Integrate Winston Logger in Node Express App

logger.js

'use strict';

const NODE_ENV = process.env.NODE_ENV || 'development';
const CloudWatchTransport = require('winston-aws-cloudwatch');
const Winston = require('winston');

let transport;
if (NODE_ENV === 'development') {
  transport = new Winston.transports.Console({
    format: Winston.format.combine(
      Winston.format.colorize(),
      Winston.format.timestamp(),
      Winston.format.align(),
      Winston.format.metadata({
        fillWith: ['error', 'user']
      }),
      Winston.format.printf(info => `${info.timestamp} ${info.level}[${info.label}]: ${info.message}`)
    )
  });
} else {
  transport = new CloudWatchTransport({
    logGroupName: 'application_name',
    logStreamName: NODE_ENV,
    createLogGroup: false,
    createLogStream: true,
    awsConfig: {
      accessKeyId: process.env.AWS_ACCESS_KEY_ID,
      secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
      region: process.env.AWS_DEFAULT_REGION
    }
  });
}

const logger = Winston.createLogger({
  transports: [transport],
  level: process.env.LOG_LEVEL || 'silly'
});

/*
 How to use...

 const { debug, error } = require('./logger')('module_name');
 error('Sample Error Message', { error });
 debug('Sample Debug Message');

*/

const Proxify = (logger, group) => new Proxy(logger, {
  get(target, propKey) {
    if (['error', 'debug'].indexOf(propKey) > -1) {
      return (...args) => {
        let message;
        [message, ...args] = args;
        return target.log({ label: group, message: message, level: propKey, meta: args || undefined });
      };
    } else {
      return target[propKey];
    }
  }
});

module.exports = group => Proxify(logger, group);