feat: support warning in remote targets

cmd/oras/internal/option/remote.go

@@ -25,6 +25,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"sync"
 
 	credentials "github.com/oras-project/oras-credentials-go"
 	"github.com/spf13/pflag"
@@ -53,6 +54,7 @@ type Remote struct {
 	distributionSpec      distributionSpec
 	headerFlags           []string
 	headers               http.Header
+	warned                sync.Map
 }
 
 // EnableDistributionSpecFlag set distribution specification flag as applicable.
@@ -248,21 +250,27 @@ func (opts *Remote) Credential() auth.Credential {
 }
 
 // NewRegistry assembles a oras remote registry.
-func (opts *Remote) NewRegistry(hostname string, common Common) (reg *remote.Registry, err error) {
+func (opts *Remote) NewRegistry(hostname string, warn func(...any), common Common) (reg *remote.Registry, err error) {
 	reg, err = remote.NewRegistry(hostname)
 	if err != nil {
 		return nil, err
 	}
 	hostname = reg.Reference.Registry
 	reg.PlainHTTP = opts.isPlainHttp(hostname)
+
+	reg.HandleWarning = func(warning remote.Warning) {
+		if _, loaded := opts.warned.LoadOrStore(warning.WarningValue, true); !loaded {
+			warn(warning.Text)
+		}
+	}
 	if reg.Client, err = opts.authClient(hostname, common.Debug); err != nil {
 		return nil, err
 	}
 	return
 }
 
 // NewRepository assembles a oras remote repository.
-func (opts *Remote) NewRepository(reference string, common Common) (repo *remote.Repository, err error) {
+func (opts *Remote) NewRepository(reference string, warn func(...any), common Common) (repo *remote.Repository, err error) {
 	repo, err = remote.NewRepository(reference)
 	if err != nil {
 		return nil, err
@@ -273,6 +281,11 @@ func (opts *Remote) NewRepository(reference string, common Common) (repo *remote
 	if repo.Client, err = opts.authClient(hostname, common.Debug); err != nil {
 		return nil, err
 	}
+	repo.HandleWarning = func(warning remote.Warning) {
+		if _, loaded := opts.warned.LoadOrStore(warning.WarningValue, true); !loaded {
+			warn(hostname, warning.Text)
+		}
+	}
 	if opts.distributionSpec.referrersAPI != nil {
 		if err := repo.SetReferrersCapability(*opts.distributionSpec.referrersAPI); err != nil {
 			return nil, err

cmd/oras/internal/option/remote_test.go

@@ -180,7 +180,7 @@ func TestRemote_NewRegistry(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	reg, err := opts.NewRegistry(uri.Host, opts.Common)
+	reg, err := opts.NewRegistry(uri.Host, nil, opts.Common)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -208,7 +208,7 @@ func TestRemote_NewRepository(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	repo, err := opts.NewRepository(uri.Host+"/"+testRepo, opts.Common)
+	repo, err := opts.NewRepository(uri.Host+"/"+testRepo, nil, opts.Common)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -255,7 +255,7 @@ func TestRemote_NewRepository_Retry(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	repo, err := opts.NewRepository(uri.Host+"/"+testRepo, opts.Common)
+	repo, err := opts.NewRepository(uri.Host+"/"+testRepo, nil, opts.Common)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

cmd/oras/internal/option/target.go

@@ -111,7 +111,7 @@ func parseOCILayoutReference(raw string) (path string, ref string, err error) {
 }
 
 // NewTarget generates a new target based on opts.
-func (opts *Target) NewTarget(common Common) (oras.GraphTarget, error) {
+func (opts *Target) NewTarget(common Common, warn func(...any)) (oras.GraphTarget, error) {
 	switch opts.Type {
 	case TargetTypeOCILayout:
 		var err error
@@ -121,7 +121,7 @@ func (opts *Target) NewTarget(common Common) (oras.GraphTarget, error) {
 		}
 		return oci.New(opts.Path)
 	case TargetTypeRemote:
-		repo, err := opts.NewRepository(opts.RawReference, common)
+		repo, err := opts.NewRepository(opts.RawReference, warn, common)
 		if err != nil {
 			return nil, err
 		}
@@ -142,7 +142,7 @@ type ReadOnlyGraphTagFinderTarget interface {
 }
 
 // NewReadonlyTargets generates a new read only target based on opts.
-func (opts *Target) NewReadonlyTarget(ctx context.Context, common Common) (ReadOnlyGraphTagFinderTarget, error) {
+func (opts *Target) NewReadonlyTarget(ctx context.Context, warn func(...any), common Common) (ReadOnlyGraphTagFinderTarget, error) {
 	switch opts.Type {
 	case TargetTypeOCILayout:
 		var err error
@@ -159,7 +159,7 @@ func (opts *Target) NewReadonlyTarget(ctx context.Context, common Common) (ReadO
 		}
 		return oci.NewFromTar(ctx, opts.Path)
 	case TargetTypeRemote:
-		repo, err := opts.NewRepository(opts.RawReference, common)
+		repo, err := opts.NewRepository(opts.RawReference, warn, common)
 		if err != nil {
 			return nil, err
 		}

cmd/oras/root/attach.go

@@ -80,7 +80,7 @@ Example - Attach file to the manifest tagged 'v1' in an OCI image layout folder
 			return nil
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return runAttach(cmd.Context(), opts)
+			return runAttach(cmd.Context(), &opts)
 		},
 	}
 
@@ -92,8 +92,8 @@ Example - Attach file to the manifest tagged 'v1' in an OCI image layout folder
 	return cmd
 }
 
-func runAttach(ctx context.Context, opts attachOptions) error {
-	ctx, _ = opts.WithContext(ctx)
+func runAttach(ctx context.Context, opts *attachOptions) error {
+	ctx, logger := opts.WithContext(ctx)
 	annotations, err := opts.LoadManifestAnnotations()
 	if err != nil {
 		return err
@@ -109,7 +109,7 @@ func runAttach(ctx context.Context, opts attachOptions) error {
 	}
 	defer store.Close()
 
-	dst, err := opts.NewTarget(opts.Common)
+	dst, err := opts.NewTarget(opts.Common, logger.Warn)
 	if err != nil {
 		return err
 	}

cmd/oras/root/blob/delete.go

@@ -62,17 +62,17 @@ Example - Delete a blob and print its descriptor:
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opts.targetRef = args[0]
-			return deleteBlob(cmd.Context(), opts)
+			return deleteBlob(cmd.Context(), &opts)
 		},
 	}
 
 	option.ApplyFlags(&opts, cmd.Flags())
 	return cmd
 }
 
-func deleteBlob(ctx context.Context, opts deleteBlobOptions) (err error) {
-	ctx, _ = opts.WithContext(ctx)
-	repo, err := opts.NewRepository(opts.targetRef, opts.Common)
+func deleteBlob(ctx context.Context, opts *deleteBlobOptions) (err error) {
+	ctx, logger := opts.WithContext(ctx)
+	repo, err := opts.NewRepository(opts.targetRef, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}

cmd/oras/root/blob/fetch.go

@@ -80,7 +80,7 @@ Example - Fetch and print a blob from OCI image layout archive file 'layout.tar'
 		},
 		Aliases: []string{"get"},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return fetchBlob(cmd.Context(), opts)
+			return fetchBlob(cmd.Context(), &opts)
 		},
 	}
 
@@ -89,10 +89,10 @@ Example - Fetch and print a blob from OCI image layout archive file 'layout.tar'
 	return cmd
 }
 
-func fetchBlob(ctx context.Context, opts fetchBlobOptions) (fetchErr error) {
-	ctx, _ = opts.WithContext(ctx)
+func fetchBlob(ctx context.Context, opts *fetchBlobOptions) (fetchErr error) {
+	ctx, logger := opts.WithContext(ctx)
 	var target oras.ReadOnlyTarget
-	target, err := opts.NewReadonlyTarget(ctx, opts.Common)
+	target, err := opts.NewReadonlyTarget(ctx, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}

cmd/oras/root/blob/push.go

@@ -85,7 +85,7 @@ Example - Push blob 'hi.txt' into an OCI image layout folder 'layout-dir':
 			return option.Parse(&opts)
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return pushBlob(cmd.Context(), opts)
+			return pushBlob(cmd.Context(), &opts)
 		},
 	}
 
@@ -95,10 +95,10 @@ Example - Push blob 'hi.txt' into an OCI image layout folder 'layout-dir':
 	return cmd
 }
 
-func pushBlob(ctx context.Context, opts pushBlobOptions) (err error) {
-	ctx, _ = opts.WithContext(ctx)
+func pushBlob(ctx context.Context, opts *pushBlobOptions) (err error) {
+	ctx, logger := opts.WithContext(ctx)
 
-	repo, err := opts.NewTarget(opts.Common)
+	repo, err := opts.NewTarget(opts.Common, logger.Warn)
 	if err != nil {
 		return err
 	}

cmd/oras/root/cp.go

@@ -86,7 +86,7 @@ Example - Copy an artifact with multiple tags with concurrency tuned:
 			return option.Parse(&opts)
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return runCopy(cmd.Context(), opts)
+			return runCopy(cmd.Context(), &opts)
 		},
 	}
 	cmd.Flags().BoolVarP(&opts.recursive, "recursive", "r", false, "[Preview] recursively copy the artifact and its referrer artifacts")
@@ -96,11 +96,11 @@ Example - Copy an artifact with multiple tags with concurrency tuned:
 	return cmd
 }
 
-func runCopy(ctx context.Context, opts copyOptions) error {
-	ctx, _ = opts.WithContext(ctx)
+func runCopy(ctx context.Context, opts *copyOptions) error {
+	ctx, logger := opts.WithContext(ctx)
 
 	// Prepare source
-	src, err := opts.From.NewReadonlyTarget(ctx, opts.Common)
+	src, err := opts.From.NewReadonlyTarget(ctx, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}
@@ -109,7 +109,7 @@ func runCopy(ctx context.Context, opts copyOptions) error {
 	}
 
 	// Prepare destination
-	dst, err := opts.To.NewTarget(opts.Common)
+	dst, err := opts.To.NewTarget(opts.Common, logger.Warn)
 	if err != nil {
 		return err
 	}

cmd/oras/root/discover.go

@@ -79,7 +79,7 @@ Example - Discover referrers of the manifest tagged 'v1' in an OCI image layout
 			return option.Parse(&opts)
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return runDiscover(cmd.Context(), opts)
+			return runDiscover(cmd.Context(), &opts)
 		},
 	}
 
@@ -90,9 +90,9 @@ Example - Discover referrers of the manifest tagged 'v1' in an OCI image layout
 	return cmd
 }
 
-func runDiscover(ctx context.Context, opts discoverOptions) error {
-	ctx, _ = opts.WithContext(ctx)
-	repo, err := opts.NewReadonlyTarget(ctx, opts.Common)
+func runDiscover(ctx context.Context, opts *discoverOptions) error {
+	ctx, logger := opts.WithContext(ctx)
+	repo, err := opts.NewReadonlyTarget(ctx, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}
@@ -110,7 +110,7 @@ func runDiscover(ctx context.Context, opts discoverOptions) error {
 
 	if opts.outputType == "tree" {
 		root := tree.New(fmt.Sprintf("%s@%s", opts.Path, desc.Digest))
-		err = fetchAllReferrers(ctx, repo, desc, opts.artifactType, root, &opts)
+		err = fetchAllReferrers(ctx, repo, desc, opts.artifactType, root, opts)
 		if err != nil {
 			return err
 		}
@@ -189,7 +189,7 @@ func printDiscoveredReferrersTable(refs []ocispec.Descriptor, verbose bool) erro
 		print(ref.ArtifactType, ref.Digest)
 		if verbose {
 			if err := printJSON(ref); err != nil {
-				return fmt.Errorf("Error printing JSON: %w", err)
+				return fmt.Errorf("Eirror printing JSON: %w", err)
 			}
 		}
 	}

cmd/oras/root/login.go

@@ -67,15 +67,15 @@ Example - Log in with username and password in an interactive terminal and no TL
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opts.Hostname = args[0]
-			return runLogin(cmd.Context(), opts)
+			return runLogin(cmd.Context(), &opts)
 		},
 	}
 	option.ApplyFlags(&opts, cmd.Flags())
 	return cmd
 }
 
-func runLogin(ctx context.Context, opts loginOptions) (err error) {
-	ctx, _ = opts.WithContext(ctx)
+func runLogin(ctx context.Context, opts *loginOptions) (err error) {
+	ctx, logger := opts.WithContext(ctx)
 
 	// prompt for credential
 	if opts.Password == "" {
@@ -108,7 +108,7 @@ func runLogin(ctx context.Context, opts loginOptions) (err error) {
 	if err != nil {
 		return err
 	}
-	remote, err := opts.Remote.NewRegistry(opts.Hostname, opts.Common)
+	remote, err := opts.Remote.NewRegistry(opts.Hostname, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}

cmd/oras/root/logout.go

@@ -44,7 +44,7 @@ Example - Logout:
 		Args: cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opts.hostname = args[0]
-			return runLogout(cmd.Context(), opts)
+			return runLogout(cmd.Context(), &opts)
 		},
 	}
 
@@ -53,7 +53,7 @@ Example - Logout:
 	return cmd
 }
 
-func runLogout(ctx context.Context, opts logoutOptions) error {
+func runLogout(ctx context.Context, opts *logoutOptions) error {
 	if opts.debug {
 		logrus.SetLevel(logrus.DebugLevel)
 	}

cmd/oras/root/manifest/delete.go

@@ -66,7 +66,7 @@ Example - Delete a manifest by digest 'sha256:99e4703fbf30916f549cd6bfa9cdbab614
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opts.targetRef = args[0]
-			return deleteManifest(cmd.Context(), opts)
+			return deleteManifest(cmd.Context(), &opts)
 		},
 	}
 
@@ -75,9 +75,9 @@ Example - Delete a manifest by digest 'sha256:99e4703fbf30916f549cd6bfa9cdbab614
 	return cmd
 }
 
-func deleteManifest(ctx context.Context, opts deleteOptions) error {
-	ctx, _ = opts.WithContext(ctx)
-	repo, err := opts.NewRepository(opts.targetRef, opts.Common)
+func deleteManifest(ctx context.Context, opts *deleteOptions) error {
+	ctx, logger := opts.WithContext(ctx)
+	repo, err := opts.NewRepository(opts.targetRef, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}

cmd/oras/root/manifest/fetch.go

@@ -79,7 +79,7 @@ Example - Fetch raw manifest from an OCI layout archive file 'layout.tar':
 		},
 		Aliases: []string{"get"},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return fetchManifest(cmd.Context(), opts)
+			return fetchManifest(cmd.Context(), &opts)
 		},
 	}
 
@@ -89,10 +89,10 @@ Example - Fetch raw manifest from an OCI layout archive file 'layout.tar':
 	return cmd
 }
 
-func fetchManifest(ctx context.Context, opts fetchOptions) (fetchErr error) {
-	ctx, _ = opts.WithContext(ctx)
+func fetchManifest(ctx context.Context, opts *fetchOptions) (fetchErr error) {
+	ctx, logger := opts.WithContext(ctx)
 
-	target, err := opts.NewReadonlyTarget(ctx, opts.Common)
+	target, err := opts.NewReadonlyTarget(ctx, logger.Warn, opts.Common)
 	if err != nil {
 		return err
 	}