@@ -949,6 +949,12 @@ definitions:

               type: "string"

           BaseLayer:

             type: "string"

+      Metadata:

+        type: "object"

+        properties:

+          LastTagTime:

+            type: "string"

+            format: "dateTime"

   ImageSummary:

     type: "object"

@@ -45,6 +45,12 @@ type ImageInspect struct {

 	VirtualSize     int64

 	GraphDriver     GraphDriverData

 	RootFS          RootFS

+	Metadata        ImageMetadata

+}

+

+// ImageMetadata contains engine-local data about the image

+type ImageMetadata struct {

+	LastTagTime time.Time `json:",omitempty"`

 }

 // Container contains response of Engine API:

@@ -61,6 +61,11 @@ func (daemon *Daemon) LookupImage(name string) (*types.ImageInspect, error) {

 		comment = img.History[len(img.History)-1].Comment

 	}

+	lastUpdated, err := daemon.stores[platform].imageStore.GetLastUpdated(img.ID())

+	if err != nil {

+		return nil, err

+	}

+

 	imageInspect := &types.ImageInspect{

 		ID:              img.ID().String(),

 		RepoTags:        repoTags,

@@ -79,6 +84,9 @@ func (daemon *Daemon) LookupImage(name string) (*types.ImageInspect, error) {

 		Size:            size,

 		VirtualSize:     size, // TODO: field unused, deprecate

 		RootFS:          rootFSToAPIType(img.RootFS),

+		Metadata: types.ImageMetadata{

+			LastTagTime: lastUpdated,

+		},

 	}

 	imageInspect.GraphDriver.Name = daemon.GraphDriverName(platform)

@@ -32,6 +32,9 @@ func (daemon *Daemon) TagImageWithReference(imageID image.ID, platform string, n

 		return err

 	}

+	if err := daemon.stores[platform].imageStore.SetLastUpdated(imageID); err != nil {

+		return err

+	}

 	daemon.LogImageEvent(imageID.String(), reference.FamiliarString(newTag), "tag")

 	return nil

 }

@@ -25,6 +25,7 @@ keywords: "API, Docker, rcli, REST, documentation"

 * `POST /session` is a new endpoint that can be used for running interactive long-running protocols between client and

   the daemon. This endpoint is experimental and only available if the daemon is started with experimental features

   enabled.

+* `GET /images/(name)/get` now includes an `ImageMetadata` field which contains image metadata that is local to the engine and not part of the image config.

 ## v1.30 API changes

@@ -6,6 +6,7 @@ import (

 	"runtime"

 	"strings"

 	"sync"

+	"time"

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/distribution/digestset"

@@ -23,6 +24,8 @@ type Store interface {

 	Search(partialID string) (ID, error)

 	SetParent(id ID, parent ID) error

 	GetParent(id ID) (ID, error)

+	SetLastUpdated(id ID) error

+	GetLastUpdated(id ID) (time.Time, error)

 	Children(id ID) []ID

 	Map() map[ID]*Image

 	Heads() map[ID]*Image

@@ -259,6 +262,22 @@ func (is *store) GetParent(id ID) (ID, error) {

 	return ID(d), nil // todo: validate?

 }

+// SetLastUpdated time for the image ID to the current time

+func (is *store) SetLastUpdated(id ID) error {

+	lastUpdated := []byte(time.Now().Format(time.RFC3339Nano))

+	return is.fs.SetMetadata(id.Digest(), "lastUpdated", lastUpdated)

+}

+

+// GetLastUpdated time for the image ID

+func (is *store) GetLastUpdated(id ID) (time.Time, error) {

+	bytes, err := is.fs.GetMetadata(id.Digest(), "lastUpdated")

+	if err != nil || len(bytes) == 0 {

+		// No lastUpdated time

+		return time.Time{}, nil

+	}

+	return time.Parse(time.RFC3339Nano, string(bytes))

+}

+

 func (is *store) Children(id ID) []ID {

 	is.RLock()

 	defer is.RUnlock()

@@ -149,6 +149,24 @@ func defaultImageStore(t *testing.T) (Store, func()) {

 	return store, cleanup

 }

+func TestGetAndSetLastUpdated(t *testing.T) {

+	store, cleanup := defaultImageStore(t)

+	defer cleanup()

+

+	id, err := store.Create([]byte(`{"comment": "abc1", "rootfs": {"type": "layers"}}`))

+	assert.NoError(t, err)

+

+	updated, err := store.GetLastUpdated(id)

+	assert.NoError(t, err)

+	assert.Equal(t, updated.IsZero(), true)

+

+	assert.NoError(t, store.SetLastUpdated(id))

+

+	updated, err = store.GetLastUpdated(id)

+	assert.NoError(t, err)

+	assert.Equal(t, updated.IsZero(), false)

+}

+

 type mockLayerGetReleaser struct{}

 func (ls *mockLayerGetReleaser) Get(layer.ChainID) (layer.Layer, error) {