oauth2 problem

oauth2.go

package main
// Goal is to obtain user consent token:
// https://developer.ebay.com/api-docs/static/oauth-consent-request.html

import (
	"fmt"
	"golang.org/x/oauth2"
	"log"
	"net/http"
	"os"
)

const (
	fakeRandomString       = "xyz"
	sandboxClientId        = "<valid sandbox client ID>"
	sandboxClientSecret    = "<valid sandbox secret>"
	productionClientId     = "<valid production client ID>"
	productionClientSecret = "<valid production client secret>"
	RuName                 = "<valid RUName>"
	port                   = ":8000"
)

var endpoint = oauth2.Endpoint{
	AuthURL:   "https://auth.ebay.com/oauth2/authorize",
	TokenURL:  "https://api.ebay.com/identity/v1/oauth2/token",
	AuthStyle: oauth2.AuthStyleInParams,
}

var sandboxEndpoint = oauth2.Endpoint{
	AuthURL:   "https://signin.sandbox.ebay.com/authorize",
	TokenURL:  "https://api.sandbox.ebay.com/identity/v1/oauth2/token",
	AuthStyle: oauth2.AuthStyleInParams,
}

// Goal is to get user access token for this API call:
// https://developer.ebay.com/api-docs/buy/offer/resources/bidding/methods/getBidding
var config = &oauth2.Config{
	ClientID:     sandboxClientId,
	ClientSecret: sandboxClientSecret,
	RedirectURL:  RuName,
	Scopes: []string{
		"https://api.ebay.com/oauth/api_scope/buy.offer.auction",
	},
	Endpoint: sandboxEndpoint,
}

func main() {
	// If not running under sudo, remind that
	// it's required.
	if os.Getenv("SUDO_USER") == "" {
		fmt.Println("\nUsage: sudo " + os.Args[0] + " 2>>stderror.log\n")
		log.Fatal("")
	}

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "<h1>Please sign in at eBay</h1>")
		u := config.AuthCodeURL(fakeRandomString)
		//http.Redirect(w, r, u, http.StatusFound) // Or http.StatusSeeOther?
		http.Redirect(w, r, u, http.StatusSeeOther) // Or http.?
	})

	http.HandleFunc("/auth-accepted.html", func(w http.ResponseWriter, r *http.Request) {
		code := r.FormValue("code")
		if code != "" {
			fmt.Fprintf(w, "<h1>Sign-in successful</h1>")
			fmt.Fprintf(w, "<p>Token is %v</p>", code)
		} else {
      // I can actually see it in the address bar!
			fmt.Fprintf(w, "<h1>Dude. Where's the token?</h1>")
			fmt.Fprintf(os.Stdout, "Token: %v\n", code)
		}
	})

	http.HandleFunc("/auth-declined.html", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "./auth-declined.html")
	})

	http.HandleFunc("/privacy.html", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, "./privacy.html")
	})

	log.Fatal(http.ListenAndServe(":80", nil))
}