1 files changed, 122 insertions, 0 deletions
diff --git a/cmd/crane/cmd/append.go b/cmd/crane/cmd/append.go
new file mode 100644
index 0000000..9eb2acc
--- /dev/null
+++ b/cmd/crane/cmd/append.go
@@ -0,0 +1,122 @@
+// Copyright 2018 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"
+	"github.com/google/go-containerregistry/pkg/logs"
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/empty"
+	"github.com/google/go-containerregistry/pkg/v1/mutate"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+	specsv1 "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/spf13/cobra"
+)
+
+// NewCmdAppend creates a new cobra.Command for the append subcommand.
+func NewCmdAppend(options *[]crane.Option) *cobra.Command {
+	var baseRef, newTag, outFile string
+	var newLayers []string
+	var annotate, ociEmptyBase bool
+
+	appendCmd := &cobra.Command{
+		Use:   "append",
+		Short: "Append contents of a tarball to a remote image",
+		Long: `This sub-command pushes an image based on an (optional)
+base image, with appended layers containing the contents of the
+provided tarballs.
+
+If the base image is a Windows base image (i.e., its config.OS is "windows"),
+the contents of the tarballs will be modified to be suitable for a Windows
+container image.`,
+		Args: cobra.NoArgs,
+		RunE: func(_ *cobra.Command, args []string) error {
+			var base v1.Image
+			var err error
+
+			if baseRef == "" {
+				logs.Warn.Printf("base unspecified, using empty image")
+				base = empty.Image
+				if ociEmptyBase {
+					base = mutate.MediaType(base, types.OCIManifestSchema1)
+					base = mutate.ConfigMediaType(base, types.OCIConfigJSON)
+				}
+			} else {
+				base, err = crane.Pull(baseRef, *options...)
+				if err != nil {
+					return fmt.Errorf("pulling %s: %w", baseRef, err)
+				}
+			}
+
+			img, err := crane.Append(base, newLayers...)
+			if err != nil {
+				return fmt.Errorf("appending %v: %w", newLayers, err)
+			}
+
+			if baseRef != "" && annotate {
+				ref, err := name.ParseReference(baseRef)
+				if err != nil {
+					return fmt.Errorf("parsing ref %q: %w", baseRef, err)
+				}
+
+				baseDigest, err := base.Digest()
+				if err != nil {
+					return err
+				}
+				anns := map[string]string{
+					specsv1.AnnotationBaseImageDigest: baseDigest.String(),
+				}
+				if _, ok := ref.(name.Tag); ok {
+					anns[specsv1.AnnotationBaseImageName] = ref.Name()
+				}
+				img = mutate.Annotations(img, anns).(v1.Image)
+			}
+
+			if outFile != "" {
+				if err := crane.Save(img, newTag, outFile); err != nil {
+					return fmt.Errorf("writing output %q: %w", outFile, err)
+				}
+			} else {
+				if err := crane.Push(img, newTag, *options...); err != nil {
+					return fmt.Errorf("pushing image %s: %w", newTag, err)
+				}
+				ref, err := name.ParseReference(newTag)
+				if err != nil {
+					return fmt.Errorf("parsing reference %s: %w", newTag, err)
+				}
+				d, err := img.Digest()
+				if err != nil {
+					return fmt.Errorf("digest: %w", err)
+				}
+				fmt.Println(ref.Context().Digest(d.String()))
+			}
+			return nil
+		},
+	}
+	appendCmd.Flags().StringVarP(&baseRef, "base", "b", "", "Name of base image to append to")
+	appendCmd.Flags().StringVarP(&newTag, "new_tag", "t", "", "Tag to apply to resulting image")
+	appendCmd.Flags().StringSliceVarP(&newLayers, "new_layer", "f", []string{}, "Path to tarball to append to image")
+	appendCmd.Flags().StringVarP(&outFile, "output", "o", "", "Path to new tarball of resulting image")
+	appendCmd.Flags().BoolVar(&annotate, "set-base-image-annotations", false, "If true, annotate the resulting image as being based on the base image")
+	appendCmd.Flags().BoolVar(&ociEmptyBase, "oci-empty-base", false, "If true, empty base image will have OCI media types instead of Docker")
+
+	appendCmd.MarkFlagsMutuallyExclusive("oci-empty-base", "base")
+	appendCmd.MarkFlagRequired("new_tag")
+	appendCmd.MarkFlagRequired("new_layer")
+	return appendCmd
+}