diff --git a/system/syscall_windows.go b/system/syscall_windows.go index 061e220..ef596f3 100644 --- a/system/syscall_windows.go +++ b/system/syscall_windows.go @@ -1,11 +1,14 @@ package system import ( - "fmt" "syscall" "unsafe" ) +var ( + ntuserApiset = syscall.NewLazyDLL("ext-ms-win-ntuser-window-l1-1-0") +) + // OSVersion is a wrapper for Windows version information // https://msdn.microsoft.com/en-us/library/windows/desktop/ms724439(v=vs.85).aspx type OSVersion struct { @@ -17,17 +20,18 @@ type OSVersion struct { // GetOSVersion gets the operating system version on Windows. Note that // docker.exe must be manifested to get the correct version information. -func GetOSVersion() (OSVersion, error) { +func GetOSVersion() OSVersion { var err error osv := OSVersion{} osv.Version, err = syscall.GetVersion() if err != nil { - return osv, fmt.Errorf("Failed to call GetVersion()") + // GetVersion never fails. + panic(err) } osv.MajorVersion = uint8(osv.Version & 0xFF) osv.MinorVersion = uint8(osv.Version >> 8 & 0xFF) osv.Build = uint16(osv.Version >> 16) - return osv, nil + return osv } // Unmount is a platform-specific helper function to call @@ -58,3 +62,12 @@ func CommandLineToArgv(commandLine string) ([]string, error) { return newArgs, nil } + +// HasWin32KSupport determines whether containers that depend on win32k can +// run on this machine. Win32k is the driver used to implement windowing. +func HasWin32KSupport() bool { + // For now, check for ntuser API support on the host. In the future, a host + // may support win32k in containers even if the host does not support ntuser + // APIs. + return ntuserApiset.Load() == nil +} diff --git a/system/syscall_windows_test.go b/system/syscall_windows_test.go new file mode 100644 index 0000000..4886b2b --- /dev/null +++ b/system/syscall_windows_test.go @@ -0,0 +1,9 @@ +package system + +import "testing" + +func TestHasWin32KSupport(t *testing.T) { + s := HasWin32KSupport() // make sure this doesn't panic + + t.Logf("win32k: %v", s) // will be different on different platforms -- informative only +} diff --git a/term/term_windows.go b/term/term_windows.go index a02e681..905c022 100644 --- a/term/term_windows.go +++ b/term/term_windows.go @@ -59,10 +59,7 @@ func StdStreams() (stdIn io.ReadCloser, stdOut, stdErr io.Writer) { // console which supports ANSI emulation, or fall-back to the golang emulator // (github.com/azure/go-ansiterm). func useNativeConsole() bool { - osv, err := system.GetOSVersion() - if err != nil { - return false - } + osv := system.GetOSVersion() // Native console is not available before major version 10 if osv.MajorVersion < 10 {