main.go

package main

import (
	"io/ioutil"
	"net/http"
)

var fwClient = NewForwardingHTTPClient()

func handler(w http.ResponseWriter, r *http.Request) {
	res, err := fwClient.NewForwardingRequest(r)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	defer res.Body.Close()

	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	// accept ALL THE THINGS
	w.Header().Set("Content-Type", r.Header.Get("content-type"))
	w.Header().Set("Access-Control-Allow-Origin", r.Header.Get("origin"))
	w.Header().Set("Access-Control-Allow-Credentials", "true")
	w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
	// might be a good idea to use * https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers
	w.Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, X-HTTP-Method-Override")
	w.Write(body)
	return
}

func main() {
	http.HandleFunc("/favicon.ico", func(w http.ResponseWriter, r *http.Request) {})
	http.HandleFunc("/", handler)

	if err := http.ListenAndServe(":8080", nil); err != nil {
		panic(err)
	}
}