cmd/dist: port commands over to use GRPC content store

Following from the rest of the work in this branch, we now are porting
the dist command to work directly against the containerd content API.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

cmd/dist/ingest.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 
+	contentapi "github.com/docker/containerd/api/services/content"
 	"github.com/docker/containerd/content"
 	"github.com/opencontainers/go-digest"
 	"github.com/urfave/cli"
@@ -41,7 +42,7 @@ var ingestCommand = cli.Command{
 			return err
 		}
 
-		cs, err := resolveContentStore(context)
+		conn, err := connectGRPC(context)
 		if err != nil {
 			return err
 		}
@@ -50,9 +51,11 @@ var ingestCommand = cli.Command{
 			return fmt.Errorf("must specify a transaction reference")
 		}
 
+		ingester := content.NewIngesterFromClient(contentapi.NewContentClient(conn))
+
 		// TODO(stevvooe): Allow ingest to be reentrant. Currently, we expect
 		// all data to be written in a single invocation. Allow multiple writes
 		// to the same transaction key followed by a commit.
-		return content.WriteBlob(ctx, cs, os.Stdin, ref, expectedSize, expectedDigest)
+		return content.WriteBlob(ctx, ingester, os.Stdin, ref, expectedSize, expectedDigest)
 	},
 }