Adding crane annotate command

Author: Adam Furbee

cmd/crane/cmd/annotate.go

@@ -0,0 +1,83 @@
+// Copyright 2021 Google LLC All Rights Reserved.
+//
+// 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 cmd
+
+import (
+	"fmt"
+
+	"github.com/google/go-containerregistry/pkg/crane"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/mutate"
+	"github.com/spf13/cobra"
+)
+
+// NewCmdAnnotate creates a new cobra.Command for the annotate subcommand.
+func NewCmdAnnotate(options *[]crane.Option) *cobra.Command {
+	var annotations map[string]string
+	var newRef string
+
+	annotateCmd := &cobra.Command{
+		Use:   "annotate",
+		Short: "Modify image or index annotations. The manifest is updated there on the registry.",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(c *cobra.Command, args []string) error {
+			ref := args[0]
+
+			desc, err := crane.Head(ref, *options...)
+			if err != nil {
+				return err
+			}
+
+			if newRef == "" {
+				newRef = ref
+			}
+
+			if desc.MediaType.IsIndex() {
+				d, err := crane.Get(ref, *options...)
+				if err != nil {
+					return err
+				}
+				idx, err := d.ImageIndex()
+				if err != nil {
+					return err
+				}
+				annotated := mutate.Annotations(idx, annotations).(v1.ImageIndex)
+				err = crane.PushIndex(annotated, newRef, *options...)
+				if err != nil {
+					return err
+				}
+				fmt.Println("Index pushed with annotations.")
+			} else if desc.MediaType.IsImage() {
+				img, err := crane.Pull(ref, *options...)
+				if err != nil {
+					return err
+				}
+				annotated := mutate.Annotations(img, annotations).(v1.Image)
+				err = crane.Push(annotated, newRef, *options...)
+				if err != nil {
+					return err
+				}
+				fmt.Println("Image pushed with annotations.")
+			} else {
+				return fmt.Errorf("unsupported manifest type only indexes and images are currently supported: %s", desc.ArtifactType)
+			}
+
+			return nil
+		},
+	}
+	annotateCmd.Flags().StringToStringVarP(&annotations, "annotation", "a", nil, "New annotations to add")
+	annotateCmd.Flags().StringVarP(&newRef, "tag", "t", "", "New tag reference to apply to annotated image/index. If not provided, push by digest to the original repository.")
+	return annotateCmd
+}

cmd/crane/cmd/root.go

@@ -108,6 +108,7 @@ func New(use, short string, options []crane.Option) *cobra.Command {
 	}
 
 	root.AddCommand(
+		NewCmdAnnotate(&options),
 		NewCmdAppend(&options),
 		NewCmdAuth(options, "crane", "auth"),
 		NewCmdBlob(&options),

pkg/crane/push.go

@@ -53,6 +53,16 @@ func Push(img v1.Image, dst string, opt ...Option) error {
 	return remote.Write(tag, img, o.Remote...)
 }
 
+// PushIndex pushes the v1.ImageIndex idx to a registry as dst.
+func PushIndex(idx v1.ImageIndex, dst string, opt ...Option) error {
+	o := makeOptions(opt...)
+	tag, err := name.ParseReference(dst, o.Name...)
+	if err != nil {
+		return fmt.Errorf("parsing reference %q: %w", dst, err)
+	}
+	return remote.Put(tag, idx, o.Remote...)
+}
+
 // Upload pushes the v1.Layer to a given repo.
 func Upload(layer v1.Layer, repo string, opt ...Option) error {
 	o := makeOptions(opt...)