api: Sort images by Created.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>

api/handlers.go

@@ -181,6 +181,7 @@ func getImagesJSON(c *context, w http.ResponseWriter, r *http.Request) {
 
 		images = append(images, image)
 	}
+	sort.Sort(sort.Reverse(ImageSorter(images)))
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(images)
 }

api/sorter.go

@@ -1,6 +1,9 @@
 package api
 
-import "github.com/docker/swarm/cluster"
+import (
+	"github.com/docker/swarm/cluster"
+	"github.com/samalba/dockerclient"
+)
 
 // ContainerSorter implements the Sort interface to sort Docker containers.
 // It is not guaranteed to be a stable sort.
@@ -21,3 +24,23 @@ func (s ContainerSorter) Swap(i, j int) {
 func (s ContainerSorter) Less(i, j int) bool {
 	return s[i].Info.Created < s[j].Info.Created
 }
+
+// ImageSorter implements the Sort interface to sort Docker Images.
+// It is not guaranteed to be a stable sort.
+type ImageSorter []dockerclient.Image
+
+// Len returns the number of images to be sorted.
+func (s ImageSorter) Len() int {
+	return len(s)
+}
+
+// Swap exchanges the container elements with indices i and j.
+func (s ImageSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+// Less reports whether the Image with index i should sort before the Image with index j.
+// Images are sorted chronologically by when they were created.
+func (s ImageSorter) Less(i, j int) bool {
+	return s[i].Created < s[j].Created
+}