Custom static file server + reverse proxy with clean HTML5 SPA routing support.

server.js

const fs = require('fs')
const url = require('url')
const path = require('path')
const http = require('http')
const static = require('node-static')
const httpProxy = require('http-proxy')

const file = new static.Server('./', { cache: 0 })
const proxy = httpProxy.createProxyServer({})

const server = http.createServer(function(req, res) {
  // requests beginning with /api should be proxied
  if (req.url.startsWith('/api')) {
    proxy.web(req, res, { target: process.env.API_HOST })
    return
  }

  const urlParts = url.parse(req.url)

  const filePath = path.join(__dirname, urlParts.pathname)
  fs.exists(filePath, exists => {
    if (exists) {
      file.serve(req, res)
      return
    }

    file.serveFile('/index.html', 200, {}, req, res)
  })
})

console.log(`hosting app at http://localhost:${process.env.PORT}`)
console.log(`proxying /api to ${process.env.API_HOST}`)
server.listen(process.env.PORT)

npm i node-static http-proxy -D
Needs PORT (i.e. 8000) and API_HOST (i.e. http://my-api-server.com) environment variables.