1 files changed, 121 insertions, 0 deletions
diff --git a/cmd/gcrane/cmd/list.go b/cmd/gcrane/cmd/list.go
new file mode 100644
index 0000000..892f2af
--- /dev/null
+++ b/cmd/gcrane/cmd/list.go
@@ -0,0 +1,121 @@
+// 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"path"
+
+	"github.com/google/go-containerregistry/cmd/crane/cmd"
+	"github.com/google/go-containerregistry/pkg/gcrane"
+	"github.com/google/go-containerregistry/pkg/name"
+	"github.com/google/go-containerregistry/pkg/v1/google"
+	"github.com/spf13/cobra"
+)
+
+func userAgent() string {
+	if cmd.Version != "" {
+		return path.Join("gcrane", cmd.Version)
+	}
+
+	return "gcrane"
+}
+
+// NewCmdList creates a new cobra.Command for the ls subcommand.
+func NewCmdList() *cobra.Command {
+	recursive := false
+	json := false
+	cmd := &cobra.Command{
+		Use:   "ls REPO",
+		Short: "List the contents of a repo",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cc *cobra.Command, args []string) error {
+			return ls(cc.Context(), args[0], recursive, json)
+		},
+	}
+
+	cmd.Flags().BoolVarP(&recursive, "recursive", "r", false, "Whether to recurse through repos")
+	cmd.Flags().BoolVar(&json, "json", false, "Format the response from the registry as JSON, one line per repo")
+
+	return cmd
+}
+
+func ls(ctx context.Context, root string, recursive, j bool) error {
+	repo, err := name.NewRepository(root)
+	if err != nil {
+		return err
+	}
+
+	opts := []google.Option{
+		google.WithAuthFromKeychain(gcrane.Keychain),
+		google.WithUserAgent(userAgent()),
+		google.WithContext(ctx),
+	}
+
+	if recursive {
+		return google.Walk(repo, printImages(j), opts...)
+	}
+
+	tags, err := google.List(repo, opts...)
+	if err != nil {
+		return err
+	}
+
+	if !j {
+		if len(tags.Manifests) == 0 && len(tags.Children) == 0 {
+			// If we didn't see any GCR extensions, just list the tags like normal.
+			for _, tag := range tags.Tags {
+				fmt.Printf("%s:%s\n", repo, tag)
+			}
+			return nil
+		}
+
+		// Since we're not recursing, print the subdirectories too.
+		for _, child := range tags.Children {
+			fmt.Printf("%s/%s\n", repo, child)
+		}
+	}
+
+	return printImages(j)(repo, tags, err)
+}
+
+func printImages(j bool) google.WalkFunc {
+	return func(repo name.Repository, tags *google.Tags, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if j {
+			b, err := json.Marshal(tags)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("%s\n", b)
+			return nil
+		}
+
+		for digest, manifest := range tags.Manifests {
+			fmt.Printf("%s@%s\n", repo, digest)
+
+			for _, tag := range manifest.Tags {
+				fmt.Printf("%s:%s\n", repo, tag)
+			}
+		}
+
+		return nil
+	}
+}