1 files changed, 48 insertions, 0 deletions
diff --git a/cmd/crane/cmd/blob.go b/cmd/crane/cmd/blob.go
new file mode 100644
index 0000000..fef405f
--- /dev/null
+++ b/cmd/crane/cmd/blob.go
@@ -0,0 +1,48 @@
+// Copyright 2020 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"
+	"io"
+
+	"github.com/google/go-containerregistry/pkg/crane"
+	"github.com/spf13/cobra"
+)
+
+// NewCmdBlob creates a new cobra.Command for the blob subcommand.
+func NewCmdBlob(options *[]crane.Option) *cobra.Command {
+	return &cobra.Command{
+		Use:     "blob BLOB",
+		Short:   "Read a blob from the registry",
+		Example: "crane blob ubuntu@sha256:4c1d20cdee96111c8acf1858b62655a37ce81ae48648993542b7ac363ac5c0e5 > blob.tar.gz",
+		Args:    cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			src := args[0]
+			layer, err := crane.PullLayer(src, *options...)
+			if err != nil {
+				return fmt.Errorf("pulling layer %s: %w", src, err)
+			}
+			blob, err := layer.Compressed()
+			if err != nil {
+				return fmt.Errorf("fetching blob %s: %w", src, err)
+			}
+			if _, err := io.Copy(cmd.OutOrStdout(), blob); err != nil {
+				return fmt.Errorf("copying blob %s: %w", src, err)
+			}
+			return nil
+		},
+	}
+}