Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/exec_unix.go

@@ -0,0 +1,66 @@
+//go:build !windows
+
+package internal
+
+import (
+	"log"
+	"os/exec"
+	"syscall"
+	"time"
+)
+
+// KillGrace is the amount of time we allow a process to shutdown before
+// sending a SIGKILL.
+const KillGrace = 5 * time.Second
+
+// WaitTimeout waits for the given command to finish with a timeout.
+// It assumes the command has already been started.
+// If the command times out, it attempts to kill the process.
+func WaitTimeout(c *exec.Cmd, timeout time.Duration) error {
+	var kill *time.Timer
+	term := time.AfterFunc(timeout, func() {
+		err := syscall.Kill(-c.Process.Pid, syscall.SIGTERM)
+		if err != nil {
+			log.Printf("E! [agent] Error terminating process children: %s", err)
+		}
+		err = c.Process.Signal(syscall.SIGTERM)
+		if err != nil {
+			log.Printf("E! [agent] Error terminating process: %s", err)
+			return
+		}
+
+		kill = time.AfterFunc(KillGrace, func() {
+			err := syscall.Kill(-c.Process.Pid, syscall.SIGKILL)
+			if err != nil {
+				log.Printf("E! [agent] Error terminating process children: %s", err)
+			}
+			err = c.Process.Kill()
+			if err != nil {
+				log.Printf("E! [agent] Error killing process: %s", err)
+				return
+			}
+		})
+	})
+
+	err := c.Wait()
+
+	// Shutdown all timers
+	if kill != nil {
+		kill.Stop()
+	}
+	termSent := !term.Stop()
+
+	// If the process exited without error treat it as success.  This allows a
+	// process to do a clean shutdown on signal.
+	if err == nil {
+		return nil
+	}
+
+	// If SIGTERM was sent then treat any process error as a timeout.
+	if termSent {
+		return ErrTimeout
+	}
+
+	// Otherwise there was an error unrelated to termination.
+	return err
+}