Merge pull request #327 from johnstep/windows-manifest-lists

[17.09] Backport version fix for Windows manifest lists

components/engine/distribution/pull_v2.go

@@ -708,29 +708,20 @@ func (p *v2Puller) pullManifestList(ctx context.Context, ref reference.Named, mf
 	}
 
 	logrus.Debugf("%s resolved to a manifestList object with %d entries; looking for a os/arch match", ref, len(mfstList.Manifests))
-	var manifestDigest digest.Digest
-	// TODO @jhowardmsft LCOW Support: Need to remove the hard coding in LCOW mode.
-	lookingForOS := runtime.GOOS
-	if system.LCOWSupported() {
-		lookingForOS = "linux"
-	}
-	for _, manifestDescriptor := range mfstList.Manifests {
-		// TODO(aaronl): The manifest list spec supports optional
-		// "features" and "variant" fields. These are not yet used.
-		// Once they are, their values should be interpreted here.
-		if manifestDescriptor.Platform.Architecture == runtime.GOARCH && manifestDescriptor.Platform.OS == lookingForOS {
-			manifestDigest = manifestDescriptor.Digest
-			logrus.Debugf("found match for %s/%s with media type %s, digest %s", runtime.GOOS, runtime.GOARCH, manifestDescriptor.MediaType, manifestDigest.String())
-			break
-		}
-	}
 
-	if manifestDigest == "" {
+	manifestMatches := filterManifests(mfstList.Manifests)
+
+	if len(manifestMatches) == 0 {
 		errMsg := fmt.Sprintf("no matching manifest for %s/%s in the manifest list entries", runtime.GOOS, runtime.GOARCH)
 		logrus.Debugf(errMsg)
 		return "", "", errors.New(errMsg)
 	}
 
+	if len(manifestMatches) > 1 {
+		logrus.Debugf("found multiple matches in manifest list, choosing best match %s", manifestMatches[0].Digest.String())
+	}
+	manifestDigest := manifestMatches[0].Digest
+
 	manSvc, err := p.repo.Manifests(ctx)
 	if err != nil {
 		return "", "", err

components/engine/distribution/pull_v2_unix.go

@@ -3,11 +3,27 @@
 package distribution
 
 import (
+	"runtime"
+
 	"github.com/docker/distribution"
 	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/manifest/manifestlist"
+	"github.com/sirupsen/logrus"
 )
 
 func (ld *v2LayerDescriptor) open(ctx context.Context) (distribution.ReadSeekCloser, error) {
 	blobs := ld.repo.Blobs(ctx)
 	return blobs.Open(ctx, ld.digest)
 }
+
+func filterManifests(manifests []manifestlist.ManifestDescriptor) []manifestlist.ManifestDescriptor {
+	var matches []manifestlist.ManifestDescriptor
+	for _, manifestDescriptor := range manifests {
+		if manifestDescriptor.Platform.Architecture == runtime.GOARCH && manifestDescriptor.Platform.OS == runtime.GOOS {
+			matches = append(matches, manifestDescriptor)
+
+			logrus.Debugf("found match for %s/%s with media type %s, digest %s", runtime.GOOS, runtime.GOARCH, manifestDescriptor.MediaType, manifestDescriptor.Digest.String())
+		}
+	}
+	return matches
+}

components/engine/distribution/pull_v2_windows.go

@@ -3,13 +3,19 @@
 package distribution
 
 import (
+	"fmt"
 	"net/http"
 	"os"
+	"runtime"
+	"sort"
+	"strings"
 
 	"github.com/docker/distribution"
 	"github.com/docker/distribution/context"
+	"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/sirupsen/logrus"
 )
 
@@ -55,3 +61,54 @@ func (ld *v2LayerDescriptor) open(ctx context.Context) (distribution.ReadSeekClo
 	}
 	return rsc, err
 }
+
+func filterManifests(manifests []manifestlist.ManifestDescriptor) []manifestlist.ManifestDescriptor {
+	version := system.GetOSVersion()
+
+	// TODO @jhowardmsft LCOW Support: Need to remove the hard coding in LCOW mode.
+	lookingForOS := runtime.GOOS
+	osVersion := fmt.Sprintf("%d.%d.%d", version.MajorVersion, version.MinorVersion, version.Build)
+	if system.LCOWSupported() {
+		lookingForOS = "linux"
+		osVersion = ""
+	}
+
+	var matches []manifestlist.ManifestDescriptor
+	for _, manifestDescriptor := range manifests {
+		// TODO: Consider filtering out greater versions, including only greater UBR
+		if manifestDescriptor.Platform.Architecture == runtime.GOARCH && manifestDescriptor.Platform.OS == lookingForOS {
+			matches = append(matches, manifestDescriptor)
+
+			logrus.Debugf("found match for %s/%s with media type %s, digest %s", runtime.GOOS, runtime.GOARCH, manifestDescriptor.MediaType, manifestDescriptor.Digest.String())
+		}
+	}
+	if lookingForOS == "windows" {
+		sort.Stable(manifestsByVersion{osVersion, matches})
+	}
+	return matches
+}
+
+func versionMatch(actual, expected string) bool {
+	// Check whether the version matches up to the build, ignoring UBR
+	return strings.HasPrefix(actual, expected+".")
+}
+
+type manifestsByVersion struct {
+	version string
+	list    []manifestlist.ManifestDescriptor
+}
+
+func (mbv manifestsByVersion) Less(i, j int) bool {
+	// TODO: Split version by parts and compare
+	// TODO: Prefer versions which have a greater version number
+	// Move compatible versions to the top, with no other ordering changes
+	return versionMatch(mbv.list[i].Platform.OSVersion, mbv.version) && !versionMatch(mbv.list[j].Platform.OSVersion, mbv.version)
+}
+
+func (mbv manifestsByVersion) Len() int {
+	return len(mbv.list)
+}
+
+func (mbv manifestsByVersion) Swap(i, j int) {
+	mbv.list[i], mbv.list[j] = mbv.list[j], mbv.list[i]
+}