Add footer to index.html and include detailed README for Node.js Kafka demo

Author: edimarlnx

nodejs-kafka/README.md

@@ -0,0 +1,106 @@
+# Node.js Kafka Demo
+
+Real-time dashboard application that demonstrates Apache Kafka message streaming with Node.js using KafkaJS, Express, and Server-Sent Events (SSE).
+
+## Architecture
+
+```
+┌─────────────┐    ┌───────────┐    ┌─────────────┐    ┌───────────────┐
+│  Generators  │───>│  Producer  │───>│    Kafka     │───>│   Consumer    │
+│ (fake data)  │    │            │    │   Broker     │    │               │
+└─────────────┘    └───────────┘    └───────────┘    └──────┬────────┘
+                                                            │
+                                                            │ SSE
+                                                            v
+                                                     ┌───────────────┐
+                                                     │   Dashboard   │
+                                                     │  (browser)    │
+                                                     └───────────────┘
+```
+
+1. **Generators** create random simulated data (orders, notifications, logs)
+2. **Producer** publishes messages to three Kafka topics every 3 seconds
+3. **Consumer** reads messages from Kafka and forwards them to the Express server
+4. **Express server** broadcasts messages to connected browsers via SSE
+5. **Dashboard** displays messages in real-time across three columns
+
+## About the displayed data
+
+All data shown in the dashboard is **simulated and fictitious**. The generators produce random data to demonstrate the Kafka messaging flow:
+
+- **Orders** — Random products (GPU, Monitor, Mouse, etc.) with random prices, quantities, and statuses
+- **Notifications** — Random types (Info, Warning, Error, Success) with messages like "SSL certificate expiring soon" or "User login detected"
+- **Logs** — Random levels (DEBUG, INFO, WARN, ERROR) from fictitious services (auth-service, api-gateway, payment-service, etc.)
+
+**None of the errors, warnings, or log messages represent real issues.** They are generated purely for demonstration purposes.
+
+## Prerequisites
+
+- Node.js >= 24
+- A Kafka broker (local or remote)
+
+## Setup
+
+1. Install dependencies:
+
+```bash
+npm install
+```
+
+2. Create a `.env` file from the example:
+
+```bash
+cp .env.example .env
+```
+
+3. Edit `.env` with your Kafka broker settings:
+
+```env
+PORT=3000
+KAFKA_BROKER=localhost:9092
+PRODUCE_INTERVAL_MS=3000
+KAFKA_USERNAME=
+KAFKA_PASSWORD=
+KAFKA_MECHANISM=scram-sha-256
+```
+
+When `KAFKA_USERNAME` and `KAFKA_PASSWORD` are set, SASL authentication and SSL are enabled automatically. Leave them empty for unauthenticated local connections.
+
+## Running
+
+```bash
+# Production
+npm start
+
+# Development (auto-reload)
+npm run dev
+```
+
+Open http://localhost:3000 in your browser to view the dashboard.
+
+## Running with Docker Compose
+
+This starts both Kafka (KRaft mode, no Zookeeper) and the application:
+
+```bash
+docker compose up --build
+```
+
+## Kafka Topics
+
+| Topic           | Description                      |
+|-----------------|----------------------------------|
+| `orders`        | Simulated e-commerce orders      |
+| `notifications` | Simulated system notifications   |
+| `logs`          | Simulated application logs       |
+
+## Environment Variables
+
+| Variable             | Default          | Description                          |
+|----------------------|------------------|--------------------------------------|
+| `PORT`               | `3000`           | Express server port                  |
+| `KAFKA_BROKER`       | `localhost:9092` | Kafka broker address                 |
+| `PRODUCE_INTERVAL_MS`| `3000`           | Interval between produced messages   |
+| `KAFKA_USERNAME`     | —                | SASL username (optional)             |
+| `KAFKA_PASSWORD`     | —                | SASL password (optional)             |
+| `KAFKA_MECHANISM`    | `scram-sha-256`  | SASL mechanism (`scram-sha-256`, `scram-sha-512`, `plain`) |

nodejs-kafka/src/public/index.html

@@ -53,6 +53,13 @@ <h2 class="text-lg font-semibold text-emerald-400">Logs</h2>
     </div>
   </main>
 
+  <footer class="text-center py-4 text-sm text-gray-500">
+    All data displayed is simulated for demonstration purposes.
+    <a href="https://github.com/zcloud-ws/zcloud-samples-multi-project/blob/main/nodejs-kafka/README.md"
+       target="_blank" rel="noopener noreferrer"
+       class="text-blue-400 hover:text-blue-300 underline">Source code &amp; documentation</a>
+  </footer>
+
   <script>
     const MAX_MESSAGES = 50;
     const counts = { orders: 0, notifications: 0, logs: 0 };