index.js

const http = require('http');

const hostname = '0.0.0.0';
const port = 3000;

const cert = `-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----`;

const server = http.createServer((req, res) => {
	res.statusCode = 200;
	res.setHeader('Content-Type', 'application/x-x509-ca-cert');
	res.end(cert);
});

server.listen(port, hostname, () => {
	console.log(`Server running at http://${hostname}:${port}/`);
});