kartik1998 / omnia-logger

An easily integratable logging library for nodejs for verbose request and app logging.

An easy to integrate NodeJS library for easily setting up logging for an express app.

Request Logger

• Generates request, response logs writes a file with those logs.
• Generates a request id for each request session which is visible in app logs. (Read section below on app logger)

Usage

const { requestLogger } = require('omnia-logger');
const app = require('express')();
requestLogger(app, 'product-name', { filename: '/path/to/request.log' });

• If you don't pass in a file name request logs are written in /var/log/omnia/requests directory by default. In that case ensure that you run your application with root permission i.e. use sudo before starting the application.
• Sample request log will look something like:

{"meta":{"req":{"url":"/","headers":{"host":"localhost:8080","user-agent":"curl/7.64.1","accept":"*/*"},"method":"GET","httpVersion":"1.1","originalUrl":"/","query":{}},"res":{"body":{"id":"1628002145706-24bf4c89-eaff-4bf3-ad90-a6747e4cc8e8"}},"responseTime":0},"level":"info","message":"HTTP GET /"}

• requestLogger logs each request by default. logged keys are: ip, id, headers and body.

App Logger

• provides a variety of log levels i.e.:

FATAL: 'fatal',
ERROR: 'error',
WARN: 'warn',
TRACE: 'trace',
INFO: 'info',
DEBUG: 'debug',

• It's singleton in nature hence needs to be initialized only once and can be used like const logger = require('omnia-logger').appLogger; in other files.

Usage

const { appLogger, requestLogger } = require('omnia-logger');
const app = require('express')();

const logger = new appLogger('product-name', 'path/to/app_log.log');
requestLogger(app, 'product-name', { filename: '/path/to/req_log.log' });
app.get('/', (req, res) => {
  logger.log(logger.LOG_LEVELS.INFO, 'successfull api call');
  logger.info('successfull api call'); // info, warn, error, debug, trace
  return res.json({ id: req.id });
});

app.listen(8080, () => console.log('listening on', 8080));

• Sample app log will look like:

[2021-05-04T17:30:37.560Z] [INFO] [apac-logger] [Users-MacBook-Air.local] [20.2.0] [1628002145706-24bf4c89-eaff-4bf3-ad90-a6747e4cc8e8] successfull api call

• App log format:

[DATE_ISO_FORMAT][LOG_LEVEL][PRODUCT_NAME][OS_HOSTNAME][OS_RELEASE][REQUEST_ID] LOG_MESSAGE