feat: implement local puller and pusher

cmd/crane/cmd/append.go

@@ -117,6 +117,5 @@ container image.`,
 
 	appendCmd.MarkFlagsMutuallyExclusive("oci-empty-base", "base")
 	appendCmd.MarkFlagRequired("new_tag")
-	appendCmd.MarkFlagRequired("new_layer")
 	return appendCmd
 }

cmd/crane/cmd/export.go

@@ -70,20 +70,14 @@ func NewCmdExport(options *[]crane.Option) *cobra.Command {
 					return fmt.Errorf("reading tarball from stdin: %w", err)
 				}
 			} else {
-				desc, err := crane.Get(src, *options...)
+				desc, err := crane.Artifact(src, *options...)
 				if err != nil {
 					return fmt.Errorf("pulling %s: %w", src, err)
 				}
-				if desc.MediaType.IsSchema1() {
-					img, err = desc.Schema1()
-					if err != nil {
-						return fmt.Errorf("pulling schema 1 image %s: %w", src, err)
-					}
-				} else {
-					img, err = desc.Image()
-					if err != nil {
-						return fmt.Errorf("pulling Image %s: %w", src, err)
-					}
+				var ok bool
+				img, ok = desc.(v1.Image)
+				if !ok {
+					return fmt.Errorf("pulling schema 1 image %s: %w", src, err)
 				}
 			}
 

cmd/crane/cmd/flatten.go

@@ -91,26 +91,23 @@ func NewCmdFlatten(options *[]crane.Option) *cobra.Command {
 }
 
 func flatten(ref name.Reference, repo name.Repository, use string, o crane.Options) (partial.Describable, error) {
-	desc, err := remote.Get(ref, o.Remote...)
+	desc, err := remote.Artifact(ref, o.Remote...)
 	if err != nil {
 		return nil, fmt.Errorf("pulling %s: %w", ref, err)
 	}
 
-	if desc.MediaType.IsIndex() {
-		idx, err := desc.ImageIndex()
-		if err != nil {
-			return nil, err
-		}
+	if idx, ok := desc.(v1.ImageIndex); ok {
 		return flattenIndex(idx, repo, use, o)
-	} else if desc.MediaType.IsImage() {
-		img, err := desc.Image()
-		if err != nil {
-			return nil, err
-		}
+	} else if img, ok := desc.(v1.Image); ok {
 		return flattenImage(img, repo, use, o)
 	}
 
-	return nil, fmt.Errorf("can't flatten %s", desc.MediaType)
+	mt, err := desc.MediaType()
+	if err != nil {
+		return nil, err
+	}
+
+	return nil, fmt.Errorf("can't flatten %s", mt)
 }
 
 func push(flat partial.Describable, ref name.Reference, o crane.Options) error {

cmd/crane/cmd/index.go

@@ -70,16 +70,19 @@ func NewCmdIndexFilter(options *[]crane.Option) *cobra.Command {
 			if err != nil {
 				return err
 			}
-			desc, err := remote.Get(ref, o.Remote...)
+			desc, err := remote.Artifact(ref, o.Remote...)
 			if err != nil {
 				return fmt.Errorf("pulling %s: %w", baseRef, err)
 			}
-			if !desc.MediaType.IsIndex() {
-				return fmt.Errorf("expected %s to be an index, got %q", baseRef, desc.MediaType)
-			}
-			base, err := desc.ImageIndex()
+			mt, err := desc.MediaType()
 			if err != nil {
-				return nil
+				return err
+			}
+
+			var base v1.ImageIndex
+			var ok bool
+			if base, ok = desc.(v1.ImageIndex); !ok {
+				return fmt.Errorf("expected %s to be an index, got %q", baseRef, mt)
 			}
 
 			idx := filterIndex(base, platforms.platforms)
@@ -142,6 +145,7 @@ The platform for appended manifests is inferred from the config file or omitted
 			var (
 				base v1.ImageIndex
 				err  error
+				ok   bool
 				ref  name.Reference
 			)
 
@@ -160,17 +164,13 @@ The platform for appended manifests is inferred from the config file or omitted
 				if err != nil {
 					return err
 				}
-				desc, err := remote.Get(ref, o.Remote...)
+				desc, err := remote.Artifact(ref, o.Remote...)
 				if err != nil {
 					return fmt.Errorf("pulling %s: %w", baseRef, err)
 				}
-				if !desc.MediaType.IsIndex() {
+				if base, ok = desc.(v1.ImageIndex); !ok {
 					return fmt.Errorf("expected %s to be an index, got %q", baseRef, desc.MediaType)
 				}
-				base, err = desc.ImageIndex()
-				if err != nil {
-					return err
-				}
 			}
 
 			adds := make([]mutate.IndexAddendum, 0, len(newManifests))
@@ -180,16 +180,11 @@ The platform for appended manifests is inferred from the config file or omitted
 				if err != nil {
 					return err
 				}
-				desc, err := remote.Get(ref, o.Remote...)
+				desc, err := remote.Artifact(ref, o.Remote...)
 				if err != nil {
 					return err
 				}
-				if desc.MediaType.IsImage() {
-					img, err := desc.Image()
-					if err != nil {
-						return err
-					}
-
+				if img, ok := desc.(v1.Image); ok {
 					cf, err := img.ConfigFile()
 					if err != nil {
 						return err
@@ -203,11 +198,7 @@ The platform for appended manifests is inferred from the config file or omitted
 						Add:        img,
 						Descriptor: *newDesc,
 					})
-				} else if desc.MediaType.IsIndex() {
-					idx, err := desc.ImageIndex()
-					if err != nil {
-						return err
-					}
+				} else if idx, ok := desc.(v1.ImageIndex); ok {
 					if flatten {
 						im, err := idx.IndexManifest()
 						if err != nil {

cmd/crane/cmd/root.go

@@ -29,6 +29,8 @@
 	"github.com/google/go-containerregistry/internal/cmd"
 	"github.com/google/go-containerregistry/pkg/crane"
 	"github.com/google/go-containerregistry/pkg/logs"
+	"github.com/google/go-containerregistry/pkg/v1/layout"
+	"github.com/google/go-containerregistry/pkg/v1/local"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
 	"github.com/spf13/cobra"
 )
@@ -47,6 +49,7 @@
 	insecure := false
 	ndlayers := false
 	platform := &platformValue{}
+	uselocal := ""
 
 	wt := &warnTransport{}
 
@@ -68,6 +71,10 @@
 			if ndlayers {
 				options = append(options, crane.WithNondistributable())
 			}
+			if uselocal != "" {
+				p, _ := layout.FromPath(uselocal)
+				options = append(options, crane.WithPuller(local.NewPuller(p)), crane.WithPusher(local.NewPusher(p)))
+			}
 			if Version != "" {
 				binary := "crane"
 				if len(os.Args[0]) != 0 {
@@ -137,7 +144,8 @@
 	root.PersistentFlags().BoolVar(&insecure, "insecure", false, "Allow image references to be fetched without TLS")
 	root.PersistentFlags().BoolVar(&ndlayers, "allow-nondistributable-artifacts", false, "Allow pushing non-distributable (foreign) layers")
 	root.PersistentFlags().Var(platform, "platform", "Specifies the platform in the form os/arch[/variant][:osversion] (e.g. linux/amd64).")
-
+	root.PersistentFlags().StringVar(&uselocal, "local", "", "Use a local oci-layout as remote registry")
+	root.PersistentFlags().MarkHidden("local")
 	return root
 }
 

cmd/crane/cmd/validate.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 
 	"github.com/google/go-containerregistry/pkg/crane"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/tarball"
 	"github.com/google/go-containerregistry/pkg/v1/validate"
 	"github.com/spf13/cobra"
@@ -52,7 +53,7 @@ func NewCmdValidate(options *[]crane.Option) *cobra.Command {
 			}
 
 			if remoteRef != "" {
-				rmt, err := crane.Get(remoteRef, *options...)
+				rmt, err := crane.Artifact(remoteRef, *options...)
 				if err != nil {
 					return fmt.Errorf("failed to read image %s: %w", remoteRef, err)
 				}
@@ -63,24 +64,27 @@ func NewCmdValidate(options *[]crane.Option) *cobra.Command {
 				if fast {
 					opt = append(opt, validate.Fast)
 				}
-				if rmt.MediaType.IsIndex() && o.Platform == nil {
-					idx, err := rmt.ImageIndex()
-					if err != nil {
-						return fmt.Errorf("reading index: %w", err)
-					}
+				var (
+					idx v1.ImageIndex
+					img v1.Image
+					ok  bool
+				)
+				if idx, ok = rmt.(v1.ImageIndex); ok && o.Platform == nil {
 					if err := validate.Index(idx, opt...); err != nil {
 						fmt.Fprintf(cmd.OutOrStdout(), "FAIL: %s: %v\n", remoteRef, err)
 						return err
 					}
-				} else {
-					img, err := rmt.Image()
-					if err != nil {
-						return fmt.Errorf("reading image: %w", err)
-					}
+				} else if img, ok = rmt.(v1.Image); ok {
 					if err := validate.Image(img, opt...); err != nil {
 						fmt.Fprintf(cmd.OutOrStdout(), "FAIL: %s: %v\n", remoteRef, err)
 						return err
 					}
+				} else {
+					mt, err := rmt.MediaType()
+					if err != nil {
+						return err
+					}
+					return fmt.Errorf("failed to validate ref %s: uknown media type %s", remoteRef, mt)
 				}
 				fmt.Fprintf(cmd.OutOrStdout(), "PASS: %s\n", remoteRef)
 			}

internal/cmd/edit.go

@@ -280,14 +280,19 @@ func editManifest(in io.Reader, out io.Writer, src string, dst string, mt string
 		return nil, err
 	}
 
-	desc, err := remote.Get(ref, o.Remote...)
+	desc, err := remote.Artifact(ref, o.Remote...)
+	if err != nil {
+		return nil, err
+	}
+
+	manifest, err := desc.RawManifest()
 	if err != nil {
 		return nil, err
 	}
 
 	var edited []byte
 	if interactive(in, out) {
-		edited, err = editor.Edit(bytes.NewReader(desc.Manifest), ".json")
+		edited, err = editor.Edit(bytes.NewReader(manifest), ".json")
 		if err != nil {
 			return nil, err
 		}
@@ -317,7 +322,11 @@ func editManifest(in io.Reader, out io.Writer, src string, dst string, mt string
 
 	if mt == "" {
 		// If --media-type is unset, use Content-Type by default.
-		mt = string(desc.MediaType)
+		mediatype, err := desc.MediaType()
+		if err != nil {
+			return nil, err
+		}
+		mt = string(mediatype)
 
 		// If document contains mediaType, default to that.
 		wmt := withMediaType{}

pkg/crane/copy.go

@@ -69,21 +69,15 @@ func Copy(src, dst string, opt ...Option) error {
 	}
 
 	logs.Progress.Printf("Copying from %v to %v", srcRef, dstRef)
-	desc, err := puller.Get(o.ctx, srcRef)
+	desc, err := puller.Artifact(o.ctx, srcRef)
 	if err != nil {
 		return fmt.Errorf("fetching %q: %w", src, err)
 	}
 
 	if o.Platform == nil {
 		return pusher.Push(o.ctx, dstRef, desc)
 	}
-
-	// If platform is explicitly set, don't copy the whole index, just the appropriate image.
-	img, err := desc.Image()
-	if err != nil {
-		return err
-	}
-	return pusher.Push(o.ctx, dstRef, img)
+	return pusher.Push(o.ctx, dstRef, desc)
 }
 
 // CopyRepository copies every tag from src to dst.
@@ -166,7 +160,7 @@ func CopyRepository(src, dst string, opt ...Option) error {
 				}
 
 				logs.Progress.Printf("Fetching %s", srcTag)
-				desc, err := puller.Get(ctx, srcTag)
+				desc, err := puller.Artifact(ctx, srcTag)
 				if err != nil {
 					return err
 				}

pkg/crane/digest.go

@@ -14,26 +14,19 @@
 
 package crane
 
-import "github.com/google/go-containerregistry/pkg/logs"
+import (
+	"github.com/google/go-containerregistry/pkg/logs"
+)
 
 // Digest returns the sha256 hash of the remote image at ref.
 func Digest(ref string, opt ...Option) (string, error) {
 	o := makeOptions(opt...)
 	if o.Platform != nil {
-		desc, err := getManifest(ref, opt...)
+		desc, err := getArtifact(ref, opt...)
 		if err != nil {
 			return "", err
 		}
-		if !desc.MediaType.IsIndex() {
-			return desc.Digest.String(), nil
-		}
-
-		// TODO: does not work for indexes which contain schema v1 manifests
-		img, err := desc.Image()
-		if err != nil {
-			return "", err
-		}
-		digest, err := img.Digest()
+		digest, err := desc.Digest()
 		if err != nil {
 			return "", err
 		}
@@ -42,11 +35,15 @@ func Digest(ref string, opt ...Option) (string, error) {
 	desc, err := Head(ref, opt...)
 	if err != nil {
 		logs.Warn.Printf("HEAD request failed, falling back on GET: %v", err)
-		rdesc, err := getManifest(ref, opt...)
+		rdesc, err := getArtifact(ref, opt...)
+		if err != nil {
+			return "", err
+		}
+		hash, err := rdesc.Digest()
 		if err != nil {
 			return "", err
 		}
-		return rdesc.Digest.String(), nil
+		return hash.String(), nil
 	}
 	return desc.Digest.String(), nil
 }