ExpressJS not redirecting configured PATH

Question

I am setting up a local proxy to redirect specific URLs to another server, I am running my expressJS server as my main server, I have another server running on a different port... My express JS config is as follows

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');
const path = require('path');

const app = express();
const PORT = process.env.PORT || 8080;
const API_URL = "<http://localhost:8989>";

app.get("/status", (req, res, next) => {
    res.send('This is a proxy service');
});

app.get('/', function(req, res) {
    res.sendFile(path.join(__dirname, '/dist/index.html'));
});
app.use(express.static('dist'))

const proxyOptions = {
    target: API_URL,
    changeOrigin: true
}

const proxy = createProxyMiddleware(proxyOptions);

app.use('/?access', proxy)

app.listen(PORT, () => {
    console.log(`Proxy Started at http://localhost:${PORT}`)
});

I want any URL starting with /?access to redirect to the other server localhost:8989 BUT keep the /?access... intact so it can submit that information to the new server. Can anyone see what I am doing wrong?

I am using FETCH to send the information I need

fetch('/?access=myAccessToken&action=off')

it is also worth noting that I get 304 in the browser console.

I managed to configure app.use('/?access', proxy) as per ExpressJS docs, and have also also consulted the http-proxy-middleware documentation and, tried a quick Google to help resolve the issue, but nothing was helpful...

I have tried adding the URL to a standard link (a href) and I still get the same issue.

<a href="/?access=myAccessToken&action=off">Click Me</a>

Answer 1

Edit: for clarity.

When you write:

app.use('/?access'

the ? in the url will tell express to match the route

/access

It is not the literal ?.

But in your front-end code you are using it to mean query parameter so your link:

<a href="/?access=myAccessToken&action=off">Click Me</a>

Is going to be routed to the / path with a query parameter key of access. It will therefore just be picked up by the / route handler on port 8080 and not proxied. For example:

http://localhost:8080/?access=myAccessToken&action=off

I think what would help you achieve the desired outcome would be to have your route to proxy be something simple like /auth which would then look like:

app.use('/auth', proxy)

Now when you navigate to:

<a href="/auth?access=myAccessToken&action=off">Click Me</a>

The request will be proxied to:

http://localhost:8989/auth?access=myAccessToken&action=off