fix: use SIGTERM, then SIGKILL to avoid zombies #266

backend/networking/shutdown.go

@@ -31,9 +31,10 @@ func ShutdownDevice(device *models.Record) error {
 
 	ctx := context.Background()
 	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
 	cmd := exec.CommandContext(ctx, shell, shell_arg, shutdown_cmd)
 	SetProcessAttributes(cmd)
-	logger.Debug.Println(cmd)
 
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
@@ -56,7 +57,6 @@ func ShutdownDevice(device *models.Record) error {
 				if err := KillProcess(cmd.Process); err != nil {
 					logger.Error.Println(err)
 				}
-				cancel()
 				return fmt.Errorf("%s not offline after 2 minutes", device.GetString("name"))
 			}
 			isOnline := PingDevice(device)
@@ -64,7 +64,6 @@ func ShutdownDevice(device *models.Record) error {
 				if err := KillProcess(cmd.Process); err != nil {
 					logger.Error.Println(err)
 				}
-				cancel()
 				return nil
 			}
 		case err := <-done:
@@ -72,7 +71,6 @@ func ShutdownDevice(device *models.Record) error {
 				if err := KillProcess(cmd.Process); err != nil {
 					logger.Error.Println(err)
 				}
-				cancel()
 				return fmt.Errorf("%s", stderr.String())
 			}
 		}

backend/networking/shutdown_linux.go

@@ -4,9 +4,8 @@ import (
 	"os"
 	"os/exec"
 
-	"golang.org/x/sys/unix"
-
 	"github.com/seriousm4x/upsnap/logger"
+	"golang.org/x/sys/unix"
 )
 
 // Set platform specifiy custom process attributes
@@ -16,10 +15,18 @@ func SetProcessAttributes(cmd *exec.Cmd) {
 
 // Kills child processes on Linux. Windows doesn't provide a direct way to kill child processes, so we kill just the main process.
 func KillProcess(process *os.Process) error {
+	logger.Warning.Println("Your shutdown cmd didn't finish in 2 minutes. It will be killed.")
 	pgid, err := unix.Getpgid(process.Pid)
-	logger.Debug.Println(pgid)
 	if err != nil {
 		return err
 	}
-	return unix.Kill(-pgid, unix.SIGKILL)
+
+	err = unix.Kill(-pgid, unix.SIGTERM)
+	if err != nil {
+		return unix.Kill(-pgid, unix.SIGKILL)
+	}
+
+	_, err = process.Wait()
+
+	return err
 }

backend/networking/shutdown_other.go

@@ -1,4 +1,5 @@
-//go:build !linux
+//go:build windows
+// +build windows
 
 package networking
 
@@ -12,8 +13,5 @@ func SetProcessAttributes(cmd *exec.Cmd) {}
 
 // Kills child processes on Linux. Windows doesn't provide a direct way to kill child processes, so we kill just the main process.
 func KillProcess(process *os.Process) error {
-	if err := process.Kill(); err != nil {
-		return err
-	}
-	return nil
+	return windows.GenerateConsoleCtrlEvent(windows.CTRL_BREAK_EVENT, uint32(process.Pid))
 }