express-status-monitor

Simple, self-hosted module based on Socket.io and Chart.js to report realtime server metrics for Express-based node servers.

Demo

Demo available here

Support for other Node.js frameworks

• koa-monitor for Koa
• hapijs-status-monitor for hapi.js

Installation & setup

1. Run npm install express-status-monitor --save
2. Before any other middleware or router add following line: app.use(require('express-status-monitor')());
3. Run server and go to /status

Note: This plugin works on Node versions > 4.x

Run examples

1. Go to cd examples/
2. Run npm i
3. Run server npm start
4. Go to http://0.0.0.0:3000

Options

Monitor can be configured by passing options object into expressMonitor constructor.

Default config:

title: 'Express Status',  // Default title
theme: 'default.css',     // Default styles
path: '/status',
socketPath: '/socket.io', // In case you use a custom path
namespace: '/',           // socket.io namespace
port: null,               // socket.io port
websocket: null,          // In case you use an existing socket.io instance
spans: [{
  interval: 1,            // Every second
  retention: 60           // Keep 60 datapoints in memory
}, {
  interval: 5,            // Every 5 seconds
  retention: 60
}, {
  interval: 15,           // Every 15 seconds
  retention: 60
}],
iframe: false,            // iframe=true will remove X-Frame-Options
chartVisibility: {
  cpu: true,
  mem: true,
  load: true,
  heap: true,
  eventLoop: true,
  responseTime: true,
  rps: true,
  statusCodes: true
},
ignoreStartsWith: '/admin',
healthChecks: []

Health Checks

You can add a series of health checks to the configuration that will appear below the other stats. The health check will be considered successful if the endpoint returns a 200 status code.

// config
healthChecks: [{
  protocol: 'http',
  host: 'localhost',
  path: '/admin/health/ex1',
  port: '3000'
}, {
  protocol: 'http',
  host: 'localhost',
  path: '/admin/health/ex2',
  port: '3000'
}]

Securing endpoint

The HTML page handler is exposed as a pageRoute property on the main middleware function. So the middleware is mounted to intercept all requests while the HTML page handler will be authenticated.

Example using custom middleware
(Credits to @peteriman)

// custom middleware to do own auth
let alt = false
const authFn = (req, res, next) => {
  alt = !alt;            // alternating
  if (alt) {
    res.sendStatus(401); // unauthorized
  } else {
    next();              // proceed
  }
};

const statusMonitor = require('express-status-monitor')({ path: '' }); // avoid serving HTML
app.use(statusMonitor);
app.get('/status', authFn, statusMonitor.pageRoute);                   // use pageRoute to serve HTML

Example using https://www.npmjs.com/package/connect-ensure-login
(Credits to @mattiaerre)

const ensureLoggedIn = require('connect-ensure-login').ensureLoggedIn()

const statusMonitor = require('express-status-monitor')({ path: '' }); // avoid serving HTML
app.use(statusMonitor);
app.get('/status', ensureLoggedIn, statusMonitor.pageRoute);           // use pageRoute to serve HTML

Example using http-auth
(Credits to @cristianossd and )

const auth = require('http-auth');
const basic = auth.basic({realm: 'Monitor Area'}, function(user, pass, callback) {
  callback(user === 'username' && pass === 'password');
});

const statusMonitor = require('express-status-monitor')({ path: '' }); // avoid serving HTML
app.use(statusMonitor);
app.get('/status', basic.check(statusMonitor.pageRoute));              // use pageRoute to serve HTML

Using module with socket.io in project

If you're using socket.io in your project, this module could break your project because this module by default will spawn its own socket.io instance. To mitigate that, fill websocket parameter with your main socket.io instance as well as port parameter.

Tests and coverage

In order to run test and coverage use the following npm commands:

npm test
npm run coverage

License

MIT License © Dynobase