dotcloud/docker

package operatingsystem // import "github.com/docker/docker/pkg/parsers/operatingsystem"

import (
    "errors"

    "github.com/Microsoft/hcsshim/osversion"
    "golang.org/x/sys/windows"
    "golang.org/x/sys/windows/registry"
)

// VER_NT_WORKSTATION, see https://docs.microsoft.com/en-us/windows/win32/api/winnt/ns-winnt-osversioninfoexa
const verNTWorkstation = 0x00000001 // VER_NT_WORKSTATION

// GetOperatingSystem gets the name of the current operating system.
func GetOperatingSystem() (string, error) {
    osversion := windows.RtlGetVersion() // Always succeeds.
    rel := windowsOSRelease{
        IsServer: osversion.ProductType != verNTWorkstation,
        Build:    osversion.BuildNumber,
    }

    // Make a best-effort attempt to retrieve the display version and
    // Update Build Revision by querying undocumented registry values.
    key, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
    if err == nil {
        defer key.Close()
        if ver, err := getFirstStringValue(key,
            "DisplayVersion", /* Windows 20H2 and above */
            "ReleaseId",      /* Windows 2009 and below */
        ); err == nil {
            rel.DisplayVersion = ver
        }
        if ubr, _, err := key.GetIntegerValue("UBR"); err == nil {
            rel.UBR = ubr
        }
    }

    return rel.String(), nil
}

func getFirstStringValue(key registry.Key, names ...string) (string, error) {
    for _, n := range names {
        val, _, err := key.GetStringValue(n)
        if err != nil {
            if !errors.Is(err, registry.ErrNotExist) {
                return "", err
            }
            continue
        }
        return val, nil
    }
    return "", registry.ErrNotExist
}

// GetOperatingSystemVersion gets the version of the current operating system, as a string.
func GetOperatingSystemVersion() (string, error) {
    return osversion.Get().ToString(), nil
}

// IsContainerized returns true if we are running inside a container.
// No-op on Windows, always returns false.
func IsContainerized() (bool, error) {
    return false, nil
}

// IsWindowsClient returns true if the SKU is client. It returns false on
// Windows server.
func IsWindowsClient() bool {
    return windows.RtlGetVersion().ProductType == verNTWorkstation
}