add options to save layers and root manifest; remove unused opts (#27)

Signed-off-by: Avi Deitcher <[email protected]>

examples/advanced/advanced.go

@@ -52,11 +52,12 @@ func main() {
 
 func copyCmd() *cobra.Command {
 	var (
-		fromStr, toStr      string
-		manifestConfig      string
-		manifestAnnotations map[string]string
-		configAnnotations   map[string]string
-		opts                content.RegistryOptions
+		fromStr, toStr               string
+		manifestConfig               string
+		manifestAnnotations          map[string]string
+		configAnnotations            map[string]string
+		showRootManifest, showLayers bool
+		opts                         content.RegistryOptions
 	)
 	cmd := &cobra.Command{
 		Use:   "copy <name:tag|name@digest>",
@@ -160,7 +161,18 @@ application/vnd.unknown.config.v1+json. You can override it by setting the path,
 			if manifestConfig != "" && fromParts[0] != "files" {
 				return fmt.Errorf("only specify --manifest-config when using --from files")
 			}
-			return runCopy(ref, from, to)
+			var copyOpts []oras.CopyOpt
+			if showRootManifest {
+				copyOpts = append(copyOpts, oras.WithRootManifest(func(b []byte) {
+					fmt.Printf("root: %s\n", b)
+				}))
+			}
+			if showLayers {
+				copyOpts = append(copyOpts, oras.WithLayerDescriptors(func(layers []ocispec.Descriptor) {
+					fmt.Printf("%#v\n", layers)
+				}))
+			}
+			return runCopy(ref, from, to, copyOpts...)
 		},
 	}
 	cmd.Flags().StringVar(&fromStr, "from", "", "source type and possible options")
@@ -175,11 +187,13 @@ application/vnd.unknown.config.v1+json. You can override it by setting the path,
 	cmd.Flags().StringVar(&manifestConfig, "manifest-config", "", "path to manifest config and its media type, e.g. path/to/file.json:application/vnd.oci.image.config.v1+json")
 	cmd.Flags().StringToStringVar(&manifestAnnotations, "manifest-annotations", nil, "key-value pairs of annotations to set on the manifest, e.g. 'annotation=foo,other=bar'")
 	cmd.Flags().StringToStringVar(&configAnnotations, "config-annotations", nil, "key-value pairs of annotations to set on the config, only if config is not passed explicitly, e.g. 'annotation=foo,other=bar'")
+	cmd.Flags().BoolVarP(&showRootManifest, "show-manifest", "", false, "when copying, show the root manifest")
+	cmd.Flags().BoolVarP(&showLayers, "show-layers", "", false, "when copying, show the descriptors for the layers")
 	return cmd
 }
 
-func runCopy(ref string, from, to target.Target) error {
-	desc, err := oras.Copy(context.Background(), from, ref, to, "")
+func runCopy(ref string, from, to target.Target, copyOpts ...oras.CopyOpt) error {
+	desc, err := oras.Copy(context.Background(), from, ref, to, "", copyOpts...)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v", err)
 		os.Exit(1)

pkg/oras/copy.go

@@ -15,6 +15,7 @@ limitations under the License.
 package oras
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"sync"
@@ -105,7 +106,7 @@ func transferContent(ctx context.Context, desc ocispec.Descriptor, fetcher remot
 	}
 
 	// fetchHandler pushes to the *store*, which may or may not cache it
-	baseFetchHandler := func(p remotes.Pusher) images.HandlerFunc {
+	baseFetchHandler := func(p remotes.Pusher, f remotes.Fetcher) images.HandlerFunc {
 		return images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
 			cw, err := p.Push(ctx, desc)
 			if err != nil {
@@ -117,7 +118,7 @@ func transferContent(ctx context.Context, desc ocispec.Descriptor, fetcher remot
 			}
 			defer cw.Close()
 
-			rc, err := fetcher.Fetch(ctx, desc)
+			rc, err := f.Fetch(ctx, desc)
 			if err != nil {
 				return nil, err
 			}
@@ -133,7 +134,7 @@ func transferContent(ctx context.Context, desc ocispec.Descriptor, fetcher remot
 			defer lock.Unlock()
 			manifests = append(manifests, desc)
 		}
-		return baseFetchHandler(store)(ctx, desc)
+		return baseFetchHandler(store, fetcher)(ctx, desc)
 	})
 
 	handlers := []images.Handler{
@@ -151,14 +152,34 @@ func transferContent(ctx context.Context, desc ocispec.Descriptor, fetcher remot
 		return err
 	}
 
-	// finally, we cached all of the manifests, so push those out
+	// we cached all of the manifests, so push those out
 	// Iterate in reverse order as seen, parent always uploaded after child
 	for i := len(manifests) - 1; i >= 0; i-- {
-		_, err := baseFetchHandler(pusher)(ctx, manifests[i])
+		_, err := baseFetchHandler(pusher, store)(ctx, manifests[i])
 		if err != nil {
 			return err
 		}
 	}
+
+	// if the option to request the root manifest was passed, accommodate it
+	if opts.saveManifest != nil && len(manifests) > 0 {
+		rc, err := store.Fetch(ctx, manifests[0])
+		if err != nil {
+			return fmt.Errorf("could not get root manifest to save based on CopyOpt: %v", err)
+		}
+		defer rc.Close()
+		buf := new(bytes.Buffer)
+		if _, err := buf.ReadFrom(rc); err != nil {
+			return fmt.Errorf("unable to read data for root manifest to save based on CopyOpt: %v", err)
+		}
+		// get the root manifest from the store
+		opts.saveManifest(buf.Bytes())
+	}
+
+	// if the option to request the layers was passed, accommodate it
+	if opts.saveLayers != nil && len(descriptors) > 0 {
+		opts.saveLayers(descriptors)
+	}
 	return nil
 }
 

pkg/oras/opts.go

@@ -50,12 +50,9 @@ type copyOpts struct {
 	filterName                          func(ocispec.Descriptor) bool
 	cachedMediaTypes                    []string
 
-	config              *ocispec.Descriptor
-	configMediaType     string
-	configAnnotations   map[string]string
-	manifest            *ocispec.Descriptor
-	manifestAnnotations map[string]string
-	validateName        func(desc ocispec.Descriptor) error
+	saveManifest func([]byte)
+	saveLayers   func([]ocispec.Descriptor)
+	validateName func(desc ocispec.Descriptor) error
 
 	userAgent string
 }
@@ -215,59 +212,43 @@ func pullStatusTrack(writer io.Writer) images.Handler {
 	})
 }
 
-// WithConfig overrides the config - setting this will ignore WithConfigMediaType and WithConfigAnnotations
-func WithConfig(config ocispec.Descriptor) CopyOpt {
-	return func(o *copyOpts) error {
-		o.config = &config
-		return nil
-	}
-}
-
-// WithConfigMediaType overrides the config media type
-func WithConfigMediaType(mediaType string) CopyOpt {
-	return func(o *copyOpts) error {
-		o.configMediaType = mediaType
-		return nil
-	}
-}
-
-// WithConfigAnnotations overrides the config annotations
-func WithConfigAnnotations(annotations map[string]string) CopyOpt {
-	return func(o *copyOpts) error {
-		o.configAnnotations = annotations
-		return nil
-	}
-}
-
-// WithManifest overrides the manifest - setting this will ignore WithManifestConfigAnnotations
-func WithManifest(manifest ocispec.Descriptor) CopyOpt {
+// WithNameValidation validates the image title in the descriptor.
+// Pass nil to disable name validation.
+func WithNameValidation(validate func(desc ocispec.Descriptor) error) CopyOpt {
 	return func(o *copyOpts) error {
-		o.manifest = &manifest
+		o.validateName = validate
 		return nil
 	}
 }
 
-// WithManifestAnnotations overrides the manifest annotations
-func WithManifestAnnotations(annotations map[string]string) CopyOpt {
+// WithUserAgent set the user agent string in http communications
+func WithUserAgent(agent string) CopyOpt {
 	return func(o *copyOpts) error {
-		o.manifestAnnotations = annotations
+		o.userAgent = agent
 		return nil
 	}
 }
 
-// WithNameValidation validates the image title in the descriptor.
-// Pass nil to disable name validation.
-func WithNameValidation(validate func(desc ocispec.Descriptor) error) CopyOpt {
+// WithLayerDescriptors passes the slice of Descriptors for layers to the
+// provided func. If the passed parameter is nil, returns an error.
+func WithLayerDescriptors(save func([]ocispec.Descriptor)) CopyOpt {
 	return func(o *copyOpts) error {
-		o.validateName = validate
+		if save == nil {
+			return errors.New("layers save func must be non-nil")
+		}
+		o.saveLayers = save
 		return nil
 	}
 }
 
-// WithUserAgent set the user agent string in http communications
-func WithUserAgent(agent string) CopyOpt {
+// WithRootManifest passes the root manifest for the artifacts to the provided
+// func. If the passed parameter is nil, returns an error.
+func WithRootManifest(save func(b []byte)) CopyOpt {
 	return func(o *copyOpts) error {
-		o.userAgent = agent
+		if save == nil {
+			return errors.New("manifest save func must be non-nil")
+		}
+		o.saveManifest = save
 		return nil
 	}
 }