Start a small ad-hoc server w/Go, and shutdown gracefully. Aimed at handling OAuth2 redirects to get auth code.

main.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

func main() {
	gotCode := make(chan struct{})

	http.HandleFunc("/getcode", func(w http.ResponseWriter, r *http.Request) {
		q := r.URL.Query()
		log.Printf("got auth-code=%s", q.Get("auth-code"))
		close(gotCode)
	})

	srv := http.Server{Addr: ":8999"}

	go func() {
		sigint := make(chan os.Signal, 1)
		signal.Notify(sigint, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)

		timeout := time.Tick(10 * time.Second)

		select {
		case <-gotCode:
			log.Println("got code")
		case <-timeout:
			log.Println("timed out")
		case <-sigint:
			fmt.Print("\r")
			log.Println("interrupted")
		}

		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
		defer cancel()
		log.Println("shutting down")
		if err := srv.Shutdown(ctx); err != nil {
			log.Fatalf("trouble shutting down listeners: %v", err)
		}
	}()

	log.Println("starting")
	if err := srv.ListenAndServe(); err != http.ErrServerClosed {
		log.Fatalf("problem with server: %v", err)
	}

	log.Println("done")
}