add better generate

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/docker/distribution/registry/root.go

@@ -0,0 +1,89 @@
+package registry
+
+import (
+	"fmt"
+	"os"
+
+	dcontext "github.com/docker/distribution/context"
+	"github.com/docker/distribution/registry/storage"
+	"github.com/docker/distribution/registry/storage/driver/factory"
+	"github.com/docker/distribution/version"
+	"github.com/docker/libtrust"
+	"github.com/spf13/cobra"
+)
+
+var showVersion bool
+
+func init() {
+	RootCmd.AddCommand(ServeCmd)
+	RootCmd.AddCommand(GCCmd)
+	GCCmd.Flags().BoolVarP(&dryRun, "dry-run", "d", false, "do everything except remove the blobs")
+	GCCmd.Flags().BoolVarP(&removeUntagged, "delete-untagged", "m", false, "delete manifests that are not currently referenced via tag")
+	RootCmd.Flags().BoolVarP(&showVersion, "version", "v", false, "show the version and exit")
+}
+
+// RootCmd is the main command for the 'registry' binary.
+var RootCmd = &cobra.Command{
+	Use:   "registry",
+	Short: "`registry`",
+	Long:  "`registry`",
+	Run: func(cmd *cobra.Command, args []string) {
+		if showVersion {
+			version.PrintVersion()
+			return
+		}
+		cmd.Usage()
+	},
+}
+
+var dryRun bool
+var removeUntagged bool
+
+// GCCmd is the cobra command that corresponds to the garbage-collect subcommand
+var GCCmd = &cobra.Command{
+	Use:   "garbage-collect <config>",
+	Short: "`garbage-collect` deletes layers not referenced by any manifests",
+	Long:  "`garbage-collect` deletes layers not referenced by any manifests",
+	Run: func(cmd *cobra.Command, args []string) {
+		config, err := resolveConfiguration(args)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "configuration error: %v\n", err)
+			cmd.Usage()
+			os.Exit(1)
+		}
+
+		driver, err := factory.Create(config.Storage.Type(), config.Storage.Parameters())
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to construct %s driver: %v", config.Storage.Type(), err)
+			os.Exit(1)
+		}
+
+		ctx := dcontext.Background()
+		ctx, err = configureLogging(ctx, config)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unable to configure logging with config: %s", err)
+			os.Exit(1)
+		}
+
+		k, err := libtrust.GenerateECP256PrivateKey()
+		if err != nil {
+			fmt.Fprint(os.Stderr, err)
+			os.Exit(1)
+		}
+
+		registry, err := storage.NewRegistry(ctx, driver, storage.Schema1SigningKey(k))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to construct registry: %v", err)
+			os.Exit(1)
+		}
+
+		err = storage.MarkAndSweep(ctx, driver, registry, storage.GCOpts{
+			DryRun:         dryRun,
+			RemoveUntagged: removeUntagged,
+		})
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to garbage collect: %v", err)
+			os.Exit(1)
+		}
+	},
+}