Add osdetail package for special os integration needs

utils/osdetail/colors_windows.go

@@ -0,0 +1,50 @@
+package osdetail
+
+import (
+	"sync"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	colorSupport bool
+
+	colorSupportChecked  bool
+	checkingColorSupport sync.Mutex
+)
+
+// EnableColorSupport tries to enable color support for cmd on windows and returns whether it is enabled.
+func EnableColorSupport() bool {
+	checkingColorSupport.Lock()
+	defer checkingColorSupport.Unlock()
+
+	if !colorSupportChecked {
+		colorSupport = enableColorSupport()
+	}
+	return colorSupport
+}
+
+func enableColorSupport() bool {
+	if IsWindowsVersion("10.") {
+
+		// check if windows.Stdout is file
+		if windows.GetFileInformationByHandle(windows.Stdout, &windows.ByHandleFileInformation{}) == nil {
+			return false
+		}
+
+		var mode uint32
+		err := windows.GetConsoleMode(windows.Stdout, &mode)
+		if err == nil {
+			if mode&windows.ENABLE_VIRTUAL_TERMINAL_PROCESSING == 0 {
+				mode |= windows.ENABLE_VIRTUAL_TERMINAL_PROCESSING
+				err = windows.SetConsoleMode(windows.Stdout, mode)
+				if err != nil {
+					return false
+				}
+			}
+			return true
+		}
+	}
+
+	return false
+}

utils/osdetail/dnscache_windows.go

@@ -0,0 +1,17 @@
+package osdetail
+
+import (
+	"os/exec"
+)
+
+// EnableDNSCache enables the Windows Service "DNS Client" by setting the registry value "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Dnscache" to 2 (Automatic).
+// A reboot is required for this setting to take effect.
+func EnableDNSCache() error {
+	return exec.Command("reg", "add", "HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\services\\Dnscache", "/v", "Start", "/t", "REG_DWORD", "/d", "2", "/f").Run()
+}
+
+// DisableDNSCache disables the Windows Service "DNS Client" by setting the registry value "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Dnscache" to 4 (Disabled).
+// A reboot is required for this setting to take effect.
+func DisableDNSCache() error {
+	return exec.Command("reg", "add", "HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\services\\Dnscache", "/v", "Start", "/t", "REG_DWORD", "/d", "4", "/f").Run()
+}

utils/osdetail/service_windows.go

@@ -0,0 +1,112 @@
+package osdetail
+
+import (
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+// Service Status
+const (
+	StatusUnknown uint8 = iota
+	StatusRunningStoppable
+	StatusRunningNotStoppable
+	StatusStartPending
+	StatusStopPending
+	StatusStopped
+)
+
+// Exported errors
+var (
+	ErrServiceNotStoppable = errors.New("the service is not stoppable")
+)
+
+// GetServiceStatus returns the current status of a Windows Service (limited implementation).
+func GetServiceStatus(name string) (status uint8, err error) {
+
+	output, err := exec.Command("sc", "query", name).Output()
+	if err != nil {
+		return StatusUnknown, fmt.Errorf("failed to query service: %s", err)
+	}
+	outputString := string(output)
+
+	switch {
+	case strings.Contains(outputString, "RUNNING"):
+		if strings.Contains(outputString, "NOT_STOPPABLE") {
+			return StatusRunningNotStoppable, nil
+		}
+		return StatusRunningStoppable, nil
+	case strings.Contains(outputString, "STOP_PENDING"):
+		return StatusStopPending, nil
+	case strings.Contains(outputString, "STOPPED"):
+		return StatusStopped, nil
+	case strings.Contains(outputString, "START_PENDING"):
+		return StatusStopPending, nil
+	}
+
+	return StatusUnknown, errors.New("unknown service status")
+}
+
+// StopService stops a Windows Service.
+func StopService(name string) (err error) {
+	pendingCnt := 0
+	for {
+
+		// get status
+		status, err := GetServiceStatus(name)
+		if err != nil {
+			return err
+		}
+
+		switch status {
+		case StatusRunningStoppable:
+			err := exec.Command("sc", "stop", name).Run()
+			if err != nil {
+				return fmt.Errorf("failed to stop service: %s", err)
+			}
+		case StatusRunningNotStoppable:
+			return ErrServiceNotStoppable
+		case StatusStartPending, StatusStopPending:
+			pendingCnt++
+			if pendingCnt > 50 {
+				return errors.New("service stuck in pending status (5s)")
+			}
+		case StatusStopped:
+			return nil
+		}
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}
+
+// SartService starts a Windows Service.
+func SartService(name string) (err error) {
+	pendingCnt := 0
+	for {
+
+		// get status
+		status, err := GetServiceStatus(name)
+		if err != nil {
+			return err
+		}
+
+		switch status {
+		case StatusRunningStoppable, StatusRunningNotStoppable:
+			return nil
+		case StatusStartPending, StatusStopPending:
+			pendingCnt++
+			if pendingCnt > 50 {
+				return errors.New("service stuck in pending status (5s)")
+			}
+		case StatusStopped:
+			err := exec.Command("sc", "start", name).Run()
+			if err != nil {
+				return fmt.Errorf("failed to stop service: %s", err)
+			}
+		}
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}

utils/osdetail/version_windows.go

@@ -0,0 +1,54 @@
+package osdetail
+
+import (
+	"os/exec"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+var (
+	versionRe = regexp.MustCompile(`[0-9\.]+`)
+
+	windowsVersion string
+
+	fetching sync.Mutex
+	fetched  bool
+)
+
+func fetchVersion() {
+	if !fetched {
+		fetched = true
+
+		output, err := exec.Command("cmd", "ver").Output()
+		if err != nil {
+			return
+		}
+
+		match := versionRe.Find(output)
+		if match == nil {
+			return
+		}
+
+		windowsVersion = string(match)
+	}
+}
+
+// WindowsVersion returns the current Windows version.
+func WindowsVersion() string {
+	fetching.Lock()
+	defer fetching.Unlock()
+	fetchVersion()
+
+	return windowsVersion
+}
+
+// IsWindowsVersion returns whether the given version matches (HasPrefix) the current Windows version.
+func IsWindowsVersion(version string) bool {
+	fetching.Lock()
+	defer fetching.Unlock()
+	fetchVersion()
+
+	// TODO: we can do better.
+	return strings.HasPrefix(windowsVersion, version)
+}

utils/osdetail/version_windows_test.go

@@ -0,0 +1,9 @@
+package osdetail
+
+import "testing"
+
+func TestWindowsVersion(t *testing.T) {
+	if WindowsVersion() == "" {
+		t.Fatal("could not get windows version")
+	}
+}