diff --git a/blobs.go b/blobs.go index 2087d0f9..40cd8295 100644 --- a/blobs.go +++ b/blobs.go @@ -61,6 +61,15 @@ type Descriptor struct { // depend on the simplicity of this type. } +// Descriptor returns the descriptor, to make it satisfy the Describable +// interface. Note that implementations of Describable are generally objects +// which can be described, not simply descriptors; this exception is in place +// to make it more convenient to pass actual descriptors to functions that +// expect Describable objects. +func (d Descriptor) Descriptor() Descriptor { + return d +} + // BlobStatter makes blob descriptors available by digest. The service may // provide a descriptor of a different digest if the provided digest is not // canonical. diff --git a/manifest/schema1/config_builder.go b/manifest/schema1/config_builder.go new file mode 100644 index 00000000..e9fe81be --- /dev/null +++ b/manifest/schema1/config_builder.go @@ -0,0 +1,278 @@ +package schema1 + +import ( + "crypto/sha512" + "encoding/json" + "errors" + "fmt" + "time" + + "github.com/docker/distribution" + "github.com/docker/distribution/context" + "github.com/docker/libtrust" + + "github.com/docker/distribution/digest" + "github.com/docker/distribution/manifest" +) + +type diffID digest.Digest + +// gzippedEmptyTar is a gzip-compressed version of an empty tar file +// (1024 NULL bytes) +var gzippedEmptyTar = []byte{ + 31, 139, 8, 0, 0, 9, 110, 136, 0, 255, 98, 24, 5, 163, 96, 20, 140, 88, + 0, 8, 0, 0, 255, 255, 46, 175, 181, 239, 0, 4, 0, 0, +} + +// digestSHA256GzippedEmptyTar is the canonical sha256 digest of +// gzippedEmptyTar +const digestSHA256GzippedEmptyTar = digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4") + +// configManifestBuilder is a type for constructing manifests from an image +// configuration and generic descriptors. +type configManifestBuilder struct { + // bs is a BlobService used to create empty layer tars in the + // blob store if necessary. + bs distribution.BlobService + // pk is the libtrust private key used to sign the final manifest. + pk libtrust.PrivateKey + // configJSON is configuration supplied when the ManifestBuilder was + // created. + configJSON []byte + // name is the name provided to NewConfigManifestBuilder + name string + // tag is the tag provided to NewConfigManifestBuilder + tag string + // descriptors is the set of descriptors referencing the layers. + descriptors []distribution.Descriptor + // emptyTarDigest is set to a valid digest if an empty tar has been + // put in the blob store; otherwise it is empty. + emptyTarDigest digest.Digest +} + +// NewConfigManifestBuilder is used to build new manifests for the current +// schema version from an image configuration and a set of descriptors. +// It takes a BlobService so that it can add an empty tar to the blob store +// if the resulting manifest needs empty layers. +func NewConfigManifestBuilder(bs distribution.BlobService, pk libtrust.PrivateKey, name, tag string, configJSON []byte) distribution.ManifestBuilder { + return &configManifestBuilder{ + bs: bs, + pk: pk, + configJSON: configJSON, + name: name, + tag: tag, + } +} + +// Build produces a final manifest from the given references +func (mb *configManifestBuilder) Build(ctx context.Context) (m distribution.Manifest, err error) { + type imageRootFS struct { + Type string `json:"type"` + DiffIDs []diffID `json:"diff_ids,omitempty"` + BaseLayer string `json:"base_layer,omitempty"` + } + + type imageHistory struct { + Created time.Time `json:"created"` + Author string `json:"author,omitempty"` + CreatedBy string `json:"created_by,omitempty"` + Comment string `json:"comment,omitempty"` + EmptyLayer bool `json:"empty_layer,omitempty"` + } + + type imageConfig struct { + RootFS *imageRootFS `json:"rootfs,omitempty"` + History []imageHistory `json:"history,omitempty"` + Architecture string `json:"architecture,omitempty"` + } + + var img imageConfig + + if err := json.Unmarshal(mb.configJSON, &img); err != nil { + return nil, err + } + + if len(img.History) == 0 { + return nil, errors.New("empty history when trying to create schema1 manifest") + } + + if len(img.RootFS.DiffIDs) != len(mb.descriptors) { + return nil, errors.New("number of descriptors and number of layers in rootfs must match") + } + + // Generate IDs for each layer + // For non-top-level layers, create fake V1Compatibility strings that + // fit the format and don't collide with anything else, but don't + // result in runnable images on their own. + type v1Compatibility struct { + ID string `json:"id"` + Parent string `json:"parent,omitempty"` + Comment string `json:"comment,omitempty"` + Created time.Time `json:"created"` + ContainerConfig struct { + Cmd []string + } `json:"container_config,omitempty"` + ThrowAway bool `json:"throwaway,omitempty"` + } + + fsLayerList := make([]FSLayer, len(img.History)) + history := make([]History, len(img.History)) + + parent := "" + layerCounter := 0 + for i, h := range img.History[:len(img.History)-1] { + var blobsum digest.Digest + if h.EmptyLayer { + if blobsum, err = mb.emptyTar(ctx); err != nil { + return nil, err + } + } else { + if len(img.RootFS.DiffIDs) <= layerCounter { + return nil, errors.New("too many non-empty layers in History section") + } + blobsum = mb.descriptors[layerCounter].Digest + layerCounter++ + } + + v1ID := digest.FromBytes([]byte(blobsum.Hex() + " " + parent)).Hex() + + if i == 0 && img.RootFS.BaseLayer != "" { + // windows-only baselayer setup + baseID := sha512.Sum384([]byte(img.RootFS.BaseLayer)) + parent = fmt.Sprintf("%x", baseID[:32]) + } + + v1Compatibility := v1Compatibility{ + ID: v1ID, + Parent: parent, + Comment: h.Comment, + Created: h.Created, + } + v1Compatibility.ContainerConfig.Cmd = []string{img.History[i].CreatedBy} + if h.EmptyLayer { + v1Compatibility.ThrowAway = true + } + jsonBytes, err := json.Marshal(&v1Compatibility) + if err != nil { + return nil, err + } + + reversedIndex := len(img.History) - i - 1 + history[reversedIndex].V1Compatibility = string(jsonBytes) + fsLayerList[reversedIndex] = FSLayer{BlobSum: blobsum} + + parent = v1ID + } + + latestHistory := img.History[len(img.History)-1] + + var blobsum digest.Digest + if latestHistory.EmptyLayer { + if blobsum, err = mb.emptyTar(ctx); err != nil { + return nil, err + } + } else { + if len(img.RootFS.DiffIDs) <= layerCounter { + return nil, errors.New("too many non-empty layers in History section") + } + blobsum = mb.descriptors[layerCounter].Digest + } + + fsLayerList[0] = FSLayer{BlobSum: blobsum} + dgst := digest.FromBytes([]byte(blobsum.Hex() + " " + parent + " " + string(mb.configJSON))) + + // Top-level v1compatibility string should be a modified version of the + // image config. + transformedConfig, err := MakeV1ConfigFromConfig(mb.configJSON, dgst.Hex(), parent, latestHistory.EmptyLayer) + if err != nil { + return nil, err + } + + history[0].V1Compatibility = string(transformedConfig) + + mfst := Manifest{ + Versioned: manifest.Versioned{ + SchemaVersion: 1, + }, + Name: mb.name, + Tag: mb.tag, + Architecture: img.Architecture, + FSLayers: fsLayerList, + History: history, + } + + return Sign(&mfst, mb.pk) +} + +// emptyTar pushes a compressed empty tar to the blob store if one doesn't +// already exist, and returns its blobsum. +func (mb *configManifestBuilder) emptyTar(ctx context.Context) (digest.Digest, error) { + if mb.emptyTarDigest != "" { + // Already put an empty tar + return mb.emptyTarDigest, nil + } + + descriptor, err := mb.bs.Stat(ctx, digestSHA256GzippedEmptyTar) + switch err { + case nil: + mb.emptyTarDigest = descriptor.Digest + return descriptor.Digest, nil + case distribution.ErrBlobUnknown: + // nop + default: + return "", err + } + + // Add gzipped empty tar to the blob store + descriptor, err = mb.bs.Put(ctx, "", gzippedEmptyTar) + if err != nil { + return "", err + } + + mb.emptyTarDigest = descriptor.Digest + + return descriptor.Digest, nil +} + +// AppendReference adds a reference to the current ManifestBuilder +func (mb *configManifestBuilder) AppendReference(d distribution.Describable) error { + // todo: verification here? + mb.descriptors = append(mb.descriptors, d.Descriptor()) + return nil +} + +// References returns the current references added to this builder +func (mb *configManifestBuilder) References() []distribution.Descriptor { + return mb.descriptors +} + +// MakeV1ConfigFromConfig creates an legacy V1 image config from image config JSON +func MakeV1ConfigFromConfig(configJSON []byte, v1ID, parentV1ID string, throwaway bool) ([]byte, error) { + // Top-level v1compatibility string should be a modified version of the + // image config. + var configAsMap map[string]*json.RawMessage + if err := json.Unmarshal(configJSON, &configAsMap); err != nil { + return nil, err + } + + // Delete fields that didn't exist in old manifest + delete(configAsMap, "rootfs") + delete(configAsMap, "history") + configAsMap["id"] = rawJSON(v1ID) + if parentV1ID != "" { + configAsMap["parent"] = rawJSON(parentV1ID) + } + if throwaway { + configAsMap["throwaway"] = rawJSON(true) + } + + return json.Marshal(configAsMap) +} + +func rawJSON(value interface{}) *json.RawMessage { + jsonval, err := json.Marshal(value) + if err != nil { + return nil + } + return (*json.RawMessage)(&jsonval) +} diff --git a/manifest/schema1/config_builder_test.go b/manifest/schema1/config_builder_test.go new file mode 100644 index 00000000..18024d6c --- /dev/null +++ b/manifest/schema1/config_builder_test.go @@ -0,0 +1,264 @@ +package schema1 + +import ( + "bytes" + "compress/gzip" + "io" + "reflect" + "testing" + + "github.com/docker/distribution" + "github.com/docker/distribution/context" + "github.com/docker/distribution/digest" + "github.com/docker/libtrust" +) + +type mockBlobService struct { + descriptors map[digest.Digest]distribution.Descriptor +} + +func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) { + if descriptor, ok := bs.descriptors[dgst]; ok { + return descriptor, nil + } + return distribution.Descriptor{}, distribution.ErrBlobUnknown +} + +func (bs *mockBlobService) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) { + d := distribution.Descriptor{ + Digest: digest.FromBytes(p), + Size: int64(len(p)), + MediaType: mediaType, + } + bs.descriptors[d.Digest] = d + return d, nil +} + +func (bs *mockBlobService) Create(ctx context.Context) (distribution.BlobWriter, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) { + panic("not implemented") +} + +func TestEmptyTar(t *testing.T) { + // Confirm that gzippedEmptyTar expands to 1024 NULL bytes. + var decompressed [2048]byte + gzipReader, err := gzip.NewReader(bytes.NewReader(gzippedEmptyTar)) + if err != nil { + t.Fatalf("NewReader returned error: %v", err) + } + n, err := gzipReader.Read(decompressed[:]) + if n != 1024 { + t.Fatalf("read returned %d bytes; expected 1024", n) + } + n, err = gzipReader.Read(decompressed[1024:]) + if n != 0 { + t.Fatalf("read returned %d bytes; expected 0", n) + } + if err != io.EOF { + t.Fatal("read did not return io.EOF") + } + gzipReader.Close() + for _, b := range decompressed[:1024] { + if b != 0 { + t.Fatal("nonzero byte in decompressed tar") + } + } + + // Confirm that digestSHA256EmptyTar is the digest of gzippedEmptyTar. + dgst := digest.FromBytes(gzippedEmptyTar) + if dgst != digestSHA256GzippedEmptyTar { + t.Fatalf("digest mismatch for empty tar: expected %s got %s", digestSHA256GzippedEmptyTar, dgst) + } +} + +func TestConfigBuilder(t *testing.T) { + imgJSON := `{ + "architecture": "amd64", + "config": { + "AttachStderr": false, + "AttachStdin": false, + "AttachStdout": false, + "Cmd": [ + "/bin/sh", + "-c", + "echo hi" + ], + "Domainname": "", + "Entrypoint": null, + "Env": [ + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "derived=true", + "asdf=true" + ], + "Hostname": "23304fc829f9", + "Image": "sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246", + "Labels": {}, + "OnBuild": [], + "OpenStdin": false, + "StdinOnce": false, + "Tty": false, + "User": "", + "Volumes": null, + "WorkingDir": "" + }, + "container": "e91032eb0403a61bfe085ff5a5a48e3659e5a6deae9f4d678daa2ae399d5a001", + "container_config": { + "AttachStderr": false, + "AttachStdin": false, + "AttachStdout": false, + "Cmd": [ + "/bin/sh", + "-c", + "#(nop) CMD [\"/bin/sh\" \"-c\" \"echo hi\"]" + ], + "Domainname": "", + "Entrypoint": null, + "Env": [ + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "derived=true", + "asdf=true" + ], + "Hostname": "23304fc829f9", + "Image": "sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246", + "Labels": {}, + "OnBuild": [], + "OpenStdin": false, + "StdinOnce": false, + "Tty": false, + "User": "", + "Volumes": null, + "WorkingDir": "" + }, + "created": "2015-11-04T23:06:32.365666163Z", + "docker_version": "1.9.0-dev", + "history": [ + { + "created": "2015-10-31T22:22:54.690851953Z", + "created_by": "/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /" + }, + { + "created": "2015-10-31T22:22:55.613815829Z", + "created_by": "/bin/sh -c #(nop) CMD [\"sh\"]" + }, + { + "created": "2015-11-04T23:06:30.934316144Z", + "created_by": "/bin/sh -c #(nop) ENV derived=true", + "empty_layer": true + }, + { + "created": "2015-11-04T23:06:31.192097572Z", + "created_by": "/bin/sh -c #(nop) ENV asdf=true", + "empty_layer": true + }, + { + "created": "2015-11-04T23:06:32.083868454Z", + "created_by": "/bin/sh -c dd if=/dev/zero of=/file bs=1024 count=1024" + }, + { + "created": "2015-11-04T23:06:32.365666163Z", + "created_by": "/bin/sh -c #(nop) CMD [\"/bin/sh\" \"-c\" \"echo hi\"]", + "empty_layer": true + } + ], + "os": "linux", + "rootfs": { + "diff_ids": [ + "sha256:c6f988f4874bb0add23a778f753c65efe992244e148a1d2ec2a8b664fb66bbd1", + "sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef", + "sha256:13f53e08df5a220ab6d13c58b2bf83a59cbdc2e04d0a3f041ddf4b0ba4112d49" + ], + "type": "layers" + } +}` + + descriptors := []distribution.Descriptor{ + {Digest: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + {Digest: digest.Digest("sha256:86e0e091d0da6bde2456dbb48306f3956bbeb2eae1b5b9a43045843f69fe4aaa")}, + {Digest: digest.Digest("sha256:b4ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + } + + pk, err := libtrust.GenerateECP256PrivateKey() + if err != nil { + t.Fatalf("could not generate key for testing: %v", err) + } + + bs := &mockBlobService{descriptors: make(map[digest.Digest]distribution.Descriptor)} + builder := NewConfigManifestBuilder(bs, pk, "testrepo", "testtag", []byte(imgJSON)) + + for _, d := range descriptors { + if err := builder.AppendReference(d); err != nil { + t.Fatalf("AppendReference returned error: %v", err) + } + } + + signed, err := builder.Build(context.Background()) + if err != nil { + t.Fatalf("Build returned error: %v", err) + } + + // Check that the gzipped empty layer tar was put in the blob store + _, err = bs.Stat(context.Background(), digestSHA256GzippedEmptyTar) + if err != nil { + t.Fatal("gzipped empty tar was not put in the blob store") + } + + manifest := signed.(*SignedManifest).Manifest + + if manifest.Versioned.SchemaVersion != 1 { + t.Fatal("SchemaVersion != 1") + } + if manifest.Name != "testrepo" { + t.Fatal("incorrect name in manifest") + } + if manifest.Tag != "testtag" { + t.Fatal("incorrect tag in manifest") + } + if manifest.Architecture != "amd64" { + t.Fatal("incorrect arch in manifest") + } + + expectedFSLayers := []FSLayer{ + {BlobSum: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + {BlobSum: digest.Digest("sha256:b4ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + {BlobSum: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + {BlobSum: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + {BlobSum: digest.Digest("sha256:86e0e091d0da6bde2456dbb48306f3956bbeb2eae1b5b9a43045843f69fe4aaa")}, + {BlobSum: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")}, + } + + if len(manifest.FSLayers) != len(expectedFSLayers) { + t.Fatalf("wrong number of FSLayers: %d", len(manifest.FSLayers)) + } + if !reflect.DeepEqual(manifest.FSLayers, expectedFSLayers) { + t.Fatal("wrong FSLayers list") + } + + expectedV1Compatibility := []string{ + `{"architecture":"amd64","config":{"AttachStderr":false,"AttachStdin":false,"AttachStdout":false,"Cmd":["/bin/sh","-c","echo hi"],"Domainname":"","Entrypoint":null,"Env":["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","derived=true","asdf=true"],"Hostname":"23304fc829f9","Image":"sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246","Labels":{},"OnBuild":[],"OpenStdin":false,"StdinOnce":false,"Tty":false,"User":"","Volumes":null,"WorkingDir":""},"container":"e91032eb0403a61bfe085ff5a5a48e3659e5a6deae9f4d678daa2ae399d5a001","container_config":{"AttachStderr":false,"AttachStdin":false,"AttachStdout":false,"Cmd":["/bin/sh","-c","#(nop) CMD [\"/bin/sh\" \"-c\" \"echo hi\"]"],"Domainname":"","Entrypoint":null,"Env":["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","derived=true","asdf=true"],"Hostname":"23304fc829f9","Image":"sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246","Labels":{},"OnBuild":[],"OpenStdin":false,"StdinOnce":false,"Tty":false,"User":"","Volumes":null,"WorkingDir":""},"created":"2015-11-04T23:06:32.365666163Z","docker_version":"1.9.0-dev","id":"0850bfdeb7b060b1004a09099846c2f023a3f2ecbf33f56b4774384b00ce0323","os":"linux","parent":"74cf9c92699240efdba1903c2748ef57105d5bedc588084c4e88f3bb1c3ef0b0","throwaway":true}`, + `{"id":"74cf9c92699240efdba1903c2748ef57105d5bedc588084c4e88f3bb1c3ef0b0","parent":"178be37afc7c49e951abd75525dbe0871b62ad49402f037164ee6314f754599d","created":"2015-11-04T23:06:32.083868454Z","container_config":{"Cmd":["/bin/sh -c dd if=/dev/zero of=/file bs=1024 count=1024"]}}`, + `{"id":"178be37afc7c49e951abd75525dbe0871b62ad49402f037164ee6314f754599d","parent":"b449305a55a283538c4574856a8b701f2a3d5ec08ef8aec47f385f20339a4866","created":"2015-11-04T23:06:31.192097572Z","container_config":{"Cmd":["/bin/sh -c #(nop) ENV asdf=true"]},"throwaway":true}`, + `{"id":"b449305a55a283538c4574856a8b701f2a3d5ec08ef8aec47f385f20339a4866","parent":"9e3447ca24cb96d86ebd5960cb34d1299b07e0a0e03801d90b9969a2c187dd6e","created":"2015-11-04T23:06:30.934316144Z","container_config":{"Cmd":["/bin/sh -c #(nop) ENV derived=true"]},"throwaway":true}`, + `{"id":"9e3447ca24cb96d86ebd5960cb34d1299b07e0a0e03801d90b9969a2c187dd6e","parent":"3690474eb5b4b26fdfbd89c6e159e8cc376ca76ef48032a30fa6aafd56337880","created":"2015-10-31T22:22:55.613815829Z","container_config":{"Cmd":["/bin/sh -c #(nop) CMD [\"sh\"]"]}}`, + `{"id":"3690474eb5b4b26fdfbd89c6e159e8cc376ca76ef48032a30fa6aafd56337880","created":"2015-10-31T22:22:54.690851953Z","container_config":{"Cmd":["/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"]}}`, + } + + if len(manifest.History) != len(expectedV1Compatibility) { + t.Fatalf("wrong number of history entries: %d", len(manifest.History)) + } + for i := range expectedV1Compatibility { + if manifest.History[i].V1Compatibility != expectedV1Compatibility[i] { + t.Errorf("wrong V1Compatibility %d. expected:\n%s\ngot:\n%s", i, expectedV1Compatibility[i], manifest.History[i].V1Compatibility) + } + } +} diff --git a/manifest/schema1/builder.go b/manifest/schema1/reference_builder.go similarity index 70% rename from manifest/schema1/builder.go rename to manifest/schema1/reference_builder.go index 461f15aa..36209e34 100644 --- a/manifest/schema1/builder.go +++ b/manifest/schema1/reference_builder.go @@ -5,21 +5,23 @@ import ( "errors" "github.com/docker/distribution" + "github.com/docker/distribution/context" "github.com/docker/distribution/digest" "github.com/docker/distribution/manifest" "github.com/docker/libtrust" ) -// ManifestBuilder is a type for constructing manifests -type manifestBuilder struct { +// referenceManifestBuilder is a type for constructing manifests from schema1 +// dependencies. +type referenceManifestBuilder struct { Manifest pk libtrust.PrivateKey } -// NewManifestBuilder is used to build new manifests for the current schema -// version. -func NewManifestBuilder(pk libtrust.PrivateKey, name, tag, architecture string) distribution.ManifestBuilder { - return &manifestBuilder{ +// NewReferenceManifestBuilder is used to build new manifests for the current +// schema version using schema1 dependencies. +func NewReferenceManifestBuilder(pk libtrust.PrivateKey, name, tag, architecture string) distribution.ManifestBuilder { + return &referenceManifestBuilder{ Manifest: Manifest{ Versioned: manifest.Versioned{ SchemaVersion: 1, @@ -32,8 +34,7 @@ func NewManifestBuilder(pk libtrust.PrivateKey, name, tag, architecture string) } } -// Build produces a final manifest from the given references -func (mb *manifestBuilder) Build() (distribution.Manifest, error) { +func (mb *referenceManifestBuilder) Build(ctx context.Context) (distribution.Manifest, error) { m := mb.Manifest if len(m.FSLayers) == 0 { return nil, errors.New("cannot build manifest with zero layers or history") @@ -47,8 +48,8 @@ func (mb *manifestBuilder) Build() (distribution.Manifest, error) { return Sign(&m, mb.pk) } -// AppendReference adds a reference to the current manifestBuilder -func (mb *manifestBuilder) AppendReference(d distribution.Describable) error { +// AppendReference adds a reference to the current ManifestBuilder +func (mb *referenceManifestBuilder) AppendReference(d distribution.Describable) error { r, ok := d.(Reference) if !ok { return fmt.Errorf("Unable to add non-reference type to v1 builder") @@ -62,7 +63,7 @@ func (mb *manifestBuilder) AppendReference(d distribution.Describable) error { } // References returns the current references added to this builder -func (mb *manifestBuilder) References() []distribution.Descriptor { +func (mb *referenceManifestBuilder) References() []distribution.Descriptor { refs := make([]distribution.Descriptor, len(mb.Manifest.FSLayers)) for i := range mb.Manifest.FSLayers { layerDigest := mb.Manifest.FSLayers[i].BlobSum diff --git a/manifest/schema1/builder_test.go b/manifest/schema1/reference_builder_test.go similarity index 87% rename from manifest/schema1/builder_test.go rename to manifest/schema1/reference_builder_test.go index a5c1cea2..a4fab57c 100644 --- a/manifest/schema1/builder_test.go +++ b/manifest/schema1/reference_builder_test.go @@ -3,6 +3,7 @@ package schema1 import ( "testing" + "github.com/docker/distribution/context" "github.com/docker/distribution/digest" "github.com/docker/distribution/manifest" "github.com/docker/libtrust" @@ -34,7 +35,7 @@ func makeSignedManifest(t *testing.T, pk libtrust.PrivateKey, refs []Reference) return signedManifest } -func TestBuilder(t *testing.T) { +func TestReferenceBuilder(t *testing.T) { pk, err := libtrust.GenerateECP256PrivateKey() if err != nil { t.Fatalf("unexpected error generating private key: %v", err) @@ -53,8 +54,8 @@ func TestBuilder(t *testing.T) { handCrafted := makeSignedManifest(t, pk, []Reference{r1, r2}) - b := NewManifestBuilder(pk, handCrafted.Manifest.Name, handCrafted.Manifest.Tag, handCrafted.Manifest.Architecture) - _, err = b.Build() + b := NewReferenceManifestBuilder(pk, handCrafted.Manifest.Name, handCrafted.Manifest.Tag, handCrafted.Manifest.Architecture) + _, err = b.Build(context.Background()) if err == nil { t.Fatal("Expected error building zero length manifest") } @@ -79,7 +80,7 @@ func TestBuilder(t *testing.T) { t.Fatalf("Unexpected reference : %v", refs[0]) } - m, err := b.Build() + m, err := b.Build(context.Background()) if err != nil { t.Fatal(err) } diff --git a/manifest/schema2/builder.go b/manifest/schema2/builder.go new file mode 100644 index 00000000..1586bb99 --- /dev/null +++ b/manifest/schema2/builder.go @@ -0,0 +1,78 @@ +package schema2 + +import ( + "github.com/docker/distribution" + "github.com/docker/distribution/context" + "github.com/docker/distribution/digest" + "github.com/docker/distribution/manifest" +) + +// builder is a type for constructing manifests. +type builder struct { + // bs is a BlobService used to publish the configuration blob. + bs distribution.BlobService + + // configJSON references + configJSON []byte + + // layers is a list of layer descriptors that gets built by successive + // calls to AppendReference. + layers []distribution.Descriptor +} + +// NewManifestBuilder is used to build new manifests for the current schema +// version. It takes a BlobService so it can publish the configuration blob +// as part of the Build process. +func NewManifestBuilder(bs distribution.BlobService, configJSON []byte) distribution.ManifestBuilder { + mb := &builder{ + bs: bs, + configJSON: make([]byte, len(configJSON)), + } + copy(mb.configJSON, configJSON) + + return mb +} + +// Build produces a final manifest from the given references. +func (mb *builder) Build(ctx context.Context) (distribution.Manifest, error) { + m := Manifest{ + Versioned: manifest.Versioned{ + SchemaVersion: 2, + }, + MediaType: MediaTypeManifest, + Layers: make([]distribution.Descriptor, len(mb.layers)), + } + copy(m.Layers, mb.layers) + + configDigest := digest.FromBytes(mb.configJSON) + + var err error + m.Config, err = mb.bs.Stat(ctx, configDigest) + switch err { + case nil: + return FromStruct(m) + case distribution.ErrBlobUnknown: + // nop + default: + return nil, err + } + + // Add config to the blob store + m.Config, err = mb.bs.Put(ctx, MediaTypeConfig, mb.configJSON) + if err != nil { + return nil, err + } + + return FromStruct(m) +} + +// AppendReference adds a reference to the current ManifestBuilder. +func (mb *builder) AppendReference(d distribution.Describable) error { + mb.layers = append(mb.layers, d.Descriptor()) + return nil +} + +// References returns the current references added to this builder. +func (mb *builder) References() []distribution.Descriptor { + return mb.layers +} diff --git a/manifest/schema2/builder_test.go b/manifest/schema2/builder_test.go new file mode 100644 index 00000000..ffe51f42 --- /dev/null +++ b/manifest/schema2/builder_test.go @@ -0,0 +1,210 @@ +package schema2 + +import ( + "reflect" + "testing" + + "github.com/docker/distribution" + "github.com/docker/distribution/context" + "github.com/docker/distribution/digest" +) + +type mockBlobService struct { + descriptors map[digest.Digest]distribution.Descriptor +} + +func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) { + if descriptor, ok := bs.descriptors[dgst]; ok { + return descriptor, nil + } + return distribution.Descriptor{}, distribution.ErrBlobUnknown +} + +func (bs *mockBlobService) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) { + d := distribution.Descriptor{ + Digest: digest.FromBytes(p), + Size: int64(len(p)), + MediaType: mediaType, + } + bs.descriptors[d.Digest] = d + return d, nil +} + +func (bs *mockBlobService) Create(ctx context.Context) (distribution.BlobWriter, error) { + panic("not implemented") +} + +func (bs *mockBlobService) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) { + panic("not implemented") +} + +func TestBuilder(t *testing.T) { + imgJSON := []byte(`{ + "architecture": "amd64", + "config": { + "AttachStderr": false, + "AttachStdin": false, + "AttachStdout": false, + "Cmd": [ + "/bin/sh", + "-c", + "echo hi" + ], + "Domainname": "", + "Entrypoint": null, + "Env": [ + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "derived=true", + "asdf=true" + ], + "Hostname": "23304fc829f9", + "Image": "sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246", + "Labels": {}, + "OnBuild": [], + "OpenStdin": false, + "StdinOnce": false, + "Tty": false, + "User": "", + "Volumes": null, + "WorkingDir": "" + }, + "container": "e91032eb0403a61bfe085ff5a5a48e3659e5a6deae9f4d678daa2ae399d5a001", + "container_config": { + "AttachStderr": false, + "AttachStdin": false, + "AttachStdout": false, + "Cmd": [ + "/bin/sh", + "-c", + "#(nop) CMD [\"/bin/sh\" \"-c\" \"echo hi\"]" + ], + "Domainname": "", + "Entrypoint": null, + "Env": [ + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "derived=true", + "asdf=true" + ], + "Hostname": "23304fc829f9", + "Image": "sha256:4ab15c48b859c2920dd5224f92aabcd39a52794c5b3cf088fb3bbb438756c246", + "Labels": {}, + "OnBuild": [], + "OpenStdin": false, + "StdinOnce": false, + "Tty": false, + "User": "", + "Volumes": null, + "WorkingDir": "" + }, + "created": "2015-11-04T23:06:32.365666163Z", + "docker_version": "1.9.0-dev", + "history": [ + { + "created": "2015-10-31T22:22:54.690851953Z", + "created_by": "/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /" + }, + { + "created": "2015-10-31T22:22:55.613815829Z", + "created_by": "/bin/sh -c #(nop) CMD [\"sh\"]" + }, + { + "created": "2015-11-04T23:06:30.934316144Z", + "created_by": "/bin/sh -c #(nop) ENV derived=true", + "empty_layer": true + }, + { + "created": "2015-11-04T23:06:31.192097572Z", + "created_by": "/bin/sh -c #(nop) ENV asdf=true", + "empty_layer": true + }, + { + "created": "2015-11-04T23:06:32.083868454Z", + "created_by": "/bin/sh -c dd if=/dev/zero of=/file bs=1024 count=1024" + }, + { + "created": "2015-11-04T23:06:32.365666163Z", + "created_by": "/bin/sh -c #(nop) CMD [\"/bin/sh\" \"-c\" \"echo hi\"]", + "empty_layer": true + } + ], + "os": "linux", + "rootfs": { + "diff_ids": [ + "sha256:c6f988f4874bb0add23a778f753c65efe992244e148a1d2ec2a8b664fb66bbd1", + "sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef", + "sha256:13f53e08df5a220ab6d13c58b2bf83a59cbdc2e04d0a3f041ddf4b0ba4112d49" + ], + "type": "layers" + } +}`) + configDigest := digest.FromBytes(imgJSON) + + descriptors := []distribution.Descriptor{ + { + Digest: digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4"), + Size: 5312, + MediaType: MediaTypeLayer, + }, + { + Digest: digest.Digest("sha256:86e0e091d0da6bde2456dbb48306f3956bbeb2eae1b5b9a43045843f69fe4aaa"), + Size: 235231, + MediaType: MediaTypeLayer, + }, + { + Digest: digest.Digest("sha256:b4ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4"), + Size: 639152, + MediaType: MediaTypeLayer, + }, + } + + bs := &mockBlobService{descriptors: make(map[digest.Digest]distribution.Descriptor)} + builder := NewManifestBuilder(bs, imgJSON) + + for _, d := range descriptors { + if err := builder.AppendReference(d); err != nil { + t.Fatalf("AppendReference returned error: %v", err) + } + } + + built, err := builder.Build(context.Background()) + if err != nil { + t.Fatalf("Build returned error: %v", err) + } + + // Check that the config was put in the blob store + _, err = bs.Stat(context.Background(), configDigest) + if err != nil { + t.Fatal("config was not put in the blob store") + } + + manifest := built.(*DeserializedManifest).Manifest + + if manifest.Versioned.SchemaVersion != 2 { + t.Fatal("SchemaVersion != 2") + } + + target := manifest.Target() + if target.Digest != configDigest { + t.Fatalf("unexpected digest in target: %s", target.Digest.String()) + } + if target.MediaType != MediaTypeConfig { + t.Fatalf("unexpected media type in target: %s", target.MediaType) + } + if target.Size != 3153 { + t.Fatalf("unexpected size in target: %d", target.Size) + } + + references := manifest.References() + + if !reflect.DeepEqual(references, descriptors) { + t.Fatal("References() does not match the descriptors added") + } +} diff --git a/manifest/schema2/manifest.go b/manifest/schema2/manifest.go new file mode 100644 index 00000000..ea422da1 --- /dev/null +++ b/manifest/schema2/manifest.go @@ -0,0 +1,125 @@ +package schema2 + +import ( + "encoding/json" + "errors" + "fmt" + + "github.com/docker/distribution" + "github.com/docker/distribution/digest" + "github.com/docker/distribution/manifest" +) + +const ( + // MediaTypeManifest specifies the mediaType for the current version. + MediaTypeManifest = "application/vnd.docker.distribution.manifest.v2+json" + + // MediaTypeConfig specifies the mediaType for the image configuration. + MediaTypeConfig = "application/vnd.docker.container.image.v1+json" + + // MediaTypeLayer is the mediaType used for layers referenced by the + // manifest. + MediaTypeLayer = "application/vnd.docker.image.rootfs.diff.tar.gzip" +) + +var ( + // SchemaVersion provides a pre-initialized version structure for this + // packages version of the manifest. + SchemaVersion = manifest.Versioned{ + SchemaVersion: 2, + } +) + +func init() { + schema2Func := func(b []byte) (distribution.Manifest, distribution.Descriptor, error) { + m := new(DeserializedManifest) + err := m.UnmarshalJSON(b) + if err != nil { + return nil, distribution.Descriptor{}, err + } + + dgst := digest.FromBytes(b) + return m, distribution.Descriptor{Digest: dgst, Size: int64(len(b)), MediaType: MediaTypeManifest}, err + } + err := distribution.RegisterManifestSchema(MediaTypeManifest, schema2Func) + if err != nil { + panic(fmt.Sprintf("Unable to register manifest: %s", err)) + } +} + +// Manifest defines a schema2 manifest. +type Manifest struct { + manifest.Versioned + MediaType string `json:"mediaType"` + + // Config references the image configuration as a blob. + Config distribution.Descriptor `json:"config"` + + // Layers lists descriptors for the layers referenced by the + // configuration. + Layers []distribution.Descriptor `json:"layers"` +} + +// References returnes the descriptors of this manifests references. +func (m Manifest) References() []distribution.Descriptor { + return m.Layers + +} + +// Target returns the target of this signed manifest. +func (m Manifest) Target() distribution.Descriptor { + return m.Config +} + +// DeserializedManifest wraps Manifest with a copy of the original JSON. +// It satisfies the distribution.Manifest interface. +type DeserializedManifest struct { + Manifest + + // canonical is the canonical byte representation of the Manifest. + canonical []byte +} + +// FromStruct takes a Manifest structure, marshals it to JSON, and returns a +// DeserializedManifest which contains the manifest and its JSON representation. +func FromStruct(m Manifest) (*DeserializedManifest, error) { + var deserialized DeserializedManifest + deserialized.Manifest = m + + var err error + deserialized.canonical, err = json.MarshalIndent(&m, "", " ") + return &deserialized, err +} + +// UnmarshalJSON populates a new Manifest struct from JSON data. +func (m *DeserializedManifest) UnmarshalJSON(b []byte) error { + m.canonical = make([]byte, len(b), len(b)) + // store manifest in canonical + copy(m.canonical, b) + + // Unmarshal canonical JSON into Manifest object + var manifest Manifest + if err := json.Unmarshal(m.canonical, &manifest); err != nil { + return err + } + + m.Manifest = manifest + + return nil +} + +// MarshalJSON returns the contents of canonical. If canonical is empty, +// marshals the inner contents. +func (m *DeserializedManifest) MarshalJSON() ([]byte, error) { + if len(m.canonical) > 0 { + return m.canonical, nil + } + + return nil, errors.New("JSON representation not initialized in DeserializedManifest") +} + +// Payload returns the raw content of the manifest. The contents can be used to +// calculate the content identifier. +func (m DeserializedManifest) Payload() (string, []byte, error) { + return m.MediaType, m.canonical, nil +} diff --git a/manifest/schema2/manifest_test.go b/manifest/schema2/manifest_test.go new file mode 100644 index 00000000..59b8af69 --- /dev/null +++ b/manifest/schema2/manifest_test.go @@ -0,0 +1,106 @@ +package schema2 + +import ( + "bytes" + "encoding/json" + "reflect" + "testing" + + "github.com/docker/distribution" +) + +var expectedManifestSerialization = []byte(`{ + "schemaVersion": 2, + "mediaType": "application/vnd.docker.distribution.manifest.v2+json", + "config": { + "mediaType": "application/vnd.docker.container.image.v1+json", + "size": 985, + "digest": "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b" + }, + "layers": [ + { + "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip", + "size": 153263, + "digest": "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b" + } + ] +}`) + +func TestManifest(t *testing.T) { + manifest := Manifest{ + Versioned: SchemaVersion, + MediaType: MediaTypeManifest, + Config: distribution.Descriptor{ + Digest: "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b", + Size: 985, + MediaType: MediaTypeConfig, + }, + Layers: []distribution.Descriptor{ + { + Digest: "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b", + Size: 153263, + MediaType: MediaTypeLayer, + }, + }, + } + + deserialized, err := FromStruct(manifest) + if err != nil { + t.Fatalf("error creating DeserializedManifest: %v", err) + } + + mediaType, canonical, err := deserialized.Payload() + + if mediaType != MediaTypeManifest { + t.Fatalf("unexpected media type: %s", mediaType) + } + + // Check that the canonical field is the same as json.MarshalIndent + // with these parameters. + p, err := json.MarshalIndent(&manifest, "", " ") + if err != nil { + t.Fatalf("error marshaling manifest: %v", err) + } + if !bytes.Equal(p, canonical) { + t.Fatalf("manifest bytes not equal: %q != %q", string(canonical), string(p)) + } + + // Check that canonical field matches expected value. + if !bytes.Equal(expectedManifestSerialization, canonical) { + t.Fatalf("manifest bytes not equal: %q != %q", string(canonical), string(expectedManifestSerialization)) + } + + var unmarshalled DeserializedManifest + if err := json.Unmarshal(deserialized.canonical, &unmarshalled); err != nil { + t.Fatalf("error unmarshaling manifest: %v", err) + } + + if !reflect.DeepEqual(&unmarshalled, deserialized) { + t.Fatalf("manifests are different after unmarshaling: %v != %v", unmarshalled, *deserialized) + } + + target := deserialized.Target() + if target.Digest != "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b" { + t.Fatalf("unexpected digest in target: %s", target.Digest.String()) + } + if target.MediaType != MediaTypeConfig { + t.Fatalf("unexpected media type in target: %s", target.MediaType) + } + if target.Size != 985 { + t.Fatalf("unexpected size in target: %d", target.Size) + } + + references := deserialized.References() + if len(references) != 1 { + t.Fatalf("unexpected number of references: %d", len(references)) + } + if references[0].Digest != "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b" { + t.Fatalf("unexpected digest in reference: %s", references[0].Digest.String()) + } + if references[0].MediaType != MediaTypeLayer { + t.Fatalf("unexpected media type in reference: %s", references[0].MediaType) + } + if references[0].Size != 153263 { + t.Fatalf("unexpected size in reference: %d", references[0].Size) + } +} diff --git a/manifests.go b/manifests.go index 7cb91ab8..1f93812d 100644 --- a/manifests.go +++ b/manifests.go @@ -25,7 +25,7 @@ type Manifest interface { // specific data is passed into the function which creates the builder. type ManifestBuilder interface { // Build creates the manifest from his builder. - Build() (Manifest, error) + Build(ctx context.Context) (Manifest, error) // References returns a list of objects which have been added to this // builder. The dependencies are returned in the order they were added,