image: implement CheckOS, deprecate pkg/system IsOSSupported

Implement a function that returns an error to replace existing uses of
the IsOSSupported utility, where callers had to produce the error after
checking.

The IsOSSupported function was used in combination with images, so implementing
a utility in "image" to prevent having to import pkg/system (which contains many
unrelated functions)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

builder/dockerfile/dispatchers.go

@@ -22,7 +22,6 @@ import (
 	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/pkg/jsonmessage"
-	"github.com/docker/docker/pkg/system"
 	"github.com/docker/go-connections/nat"
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
@@ -331,8 +330,8 @@ func dispatchWorkdir(ctx context.Context, d dispatchRequest, c *instructions.Wor
 // RUN echo hi          # cmd /S /C echo hi   (Windows)
 // RUN [ "echo", "hi" ] # echo hi
 func dispatchRun(ctx context.Context, d dispatchRequest, c *instructions.RunCommand) error {
-	if !system.IsOSSupported(d.state.operatingSystem) {
-		return system.ErrNotSupportedOperatingSystem
+	if err := image.CheckOS(d.state.operatingSystem); err != nil {
+		return err
 	}
 
 	if len(c.FlagsUsed) > 0 {

builder/dockerfile/evaluator.go

@@ -28,8 +28,8 @@ import (
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/builder"
 	"github.com/docker/docker/errdefs"
+	"github.com/docker/docker/image"
 	"github.com/docker/docker/oci"
-	"github.com/docker/docker/pkg/system"
 	"github.com/docker/docker/runconfig/opts"
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/shell"
@@ -213,21 +213,21 @@ func (s *dispatchState) hasFromImage() bool {
 	return s.imageID != "" || (s.baseImage != nil && s.baseImage.ImageID() == "")
 }
 
-func (s *dispatchState) beginStage(stageName string, image builder.Image) error {
+func (s *dispatchState) beginStage(stageName string, img builder.Image) error {
 	s.stageName = stageName
-	s.imageID = image.ImageID()
-	s.operatingSystem = image.OperatingSystem()
-	if !system.IsOSSupported(s.operatingSystem) {
-		return system.ErrNotSupportedOperatingSystem
+	s.imageID = img.ImageID()
+	s.operatingSystem = img.OperatingSystem()
+	if err := image.CheckOS(s.operatingSystem); err != nil {
+		return err
 	}
 
-	if image.RunConfig() != nil {
+	if img.RunConfig() != nil {
 		// copy avoids referencing the same instance when 2 stages have the same base
-		s.runConfig = copyRunConfig(image.RunConfig())
+		s.runConfig = copyRunConfig(img.RunConfig())
 	} else {
 		s.runConfig = &container.Config{}
 	}
-	s.baseImage = image
+	s.baseImage = img
 	s.setDefaultPath()
 	s.runConfig.OpenStdin = false
 	s.runConfig.StdinOnce = false

daemon/containerd/image_builder.go

@@ -31,7 +31,6 @@ import (
 	"github.com/docker/docker/pkg/progress"
 	"github.com/docker/docker/pkg/streamformatter"
 	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/system"
 	"github.com/opencontainers/go-digest"
 	"github.com/opencontainers/image-spec/identity"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -49,8 +48,8 @@ func (i *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID s
 		if opts.Platform != nil {
 			imgOS = opts.Platform.OS
 		}
-		if !system.IsOSSupported(imgOS) {
-			return nil, nil, system.ErrNotSupportedOperatingSystem
+		if err := dimage.CheckOS(imgOS); err != nil {
+			return nil, nil, err
 		}
 		return nil, &rolayer{
 			key:         "",
@@ -72,8 +71,8 @@ func (i *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID s
 			return nil, nil, err
 		}
 		if img != nil {
-			if !system.IsOSSupported(img.OperatingSystem()) {
-				return nil, nil, system.ErrNotSupportedOperatingSystem
+			if err := dimage.CheckOS(img.OperatingSystem()); err != nil {
+				return nil, nil, err
 			}
 
 			roLayer, err := newROLayerForImage(ctx, &imgDesc, i, opts.Platform)
@@ -161,8 +160,8 @@ Please notify the image author to correct the configuration.`,
 		}
 	}
 
-	if !system.IsOSSupported(img.OperatingSystem()) {
-		return nil, system.ErrNotSupportedOperatingSystem
+	if err := dimage.CheckOS(img.OperatingSystem()); err != nil {
+		return nil, err
 	}
 
 	imgDesc, err := i.resolveDescriptor(ctx, name)

daemon/images/image_builder.go

@@ -18,7 +18,6 @@ import (
 	"github.com/docker/docker/pkg/progress"
 	"github.com/docker/docker/pkg/streamformatter"
 	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/system"
 	registrypkg "github.com/docker/docker/registry"
 	"github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -208,8 +207,8 @@ func (i *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID s
 		if opts.Platform != nil {
 			os = opts.Platform.OS
 		}
-		if !system.IsOSSupported(os) {
-			return nil, nil, system.ErrNotSupportedOperatingSystem
+		if err := image.CheckOS(os); err != nil {
+			return nil, nil, err
 		}
 		lyr, err := newROLayerForImage(nil, i.layerStore)
 		return nil, lyr, err
@@ -224,8 +223,8 @@ func (i *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID s
 			return nil, nil, err
 		}
 		if img != nil {
-			if !system.IsOSSupported(img.OperatingSystem()) {
-				return nil, nil, system.ErrNotSupportedOperatingSystem
+			if err := image.CheckOS(img.OperatingSystem()); err != nil {
+				return nil, nil, err
 			}
 			lyr, err := newROLayerForImage(img, i.layerStore)
 			return img, lyr, err
@@ -236,8 +235,8 @@ func (i *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID s
 	if err != nil {
 		return nil, nil, err
 	}
-	if !system.IsOSSupported(img.OperatingSystem()) {
-		return nil, nil, system.ErrNotSupportedOperatingSystem
+	if err := image.CheckOS(img.OperatingSystem()); err != nil {
+		return nil, nil, err
 	}
 	lyr, err := newROLayerForImage(img, i.layerStore)
 	return img, lyr, err

daemon/images/image_import.go

@@ -16,7 +16,6 @@ import (
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/layer"
 	"github.com/docker/docker/pkg/archive"
-	"github.com/docker/docker/pkg/system"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -32,8 +31,8 @@ func (i *ImageService) ImportImage(ctx context.Context, newRef reference.Named,
 		def := platforms.DefaultSpec()
 		platform = &def
 	}
-	if !system.IsOSSupported(platform.OS) {
-		return "", errdefs.InvalidParameter(system.ErrNotSupportedOperatingSystem)
+	if err := image.CheckOS(platform.OS); err != nil {
+		return "", err
 	}
 
 	config, err := dockerfile.BuildFromConfig(ctx, &container.Config{}, changes, platform.OS)

daemon/images/image_list.go

@@ -13,7 +13,6 @@ import (
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/layer"
-	"github.com/docker/docker/pkg/system"
 )
 
 var acceptedImageFilterTags = map[string]bool{
@@ -116,7 +115,7 @@ func (i *ImageService) Images(ctx context.Context, opts types.ImageListOptions)
 		// Skip any images with an unsupported operating system to avoid a potential
 		// panic when indexing through the layerstore. Don't error as we want to list
 		// the other images. This should never happen, but here as a safety precaution.
-		if !system.IsOSSupported(img.OperatingSystem()) {
+		if err := image.CheckOS(img.OperatingSystem()); err != nil {
 			continue
 		}
 

daemon/images/image_windows.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/layer"
-	"github.com/docker/docker/pkg/system"
 	"github.com/pkg/errors"
 )
 
@@ -22,8 +21,8 @@ func (i *ImageService) GetLayerFolders(img *image.Image, rwLayer layer.RWLayer)
 	for index := 1; index <= rd; index++ {
 		// FIXME: why does this mutate the RootFS?
 		img.RootFS.DiffIDs = img.RootFS.DiffIDs[:index]
-		if !system.IsOSSupported(img.OperatingSystem()) {
-			return nil, errors.Wrapf(system.ErrNotSupportedOperatingSystem, "cannot get layerpath for ImageID %s", img.RootFS.ChainID())
+		if err := image.CheckOS(img.OperatingSystem()); err != nil {
+			return nil, errors.Wrapf(err, "cannot get layerpath for ImageID %s", img.RootFS.ChainID())
 		}
 		layerPath, err := layer.GetLayerPath(i.layerStore, img.RootFS.ChainID())
 		if err != nil {

daemon/oci_windows.go

@@ -15,6 +15,7 @@ import (
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/daemon/config"
 	"github.com/docker/docker/errdefs"
+	"github.com/docker/docker/image"
 	"github.com/docker/docker/oci"
 	"github.com/docker/docker/pkg/sysinfo"
 	"github.com/docker/docker/pkg/system"
@@ -33,8 +34,8 @@ func (daemon *Daemon) createSpec(ctx context.Context, daemonCfg *configStore, c
 	if err != nil {
 		return nil, err
 	}
-	if !system.IsOSSupported(img.OperatingSystem()) {
-		return nil, system.ErrNotSupportedOperatingSystem
+	if err := image.CheckOS(img.OperatingSystem()); err != nil {
+		return nil, err
 	}
 
 	s := oci.DefaultSpec()

distribution/config.go

@@ -16,7 +16,6 @@ import (
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/layer"
 	"github.com/docker/docker/pkg/progress"
-	"github.com/docker/docker/pkg/system"
 	refstore "github.com/docker/docker/reference"
 	registrypkg "github.com/docker/docker/registry"
 	"github.com/opencontainers/go-digest"
@@ -152,8 +151,8 @@ func platformFromConfig(c []byte) (*ocispec.Platform, error) {
 	if os == "" {
 		os = runtime.GOOS
 	}
-	if !system.IsOSSupported(os) {
-		return nil, errors.Wrapf(system.ErrNotSupportedOperatingSystem, "image operating system %q cannot be used on this platform", os)
+	if err := image.CheckOS(os); err != nil {
+		return nil, errors.Wrapf(err, "image operating system %q cannot be used on this platform", os)
 	}
 	return &ocispec.Platform{
 		OS:           os,

distribution/pull_v2.go

@@ -27,7 +27,6 @@ import (
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/docker/docker/pkg/progress"
 	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/system"
 	refstore "github.com/docker/docker/reference"
 	"github.com/docker/docker/registry"
 	"github.com/opencontainers/go-digest"
@@ -517,7 +516,7 @@ func (p *puller) pullSchema1(ctx context.Context, ref reference.Reference, unver
 	if platform != nil {
 		// Early bath if the requested OS doesn't match that of the configuration.
 		// This avoids doing the download, only to potentially fail later.
-		if !system.IsOSSupported(platform.OS) {
+		if err := image.CheckOS(platform.OS); err != nil {
 			return "", "", fmt.Errorf("cannot download image with operating system %q when requesting %q", runtime.GOOS, platform.OS)
 		}
 	}
@@ -701,7 +700,7 @@ func (p *puller) pullSchema2Layers(ctx context.Context, target distribution.Desc
 		if platform == nil {
 			// Early bath if the requested OS doesn't match that of the configuration.
 			// This avoids doing the download, only to potentially fail later.
-			if !system.IsOSSupported(configPlatform.OS) {
+			if err := image.CheckOS(configPlatform.OS); err != nil {
 				return "", fmt.Errorf("cannot download image with operating system %q when requesting %q", configPlatform.OS, layerStoreOS)
 			}
 			layerStoreOS = configPlatform.OS
@@ -716,8 +715,10 @@ func (p *puller) pullSchema2Layers(ctx context.Context, target distribution.Desc
 
 	// Assume that the operating system is the host OS if blank, and validate it
 	// to ensure we don't cause a panic by an invalid index into the layerstores.
-	if layerStoreOS != "" && !system.IsOSSupported(layerStoreOS) {
-		return "", system.ErrNotSupportedOperatingSystem
+	if layerStoreOS != "" {
+		if err := image.CheckOS(layerStoreOS); err != nil {
+			return "", err
+		}
 	}
 
 	if p.config.DownloadManager != nil {

distribution/pull_v2_windows.go

@@ -18,7 +18,7 @@ import (
 	"github.com/docker/distribution/manifest/manifestlist"
 	"github.com/docker/distribution/manifest/schema2"
 	"github.com/docker/distribution/registry/client/transport"
-	"github.com/docker/docker/pkg/system"
+	"github.com/docker/docker/image"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -86,7 +86,7 @@ func filterManifests(manifests []manifestlist.ManifestDescriptor, p ocispec.Plat
 			// Explicit user request for an OS
 			os = p.OS
 		}
-		if !system.IsOSSupported(os) {
+		if err := image.CheckOS(os); err != nil {
 			skip()
 			continue
 		}

image/image_os.go

@@ -0,0 +1,18 @@
+package image
+
+import (
+	"errors"
+	"runtime"
+	"strings"
+
+	"github.com/docker/docker/errdefs"
+)
+
+// CheckOS checks if the given OS matches the host's platform, and
+// returns an error otherwise.
+func CheckOS(os string) error {
+	if !strings.EqualFold(runtime.GOOS, os) {
+		return errdefs.InvalidParameter(errors.New("operating system is not supported"))
+	}
+	return nil
+}

image/store.go

@@ -9,7 +9,6 @@ import (
 	"github.com/containerd/containerd/log"
 	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/layer"
-	"github.com/docker/docker/pkg/system"
 	"github.com/opencontainers/go-digest"
 	"github.com/opencontainers/go-digest/digestset"
 	"github.com/pkg/errors"
@@ -83,7 +82,7 @@ func (is *store) restore() error {
 		}
 		var l layer.Layer
 		if chainID := img.RootFS.ChainID(); chainID != "" {
-			if !system.IsOSSupported(img.OperatingSystem()) {
+			if err := CheckOS(img.OperatingSystem()); err != nil {
 				log.G(context.TODO()).WithFields(f{"chainID": chainID, "os": img.OperatingSystem()}).Error("not restoring image with unsupported operating system")
 				return nil
 			}
@@ -164,8 +163,8 @@ func (is *store) Create(config []byte) (ID, error) {
 
 	var l layer.Layer
 	if layerID != "" {
-		if !system.IsOSSupported(img.OperatingSystem()) {
-			return "", errdefs.InvalidParameter(system.ErrNotSupportedOperatingSystem)
+		if err := CheckOS(img.OperatingSystem()); err != nil {
+			return "", err
 		}
 		l, err = is.lss.Get(layerID)
 		if err != nil {

image/tarexport/load.go

@@ -23,7 +23,6 @@ import (
 	"github.com/docker/docker/pkg/progress"
 	"github.com/docker/docker/pkg/streamformatter"
 	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/system"
 	"github.com/moby/sys/sequential"
 	"github.com/moby/sys/symlink"
 	"github.com/opencontainers/go-digest"
@@ -85,7 +84,7 @@ func (l *tarexporter) Load(inTar io.ReadCloser, outStream io.Writer, quiet bool)
 		if err != nil {
 			return err
 		}
-		if !system.IsOSSupported(img.OperatingSystem()) {
+		if err := image.CheckOS(img.OperatingSystem()); err != nil {
 			return fmt.Errorf("cannot load %s image on %s", img.OperatingSystem(), runtime.GOOS)
 		}
 		rootFS := *img.RootFS
@@ -297,7 +296,7 @@ func (l *tarexporter) legacyLoadImage(oldID, sourceDir string, loadedMap map[str
 	if img.OS == "" {
 		img.OS = runtime.GOOS
 	}
-	if !system.IsOSSupported(img.OS) {
+	if err := image.CheckOS(img.OS); err != nil {
 		return fmt.Errorf("cannot load %s image on %s", img.OS, runtime.GOOS)
 	}
 

image/tarexport/save.go

@@ -151,8 +151,8 @@ func (l *tarexporter) takeLayerReference(id image.ID, imgDescr *imageDescriptor)
 	if err != nil {
 		return err
 	}
-	if os := img.OperatingSystem(); !system.IsOSSupported(os) {
-		return fmt.Errorf("os %q is not supported", os)
+	if err := image.CheckOS(img.OperatingSystem()); err != nil {
+		return fmt.Errorf("os %q is not supported", img.OperatingSystem())
 	}
 	imgDescr.image = img
 	topLayerID := img.RootFS.ChainID()

pkg/system/image_os_deprecated.go

@@ -7,9 +7,13 @@ import (
 )
 
 // ErrNotSupportedOperatingSystem means the operating system is not supported.
+//
+// Deprecated: use [github.com/docker/docker/image.CheckOS] and check the error returned.
 var ErrNotSupportedOperatingSystem = errors.New("operating system is not supported")
 
 // IsOSSupported determines if an operating system is supported by the host.
+//
+// Deprecated: use [github.com/docker/docker/image.CheckOS] and check the error returned.
 func IsOSSupported(os string) bool {
 	return strings.EqualFold(runtime.GOOS, os)
 }