Logging with Morgan and Winston
Logging with Morgan and Winston
In a Node.js application, logging is crucial for monitoring, debugging, and maintaining the application. Two popular libraries for logging are:
Morgan: A middleware for logging HTTP requests.
Winston: A flexible and powerful logging library for general-purpose logging.
They are often used together: Morgan for HTTP request logs, and Winston for application-level logs.
📘 What is Morgan?
Morgan is an HTTP request logger middleware for Node.js. It's used with frameworks like Express to log details about incoming requests.
Installation:
bash
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npm install morgan
Basic Usage:
javascript
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const express = require('express');
const morgan = require('morgan');
const app = express();
// Use 'combined' format for detailed logs
app.use(morgan('combined'));
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(3000);
Available Formats:
combined – Standard Apache combined log output
common – Standard Apache common log output
dev – Concise colored output for development
short – Shorter than common
tiny – Minimal output
You can also define a custom format if needed.
🔧 What is Winston?
Winston is a versatile logging library for Node.js that supports:
Multiple transports (console, files, databases)
Logging levels
Log formatting
Customization
Installation:
bash
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npm install winston
Basic Usage:
javascript
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const winston = require('winston');
const logger = winston.createLogger({
level: 'info',
format: winston.format.simple(),
transports: [
new winston.transports.Console(), // Logs to console
new winston.transports.File({ filename: 'app.log' }) // Logs to a file
],
});
// Logging messages
logger.info('Application started');
logger.warn('This is a warning');
logger.error('An error occurred');
Logging Levels (Default):
error
warn
info
http
verbose
debug
silly
🧩 Combining Morgan with Winston
You can route Morgan’s HTTP logs to Winston for centralized logging.
javascript
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const express = require('express');
const morgan = require('morgan');
const winston = require('winston');
const stream = require('stream');
const app = express();
// Winston logger setup
const logger = winston.createLogger({
transports: [
new winston.transports.File({ filename: 'combined.log' }),
new winston.transports.Console()
],
format: winston.format.combine(
winston.format.timestamp(),
winston.format.simple()
)
});
// Stream for Morgan to use Winston
const morganStream = {
write: (message) => logger.info(message.trim())
};
// Use Morgan with Winston stream
app.use(morgan('combined', { stream: morganStream }));
app.get('/', (req, res) => {
logger.info('Root endpoint hit');
res.send('Hello with Winston and Morgan!');
});
app.listen(3000, () => {
logger.info('Server is running on port 3000');
});
✅ When to Use What
Task Use
Log HTTP requests Morgan
Log application events Winston
Centralize all logs Combine both
Log to files or services Winston
🧩 Conclusion
Morgan is great for quick HTTP request logging in Express.
Winston is a powerful logging tool for application logs.
Combine them to create a complete logging solution for your Node.js application.
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