Merge pull request #497 from timeoff-management/tom-xxx-redis-as-sess…

…ion-store

Introduce Redis as alternative session storage.

app.js

@@ -6,6 +6,7 @@ var logger       = require('morgan');
 var cookieParser = require('cookie-parser');
 var bodyParser   = require('body-parser');
 var moment       = require('moment');
+const createSessionMiddleware = require('./lib/middleware/withSession');
 
 var app = express();
 
@@ -37,16 +38,8 @@ app.use(express.static(path.join(__dirname, 'public')));
 // Setup authentication mechanism
 const passport = require('./lib/passport')();
 
-var session = require('express-session');
-// Initialize sequelize with session store
-var SequelizeStore = require('connect-session-sequelize')(session.Store);
-app.use(session({
-    secret            : 'my dirty secret ;khjsdkjahsdajhasdam,nnsnad,',
-    resave            : false,
-    saveUninitialized : false,
-    store: new SequelizeStore({
-      db: app.get('db_model').sequelize
-    }),
+app.use(createSessionMiddleware({
+  sequelizeDb: app.get('db_model').sequelize,
 }))
 app.use(passport.initialize());
 app.use(passport.session());

config/app.json

@@ -10,6 +10,13 @@
       "pass" : "pass"
     }
   },
+  "sessionStore": {
+    "useRedis": false,
+    "redisConnectionConfiguration": {
+      "host": "localhost",
+      "port": 6379
+    }
+  },
   "ga_analytics_on" : false,
   "crypto_secret" : "!2~`HswpPPLa22+=±§sdq qwe,appp qwwokDF_",
   "application_domain" : "http://app.timeoff.management",

config/db.json

@@ -2,7 +2,7 @@
   "development": {
     "dialect": "sqlite",
     "storage": "./db.development.sqlite",
-    "logging": false
+    "logging": false 
   },
   "test": {
     "username": "root",

docs/SessionStoreInRedis.md

@@ -0,0 +1,15 @@
+# How to use Redis as storage for Sessions
+
+By default application uses its database as a storage for session data (`Sessions` table).
+
+It is possible to use different storage mechanism for Sessions data: [Redis](https://redis.io/).
+
+## Steps
+
+* Ensure the application's source is at least `1.4.0`
+* Stop the application
+* Open `config/app.json` for editing
+* Update `sessionStore.useRedis` section to be `true`
+* Update `sessionStore.redisConnectionConfiguration`'s `host` and `port` pointing to corresponding instance of Redis
+* Save the configuration file 
+* Restart the application

lib/middleware/withSession.js

@@ -0,0 +1,47 @@
+
+const session = require('express-session');
+const SequelizeStore = require('connect-session-sequelize')(session.Store);
+
+const redis = require('redis');
+const connectRedis = require('connect-redis');
+
+const {sessionStore: sessionStoreConfig} = require(__dirname + '/../../config/app.json') || {};
+
+const createSessionMiddleware = ({
+  sequelizeDb,
+}) => {
+  let store;
+
+  if (sessionStoreConfig && sessionStoreConfig.useRedis) {
+    const RedisStore = connectRedis(session);
+    const {redisConnectionConfiguration = {}} = sessionStoreConfig;
+    const {host, port} = redisConnectionConfiguration;
+    if (!(host && port)) {
+      throw new Error('Missing configuration for Redis to use with Sessions');
+    }
+    const redisClient = redis.createClient({ host, port });
+
+    redisClient.on('error', function (err) {
+      throw new Error(`Failed to connect to Redis: ${err}`);
+    });
+    redisClient.on('connect', function (err) {
+        console.log('Connected to redis successfully');
+    });
+
+    store = new RedisStore({ client: redisClient });
+  } else {
+    if (!sequelizeDb) {
+      throw new Error('Database connection was not provided into Session store manager!');
+    }
+    store = new SequelizeStore({ db: sequelizeDb });
+  }
+
+  return session({
+    store,
+    secret: 'my dirty secret ;khjsdkjahsdajhasdam,nnsnad,',
+    resave: false,
+    saveUninitialized: false,
+  });
+};
+
+module.exports = createSessionMiddleware;

package.json

@@ -9,6 +9,7 @@
   "dependencies": {
     "bluebird": "^2.10.2",
     "body-parser": "^1.8.4",
+    "connect-redis": "^6.0.0",
     "connect-session-sequelize": "3.0.0",
     "cookie-parser": "^1.3.5",
     "csv": "~0.4.6",
@@ -33,6 +34,7 @@
     "passport": "^0.3.2",
     "passport-http-bearer": "^1.0.1",
     "passport-local": "^1.0.0",
+    "redis": "^3.1.2",
     "sequelize": "^3.19.2",
     "sequelize-cli": "2.5.1",
     "serve-favicon": "^2.1.7",