feat: add --skip-verify flag to nerdctl save command

cmd/nerdctl/image/image_save.go

@@ -42,6 +42,7 @@ func SaveCommand() *cobra.Command {
 		SilenceErrors:     true,
 	}
 	cmd.Flags().StringP("output", "o", "", "Write to a file, instead of STDOUT")
+	cmd.Flags().Bool("skip-verify", false, "Skip verification of remote layers. Use this when the original registry is unavailable but you have all layers locally.")
 
 	// #region platform flags
 	// platform is defined as StringSlice, not StringArray, to allow specifying "--platform=amd64,arm64"
@@ -67,11 +68,16 @@ func saveOptions(cmd *cobra.Command) (types.ImageSaveOptions, error) {
 	if err != nil {
 		return types.ImageSaveOptions{}, err
 	}
+	skipVerify, err := cmd.Flags().GetBool("skip-verify")
+	if err != nil {
+		return types.ImageSaveOptions{}, err
+	}
 
 	return types.ImageSaveOptions{
 		GOptions:     globalOptions,
 		AllPlatforms: allPlatforms,
 		Platform:     platform,
+		SkipVerify:   skipVerify,
 	}, err
 }
 

cmd/nerdctl/image/image_save_test.go

@@ -66,6 +66,23 @@ func TestSaveContent(t *testing.T) {
 	testCase.Run(t)
 }
 
+func TestSaveSkipVerify(t *testing.T) {
+	nerdtest.Setup()
+
+	testCase := &test.Case{
+		Require: require.Not(require.Windows),
+		Setup: func(data test.Data, helpers test.Helpers) {
+			helpers.Ensure("pull", "--quiet", testutil.CommonImage)
+		},
+		Command: func(data test.Data, helpers test.Helpers) test.TestableCommand {
+			return helpers.Command("save", "--skip-verify", "-o", filepath.Join(data.Temp().Path(), "out.tar"), testutil.CommonImage)
+		},
+		Expected: test.Expects(0, nil, nil),
+	}
+
+	testCase.Run(t)
+}
+
 func TestSave(t *testing.T) {
 	testCase := nerdtest.Setup()
 

pkg/api/types/image_types.go

@@ -274,6 +274,8 @@ type ImageSaveOptions struct {
 	AllPlatforms bool
 	// Export content for a specific platform
 	Platform []string
+	// Skip verification of remote layers
+	SkipVerify bool
 }
 
 // ImageSignOptions contains options for signing an image. It contains options from

pkg/cmd/image/save.go

@@ -22,6 +22,7 @@ import (
 
 	containerd "github.com/containerd/containerd/v2/client"
 	"github.com/containerd/containerd/v2/core/images/archive"
+	"github.com/containerd/log"
 
 	"github.com/containerd/nerdctl/v2/pkg/api/types"
 	"github.com/containerd/nerdctl/v2/pkg/idutil/imagewalker"
@@ -50,9 +51,13 @@ func Save(ctx context.Context, client *containerd.Client, images []string, optio
 			}
 
 			// Ensure all the layers are here: https://github.com/containerd/nerdctl/issues/3425
-			err = EnsureAllContent(ctx, client, found.Image.Name, platMC, options.GOptions)
-			if err != nil {
-				return err
+			if !options.SkipVerify {
+				err = EnsureAllContent(ctx, client, found.Image.Name, platMC, options.GOptions)
+				if err != nil {
+					return err
+				}
+			} else {
+				log.G(ctx).Info("Skipping remote layer verification (--skip-verify enabled)")
 			}
 
 			imgName := found.Image.Name

pkg/cmd/image/tag.go

@@ -23,8 +23,7 @@
 	containerd "github.com/containerd/containerd/v2/client"
 	"github.com/containerd/containerd/v2/core/images"
 	"github.com/containerd/errdefs"
 	"github.com/containerd/log"
-
 	"github.com/containerd/nerdctl/v2/pkg/api/types"
 	"github.com/containerd/nerdctl/v2/pkg/idutil/imagewalker"
 	"github.com/containerd/nerdctl/v2/pkg/platformutil"
@@ -70,8 +69,8 @@
 
 	err = EnsureAllContent(ctx, client, srcName, platMC, options.GOptions)
 	if err != nil {
-		log.G(ctx).Warn("Unable to fetch missing layers before committing. " +
-			"If you try to save or push this image, it might fail. See https://github.com/containerd/nerdctl/issues/3439.")
+		log.G(ctx).Warn("Unable to verify all image layers are present locally (this does not affect the tag operation). " +
+			"If you later save or push this image, some layers may need to be re-downloaded. See https://github.com/containerd/nerdctl/issues/3439.")
 	}
 
 	img, err := imageService.Get(ctx, srcName)
@@ -92,5 +91,8 @@
 			return err
 		}
 	}
+
+	// Log successful tag operation
+	log.G(ctx).Infof("Successfully tagged %s", parsedReference.String())
 	return nil
 }