Add infrastructure for doing proper sessions

The sessions are stored server-side and in a persistent file store.

diff --git a/index.js b/index.js
index 638c59dc6543fbab851e179d9b59b74aa123c51c..cd1911def06ba21b1197a72c9bd6b1d5405b0989 100644 (file)
--- a/index.js
+++ b/index.js
@@ -5,6 +5,8 @@ const execFile = util.promisify(require('child_process').execFile);
 
 const express = require('express');
 const app = express();
+const session = require('express-session');
+const FileStore = require('session-file-store')(session);
 const http = require('http');
 const server = http.createServer(app);
 const { Server } = require("socket.io");
@@ -17,6 +19,26 @@ const state_file = 'zombocom-state.json'
 
 var state;
 
+if (!process.env.ZOMBOCOM_SESSION_SECRET) {
+    console.log("Error: Environment variable ZOMBOCOM_SESSION_SECRET not set.");
+    console.log("Please set it to a random, but persistent, value.")
+    process.exit();
+}
+
+const session_middleware =  session(
+    {store: new FileStore,
+     secret: process.env.ZOMBOCOM_SESSION_SECRET,
+     resave: false,
+     saveUninitialized: true
+    });
+
+app.use(session_middleware);
+
+// convert a connect middleware to a Socket.IO middleware
+const wrap = middleware => (socket, next) => middleware(socket.request, {}, next);
+
+io.use(wrap(session_middleware));
+
 // Load comments at server startup
 fs.readFile(state_file, (err, data) => {
     if (err)
@@ -43,11 +65,18 @@ process.on('SIGINT', () => {
 });
 
 app.get('/index.html', (req, res) => {
+    if (req.session.views) {
+        req.session.views++;
+    } else {
+        req.session.views = 1;
+    }
     res.sendFile(__dirname + '/index.html');
 });
 
 io.on('connection', (socket) => {
 
+    console.log("Connection from client with " + socket.request.session.views + " views.");
+
     // Replay old comments and images to a newly-joining client
     state.comments.forEach((comment) => {
         socket.emit('comment', comment)