Graceful shutdown: draining HTTP + background workers

                  package main

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

func main() {
  srv := &http.Server{Addr: ":8080", Handler: http.DefaultServeMux}

  var wg sync.WaitGroup
  wg.Add(1)
  go func() {
    defer wg.Done()
    if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
      log.Fatalf("listen: %v", err)
    }
  }()

  sigCh := make(chan os.Signal, 1)
  signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
  <-sigCh

  ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
  defer cancel()

  _ = srv.Shutdown(ctx)
  wg.Wait()
}