The @welib/web-server package exports a function that can be used to setup an http.Server or https.Server object, depending on the options.

@welib/web-server

This package exports a single function (createServer), which accpets two optional arguments: an options object and a request listener function. This is intended to work very much like the standard Node.js createServer functions exported by the http and https modules, but the supported options are limited and different.

Example: negotiate TLS

In the following example, the configuration has a tls key, so the createServer function will return an https.Server. Otherwise, the function would return an http.Server. The Server instance will have a .secure property set to true if TLS was provided.

When configuring TLS, the function will read files from the paths specified in the .tls.cert, .tls.key, .tls.ca, and .tls.pfx options. These files must exist and be readable if set in the options.

import {createServer} from "@welib/web-server";

const cert = "/path/to/cert.pem";
const key = "/path/to/key.pem";
const config = {tls: {cert, key}};
const server = createServer(config, requestListener);
const port = server.tls ? 443 : 80;

server.listen(port);

function requestListener(req, res) {
  res.writeHead(404);
  res.end("Not Found\n");
}

Example: handling Forwarded header

If the server is running behind a trusted proxy, the trust_proxy option can be used to process the Forwarded header. This MUST NOT be used unless you are running behind a proxy which is setting the Forwarded header in a safe manner.

In the following example, the server will response with the requested URL. If a Forwarded header is provided, the URL will use it to determine the URL.

import {createServer} from "@welib/web-server";

const config = {trust_proxy: true};
const server = createServer(config, requestListener);

server.listen(8000, "127.0.0.1");

function requestListener(req, res) {
  const proto = req.connection.encrypted ? "https" : "http";
  const {headers: {host}, url: path} = req;
  const url = new URL(`${proto}://${host}${path}`);

  if (req.forwarded.proto) url.protocol = `${req.forwarded.proto}:`;
  if (req.forwarded.host) url.port = "", url.host = req.forwarded.host;

  res.writeHead(200);
  res.end(`${url}\n`);
}