Setup

Before we dive into logging WebSocket events, let’s set up a basic WebSocket server using the ws library in Node.js. Open your favorite terminal and follow these steps:

1. Create a new directory for your project:

   mkdir websocket-logger
   cd websocket-logger
   

2. Initialize a new Node.js project and install the ws package:

   npm init -y
   npm install ws
   

3. Create a new file called server.js and add the following code:

   const WebSocket = require('ws');
   
   const wss = new WebSocket.Server({ port: 8080 });
   
   wss.on('connection', (ws) => {
     ws.on('message', (message) => {
       console.log('Received message:', message);
     });
   
     ws.on('close', () => {
       console.log('WebSocket connection closed');
     });
   });
   

4. Run the server:

   node server.js
   

Now we have a WebSocket server listening on port 8080. Any messages received will be logged to the console.

Logging WebSocket Events

To log WebSocket events in real-time, we can modify the server code to listen for additional event types. Let’s add logging for the open and error events.

const WebSocket = require('ws');

const wss = new WebSocket.Server({ port: 8080 });

wss.on('connection', (ws) => {
  ws.on('message', (message) => {
    console.log('Received message:', message);
  });

  ws.on('close', () => {
    console.log('WebSocket connection closed');
  });

  ws.on('open', () => {
    console.log('WebSocket connection opened');
  });

  ws.on('error', (error) => {
    console.error('WebSocket error:', error);
  });
});

With these additional event handlers, we can now log the open and error events along with the existing message and close events.

Real-time Logging

To view the WebSocket events in real-time, we can use a logging library like winston and configure it to log to a file. Here’s how to set it up:

1. Install winston as a dependency:

   npm install winston
   

2. Update the server.js file:

   const WebSocket = require('ws');
   const winston = require('winston');
   
   const logger = winston.createLogger({
     transports: [
       new winston.transports.File({ filename: 'websocket.log' }),
     ],
   });
   
   const wss = new WebSocket.Server({ port: 8080 });
   
   wss.on('connection', (ws) => {
     ws.on('message', (message) => {
       logger.info('Received message:', message);
     });
   
     ws.on('close', () => {
       logger.info('WebSocket connection closed');
     });
   
     ws.on('open', () => {
       logger.info('WebSocket connection opened');
     });
   
     ws.on('error', (error) => {
       logger.error('WebSocket error:', error);
     });
   });
   

3. Run the server again:

   node server.js
   

Now, every WebSocket event will be logged to the websocket.log file in real-time.

Conclusion

Logging WebSocket events in real-time is crucial for monitoring and debugging WebSocket connections. By listening to the open, message, close, and error events, we can log important information about the connection. Additionally, using a logging library like winston allows us to store the logs and analyze them later if needed.

Start logging your WebSocket events today and gain valuable insights into your real-time communication system.

#WebSocket #NodeJS