지극히 주관적인 node.js 의 logging 전략 (with winston)

logger.js

const DailyRotateFile = require('winston-daily-rotate-file');
const moment = require('moment');
const fs = require('fs');
const { createLogger, format, transports } = require('winston');

const {
  printf, combine, timestamp, prettyPrint,
} = format;

const logDir = 'logs';
moment.locale('ko');
const timeStampFormat = () => moment().format('HH:mm:ss.SSS ZZ');

if (!fs.existsSync(logDir)) {
  fs.mkdirSync(logDir);
}

const myFormat = printf((info) => {
  const { level, message } = info;
  const { req, err } = message;
  let log = {
    time: timeStampFormat(), level,
  };

  switch (level) {
    case 'info':
      log = {
        ...log,
        method: req.method,
        router: req.originalUrl,
        ip: req.ip,
        userAgent: req.headers['user-agent'],
        token: req.headers['x-access-token'],
        param: req.params,
        query: req.query,
        body: req.body,
      };
      break;
    case 'error':
      log = {
        method: req.method,
        router: req.originalUrl,
        ip: req.ip,
        userAgent: req.headers['user-agent'],
        token: req.headers['x-access-token'],
        err,
      };
      break;
    default:
      log = { ...log, ...message };
  }

  return JSON.stringify(log, null, '\t');
});

const requestInfoLogger = (message) => {
  const logger = createLogger({
    level: 'info',
    format: myFormat,
    transports: [
      new transports.Console({
        name: 'debug-console',
        colorize: true,
        showLevel: true,
        timestamp: timeStampFormat,
      }),
      new DailyRotateFile({
        name: 'info-log',
        filename: 'logs/info-%DATE%.log',
        showLevel: true,
        zippedArchive: true,
        maxSize: '25m',
        maxFiles: '14d',
      }),
    ],
  });

  return logger.info(message);
};

const errorLogger = (message) => {
  const logger = createLogger({
    level: 'error',
    format: myFormat,
    transports: [
      new transports.Console({
        name: 'debug-console',
        colorize: true,
        showLevel: true,
        timestamp: timeStampFormat,
      }),
      new DailyRotateFile({
        name: 'info-log',
        filename: 'logs/error-%DATE%.log',
        showLevel: true,
        zippedArchive: true,
        maxSize: '25m',
        maxFiles: '14d',
      }),
    ],
  });
  return logger.error(message);
};

const exceptionLogger = createLogger({
  level: 'error',
  format: combine(
    timestamp(),
    prettyPrint(),
  ),
  exceptionHandlers: [
    new transports.Console({
      name: 'debug-console',
      colorize: true,
      showLevel: true,
      timestamp: timeStampFormat,
    }),
    new DailyRotateFile({
      name: 'error-log',
      filename: 'logs/exception-%DATE%.log',
      showLevel: true,
      zippedArchive: true,
      maxSize: '25m',
      maxFiles: '14d',
    }),
  ],
});

module.exports = { requestInfoLogger, errorLogger };

const { reqInfoLogger, errorLogger } = require('logger의 위치');

reqInfoLogger({req});
형태로 사용

의견남겨주시면 감사합니다

const { requestInfoLogger, errorLogger } = require('path/to/logger');