Fix error when image has already been pulled

CRI and containerd APIs disagree about the registry names - CRI supports
index.docker.io as an alias for docker.io, while containerd does not.
Use the actual stored RepoTag to determine what image to ask containerd for.

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

pkg/agent/containerd/containerd.go

@@ -353,19 +353,23 @@ func prePullImages(ctx context.Context, client *containerd.Client, imageClient r
 	scanner := bufio.NewScanner(imageList)
 	for scanner.Scan() {
 		name := strings.TrimSpace(scanner.Text())
-		if _, err := imageClient.ImageStatus(ctx, &runtimeapi.ImageStatusRequest{
+
+		if status, err := imageClient.ImageStatus(ctx, &runtimeapi.ImageStatusRequest{
 			Image: &runtimeapi.ImageSpec{
 				Image: name,
 			},
-		}); err == nil {
+		}); err == nil && status.Image != nil && len(status.Image.RepoTags) > 0 {
 			logrus.Infof("Image %s has already been pulled", name)
-			if image, err := imageService.Get(ctx, name); err != nil {
-				errs = append(errs, err)
-			} else {
-				images = append(images, image)
+			for _, tag := range status.Image.RepoTags {
+				if image, err := imageService.Get(ctx, tag); err != nil {
+					errs = append(errs, err)
+				} else {
+					images = append(images, image)
+				}
 			}
 			continue
 		}
+
 		logrus.Infof("Pulling image %s", name)
 		if _, err := imageClient.PullImage(ctx, &runtimeapi.PullImageRequest{
 			Image: &runtimeapi.ImageSpec{