Stupid JSONRPC proxy

geth-jsonrpc-authorizzation-proxy.js

/* file:./proxy.json
{
	"servers": [
		{
			"token": "abc",
			"port": "8007",
			"target": "http://localhost:8008"
		},
		{
			"token": "def",
			"port": "8006",
			"target": "http://localhost:8005"
		}

	]
}
*/

const url = require('url');
const httpProxy = require('http-proxy');
const exitHook = require('exit-hook');
const config = require('./proxy.json');

process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0';

function proxy(target, port, token) {
	const proxy = httpProxy.createProxyServer({
		target,
		preserveHeaderKeyCase: true,
		followRedirects: true,
		ignorePath: true,
	});
	
	proxy.on('error', e => {
	  console.error(e);
	});

	proxy.on('proxyReq', function(proxyReq, req, res, options) {
		const request = url.parse(req.url, true);

		if (request.query.token !== token) {
			console.warn(
        `Unauthorized on *:${port}: token="${request.query.token ||
          'N/A'}" ip="${req.connection.remoteAddress || 'N/A'}"`,
      );
			res.writeHead(401, { 'Content-Type': 'application/json' });
			res.end('{"jsonrpc": "2.0", "error": {"code": -32000, "message": "Missing or Invalid Access Token"}, "id": "0"}');
			req.destroy('Unauthorized Client');
		}
	});

	console.info(`Proxying *:${ port } > ${ target }`);
	proxy.listen(port);

	return () => {
		console.info(`Stop proxying *:${ port } > ${target}`);
		proxy.close();
	}
}

const proxies = [];

exitHook(() => {
	for (const stopProxy of proxies) {
		stopProxy();
	}
});

for (const server of config.servers) {
		const { port, target, token } = server;
		proxies.push(proxy(target, port, token));
}