Which node logger did you use in your project?

Following are the common logger modules:

1) logger

SUMMARY

A simple logging library that combines the simple APIs of Ruby's logger.rb and browser-js console.log()

USAGE

A logger has 5 different levels of logging in a specific order:

'fatal', 'error', 'warn', 'info', 'debug'

Each of these log levels has its own method on the logging instance. You can set the maximum log level on a logger at runtime.

By default, a logger writes to STDOUT, but given a writeable file path, it will log directly to a file.

Instantiation:

// node/common.js style 
var logger = require('./logger').createLogger(); // logs to STDOUT
var logger = require('./logger').createLogger('development.log'); // logs to a file

2) simple-node-logger

A simple multi-level logger for console, file, and rolling file appenders. Features include:

• levels: trace, debug, info, warn, error and fatal levels (plus all and off)
• flexible appender/formatters with default to HH:mm:ss.SSS LEVEL message
• add appenders to send output to console, file, rolling file, etc
• change log levels on the fly
• domain and category columns
• overridable format methods in base appender
• stats that track counts of all log statements including warn, error, etc
• ability to configure to emit process error event for central trapping

How to use

// create a stdout console logger

const log = require('simple-node-logger').createSimpleLogger();

or

// create a stdout and file logger

const log = require('simple-node-logger').createSimpleLogger('project.log');

or

// create a custom timestamp format for log statements

const SimpleNodeLogger = require('simple-node-logger'),

    opts = {

        logFilePath:'mylogfile.log',

        timestampFormat:'YYYY-MM-DD HH:mm:ss.SSS'

    },

log = SimpleNodeLogger.createSimpleLogger( opts );

or

// create a file only file logger

const log = require('simple-node-logger').createSimpleFileLogger('project.log');

or

// create a rolling file logger based on date/time that fires process events

const opts = {

    errorEventName:'error',

        logDirectory:'/mylogfiles', // NOTE: folder must exist and be writable...

        fileNamePattern:'roll-<DATE>.log',

        dateFormat:'YYYY.MM.DD'

};

const log = require('simple-node-logger').createRollingFileLogger( opts );

3) log4js

Features

• coloured console logging to stdout or stderr
• file appender, with configurable log rolling based on file size or date
• a logger for connect/express servers
• configurable log message layout/patterns
• different log levels for different log categories (make some parts of your app log as DEBUG, others only ERRORS, etc.)

Usage

Minimalist version:

var log4js = require('log4js');

var logger = log4js.getLogger();

logger.level = 'debug';

logger.debug("Some debug messages");

4) Winston