chore: related timer with context.Done (#2471)

Co-authored-by: Dominik Menke <git@dmke.org>

cmd/hook.go

@@ -11,7 +11,6 @@ import (
 	"time"
 
 	"github.com/go-acme/lego/v4/certificate"
-	"github.com/go-acme/lego/v4/log"
 )
 
 const (
@@ -49,13 +48,13 @@ func launchHook(hook string, timeout time.Duration, meta map[string]string) erro
 		return fmt.Errorf("start command: %w", err)
 	}
 
-	timer := time.AfterFunc(timeout, func() {
-		log.Println("hook timed out: killing command")
-		_ = cmd.Process.Kill()
-		_ = stdout.Close()
-	})
-
-	defer timer.Stop()
+	go func() {
+		<-ctxCmd.Done()
+		if ctxCmd.Err() != nil {
+			_ = cmd.Process.Kill()
+			_ = stdout.Close()
+		}
+	}()
 
 	scanner := bufio.NewScanner(stdout)
 	for scanner.Scan() {

cmd/hook_test.go

@@ -8,6 +8,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func Test_launchHook(t *testing.T) {
+	err := launchHook("echo foo", 1*time.Second, map[string]string{})
+	require.NoError(t, err)
+}
+
 func Test_launchHook_errors(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		t.Skip("skipping test on Windows")