molindo-node-logger

molindo-node-logger

A node.js logger that can be used instead of console.log and friends.

Features

• Pretty prints messages in development mode.
• Prints JSON messages in production mode.
• Errors are printed to stderr, while all other levels are printed to stdout.
• In development only warnings and errors are printed, while in production all levels are printed.
• If the process encounters an error, it will log it to the console before shutting down. unhandledRejection errors thrown from promises are logged as well.
• Offers an express integration that logs HTTP requests, including the operationName in the case of GraphQL requests.
• Uses the levels and level values from logback: ERROR (40000), WARN (30000), INFO (20000), DEBUG (10000), TRACE (5000).

Usage

import Logger from 'molindo-node-logger';

const logger = new Logger({service: 'pizza-shop'});
logger.trace('Making a salami pizza.');
logger.debug('Adding salami.');
logger.info('Putting it in the oven.');
logger.warn('Don\'t forget to get it out in time …');
logger.error('Oh no, the pizza is burned!');

In production the printed JSON will look like this, except that it's not pretty printed:

{
  "service": "pizza-shop",
  "@timestamp": "2017-10-19T08:26:13.168Z",
  "level": "INFO",
  "level_value": 20000,
  "message": "Pizza is ready!"
}

Express integration

If you're running an express server, you can register the logger middleware to log HTTP requests.

import express from 'express';
import Logger, {createLoggerMiddleware} from 'molindo-node-logger';

const app = express();

const logger = new Logger({service: 'pizza-shop'});
app.use(createLoggerMiddleware({logger}));