open-nomad/drivers/shared/executor/executor_windows.go
Seth Hoenig 52aaf86f52 raw_exec: make raw exec driver work with cgroups v2
This PR adds support for the raw_exec driver on systems with only cgroups v2.

The raw exec driver is able to use cgroups to manage processes. This happens
only on Linux, when exec_driver is enabled, and the no_cgroups option is not
set. The driver uses the freezer controller to freeze processes of a task,
issue a sigkill, then unfreeze. Previously the implementation assumed cgroups
v1, and now it also supports cgroups v2.

There is a bit of refactoring in this PR, but the fundamental design remains
the same.

Closes #12351 #12348
2022-04-04 16:11:38 -05:00

72 lines
2.1 KiB
Go

//go:build windows
package executor
import (
"fmt"
"os"
"syscall"
)
// 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.childCmd.SysProcAttr == nil {
e.childCmd.SysProcAttr = &syscall.SysProcAttr{}
}
e.childCmd.SysProcAttr.CreationFlags = syscall.CREATE_NEW_PROCESS_GROUP
return nil
}
// Cleanup any still hanging user processes
func (e *UniversalExecutor) killProcessTree(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
}
// Send the process a Ctrl-Break event, allowing it to shutdown by itself
// before being Terminate.
func (e *UniversalExecutor) shutdownProcess(_ os.Signal, proc *os.Process) error {
if err := sendCtrlBreak(proc.Pid); err != nil {
return fmt.Errorf("executor shutdown error: %v", err)
}
e.logger.Debug("sent Ctrl-Break to process", "pid", proc.Pid)
return nil
}