containerd/cmd/dist/get.go

package main

import (
	"io"
	"os"

	contentapi "github.com/docker/containerd/api/services/content"
	"github.com/docker/containerd/content"
	digest "github.com/opencontainers/go-digest"
	"github.com/urfave/cli"
)

var getCommand = cli.Command{
	Name:      "get",
	Usage:     "get the data for an object",
	ArgsUsage: "[flags] [<digest>, ...]",
	Description: `Display the paths to one or more blobs.
	
Output paths can be used to directly access blobs on disk.`,
	Flags: []cli.Flag{},
	Action: func(context *cli.Context) error {
		var (
			ctx = background
		)

		dgst, err := digest.Parse(context.Args().First())
		if err != nil {
			return err
		}

		conn, err := connectGRPC(context)
		if err != nil {
			return err
		}

		cs := content.NewProviderFromClient(contentapi.NewContentClient(conn))

		rc, err := cs.Reader(ctx, dgst)
		if err != nil {
			return err
		}
		defer rc.Close()

		_, err = io.Copy(os.Stdout, rc)
		return err
	},
}