How do you handle HTTP server shutdown gracefully in Go?

package main

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

func main() {
    // Create a new HTTP server
    srv := &http.Server{
        Addr: ":8080",
        Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            // Simulate a long-running request
            time.Sleep(10 * time.Second)
            w.Write([]byte("Hello, World!"))
        }),
    }

    // Create a channel to receive signals
    signalCh := make(chan os.Signal, 1)
    signal.Notify(signalCh, syscall.SIGINT, syscall.SIGTERM)

    // Start the server in a separate goroutine
    go func() {
        log.Printf("Server listening on %s\n", srv.Addr)
        if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
            log.Fatalf("listen: %s\n", err)
        }
    }()

    // Wait for a signal to shutdown the server
    sig := <-signalCh
    log.Printf("Received signal: %v\n", sig)

    // Create a context with a timeout
    ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
    defer cancel()

    // Shutdown the server gracefully
    if err := srv.Shutdown(ctx); err != nil {
        log.Fatalf("Server shutdown failed: %v\n", err)
    }

    log.Println("Server shutdown gracefully")
}