down.');
+        }
+    };
+
+};