Node.js Logger with Daily Rotation

A flexible and efficient logging solution for Node.js applications, built using winston, offering daily log rotation, compression, custom log levels, and more.

Features

• Daily Log Rotation: Automatically rotates log files daily.
• Compression: Compresses old log files to save disk space.
• Custom Log Levels: Supports multiple log levels (info, error, warn, debug, etc.).
• Console Logging: Optionally logs to both files and the console.
• Environment Variables Support: Control logging behavior (log level, file size, retention) via environment variables.
• Supports ES6 and CommonJS: Works with both import (ES6) and require (CommonJS).

Installation

To install the logger package, run:

npm install super-logger-winston
npm i super-logger-winston

Usage

1. ES6 Modules (Using import)

import Logs from 'super-logger-winston';

const loggingConsole = true  // default false
const loggingPath = './logs/application'
const logger = new Logs( loggingPath , loggingConsole);

// Log info
logger.info('Application started');
logger.info({server:'Server started successfuly'});     // it accept both string and object

// Log errors
logger.error({ error: 'Unhandled exception', stackTrace: 'stack trace here' });

2. CommonJS Modules (Using require)

const Logs = require('super-logger-winston');

const loggingConsole = true  // default false
const loggingPath = './logs/application'
const logger = new Logs( loggingPath , loggingConsole);

// Log info
logger.info('Application started');
logger.info({server:'Server started successfuly'});     // it accept both string and object


// Log errors
logger.error({ error: 'Unhandled exception', stackTrace: 'stack trace here' });

Constructor Parameters

• filePath: Base path for storing log files (e.g., ./logs/application). Log files will be named with the pattern application-YYYY-MM-DD.log.
• loggingConsole: (Optional) If true, logs will be output to both files and the console.

Example

const logger = new Logs('./logs/app', true);

logger.info('Server started successfully');
logger.info({Server:'Server started successfully'});
logger.warn('Low disk space');
logger.error('Failed to connect to database');

Log Levels

The logger supports the following log levels:

• info: General operational messages (e.g., "Server started").
• error: Critical issues that require immediate attention.
• warn: Non-critical issues, potential problems (e.g., "Low disk space").
• debug: Detailed debugging information for development.

Example Usage

logger.info('Application started');
logger.warn('User has low storage space');
logger.error('Failed to connect to database');
logger.debug('Database query executed successfully');

// Json format

logger.info({server:'Application started'});
logger.warn({DiskStorage:'User has low storage space'});
logger.error({DBConnection:'Failed to connect to database'});
logger.debug({DBConnection:'Database query executed successfully'});

Log Rotation and File Management

• Log Rotation: Logs are rotated daily and saved with a timestamped filename, e.g., application-2024-09-21.log.
• Compression: Old logs are compressed into .gz format, e.g., application-2024-09-20.log.gz.
• Retention: Configure how long to keep old log files using the maxFiles option.

Environment Variables

You can control various logger behaviors using environment variables:

| Variable | Description | Default Value | |----------------|-----------------------------------------------------|---------------| | LOGGING_LEVEL | Sets the log level (info, warn, error, debug) | 'debug' | | MAX_FILE_SIZE | Maximum size for each log file before rotation | '200m' | | FILE_ROTATION_PERIOD | Maximum number of days to retain old log files | '14d' |

Example:

LOGGING_LEVEL=debug MAX_FILE_SIZE=5m FILE_ROTATION_PERIOD=7d node your-app.js

Code with Environment Variables

const loggingConsole= true
const logger = new Logs('./logs/app', loggingConsole);

logger.info('Server started in debug mode');

License

This project is licensed under the MIT License. See the LICENSE file for more details.