Set Created to 0001-01-01T00:00:00Z on older API versions

This matches the prior behavior before 2a6ff3c24f.

This also updates the Swagger documentation for the current version to note that the field might be the empty string and what that means.

Signed-off-by: Tianon Gravi <admwiggin@gmail.com>

api/server/router/image/image_routes.go

@@ -299,6 +299,12 @@ func (ir *imageRouter) getImagesByName(ctx context.Context, w http.ResponseWrite
 	version := httputils.VersionFromContext(ctx)
 	if versions.LessThan(version, "1.44") {
 		imageInspect.VirtualSize = imageInspect.Size //nolint:staticcheck // ignore SA1019: field is deprecated, but still set on API < v1.44.
+
+		if imageInspect.Created == "" {
+			// backwards compatibility for Created not existing returning "0001-01-01T00:00:00Z"
+			// https://github.com/moby/moby/issues/47368
+			imageInspect.Created = time.Time{}.Format(time.RFC3339Nano)
+		}
 	}
 	return httputils.WriteJSON(w, http.StatusOK, imageInspect)
 }

api/swagger.yaml

@@ -1746,7 +1746,7 @@ definitions:
       Created:
         description: |
           Date and time at which the image was created, formatted in
-          [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format with nano-seconds.
+          [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format with nano-seconds, or empty if the field was not set in the image config.
         type: "string"
         x-nullable: false
         example: "2022-02-04T21:20:12.497794809Z"

docs/api/v1.44.yaml

@@ -1742,7 +1742,7 @@ definitions:
       Created:
         description: |
           Date and time at which the image was created, formatted in
-          [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format with nano-seconds.
+          [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt) format with nano-seconds, or empty if the field was not set in the image config.
         type: "string"
         x-nullable: false
         example: "2022-02-04T21:20:12.497794809Z"