Add new windows installer and build

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

cmd/podman-wslkerninst/main.go

@@ -0,0 +1,103 @@
+//go:build windows
+// +build windows
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/containers/podman/v4/pkg/machine/wsl"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/windows/svc/eventlog"
+)
+
+const (
+	MB_ICONWARNING = 0x00000030
+	MB_OK          = 0x00000000
+	MB_DEFBUTTON1  = 0x00000000
+)
+
+const KernelWarning = "WSL Kernel installation did not complete successfully. " +
+	"Podman machine will attempt to install this at a later time. " +
+	"You can also manually complete the installation using the " +
+	"\"wsl --update\" command."
+
+func setupLogging(name string) (*eventlog.Log, error) {
+	// Reuse the Built-in .NET Runtime Source so that we do not
+	// have to provide a messaage table and modify the system
+	// event configuration
+	log, err := eventlog.Open(".NET Runtime")
+	if err != nil {
+		return nil, err
+	}
+
+	logrus.AddHook(NewEventHook(log, name))
+	logrus.SetLevel(logrus.InfoLevel)
+
+	return log, nil
+}
+
+func installWslKernel() error {
+	logrus.Info("Installing WSL Kernel update")
+	var (
+		err error
+	)
+	backoff := 500 * time.Millisecond
+	for i := 1; i < 6; i++ {
+		err = wsl.SilentExec("wsl", "--update")
+		if err == nil {
+			break
+		}
+
+		// In case of unusual circumstances (e.g. race with installer actions)
+		// retry a few times
+		logrus.Warn("An error occurred attempting the WSL Kernel update, retrying...")
+		time.Sleep(backoff)
+		backoff *= 2
+	}
+
+	if err != nil {
+		err = fmt.Errorf("could not install WSL Kernel: %w", err)
+	}
+
+	return err
+}
+
+// Creates an "warn" style pop-up window
+func warn(title string, caption string) int {
+	format := MB_ICONWARNING | MB_OK | MB_DEFBUTTON1
+
+	user32 := syscall.NewLazyDLL("user32.dll")
+	captionPtr, _ := syscall.UTF16PtrFromString(caption)
+	titlePtr, _ := syscall.UTF16PtrFromString(title)
+	ret, _, _ := user32.NewProc("MessageBoxW").Call(
+		uintptr(0),
+		uintptr(unsafe.Pointer(captionPtr)),
+		uintptr(unsafe.Pointer(titlePtr)),
+		uintptr(format))
+
+	return int(ret)
+}
+
+func main() {
+	args := os.Args
+	setupLogging(path.Base(args[0]))
+	if wsl.IsWSLInstalled() {
+		// nothing to do
+		logrus.Info("WSL Kernel already installed")
+		return
+	}
+
+	result := installWslKernel()
+	if result != nil {
+		logrus.Error(result.Error())
+		_ = warn("Podman Setup", KernelWarning)
+	}
+
+	logrus.Info("WSL Kernel update successful")
+}