Real-Time Log Viewer

A simple, dependency-light solution for monitoring server logs in real-time directly through a web browser. It uses Node.js and WebSockets to mimic the functionality of tail -f without requiring external client tools.

Project Structure

root/
├── index.html 
├── server.js
├── test.log
└── README.md

Requirements

• Node.js (v14 or later recommended)
• The ws package (WebSocket library).

Installation

Install the required WebSocket package:

npm install ws

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Usage

1. Start the Server

Run the main backend file:

node server.js

2. View Real-Time Logs

Open the web browser and navigate to:

http://localhost:8080

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How It Works

1. Client Connects: The browser loads index.html and initiates a WebSocket connection to the server.
2. Initial Data: server.js reads the last 15 lines of test.log and sends them to the client.
3. File Watcher: The fs.watch module monitors test.log for changes.
4. Live Stream: When data is appended, the server reads only the new content and broadcasts it to all clients via the WebSocket connection.

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Configuration

All configuration constants are located at the top of server.js:

Constant	Default Value	Description
PORT	8080	The port for the HTTP and WebSocket server.
LOG_FILE_PATH	./test.log	The path to the log file to monitor.
INITIAL_LINES	15	The number of log lines to show on initial client connect.

Disabling the Mock Log Generator

To monitor a real log file instead of the mock one, comment out the setInterval call near the end of server.js:

// Comment out this line to disable the mock generator:
// setInterval(() => { ... }, LOG_GENERATION_INTERVAL);

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Notes

• Attempting to open index.html directly (using file://) will not work, as WebSockets require a running HTTP server context.
• The target log file (test.log by default) is created automatically if it doesn't exist.