Fix Redis, add Docker compose, show how to setup project in README.md

README.md

@@ -2,11 +2,28 @@
 Realtime chat app with websockets using Node.js, Express and Socket.io with Vanilla JS on the frontend with a custom UI
 [![Run on Repl.it](https://repl.it/badge/github/bradtraversy/chatcord)](https://repl.it/github/bradtraversy/chatcord)
 ## Usage
+
+### To start the application
+
+Ensure Docker Desktop is up and running. 
+See [the Docker website](https://www.docker.com/products/docker-desktop/) to get started.
+
 ```
 npm install
 npm run dev
-
+```
 Go to localhost:3000
+
+### To shutdown the application & the Redis image (Docker container)
+
+```
+npm run stop
+```
+
+### To shutdown the application, Redis image (Docker container) & cleanup Redis volume data
+
+```
+npm run docker-down
 ```
 
 ## Notes

docker-compose.yml

@@ -0,0 +1,12 @@
+version: "3"
+
+services:
+  redis:
+    image: redis:5
+    ports:
+      - "6379:6379"
+    volumes:
+      - redis_data:/data
+
+volumes:
+  redis_data:

package.json

@@ -4,8 +4,11 @@
   "description": "Realtime chat app with rooms",
   "main": "server.js",
   "scripts": {
-    "start": "node server",
-    "dev": "nodemon server"
+    "docker-up": "docker-compose -p chatcord up -d",
+    "start": "npm run docker-up && node server",
+    "dev": "npm run docker-up && nodemon server",
+    "stop": "docker-compose -p chatcord down",
+    "docker-down": "docker-compose -p chatcord down -v --rmi all"
   },
   "author": "Brad Traversy",
   "license": "MIT",

server.js

@@ -22,12 +22,60 @@ const io = socketio(server);
 app.use(express.static(path.join(__dirname, "public")));
 
 const botName = "ChatCord Bot";
+let pubClient, subClient;
 
 (async () => {
-  pubClient = createClient({ url: "redis://127.0.0.1:6379" });
-  await pubClient.connect();
-  subClient = pubClient.duplicate();
-  io.adapter(createAdapter(pubClient, subClient));
+  try {
+    pubClient = createClient({ url: "redis://127.0.0.1:6379" });
+    await pubClient.connect();
+    subClient = pubClient.duplicate();
+    io.adapter(createAdapter(pubClient, subClient));
+    console.log("Successfully connected to Redis adapter");
+  } catch (err) {
+    if (err.code === 'ECONNREFUSED') {
+      console.warn("Redis server is not available. Make sure it's running.");
+    } else {
+      console.error("Error connecting to Redis:", err);
+    }
+  }
+
+  let reconnectAttempts = 0;
+  const maxReconnectAttempts = 3;
+
+  const handleRedisError = async (err, client) => {
+    if (err && err.name === 'AbortError') {
+      console.warn(`${client === pubClient ? 'pubClient' : 'subClient'}: Redis connection aborted.`);
+    } else if (err && err.errors && err.errors.length > 0) {
+      const firstError = err.errors[0];
+      console.warn(`${client === pubClient ? 'pubClient' : 'subClient'}: ${firstError.message}`);
+    } else {
+      console.error(`${client === pubClient ? 'pubClient' : 'subClient'} error:`, err);
+    }
+
+    // Reconnect retry mechanism
+    if (reconnectAttempts < maxReconnectAttempts) {
+      reconnectAttempts++;
+      console.log(`Reconnecting ${client === pubClient ? 'pubClient' : 'subClient'} (Attempt ${reconnectAttempts} of ${maxReconnectAttempts})...`);
+      try {
+        await client.connect();
+        console.log(`Successfully reconnected to ${client === pubClient ? 'pubClient' : 'subClient'}`);
+        reconnectAttempts = 0; // resets the counter if reconnection is successfull
+      } catch (reconnectError) {
+        console.error(`Error reconnecting ${client === pubClient ? 'pubClient' : 'subClient'}:`, reconnectError);
+      }
+    } else {
+      console.error(`Max reconnect attempts reached. Shutting down the application.`);
+      process.exit(1);
+    }
+  };
+
+  pubClient.on('error', (err) => {
+    handleRedisError(err, pubClient);
+  });
+
+  subClient.on('error', (err) => {
+    handleRedisError(err, subClient);
+  });
 })();
 
 // Run when client connects