dynamically created proxy URL using node/express

I want to use express to create unique proxy instances using URLs that I am storing in a database. I found an npm module that may help with this called http-express-proxy but open to other solutions that uses express.

For example, lets say I have 2 addresses associated with 2 names: { name: google', url: 'www.google.com'} { name: facebook', url: 'www.facebook.com'}

And I have a route like this (using http-express-proxy): app.post('/', proxy(user.URL))

I did find a solution that dynamically creates a regular express route during runtime, but I cannot get it to work using the proxy() method from http-express-proxy:

https://alexanderzeitler.com/articles/expressjs-dynamic-runtime-routing/

According to that approach, I can require a 2nd file inside the POST route that looks like this: (and includes a call to the database using sequelize)

const express = require('express')
const proxy = require('express-http-proxy')

const User = require('../db/models/user')

const app = express()

module.exports= {
    init : init
}
function init(app) {
    User.findOne({where: {id: 1}})
        .then(user => app.post('/', proxy(user.URL)))   
}

And in my main app.js file, I am then doing this:

// ...

app.post('/', function(req, res, next) { 
    var dynamic = require('./dynamic')
    dynamic.init(app)
})

// ...

But I am getting a 503 response when I post using this approach using http-express-proxy, which was not used in his example.

via Jonathan