Log Enrichment

Enrich logs with additional context or metadata. For example, you might add user-specific information or request context.

const winston = require('winston');

const requestLogger = winston.createLogger({
  level: 'info',
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.json(),
    winston.format.printf(({ level, message, timestamp, requestId }) => {
      return `${timestamp} [${level}] [RequestId: ${requestId}] ${message}`;
    })
  ),
  transports: [
    new winston.transports.Console()
  ]
});

// Middleware to attach requestId
app.use((req, res, next) => {
  req.requestId = Math.random().toString(36).substring(2);
  next();
});

// Log with requestId
app.get('/', (req, res) => {
  requestLogger.info('Handled request', { requestId: req.requestId });
  res.send('Hello World!');
});