Winston Logger

Advanced structured logging system for Node.js and Express using Winston. Supports console and file logs, JSON formatting, and request tracking middleware.

loggingwinstonexpressnodemonitoringjson

v2.0.0utility

Overview

A robust, developer-ready logging component built on Winston, providing structured, leveled, and environment-based logging for Express and Node.js apps. Supports file and console transports, request logging middleware, and JSON-structured log output for analysis tools like ELK or Datadog.

Installation

CLI

npx backternity add logger-winston

What This Does

Installs a Winston-based logger with default transports (console and optional file). Includes structured JSON logging and Express middleware for request and error logging.

Files & Folders Created

File / Path	Description
/src/services/logger.js	Configures Winston logger with transports and formats.
/server.js.example	Demonstrates request logging and error handling.
/.env.example	Configures log level and file output settings.

Files to be modified

File / Path	Description
server.js	Integrates logger middleware and error tracking.
.env	Adds logging configuration (level, file path, output toggle).

Configuration

LOG_LEVEL=info          
LOG_TO_FILE=true        
LOG_FILE_PATH=./logs/app.log
SERVICE_NAME=api-service
NODE_ENV=development

Frontend Integration

Although this is a backend logger, it supports frontend-compatible structured logs when used in full-stack apps (e.g., for API request metrics). Use with tools like Datadog, Logtail, or custom dashboards to visualize logs.

POST/api/log-event

Send a custom log event from frontend to backend logger.

GET/api/logs/health

Get logging system health and recent stats.

GET/api/logs/recent

Retrieve recent log entries (last 50).

GET/

Root route to confirm the logger is active.

GET/error

Simulates a server error and logs it through Winston.

Example

// app/components/LogEventButton.jsx (Next.js example)
'use client';
import { useState } from 'react';

export default function LogEventButton() {
  const [status, setStatus] = useState('');

  const sendLog = async () => {
    setStatus('Sending log...');
    try {
      const res = await fetch('/api/log-event', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          level: 'info',
          message: 'User triggered frontend log event',
          context: { page: '/dashboard', action: 'button_click' }
        }),
      });
      if (res.ok) setStatus('✅ Log sent successfully');
      else setStatus('⚠️ Log send failed');
    } catch {
      setStatus('❌ Failed to send log');
    }
  };

  return (
    <div className="p-4 border border-white/10 rounded-lg bg-black/30">
      <button
        onClick={sendLog}
        className="bg-emerald-600 hover:bg-emerald-700 text-white font-medium px-4 py-2 rounded"
      >
        Send Log Event
      </button>
      <p className="text-sm text-gray-400 mt-2">{status}</p>
    </div>
  );
}

Usage

// Logging different events
const logger = require('./src/services/logger');

// Informational
logger.info('User login successful', { userId: 123 });

// Warnings
logger.warn('High response time', { route: '/api/data', duration: 1200 });

// Errors
logger.error('Database connection failed', { service: 'db', retrying: true });

// Debug logs
logger.debug('Fetched records', { count: 34, source: 'cache' });