feat: support deleting a manifest from a remote registry

cmd/oras/internal/option/confirmation.go

@@ -0,0 +1,54 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package option
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/spf13/pflag"
+)
+
+// Confirmation option struct.
+type Confirmation struct {
+	Confirmed bool
+}
+
+// ApplyFlags applies flags to a command flag set.
+func (opts *Confirmation) ApplyFlags(fs *pflag.FlagSet) {
+	fs.BoolVarP(&opts.Confirmed, "yes", "y", false, "do not prompt for confirmation")
+}
+
+func (opts *Confirmation) AskForConfirmation(r io.Reader, prompt string) (bool, error) {
+	if opts.Confirmed {
+		return true, nil
+	}
+
+	fmt.Print(prompt, "[y/N]")
+
+	var response string
+	if _, err := fmt.Fscanln(r, &response); err != nil {
+		return false, err
+	}
+
+	switch strings.ToLower(response) {
+	case "y", "yes":
+		return true, nil
+	default:
+		return false, nil
+	}
+}

cmd/oras/internal/option/confirmation_test.go

@@ -0,0 +1,82 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package option
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/spf13/pflag"
+)
+
+func TestConfirmation_ApplyFlags(t *testing.T) {
+	var test struct{ Confirmation }
+	ApplyFlags(&test, pflag.NewFlagSet("oras-test", pflag.ExitOnError))
+	if test.Confirmation.Confirmed != false {
+		t.Fatalf("expecting Confirmed to be false but got: %v", test.Confirmation.Confirmed)
+	}
+}
+
+func TestConfirmation_AskForConfirmation_forciblyConfirmed(t *testing.T) {
+	opts := Confirmation{
+		Confirmed: true,
+	}
+	r := strings.NewReader("")
+
+	got, err := opts.AskForConfirmation(r, "")
+	if err != nil {
+		t.Fatal("Confirmation.AskForConfirmation() error =", err)
+	}
+	if !reflect.DeepEqual(got, true) {
+		t.Fatalf("Confirmation.AskForConfirmation() got %v, want %v", got, true)
+	}
+}
+
+func TestConfirmation_AskForConfirmation_manuallyConfirmed(t *testing.T) {
+	opts := Confirmation{
+		Confirmed: false,
+	}
+
+	r := strings.NewReader("yes")
+	got, err := opts.AskForConfirmation(r, "")
+	if err != nil {
+		t.Fatal("Confirmation.AskForConfirmation() error =", err)
+	}
+	if !reflect.DeepEqual(got, true) {
+		t.Fatalf("Confirmation.AskForConfirmation() got %v, want %v", got, true)
+	}
+
+	r = strings.NewReader("no")
+	got, err = opts.AskForConfirmation(r, "")
+	if err != nil {
+		t.Fatal("Confirmation.AskForConfirmation() error =", err)
+	}
+	if !reflect.DeepEqual(got, false) {
+		t.Fatalf("Confirmation.AskForConfirmation() got %v, want %v", got, false)
+	}
+}
+
+func TestConfirmation_AskForConfirmation_FscanlnErr(t *testing.T) {
+	opts := Confirmation{
+		Confirmed: false,
+	}
+	r := strings.NewReader("yes no")
+
+	_, err := opts.AskForConfirmation(r, "")
+	expected := "expected newline"
+	if err.Error() != expected {
+		t.Fatalf("AskForConfirmation() error = %v, wantErr %v", err, expected)
+	}
+}

cmd/oras/manifest/cmd.go

@@ -21,12 +21,13 @@ import (
 
 func Cmd() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "manifest [fetch]",
+		Use:   "manifest [command]",
 		Short: "[Preview] Manifest operations",
 	}
 
 	cmd.AddCommand(
 		fetchCmd(),
+		deleteCmd(),
 	)
 	return cmd
 }

cmd/oras/manifest/delete.go

@@ -0,0 +1,119 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package manifest
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"oras.land/oras-go/v2/errdef"
+	oerrors "oras.land/oras/cmd/oras/internal/errors"
+	"oras.land/oras/cmd/oras/internal/option"
+)
+
+type deleteOptions struct {
+	option.Common
+	option.Confirmation
+	option.Descriptor
+	option.Pretty
+	option.Remote
+
+	targetRef string
+}
+
+func deleteCmd() *cobra.Command {
+	var opts deleteOptions
+	cmd := &cobra.Command{
+		Use:   "delete [flags] name[:tag|@digest]",
+		Short: "[Preview] Delete a manifest from remote registry",
+		Long: `[Preview] Delete a manifest from remote registry
+
+** This command is in preview and under development. **
+
+Example - Delete a manifest tagged with 'latest' from repository 'locahost:5000/hello':
+  oras manifest delete localhost:5000/hello:latest
+
+Example - Delete a manifest without prompting confirmation:
+  oras manifest delete --yes localhost:5000/hello:latest
+
+Example - Delete a manifest and print its descriptor:
+  oras manifest delete --descriptor localhost:5000/hello:latest
+
+Example - Delete a manifest by digest 'sha256:99e4703fbf30916f549cd6bfa9cdbab614b5392fbe64fdee971359a77073cdf9' from repository 'locahost:5000/hello':
+  oras manifest delete localhost:5000/hello@sha:99e4703fbf30916f549cd6bfa9cdbab614b5392fbe64fdee971359a77073cdf9
+`,
+		Args: cobra.ExactArgs(1),
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if opts.OutputDescriptor && !opts.Confirmed {
+				return errors.New("must apply --yes to confirm the deletion if the descriptor is outputted")
+			}
+			return opts.ReadPassword()
+		},
+		RunE: func(_ *cobra.Command, args []string) error {
+			opts.targetRef = args[0]
+			return deleteManifest(opts)
+		},
+	}
+
+	option.ApplyFlags(&opts, cmd.Flags())
+	return cmd
+}
+
+func deleteManifest(opts deleteOptions) error {
+	ctx, _ := opts.SetLoggerLevel()
+	repo, err := opts.NewRepository(opts.targetRef, opts.Common)
+	if err != nil {
+		return err
+	}
+
+	if repo.Reference.Reference == "" {
+		return oerrors.NewErrInvalidReference(repo.Reference)
+	}
+
+	manifests := repo.Manifests()
+	desc, err := manifests.Resolve(ctx, opts.targetRef)
+	if err != nil {
+		if errors.Is(err, errdef.ErrNotFound) {
+			return fmt.Errorf("%s: the specified manifest does not exist", opts.targetRef)
+		}
+		return err
+	}
+
+	prompt := fmt.Sprintf("Are you sure you want to delete the manifest %q and all tags associated with it?", desc.Digest)
+	confirmed, err := opts.AskForConfirmation(os.Stdin, prompt)
+	if err != nil {
+		return err
+	}
+	if !confirmed {
+		return nil
+	}
+
+	if err = manifests.Delete(ctx, desc); err != nil {
+		return fmt.Errorf("failed to delete %s: %w", opts.targetRef, err)
+	}
+
+	if opts.OutputDescriptor {
+		descJSON, err := opts.Marshal(desc)
+		if err != nil {
+			return err
+		}
+		return opts.Output(os.Stdout, descJSON)
+	}
+
+	fmt.Println("Deleted", opts.targetRef)
+
+	return nil
+}