vendor: update oci image spec dependency

Signed-off-by: Stephen J Day <stephen.day@docker.com>

vendor.conf

@@ -55,7 +55,7 @@ github.com/opencontainers/go-digest 21dfd564fd89c944783d00d069f33e3e7123c448
 # sys/unix; master as of 1/12/2017
 golang.org/x/sys/unix d75a52659825e75fff6158388dddc6a5b04f9ba5
 # image-spec master as of 1/17/2017
-github.com/opencontainers/image-spec 0ff14aabcda3b2ee62621174f1b29fc157bdf335
+github.com/opencontainers/image-spec a431dbcf6a74fca2e0e040b819a836dbe3fb23ca
 # continuity master as of 2/1/2017
 github.com/stevvooe/continuity 1530f13d23b34e2ccaf33881fefecc7e28e3577b
 # sync master as of 12/5/2016

vendor/github.com/opencontainers/image-spec/README.md

@@ -9,6 +9,9 @@ The OCI Image Format project creates and maintains the software shipping contain
 
 The specification can be found [here](spec.md).
 
+This repository also provides [Go types](specs-go), [intra-blob validation tooling, and JSON Schema](schema).
+The Go types and validation should be compatible with the current Go release; earlier Go releases are not supported.
+
 Additional documentation about how this group operates:
 
 - [Code of Conduct](https://github.com/opencontainers/tob/blob/d2f9d68c1332870e40693fe077d311e0742bc73d/code-of-conduct.md)
@@ -16,7 +19,7 @@ Additional documentation about how this group operates:
 - [Releases](RELEASES.md)
 - [Project Documentation](project.md)
 
-The _optional_ and _base_ layers of all OCI projects are tracked in the [OCI Scope Table](https://www.opencontainers.org/governance/oci-scope-table).
+The _optional_ and _base_ layers of all OCI projects are tracked in the [OCI Scope Table](https://www.opencontainers.org/about/oci-scope-table).
 
 ## Running an OCI Image
 
@@ -36,7 +39,7 @@ To support this UX the OCI Image Format contains sufficient information to launc
 
 **Q: Why doesn't this project mention distribution?**
 
-A: Distribution, for example using HTTP as both Docker v2.2 and AppC do today, is currently out of scope on the [OCI Scope Table](https://www.opencontainers.org/governance/oci-scope-table).
+A: Distribution, for example using HTTP as both Docker v2.2 and AppC do today, is currently out of scope on the [OCI Scope Table](https://www.opencontainers.org/about/oci-scope-table).
 There has been [some discussion on the TOB mailing list](https://groups.google.com/a/opencontainers.org/d/msg/tob/A3JnmI-D-6Y/tLuptPDHAgAJ) to make distribution an optional layer, but this topic is a work in progress.
 
 **Q: Why a new project?**

vendor/github.com/opencontainers/image-spec/specs-go/v1/config.go

@@ -14,6 +14,8 @@
 
 package v1
 
+import "time"
+
 // ImageConfig defines the execution parameters which should be used as a base when running a container using an image.
 type ImageConfig struct {
 	// User defines the username or UID which the process in the container should run as.
@@ -52,8 +54,8 @@ type RootFS struct {
 
 // History describes the history of a layer.
 type History struct {
-	// Created is the creation time.
-	Created string `json:"created,omitempty"`
+	// Created is the combined date and time at which the layer was created, formatted as defined by RFC 3339, section 5.6.
+	Created time.Time `json:"created,omitempty"`
 
 	// CreatedBy is the command which created the layer.
 	CreatedBy string `json:"created_by,omitempty"`
@@ -69,9 +71,10 @@ type History struct {
 }
 
 // Image is the JSON structure which describes some basic information about the image.
+// This provides the `application/vnd.oci.image.config.v1+json` mediatype when marshalled to JSON.
 type Image struct {
-	// Created defines an ISO-8601 formatted combined date and time at which the image was created.
-	Created string `json:"created,omitempty"`
+	// Created is the combined date and time at which the image was created, formatted as defined by RFC 3339, section 5.6.
+	Created time.Time `json:"created,omitempty"`
 
 	// Author defines the name and/or email address of the person or entity which created and is responsible for maintaining the image.
 	Author string `json:"author,omitempty"`

vendor/github.com/opencontainers/image-spec/specs-go/v1/descriptor.go

@@ -14,17 +14,23 @@
 
 package v1
 
+import digest "github.com/opencontainers/go-digest"
+
 // Descriptor describes the disposition of targeted content.
+// This structure provides `application/vnd.oci.descriptor.v1+json` mediatype when marshalled to JSON
 type Descriptor struct {
-	// MediaType contains the MIME type of the referenced object.
-	MediaType string `json:"mediaType"`
+	// MediaType is the media type of the object this schema refers to.
+	MediaType string `json:"mediaType,omitempty"`
 
 	// Digest is the digest of the targeted content.
-	Digest string `json:"digest"`
+	Digest digest.Digest `json:"digest"`
 
 	// Size specifies the size in bytes of the blob.
 	Size int64 `json:"size"`
 
 	// URLs specifies a list of URLs from which this object MAY be downloaded
 	URLs []string `json:"urls,omitempty"`
+
+	// Annotations contains arbitrary metadata relating to the targeted content.
+	Annotations map[string]string `json:"annotations,omitempty"`
 }

vendor/github.com/opencontainers/image-spec/specs-go/v1/image_index.go

@@ -50,13 +50,14 @@ type ManifestDescriptor struct {
 	Platform Platform `json:"platform"`
 }
 
-// ManifestList  references manifests for various platforms.
-type ManifestList struct {
+// ImageIndex references manifests for various platforms.
+// This structure provides `application/vnd.oci.image.index.v1+json` mediatype when marshalled to JSON.
+type ImageIndex struct {
 	specs.Versioned
 
 	// Manifests references platform specific manifests.
 	Manifests []ManifestDescriptor `json:"manifests"`
 
-	// Annotations contains arbitrary metadata for the manifest list.
+	// Annotations contains arbitrary metadata for the image index.
 	Annotations map[string]string `json:"annotations,omitempty"`
 }

vendor/github.com/opencontainers/image-spec/specs-go/v1/layout.go

@@ -14,18 +14,15 @@
 
 package v1
 
-import "regexp"
-
-// ImageLayoutVersion is the version of ImageLayout
-const ImageLayoutVersion = "1.0.0"
+const (
+	// ImageLayoutFile is the file name of oci image layout file
+	ImageLayoutFile = "oci-layout"
+	// ImageLayoutVersion is the version of ImageLayout
+	ImageLayoutVersion = "1.0.0"
+)
 
 // ImageLayout is the structure in the "oci-layout" file, found in the root
 // of an OCI Image-layout directory.
 type ImageLayout struct {
 	Version string `json:"imageLayoutVersion"`
 }
-
-var (
-	// RefsRegexp matches requirement of image-layout 'refs' charset.
-	RefsRegexp = regexp.MustCompile(`^[a-zA-Z0-9-._]+$`)
-)

vendor/github.com/opencontainers/image-spec/specs-go/v1/manifest.go

@@ -16,7 +16,7 @@ package v1
 
 import "github.com/opencontainers/image-spec/specs-go"
 
-// Manifest defines a schema2 manifest
+// Manifest provides `application/vnd.oci.image.manifest.v1+json` mediatype structure when marshalled to JSON.
 type Manifest struct {
 	specs.Versioned
 
@@ -27,6 +27,6 @@ type Manifest struct {
 	// Layers is an indexed list of layers referenced by the manifest.
 	Layers []Descriptor `json:"layers"`
 
-	// Annotations contains arbitrary metadata for the manifest list.
+	// Annotations contains arbitrary metadata for the manifest.
 	Annotations map[string]string `json:"annotations,omitempty"`
 }

vendor/github.com/opencontainers/image-spec/specs-go/v1/mediatype.go

@@ -21,15 +21,24 @@ const (
 	// MediaTypeImageManifest specifies the media type for an image manifest.
 	MediaTypeImageManifest = "application/vnd.oci.image.manifest.v1+json"
 
-	// MediaTypeImageManifestList specifies the media type for an image manifest list.
-	MediaTypeImageManifestList = "application/vnd.oci.image.manifest.list.v1+json"
+	// MediaTypeImageIndex specifies the media type for an image index.
+	MediaTypeImageIndex = "application/vnd.oci.image.index.v1+json"
 
 	// MediaTypeImageLayer is the media type used for layers referenced by the manifest.
-	MediaTypeImageLayer = "application/vnd.oci.image.layer.v1.tar+gzip"
+	MediaTypeImageLayer = "application/vnd.oci.image.layer.v1.tar"
+
+	// MediaTypeImageLayerGzip is the media type used for gzipped layers
+	// referenced by the manifest.
+	MediaTypeImageLayerGzip = "application/vnd.oci.image.layer.v1.tar+gzip"
 
 	// MediaTypeImageLayerNonDistributable is the media type for layers referenced by
 	// the manifest but with distribution restrictions.
-	MediaTypeImageLayerNonDistributable = "application/vnd.oci.image.layer.nondistributable.v1.tar+gzip"
+	MediaTypeImageLayerNonDistributable = "application/vnd.oci.image.layer.nondistributable.v1.tar"
+
+	// MediaTypeImageLayerNonDistributableGzip is the media type for
+	// gzipped layers referenced by the manifest but with distribution
+	// restrictions.
+	MediaTypeImageLayerNonDistributableGzip = "application/vnd.oci.image.layer.nondistributable.v1.tar+gzip"
 
 	// MediaTypeImageConfig specifies the media type for the image configuration.
 	MediaTypeImageConfig = "application/vnd.oci.image.config.v1+json"

vendor/github.com/opencontainers/image-spec/specs-go/version.go

@@ -25,7 +25,7 @@ const (
 	VersionPatch = 0
 
 	// VersionDev indicates development branch. Releases will be empty string.
-	VersionDev = "-rc3-dev"
+	VersionDev = "-rc4-dev"
 )
 
 // Version is the specification version that the package types support.

vendor/github.com/opencontainers/image-spec/specs-go/versioned.go

@@ -20,7 +20,4 @@ package specs
 type Versioned struct {
 	// SchemaVersion is the image manifest schema that this image follows
 	SchemaVersion int `json:"schemaVersion"`
-
-	// MediaType is the media type of this schema.
-	MediaType string `json:"mediaType"`
 }