B 2117 windows group process

CHANGELOG.md

@@ -3,6 +3,9 @@
 IMPROVEMENTS:
  * client: Create new process group on process startup. [[GH-3572](https://github.com/hashicorp/nomad/issues/3572)]
 
+BUG FIXES:
+ * driver/exec: Create process group for Windows process and send Ctrl-Break signal on Shutdown [[GH-2117](https://github.com/hashicorp/nomad/issues/2117)]
+
 ## 0.8.0 (April 12, 2018)
 
 __BACKWARDS INCOMPATIBILITIES:__

client/driver/executor/executor.go

@@ -452,20 +452,6 @@ func ClientCleanup(ic *dstructs.IsolationConfig, pid int) error {
 	return clientCleanup(ic, pid)
 }
 
-// Cleanup any still hanging user processes
-func (e *UniversalExecutor) cleanupChildProcesses(proc *os.Process) error {
-	// If new process group was created upon command execution
-	// we can kill the whole process group now to cleanup any leftovers.
-	if e.cmd.SysProcAttr != nil && e.cmd.SysProcAttr.Setpgid {
-		if err := syscall.Kill(-proc.Pid, syscall.SIGKILL); err != nil && err.Error() != noSuchProcessErr {
-			return err
-		}
-		return nil
-	} else {
-		return proc.Kill()
-	}
-}
-
 // Exit cleans up the alloc directory, destroys resource container and kills the
 // user process
 func (e *UniversalExecutor) Exit() error {
@@ -516,27 +502,7 @@ func (e *UniversalExecutor) ShutDown() error {
 	if err != nil {
 		return fmt.Errorf("executor.shutdown failed to find process: %v", err)
 	}
-	if runtime.GOOS == "windows" {
-		if err := proc.Kill(); err != nil && err.Error() != finishedErr {
-			return err
-		}
-		return nil
-	}
-
-	// Set default kill signal, as some drivers don't support configurable
-	// signals (such as rkt)
-	var osSignal os.Signal
-	if e.command.TaskKillSignal != nil {
-		osSignal = e.command.TaskKillSignal
-	} else {
-		osSignal = os.Interrupt
-	}
-
-	if err = proc.Signal(osSignal); err != nil && err.Error() != finishedErr {
-		return fmt.Errorf("executor.shutdown error: %v", err)
-	}
-
-	return nil
+	return e.shutdownProcess(proc)
 }
 
 // pidStats returns the resource usage stats per pid

client/driver/executor/executor_unix.go

@@ -1,11 +1,11 @@
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris windows
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package executor
 
 import (
 	"fmt"
 	"io"
-	"runtime"
+	"os"
 	"syscall"
 
 	syslog "github.com/RackSec/srslog"
@@ -53,12 +53,40 @@ func (e *UniversalExecutor) collectLogs(we io.Writer, wo io.Writer) {
 // configure new process group for child process
 func (e *UniversalExecutor) setNewProcessGroup() error {
 	// We need to check that as build flags includes windows for this file
-	if runtime.GOOS == "windows" {
-		return nil
-	}
 	if e.cmd.SysProcAttr == nil {
 		e.cmd.SysProcAttr = &syscall.SysProcAttr{}
 	}
 	e.cmd.SysProcAttr.Setpgid = true
 	return nil
 }
+
+// Cleanup any still hanging user processes
+func (e *UniversalExecutor) cleanupChildProcesses(proc *os.Process) error {
+	// If new process group was created upon command execution
+	// we can kill the whole process group now to cleanup any leftovers.
+	if e.cmd.SysProcAttr != nil && e.cmd.SysProcAttr.Setpgid {
+		if err := syscall.Kill(-proc.Pid, syscall.SIGKILL); err != nil && err.Error() != noSuchProcessErr {
+			return err
+		}
+		return nil
+	} else {
+		return proc.Kill()
+	}
+}
+
+func (e *UniversalExecutor) shutdownProcess(proc *os.Process) error {
+	// Set default kill signal, as some drivers don't support configurable
+	// signals (such as rkt)
+	var osSignal os.Signal
+	if e.command.TaskKillSignal != nil {
+		osSignal = e.command.TaskKillSignal
+	} else {
+		osSignal = os.Interrupt
+	}
+
+	if err := proc.Signal(osSignal); err != nil && err.Error() != finishedErr {
+		return fmt.Errorf("executor.shutdown error: %v", err)
+	}
+
+	return nil
+}

client/driver/executor/executor_windows.go

@@ -0,0 +1,111 @@
+// +build windows
+
+package executor
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+
+	syslog "github.com/RackSec/srslog"
+
+	"github.com/hashicorp/nomad/client/driver/logging"
+)
+
+func (e *UniversalExecutor) LaunchSyslogServer() (*SyslogServerState, error) {
+	// Ensure the context has been set first
+	if e.ctx == nil {
+		return nil, fmt.Errorf("SetContext must be called before launching the Syslog Server")
+	}
+
+	e.syslogChan = make(chan *logging.SyslogMessage, 2048)
+	l, err := e.getListener(e.ctx.PortLowerBound, e.ctx.PortUpperBound)
+	if err != nil {
+		return nil, err
+	}
+	e.logger.Printf("[DEBUG] syslog-server: launching syslog server on addr: %v", l.Addr().String())
+	if err := e.configureLoggers(); err != nil {
+		return nil, err
+	}
+
+	e.syslogServer = logging.NewSyslogServer(l, e.syslogChan, e.logger)
+	go e.syslogServer.Start()
+	go e.collectLogs(e.lre, e.lro)
+	syslogAddr := fmt.Sprintf("%s://%s", l.Addr().Network(), l.Addr().String())
+	return &SyslogServerState{Addr: syslogAddr}, nil
+}
+
+func (e *UniversalExecutor) collectLogs(we io.Writer, wo io.Writer) {
+	for logParts := range e.syslogChan {
+		// If the severity of the log line is err then we write to stderr
+		// otherwise all messages go to stdout
+		if logParts.Severity == syslog.LOG_ERR {
+			e.lre.Write(logParts.Message)
+			e.lre.Write([]byte{'\n'})
+		} else {
+			e.lro.Write(logParts.Message)
+			e.lro.Write([]byte{'\n'})
+		}
+	}
+}
+
+// configure new process group for child process
+func (e *UniversalExecutor) setNewProcessGroup() error {
+	// We need to check that as build flags includes windows for this file
+	if e.cmd.SysProcAttr == nil {
+		e.cmd.SysProcAttr = &syscall.SysProcAttr{}
+	}
+	e.cmd.SysProcAttr.CreationFlags = syscall.CREATE_NEW_PROCESS_GROUP
+	return nil
+}
+
+// Cleanup any still hanging user processes
+func (e *UniversalExecutor) cleanupChildProcesses(proc *os.Process) error {
+	// We must first verify if the process is still running.
+	// (Windows process often lingered around after being reported as killed).
+	handle, err := syscall.OpenProcess(syscall.PROCESS_TERMINATE|syscall.SYNCHRONIZE|syscall.PROCESS_QUERY_INFORMATION, false, uint32(proc.Pid))
+	if err != nil {
+		return os.NewSyscallError("OpenProcess", err)
+	}
+	defer syscall.CloseHandle(handle)
+
+	result, err := syscall.WaitForSingleObject(syscall.Handle(handle), 0)
+
+	switch result {
+	case syscall.WAIT_OBJECT_0:
+		return nil
+	case syscall.WAIT_TIMEOUT:
+		// Process still running.  Just kill it.
+		return proc.Kill()
+	default:
+		return os.NewSyscallError("WaitForSingleObject", err)
+	}
+}
+
+// Send a Ctrl-Break signal for shutting down the process,
+// like in https://golang.org/src/os/signal/signal_windows_test.go
+func sendCtrlBreak(pid int) error {
+	dll, err := syscall.LoadDLL("kernel32.dll")
+	if err != nil {
+		return fmt.Errorf("Error loading kernel32.dll: %v", err)
+	}
+	proc, err := dll.FindProc("GenerateConsoleCtrlEvent")
+	if err != nil {
+		return fmt.Errorf("Cannot find procedure GenerateConsoleCtrlEvent: %v", err)
+	}
+	result, _, err := proc.Call(syscall.CTRL_BREAK_EVENT, uintptr(pid))
+	if result == 0 {
+		return fmt.Errorf("Error sending ctrl-break event: %v", err)
+	}
+	return nil
+}
+
+func (e *UniversalExecutor) shutdownProcess(proc *os.Process) error {
+	if err := sendCtrlBreak(proc.Pid); err != nil {
+		return fmt.Errorf("executor.shutdown error: %v", err)
+	}
+	e.logger.Printf("Sent Ctrl-Break to process %v", proc.Pid)
+
+	return nil
+}