Basic winstonjs logger setup

logger.js

// Libraries
const util = require('util');
const winston = require('winston');
const dailyRotater = require('winston-daily-rotate-file'); // for daily file rotating
const fs = require('fs');
const path = require('path');
const chalk = require('chalk'); // for colors
const moment = require('moment');

/** 
 * 
 */
class appLogger {

  /**  
   * 
   */
  constructor() {

    // our logs folder
    this.logDir = path.resolve(__dirname, 'logs');
    const dir = this.logDir;
    // Create the logs directory if it does not exist
    try {
      if (!fs.existsSync(this.logDir)) {
        fs.mkdirSync(this.logDir);
      }
    } catch (e) {
      console.log(e);
    }

    // levels for our logs
    const logLevels = {
      levels: {
        error: 0,
        warn: 1,
        info: 2,
        verbose: 3,
        debug: 4,
        silly: 5
      }
    };

    const colors = {
      error: chalk.red,
      warn: chalk.yellow,
      info: chalk.green,
      verbose: chalk.white,
      debug: chalk.blue,
      silly: chalk.magenta
    };
  
    // timestamp format
    const tsFormat = () => moment().format('YYYY-MM-DD HH:mm:ss');
    
    // transports for our logs
    const logTransports = [];
    // specific options for each transport -- console has a separate format for colors
    const consoleOptions = {
      format: winston.format.printf(info => colors[info.level](`${tsFormat()} [${info.level.toUpperCase()}]: ${info.message.trim()}`))
    };

    const debugFileOptions = {
      level: 'debug',
      filename: 'debug-%DATE%.log',
      dirname: dir,
      datePattern: 'YYYY-MM-DD',
      zippedArchive: true,
      maxSize: '20m',
      maxFiles: '14d'
    };
    
    const combinedLogFileOptions = {
      level: 'info',
      filename: '%DATE%.log',
      dirname: dir,
      datePattern: 'YYYY-MM-DD',
      zippedArchive: true,
      maxSize: '20m',
      maxFiles: '14d'
    };
    
    // push transports to offer
    logTransports.push(new winston.transports.Console(consoleOptions));
    logTransports.push(new dailyRotater(debugFileOptions));
    logTransports.push(new dailyRotater(combinedLogFileOptions));

    // THE LOGGER
    this.logger = winston.createLogger({
      levels: logLevels.levels,
      level: 'silly',
      exitOnError: false,
      format: winston.format.printf(info => (`${tsFormat()} [${info.level.toUpperCase()}]: ${info.message.trim()}`)),
      transports: logTransports
    });

  } // end ctor

  // expose our logger
  getLogger() {
    return this.logger;
  }

  // expose our root log dir
  getRoot() {
    return this.logDir;
  }

}


const logMonitor = new appLogger();
const logger = logMonitor.getLogger();

function formatArgs(args) {
  return [util.format.apply(util.format, Array.prototype.slice.call(args))];
}

// replace console stdout with Winston
console.log = function () {
  logger.info.apply(logger, formatArgs(arguments));
};
console.info = function () {
  logger.info.apply(logger, formatArgs(arguments));
};
console.warn = function () {
  logger.warn.apply(logger, formatArgs(arguments));
};
console.error = function () {
  logger.error.apply(logger, formatArgs(arguments));
};
console.debug = function () {
  logger.debug.apply(logger, formatArgs(arguments));
};



// export our Logger Singleton
module.exports = logger;