CPU Monitor Mini-App

This project was bootstrapped with Create React App.

Future Improvements

• Improve alerting logic (above cpu threshold for a specific amount of time to trigger, vice versa to resolve)
• Create a better testing story, specifically, unit testing the services/index.tsx methods and hooks/useTick.tsx, as well as at least one integration test against pages/App.tsx (beyond the boilerplate test currently there.

Start app

cp .env.sample .env

Configuration is derived from environment variables, so a sample set of environment variables have been provided.

npm install

Installs dependencies. Might take a bit first time CRACO/PostCSS/Tailwind

npm start

Runs the app in the development mode. Open http://localhost:3000 to view it in the browser.

Server Instructions

The app expects an endpoint at localhost:3001/cpu. This address is configurable in config.tsx as well as via environment variable CPU_URL. This enable the app to poll for the lastest cpu usage. The server expects a json response { cpu: <value: number> }.

Example NodeJS (Express) Server

const express = require('express');
const os = require('os');
const cors = require('cors');
const app = express();
const port = 3001;
app.use(cors());
app.options('*', cors());

app.get('/', (_req, res) => { res.send(); });

app.get('/cpu', (_req, res) => {
	const loadAvg = os.loadavg()[0]/os.cpus().length;
	console.debug("load avg: " + Math.floor(loadAvg*100)/100);
	res.json({ cpu: loadAvg });
});

app.listen(port, () => {
	console.log(`Example app listening at http://localhost:${port}`);
});

Install & Run Sample Server

npm install express cors --save

node index.js