Node.js Logging Service Code Example in 2024

Cabin is the best self-hosted JavaScript and Node.js logging service.
Supports Node v14+, Browser Environments, Express, Koa, and Lad

Cabin is compatible with Sentry, Airbrake, Papertrail, Loggly, and Bugsnag.

Foreword

Please defer to Axe's Foreword for more insight.

Cabin is a layer on top of Axe that provides automatic logging for route middleware requests and errors.

Quick Start

npm install express axe cabin signale

const express = require('express');
const Axe = require('axe');
const Cabin = require('cabin');
const app = express();
const { Signale } = require('signale');

// initialize a new instance of Axe (see below TODO's that appeal to you)
const logger = new Axe({
  logger: new Signale()
});

// TODO: if you want to send logs to an HTTP endpoint then follow this guide:
// https://github.com/cabinjs/axe/#send-logs-to-http-endpoint

// TODO: if you want to send logs to Slack then follow this guide:
// https://github.com/cabinjs/axe/#send-logs-to-slack

// TODO: if you want to send logs to Sentry then follow this guide:
// https://github.com/cabinjs/axe/#send-logs-to-sentry

// TODO: if you want to send logs to Datadog then follow this guide:
// https://github.com/cabinjs/axe/#send-logs-to-datadog

// TODO: if you want to send logs to Papertrail then follow this guide:
// https://github.com/cabinjs/axe/#send-logs-to-papertrail

// TODO: if you want to suppress specific log metadata then follow this guide:
// https://github.com/cabinjs/axe/#suppress-logger-data

// initialize a new instance of Cabin with an Axe logger instance
const cabin = new Cabin({ logger });

//
// initialize route logging middleware
//
// NOTE: this will automatically log route middleware requests and errors
//
app.use(cabin.middleware);

app.get('/', (req, res, next) => res.send('OK'));

// start the server
app.listen(3000);

curl http://localhost:3000

Features

Security, Privacy, and Business Focused

Cabin will automatically detect and mask the following list of extremely sensitive types of data in your logs:

1600+ Sensitive Field Names
Credit Card Numbers^*
BasicAuth Headers
Social Security Numbers
JSON Web Tokens ("JWT")
API Keys, CSRF Tokens, and Stripe Tokens
Passwords, Salts, and Hashes
Bank Account Numbers and Bank Routing Numbers

^*Credit card numbers from the following providers are automatically detected and masked: Visa, Mastercard, American Express, Diners Club, Discover, JCB, UnionPay, Maestro, Mir, Elo, Hiper, Hipercard

Reduce Disk Storage Costs

Reduce your disk storage costs through Cabin's automatic conversion of Streams, Buffers, and ArrayBuffers to simplified, descriptive-only objects that otherwise would be unreadable (and obviously pollute your log files and disk storage).

Before:

{
  "request": {
    "body": {
      "file": {
        "type": "Buffer",
        "data": [
          76,
          111,
          114,
          101,
          109,
          32,
          105,
          112,
          115,
          117,
          109,
          32,
          100,
          111,
          108,
          111,
          114,
          32,
          115,
          105,
          116,
          '...'
        ]
      }
    }
  }
}

After

{
  "request": {
    "body": {
      "file": {
        "type": "Buffer",
        "byteLength": 2787
      }
    }
  }
}

Cross-Platform and Cross-Browser Compatible

Cabin works with the most popular Node.js HTTP frameworks (e.g. Express and Koa), request body handling packages (e.g. multer and body-parser), and the passport authentication framework.

It supports Node v14+ and modern browsers out of the box (its browser-ready bundle is only 20 KB).

npx browserslist

and_chr 107
and_ff 106
and_qq 13.1
and_uc 13.4
android 107
chrome 107
chrome 106
chrome 105
edge 107
edge 106
edge 105
firefox 106
firefox 105
firefox 102
ios_saf 16.1
ios_saf 16.0
ios_saf 15.6
ios_saf 15.5
ios_saf 14.5-14.8
kaios 2.5
op_mini all
op_mob 64
opera 91
opera 90
safari 16.1
safari 16.0
safari 15.6
samsung 18.0
samsung 17.0

Send Logs to an HTTP endpoint

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#send-logs-to-http-endpoint.

Send Logs to Slack

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#send-logs-to-slack.

Send Logs to Sentry

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#send-logs-to-sentry.

Send Logs to Datadog

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#send-logs-to-datadog.

Send Logs to Papertrail

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#send-logs-to-papertrail.

Suppress Logger Data

See the Quick Start section above and our guide at https://github.com/cabinjs/axe/#suppress-logger-data.

Install

Note that as of v11.0.0 Cabin requires a peer dependency of Axe to be installed.

npm:

npm install cabin axe

Usage

Logging

const Cabin = require('cabin');
const cabin = new Cabin({
  // ... see the Quick Start and Options sections
});

cabin.info('hello world');
cabin.error(new Error('oops!'));

Route Logging Middleware

app.use(cabin.middleware);

See either the Node or Browser instructions below for further route middleware usage and proper setup.

Node

The examples below show how to use Cabin in combination with Axe, Signale (instead of console), and how to add an accurate X-Response-Time response time metric to your logs and response headers automatically.

Koa

Install required and recommended dependencies:

npm install koa cabin signale request-received koa-better-response-time koa-better-request-id

Implement the example code below (also found here):

const Koa = require('koa');
const Cabin = require('cabin');
const Router = require('koa-router');
const requestReceived = require('request-received');
const responseTime = require('koa-better-response-time');
const requestId = require('koa-better-request-id');
const { Signale } = require('signale');

const app = new Koa();
const router = new Router();
const cabin = new Cabin({
  logger: new Signale()
});

// adds request received hrtime and date symbols to request object
// (which is used by Cabin internally to add `request.timestamp` to logs
app.use(requestReceived);

// adds `X-Response-Time` header to responses
app.use(responseTime());

// adds or re-uses `X-Request-Id` header
app.use(requestId());

// use the cabin middleware (adds request-based logging and helpers)
app.use(cabin.middleware);

// add your user/session management middleware here (e.g. passport)
// ...

// an example home page route
router.get('/', ctx => {
  ctx.logger.info('visited home page');
  ctx.body = 'hello world';
});

// this assumes that you are using passport which
// exposes `ctx.logout` to log out the logged in user
router.get('/logout', ctx => {
  ctx.logger.warn('Logged out');
  ctx.logout();
  ctx.redirect('/');
});

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3000, () => {
  cabin.info('app started');
});

See Koa convenience methods below for helper utilities you can use while writing code.

Express

Install required and recommended dependencies:

npm install express cabin signale request-received response-time express-request-id

Implement the example code below (also found here):

const express = require('express');
const Cabin = require('cabin');
const requestReceived = require('request-received');
const responseTime = require('response-time');
const requestId = require('express-request-id');
const { Signale } = require('signale');

const app = express();
const cabin = new Cabin({
  logger: new Signale()
});

// adds request received hrtime and date symbols to request object
// (which is used by Cabin internally to add `request.timestamp` to logs
app.use(requestReceived);

// adds `X-Response-Time` header to responses
app.use(responseTime());

// adds or re-uses `X-Request-Id` header
app.use(requestId());

// use the cabin middleware (adds request-based logging and helpers)
app.use(cabin.middleware);

// add your user/session management middleware here (e.g. passport)
// ...

// an example home page route
app.get('/', (req, res) => {
  req.logger.info('visited home page');
  res.send('hello world');
});

// this assumes that you are using passport which
// exposes `req.logout` to log out the logged in user
app.get('/logout', (req, res) => {
  req.logger.warn('logged out');
  req.logout();
  res.redirect('/');
});

app.listen(3000, () => {
  cabin.info('app started');
});

See Express convenience methods below for helper utilities you can use while writing code.

Convenience Methods

In order to easily interact and use the logger utility function exposed by app.use(cabin.middleware), we expose convenient helper methods in Express and Koa:

Express

req.log
req.logger
res.log
res.logger

Koa

ctx.log
ctx.logger
ctx.request.log
ctx.request.logger
ctx.response.log
ctx.response.logger

Browser

This package requires Promise support, therefore you will need to polyfill if you are using an unsupported browser (namely Opera mini).

We no longer support IE as of Cabin v10.0.0+.

VanillaJS

This is the solution for you if you're just using <script> tags everywhere!

<script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=Promise"></script>
<script src="https://unpkg.com/cabin"></script>
<script type="text/javascript">
  (function() {
    var cabin = new Cabin();
    cabin.setUser({
      id: '1',
      email: 'test@example.com',
      full_name: 'Test'
    });
    cabin.info('viewed docs');
  })();
</script>

Required Browser Features

We recommend using https://cdnjs.cloudflare.com/polyfill (specifically with the bundle mentioned in VanillaJS above):

<script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=Promise"></script>

Promise is not supported in op_mini all

Bundler

This assumes you are using browserify, webpack, rollup, or another bundler.

const Cabin = require('cabin');

const cabin = new Cabin();

cabin.setUser({
  id: '1',
  email: 'test@example.com',
  full_name: 'Test'
});

cabin.info('viewed docs');

Automatic Request Logging

Server

For server-side logging of requests, the Cabin middleware cabin.middleware will automatically log requests for you upon completion. Just make sure you are using express-request-id middleware like in the examples above in order for the X-Request-Id header to be set (and re-used if already exists, e.g. generated from client side as in below). If you're using Koa make sure to use koa-better-request-id as shown in the examples above.

Browser

We strongly recommend that you implement one of the following code snippets with xhook (for either VanillaJS or Bundler approaches) so that all your XHR requests have a X-Request-Id automatically added (which in turn ensures both client and server have matching request ID's). Imagine how awesome your logs will be when you can see the full trace starting with the client!

HTML

<script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=Promise"></script>
<script src="https://unpkg.com/xhook"></script>
<script src="https://unpkg.com/cabin"></script>
<script src="https://unpkg.com/parse-request"></script>
<script src="https://unpkg.com/cuid"></script>
<script>
  (function() {
    var cabin = new Cabin();
    cabin.setUser({
      id: '1',
      email: 'test@example.com',
      full_name: 'Test'
    });
    xhook.before(function(req) {
      if (typeof req.headers !== 'object') req.headers = {};

      if (!req.headers['X-Request-Id'])
        req.headers['X-Request-Id'] = cuid();

      if (!req.headers['User-Agent'])
        req.headers['User-Agent'] = window.navigator.userAgent;

      if (!req.headers['Referer'])
        req.headers['Referer'] = window.document.referrer;

      if (!req.headers['Cookie'])
        req.headers['Cookie'] = window.document.cookie;

      cabin.info('xhr', parseRequest({ req: req }));
    });
  })();
</script>

Pug

You can do a similar approach with React, EJS, or another templating language.

script(src='https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=Promise')
script(src='https://unpkg.com/xhook')
script(src='https://unpkg.com/cabin')
script(src='https://unpkg.com/parse-request')
script(src='https://unpkg.com/cuid')
script.
  (function() {
    var cabin = new Cabin();
    cabin.setUser({
      id: '1',
      email: 'test@example.com',
      full_name: 'Test'
    });
    xhook.before(function(req) {
      if (typeof req.headers !== 'object') req.headers = {};

      if (!req.headers['X-Request-Id'])
        req.headers['X-Request-Id'] = cuid();

      if (!req.headers['X-Request-Id'])
        req.headers['X-Request-Id'] = cuid();

      if (!req.headers['User-Agent'])
        req.headers['User-Agent'] = window.navigator.userAgent;

      if (!req.headers['Referer'])
        req.headers['Referer'] = window.document.referrer;

      if (!req.headers['Cookie'])
        req.headers['Cookie'] = window.document.cookie;

      cabin.info('xhr', parseRequest({ req: req }));
    });
  })();

Bundler

npm:

npm install cabin xhook cuid

const Cabin = require('cabin');
const xhook = require('xhook');
const parseRequest = require('parse-request');
const cuid = require('cuid');

const cabin = new Cabin();

cabin.setUser({
  id: '1',
  email: 'test@example.com',
  full_name: 'Test'
});

xhook.before(req => {
  if (typeof req.headers !== 'object') req.headers = {};

  if (!req.headers['X-Request-Id'])
    req.headers['X-Request-Id'] = cuid();

  //
  // NOTE: you may want to add User-Agent, Referer, and Cookie (see above)
  //
  cabin.info('xhr', parseRequest({ req: req }));
});

Stack Traces and Error Handling

We leave it up to you to decide how you wish to handle stack traces and errors, but we've documented our approaches for Node and Browser environments below.

Node

If you're using Lad, then you don't need to worry about error handling, as it's built-in (complete with graceful reloading, even for database connections).

However you can otherwise use a tool such as uncaught to listen for errors, or bind purely to process events emitted as shown below:

const Cabin = require('cabin');

const cabin = new Cabin();

process.on('uncaughtException', err => {
  cabin.error(err);
  process.exit(1);
});

process.on('unhandledRejection', err => {
  cabin.error(err);
});

Browser

Since cross-browser support is very limited and non-standardized for errors and stack traces, we highly recommend to use StackTrace.

StackTrace

We recommend to use StackTrace instead of TraceKit as it is a more modern alternative and provides much similarity between your Browser and your Node errors (stackframes are basically similar to representations in Gecko and V8, aka the ones you get with Node).

It does require you to have a polyfill if you're using it in the browser (only if you're supporting browsers that don't support standardized Promises/JSON). You'll basically need es6-promise and json3 polyfills for browsers you wish to support that don't have them. The example below shows you how to polyfill, don't worry! You can reference Caniuse data on Promises and JSON respectively if you need.

The example below demonstrates using StackTrace with uncaught to catch global errors below.

<script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js?features=Promise"></script>
<script src="https://unpkg.com/stackframe"></script>
<script src="https://unpkg.com/stacktrace-js"></script>
<script src="https://unpkg.com/uncaught"></script>
<script src="https://unpkg.com/cabin"></script>
<script src="https://unpkg.com/prepare-stack-trace"></script>

<script type="text/javascript">
  (function() {
    //
    // Sourced from the StackTrace example from CabinJS docs
    // <https://github.com/cabinjs/cabin#stacktrace>
    //
    var cabin = new Cabin();

    // Use cabin globally in your app (instead of `console`)
    window.cabin = cabin;

    // Bind event listeners
    uncaught.start();
    uncaught.addListener(function(err, event) {
      if (!err) {
        if (typeof ErrorEvent === 'function' && event instanceof ErrorEvent)
          return cabin.error(event.message, { event: event });
        cabin.error({ event: event });
        return;
      }
      // this will transform the error's `stack` property
      // to be consistently similar to Gecko and V8 stackframes
      StackTrace.fromError(err)
        .then(function(stackframes) {
          err.stack = prepareStackTrace(err, stackframes);
          cabin.error(err);
        })
        .catch(function(err2) {
          cabin.error(err);
          cabin.error(err2);
        });
    });
  })();
</script>

Options

logger (Object or Axe instance) - if you have a custom logger you wish to use or an existing Axe instance – defaults to an instance of Axe which uses console as the logger – if you do not pass an instance of Axe, then an instance will be created and the logger option will be passed down
meta (Object) - defaults to an empty object - this will get passed as metadata (e.g. you could set a custom meta.user object here for every request)
parseRequest (Object) - defaults to an empty object, which means it will use the defaults from parse-request (see Metadata below)
errorProps (Array) - a list of properties to cherry-pick from the error object parsed out of err thanks to parse-err (by default all properties are returned; even non-enumerable ones and ones on the prototype object) (see Metadata below)
message (Function) - inspired by morgan, and defaults to a dev-friendly format (or if in production mode, then it uses a standard Apache common log format)). – when requests finish, it will utilize logger to output an error, warn, or info level log based off the status code, and this function is used to determine the string sent to the logger. It accepts one argument options, which is comprised of options.level, options.req, options.res, and optionally (if and only if Koa) options.ctx. It is required that this function return a String. See src/message.js for the default message function. Note that both dev-friendly and Apache common log formats are stripped of basic auth lines for obvious security reasons. Note that if a null or undefined value is returned from the message function, then the logger will not be invoked unless there is an error.

Display Metadata and Stack Traces

Under the hood, Cabin uses Axe which provides us with several options, including one to show metadata (e.g. request headers, body, and user) and another to show stack traces for errors.

To show/hide application metadata and/or stack traces, see the Axe options documentation.

Cabin uses the package parse-request to parse the request metadata for you automatically in your Express and Koa applications.

Here's an example of a parsed metadata object:

{
  request: {
    method: 'POST',
    query: {
      foo: 'bar',
      beep: 'boop'
    },
    headers: {
      host: '127.0.0.1:63955',
      'accept-encoding': 'gzip, deflate',
      'user-agent': 'node-superagent/3.8.3',
      authorization: 'Basic ********************',
      accept: 'application/json',
      cookie: 'foo=bar;beep=boop',
      'content-type': 'multipart/form-data; boundary=--------------------------930511303948232291410214',
      'content-length': '1599',
      connection: 'close'
    },
    cookies: {
      foo: 'bar',
      beep: 'boop'
    },
    body: '{"product_id":"5d0350ef2ca74d11ee6e4f00","name":"nifty","surname":"lettuce","bank_account_number":"1234567890","card":{"number":"****-****-****-****"},"stripe_token":"***************","favorite_color":"green"}',
    url: '/?foo=bar&beep=boop',
    timestamp: '2019-06-14T07:46:55.568Z',
    id: 'fd6225ed-8db0-4862-8566-0c0ad6f4c7c9',
    http_version: '1.1',
    files: '{"avatar":[{"fieldname":"avatar","originalname":"avatar.png","encoding":"7bit","mimetype":"image/png","buffer":{"type":"Buffer","byteLength":216},"size":216}],"boop":[{"fieldname":"boop","originalname":"boop-1.txt","encoding":"7bit","mimetype":"text/plain","buffer":{"type":"Buffer","byteLength":7},"size":7},{"fieldname":"boop","originalname":"boop-2.txt","encoding":"7bit","mimetype":"text/plain","buffer":{"type":"Buffer","byteLength":7},"size":7}]}'
  },
  user: {
    ip_address: '::ffff:127.0.0.1'
  },
  id: '5d0350ef2ca74d11ee6e4f01',
  timestamp: '2019-06-14T07:46:55.000Z',
  duration: 6.651317
}

As you can see, sensitive data is masked and contextual user information metadata is automatically populated.

Forward Email - Free, encrypted, and open-source email forwarding service for custom domains
Axe - Logging utility for Node and Browser environments. Chop up your logs!
Bree - The best job scheduler for Node.js
Lad - Scaffold a Koa webapp and API framework for Node.js
Lass - Scaffold a modern boilerplate for Node.js
koa-better-error-handler - A better error-handler for Lad and Koa. Makes ctx.throw awesome!

Node.js Logging Service Code Example in 2024

Foreword

Quick Start

Features

Security, Privacy, and Business Focused

Reduce Disk Storage Costs

Cross-Platform and Cross-Browser Compatible

Send Logs to an HTTP endpoint

Send Logs to Slack

Send Logs to Sentry

Send Logs to Datadog

Send Logs to Papertrail

Suppress Logger Data

Install

Usage

Logging

Route Logging Middleware

Node

Koa

Express

Convenience Methods

Express

Koa

Browser

VanillaJS

Required Browser Features

Bundler

Automatic Request Logging

Server

Browser

HTML

Pug

Bundler

Stack Traces and Error Handling

Node

Browser

StackTrace

Options

Display Metadata and Stack Traces

Related