Add support to kustomize edit set image with both tag and digest

Currently kustomize edit set image supports images specified with tag OR
digest, but NOT both. This change allows specifying images with both tag
and digest.

kustomize/commands/edit/set/setimage.go

@@ -229,8 +229,16 @@ func parse(arg string) (types.Image, error) {
 // parseOverwrite parses the overwrite parameters
 // from the given arg into a struct
 func parseOverwrite(arg string, overwriteImage bool) (overwrite, error) {
-	// match <image>@<digest>
+	// match <image[:tag]>@<digest>
 	if d := strings.Split(arg, "@"); len(d) > 1 {
+		// match <image>:<tag>@<digest>
+		if t := strings.Split(d[0], ":"); len(t) > 1 {
+			return overwrite{
+				name:   t[0],
+				tag:    t[1],
+				digest: d[1],
+			}, nil
+		}
 		return overwrite{
 			name:   d[0],
 			digest: d[1],

kustomize/commands/edit/set/setimage_test.go

@@ -96,6 +96,19 @@ func TestSetImage(t *testing.T) {
 					"  name: image1",
 				}},
 		},
+		{
+			description: "image with tag and digest",
+			given: given{
+				args: []string{"org/image1:tag@sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3"},
+			},
+			expected: expected{
+				fileOutput: []string{
+					"images:",
+					"- digest: sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3",
+					"  name: org/image1",
+					"  newTag: tag",
+				}},
+		},
 		{
 			description: "<image>=<image>",
 			given: given{