package handlers import ( "bytes" "fmt" "net/http" "strings" "github.com/docker/distribution" ctxu "github.com/docker/distribution/context" "github.com/docker/distribution/manifest/manifestlist" "github.com/docker/distribution/manifest/schema1" "github.com/docker/distribution/manifest/schema2" "github.com/docker/distribution/reference" "github.com/docker/distribution/registry/api/errcode" "github.com/docker/distribution/registry/api/v2" "github.com/docker/distribution/registry/auth" "github.com/gorilla/handlers" "github.com/opencontainers/go-digest" ) // These constants determine which architecture and OS to choose from a // manifest list when downconverting it to a schema1 manifest. const ( defaultArch = "amd64" defaultOS = "linux" ) // imageManifestDispatcher takes the request context and builds the // appropriate handler for handling image manifest requests. func imageManifestDispatcher(ctx *Context, r *http.Request) http.Handler { imageManifestHandler := &imageManifestHandler{ Context: ctx, } reference := getReference(ctx) dgst, err := digest.Parse(reference) if err != nil { // We just have a tag imageManifestHandler.Tag = reference } else { imageManifestHandler.Digest = dgst } mhandler := handlers.MethodHandler{ "GET": http.HandlerFunc(imageManifestHandler.GetImageManifest), "HEAD": http.HandlerFunc(imageManifestHandler.GetImageManifest), } if !ctx.readOnly { mhandler["PUT"] = http.HandlerFunc(imageManifestHandler.PutImageManifest) mhandler["DELETE"] = http.HandlerFunc(imageManifestHandler.DeleteImageManifest) } return mhandler } // imageManifestHandler handles http operations on image manifests. type imageManifestHandler struct { *Context // One of tag or digest gets set, depending on what is present in context. Tag string Digest digest.Digest } // GetImageManifest fetches the image manifest from the storage backend, if it exists. func (imh *imageManifestHandler) GetImageManifest(w http.ResponseWriter, r *http.Request) { ctxu.GetLogger(imh).Debug("GetImageManifest") manifests, err := imh.Repository.Manifests(imh) if err != nil { imh.Errors = append(imh.Errors, err) return } var manifest distribution.Manifest if imh.Tag != "" { tags := imh.Repository.Tags(imh) desc, err := tags.Get(imh, imh.Tag) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err)) return } imh.Digest = desc.Digest } if etagMatch(r, imh.Digest.String()) { w.WriteHeader(http.StatusNotModified) return } var options []distribution.ManifestServiceOption if imh.Tag != "" { options = append(options, distribution.WithTag(imh.Tag)) } manifest, err = manifests.Get(imh, imh.Digest, options...) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err)) return } supportsSchema2 := false supportsManifestList := false // this parsing of Accept headers is not quite as full-featured as godoc.org's parser, but we don't care about "q=" values // https://github.com/golang/gddo/blob/e91d4165076d7474d20abda83f92d15c7ebc3e81/httputil/header/header.go#L165-L202 for _, acceptHeader := range r.Header["Accept"] { // r.Header[...] is a slice in case the request contains the same header more than once // if the header isn't set, we'll get the zero value, which "range" will handle gracefully // we need to split each header value on "," to get the full list of "Accept" values (per RFC 2616) // https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1 for _, mediaType := range strings.Split(acceptHeader, ",") { // remove "; q=..." if present if i := strings.Index(mediaType, ";"); i >= 0 { mediaType = mediaType[:i] } // it's common (but not required) for Accept values to be space separated ("a/b, c/d, e/f") mediaType = strings.TrimSpace(mediaType) if mediaType == schema2.MediaTypeManifest { supportsSchema2 = true } if mediaType == manifestlist.MediaTypeManifestList { supportsManifestList = true } } } schema2Manifest, isSchema2 := manifest.(*schema2.DeserializedManifest) manifestList, isManifestList := manifest.(*manifestlist.DeserializedManifestList) // Only rewrite schema2 manifests when they are being fetched by tag. // If they are being fetched by digest, we can't return something not // matching the digest. if imh.Tag != "" && isSchema2 && !supportsSchema2 { // Rewrite manifest in schema1 format ctxu.GetLogger(imh).Infof("rewriting manifest %s in schema1 format to support old client", imh.Digest.String()) manifest, err = imh.convertSchema2Manifest(schema2Manifest) if err != nil { return } } else if imh.Tag != "" && isManifestList && !supportsManifestList { // Rewrite manifest in schema1 format ctxu.GetLogger(imh).Infof("rewriting manifest list %s in schema1 format to support old client", imh.Digest.String()) // Find the image manifest corresponding to the default // platform var manifestDigest digest.Digest for _, manifestDescriptor := range manifestList.Manifests { if manifestDescriptor.Platform.Architecture == defaultArch && manifestDescriptor.Platform.OS == defaultOS { manifestDigest = manifestDescriptor.Digest break } } if manifestDigest == "" { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown) return } manifest, err = manifests.Get(imh, manifestDigest) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown.WithDetail(err)) return } // If necessary, convert the image manifest if schema2Manifest, isSchema2 := manifest.(*schema2.DeserializedManifest); isSchema2 && !supportsSchema2 { manifest, err = imh.convertSchema2Manifest(schema2Manifest) if err != nil { return } } } ct, p, err := manifest.Payload() if err != nil { return } w.Header().Set("Content-Type", ct) w.Header().Set("Content-Length", fmt.Sprint(len(p))) w.Header().Set("Docker-Content-Digest", imh.Digest.String()) w.Header().Set("Etag", fmt.Sprintf(`"%s"`, imh.Digest)) w.Write(p) } func (imh *imageManifestHandler) convertSchema2Manifest(schema2Manifest *schema2.DeserializedManifest) (distribution.Manifest, error) { targetDescriptor := schema2Manifest.Target() blobs := imh.Repository.Blobs(imh) configJSON, err := blobs.Get(imh, targetDescriptor.Digest) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err)) return nil, err } ref := imh.Repository.Named() if imh.Tag != "" { ref, err = reference.WithTag(ref, imh.Tag) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeTagInvalid.WithDetail(err)) return nil, err } } builder := schema1.NewConfigManifestBuilder(imh.Repository.Blobs(imh), imh.Context.App.trustKey, ref, configJSON) for _, d := range schema2Manifest.Layers { if err := builder.AppendReference(d); err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err)) return nil, err } } manifest, err := builder.Build(imh) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err)) return nil, err } imh.Digest = digest.FromBytes(manifest.(*schema1.SignedManifest).Canonical) return manifest, nil } func etagMatch(r *http.Request, etag string) bool { for _, headerVal := range r.Header["If-None-Match"] { if headerVal == etag || headerVal == fmt.Sprintf(`"%s"`, etag) { // allow quoted or unquoted return true } } return false } // PutImageManifest validates and stores an image in the registry. func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http.Request) { ctxu.GetLogger(imh).Debug("PutImageManifest") manifests, err := imh.Repository.Manifests(imh) if err != nil { imh.Errors = append(imh.Errors, err) return } var jsonBuf bytes.Buffer if err := copyFullPayload(w, r, &jsonBuf, imh, "image manifest PUT", &imh.Errors); err != nil { // copyFullPayload reports the error if necessary return } mediaType := r.Header.Get("Content-Type") manifest, desc, err := distribution.UnmarshalManifest(mediaType, jsonBuf.Bytes()) if err != nil { imh.Errors = append(imh.Errors, v2.ErrorCodeManifestInvalid.WithDetail(err)) return } if imh.Digest != "" { if desc.Digest != imh.Digest { ctxu.GetLogger(imh).Errorf("payload digest does match: %q != %q", desc.Digest, imh.Digest) imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid) return } } else if imh.Tag != "" { imh.Digest = desc.Digest } else { imh.Errors = append(imh.Errors, v2.ErrorCodeTagInvalid.WithDetail("no tag or digest specified")) return } var options []distribution.ManifestServiceOption if imh.Tag != "" { options = append(options, distribution.WithTag(imh.Tag)) } if err := imh.applyResourcePolicy(manifest); err != nil { imh.Errors = append(imh.Errors, err) return } _, err = manifests.Put(imh, manifest, options...) if err != nil { // TODO(stevvooe): These error handling switches really need to be // handled by an app global mapper. if err == distribution.ErrUnsupported { imh.Errors = append(imh.Errors, errcode.ErrorCodeUnsupported) return } if err == distribution.ErrAccessDenied { imh.Errors = append(imh.Errors, errcode.ErrorCodeDenied) return } switch err := err.(type) { case distribution.ErrManifestVerification: for _, verificationError := range err { switch verificationError := verificationError.(type) { case distribution.ErrManifestBlobUnknown: imh.Errors = append(imh.Errors, v2.ErrorCodeManifestBlobUnknown.WithDetail(verificationError.Digest)) case distribution.ErrManifestNameInvalid: imh.Errors = append(imh.Errors, v2.ErrorCodeNameInvalid.WithDetail(err)) case distribution.ErrManifestUnverified: imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnverified) default: if verificationError == digest.ErrDigestInvalidFormat { imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid) } else { imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown, verificationError) } } } case errcode.Error: imh.Errors = append(imh.Errors, err) default: imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err)) } return } // Tag this manifest if imh.Tag != "" { tags := imh.Repository.Tags(imh) err = tags.Tag(imh, imh.Tag, desc) if err != nil { imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err)) return } } // Construct a canonical url for the uploaded manifest. ref, err := reference.WithDigest(imh.Repository.Named(), imh.Digest) if err != nil { imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown.WithDetail(err)) return } location, err := imh.urlBuilder.BuildManifestURL(ref) if err != nil { // NOTE(stevvooe): Given the behavior above, this absurdly unlikely to // happen. We'll log the error here but proceed as if it worked. Worst // case, we set an empty location header. ctxu.GetLogger(imh).Errorf("error building manifest url from digest: %v", err) } w.Header().Set("Location", location) w.Header().Set("Docker-Content-Digest", imh.Digest.String()) w.WriteHeader(http.StatusCreated) } // applyResourcePolicy checks whether the resource class matches what has // been authorized and allowed by the policy configuration. func (imh *imageManifestHandler) applyResourcePolicy(manifest distribution.Manifest) error { allowedClasses := imh.App.Config.Policy.Repository.Classes if len(allowedClasses) == 0 { return nil } var class string switch m := manifest.(type) { case *schema1.SignedManifest: class = "image" case *schema2.DeserializedManifest: switch m.Config.MediaType { case schema2.MediaTypeImageConfig: class = "image" case schema2.MediaTypePluginConfig: class = "plugin" default: message := fmt.Sprintf("unknown manifest class for %s", m.Config.MediaType) return errcode.ErrorCodeDenied.WithMessage(message) } } if class == "" { return nil } // Check to see if class is allowed in registry var allowedClass bool for _, c := range allowedClasses { if class == c { allowedClass = true break } } if !allowedClass { message := fmt.Sprintf("registry does not allow %s manifest", class) return errcode.ErrorCodeDenied.WithMessage(message) } resources := auth.AuthorizedResources(imh) n := imh.Repository.Named().Name() var foundResource bool for _, r := range resources { if r.Name == n { if r.Class == "" { r.Class = "image" } if r.Class == class { return nil } foundResource = true } } // resource was found but no matching class was found if foundResource { message := fmt.Sprintf("repository not authorized for %s manifest", class) return errcode.ErrorCodeDenied.WithMessage(message) } return nil } // DeleteImageManifest removes the manifest with the given digest from the registry. func (imh *imageManifestHandler) DeleteImageManifest(w http.ResponseWriter, r *http.Request) { ctxu.GetLogger(imh).Debug("DeleteImageManifest") manifests, err := imh.Repository.Manifests(imh) if err != nil { imh.Errors = append(imh.Errors, err) return } err = manifests.Delete(imh, imh.Digest) if err != nil { switch err { case digest.ErrDigestUnsupported: case digest.ErrDigestInvalidFormat: imh.Errors = append(imh.Errors, v2.ErrorCodeDigestInvalid) return case distribution.ErrBlobUnknown: imh.Errors = append(imh.Errors, v2.ErrorCodeManifestUnknown) return case distribution.ErrUnsupported: imh.Errors = append(imh.Errors, errcode.ErrorCodeUnsupported) return default: imh.Errors = append(imh.Errors, errcode.ErrorCodeUnknown) return } } tagService := imh.Repository.Tags(imh) referencedTags, err := tagService.Lookup(imh, distribution.Descriptor{Digest: imh.Digest}) if err != nil { imh.Errors = append(imh.Errors, err) return } for _, tag := range referencedTags { if err := tagService.Untag(imh, tag); err != nil { imh.Errors = append(imh.Errors, err) return } } w.WriteHeader(http.StatusAccepted) }