| package distribution // import "github.com/docker/docker/distribution" |
| |
| import ( |
| "context" |
| "errors" |
| "fmt" |
| "io" |
| "net/http" |
| "runtime" |
| "sort" |
| "strconv" |
| "strings" |
| |
| "github.com/Microsoft/hcsshim/osversion" |
| "github.com/containerd/containerd/platforms" |
| "github.com/docker/distribution" |
| "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" |
| specs "github.com/opencontainers/image-spec/specs-go/v1" |
| "github.com/sirupsen/logrus" |
| ) |
| |
| var _ distribution.Describable = &v2LayerDescriptor{} |
| |
| func (ld *v2LayerDescriptor) Descriptor() distribution.Descriptor { |
| if ld.src.MediaType == schema2.MediaTypeForeignLayer && len(ld.src.URLs) > 0 { |
| return ld.src |
| } |
| return distribution.Descriptor{} |
| } |
| |
| func (ld *v2LayerDescriptor) open(ctx context.Context) (distribution.ReadSeekCloser, error) { |
| blobs := ld.repo.Blobs(ctx) |
| rsc, err := blobs.Open(ctx, ld.digest) |
| |
| if len(ld.src.URLs) == 0 { |
| return rsc, err |
| } |
| |
| // We're done if the registry has this blob. |
| if err == nil { |
| // Seek does an HTTP GET. If it succeeds, the blob really is accessible. |
| if _, err = rsc.Seek(0, io.SeekStart); err == nil { |
| return rsc, nil |
| } |
| rsc.Close() |
| } |
| |
| // Find the first URL that results in a 200 result code. |
| for _, url := range ld.src.URLs { |
| logrus.Debugf("Pulling %v from foreign URL %v", ld.digest, url) |
| rsc = transport.NewHTTPReadSeeker(http.DefaultClient, url, nil) |
| |
| // Seek does an HTTP GET. If it succeeds, the blob really is accessible. |
| _, err = rsc.Seek(0, io.SeekStart) |
| if err == nil { |
| break |
| } |
| logrus.Debugf("Download for %v failed: %v", ld.digest, err) |
| rsc.Close() |
| rsc = nil |
| } |
| return rsc, err |
| } |
| |
| func filterManifests(manifests []manifestlist.ManifestDescriptor, p specs.Platform) []manifestlist.ManifestDescriptor { |
| version := osversion.Get() |
| osVersion := fmt.Sprintf("%d.%d.%d", version.MajorVersion, version.MinorVersion, version.Build) |
| logrus.Debugf("will prefer Windows entries with version %s", osVersion) |
| |
| var matches []manifestlist.ManifestDescriptor |
| foundWindowsMatch := false |
| for _, manifestDescriptor := range manifests { |
| if (manifestDescriptor.Platform.Architecture == runtime.GOARCH) && |
| ((p.OS != "" && manifestDescriptor.Platform.OS == p.OS) || // Explicit user request for an OS we know we support |
| (p.OS == "" && system.IsOSSupported(manifestDescriptor.Platform.OS))) { // No user requested OS, but one we can support |
| if strings.EqualFold("windows", manifestDescriptor.Platform.OS) { |
| if err := checkImageCompatibility("windows", manifestDescriptor.Platform.OSVersion); err != nil { |
| continue |
| } |
| foundWindowsMatch = true |
| } |
| matches = append(matches, manifestDescriptor) |
| logrus.Debugf("found match %s/%s %s with media type %s, digest %s", manifestDescriptor.Platform.OS, runtime.GOARCH, manifestDescriptor.Platform.OSVersion, manifestDescriptor.MediaType, manifestDescriptor.Digest.String()) |
| } else { |
| logrus.Debugf("ignoring %s/%s %s with media type %s, digest %s", manifestDescriptor.Platform.OS, manifestDescriptor.Platform.Architecture, manifestDescriptor.Platform.OSVersion, manifestDescriptor.MediaType, manifestDescriptor.Digest.String()) |
| } |
| } |
| if foundWindowsMatch { |
| 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 (strings.EqualFold("windows", mbv.list[i].Platform.OS) && !strings.EqualFold("windows", mbv.list[j].Platform.OS)) || |
| (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] |
| } |
| |
| // checkImageCompatibility blocks pulling incompatible images based on a later OS build |
| // Fixes https://github.com/moby/moby/issues/36184. |
| func checkImageCompatibility(imageOS, imageOSVersion string) error { |
| if imageOS == "windows" { |
| hostOSV := osversion.Get() |
| splitImageOSVersion := strings.Split(imageOSVersion, ".") // eg 10.0.16299.nnnn |
| if len(splitImageOSVersion) >= 3 { |
| if imageOSBuild, err := strconv.Atoi(splitImageOSVersion[2]); err == nil { |
| if imageOSBuild > int(hostOSV.Build) { |
| errMsg := fmt.Sprintf("a Windows version %s.%s.%s-based image is incompatible with a %s host", splitImageOSVersion[0], splitImageOSVersion[1], splitImageOSVersion[2], hostOSV.ToString()) |
| logrus.Debugf(errMsg) |
| return errors.New(errMsg) |
| } |
| } |
| } |
| } |
| return nil |
| } |
| |
| func formatPlatform(platform specs.Platform) string { |
| if platform.OS == "" { |
| platform = platforms.DefaultSpec() |
| } |
| return fmt.Sprintf("%s %s", platforms.Format(platform), osversion.Get().ToString()) |
| } |