Merge pull request #786 from stevvooe/edit-content-command

cmd/dist: add ability to edit content

cmd/dist/edit.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+
+	contentapi "github.com/containerd/containerd/api/services/content"
+	contentservice "github.com/containerd/containerd/services/content"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/urfave/cli"
+)
+
+var editCommand = cli.Command{
+	Name:        "edit",
+	Usage:       "edit a blob and return a new digest.",
+	ArgsUsage:   "[flags] <digest>",
+	Description: `Edit a blob and return a new digest.`,
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "validate",
+			Usage: "validate the result against a format (json, mediatype, etc.)",
+		},
+	},
+	Action: func(context *cli.Context) error {
+		var (
+			ctx      = background
+			validate = context.String("validate")
+			object   = context.Args().First()
+		)
+
+		if validate != "" {
+			return errors.New("validating the edit result not supported")
+		}
+
+		// TODO(stevvooe): Support looking up objects by a reference through
+		// the image metadata storage.
+
+		dgst, err := digest.Parse(object)
+		if err != nil {
+			return err
+		}
+
+		conn, err := connectGRPC(context)
+		if err != nil {
+			return err
+		}
+
+		provider := contentservice.NewProviderFromClient(contentapi.NewContentClient(conn))
+		ingester := contentservice.NewIngesterFromClient(contentapi.NewContentClient(conn))
+
+		rc, err := provider.Reader(ctx, dgst)
+		if err != nil {
+			return err
+		}
+		defer rc.Close()
+
+		nrc, err := edit(rc)
+		if err != nil {
+			return err
+		}
+
+		wr, err := ingester.Writer(ctx, "edit-"+object, 0, "") // TODO(stevvooe): Choose a better key?
+		if err != nil {
+			return err
+		}
+
+		if _, err := io.Copy(wr, nrc); err != nil {
+			return err
+		}
+
+		if err := wr.Commit(0, wr.Digest()); err != nil {
+			return err
+		}
+
+		fmt.Println(wr.Digest())
+		return nil
+	},
+}
+
+func edit(rd io.Reader) (io.ReadCloser, error) {
+	tmp, err := ioutil.TempFile("", "edit-")
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := io.Copy(tmp, rd); err != nil {
+		tmp.Close()
+		return nil, err
+	}
+
+	cmd := exec.Command("sh", "-c", "$EDITOR "+tmp.Name())
+
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Env = os.Environ()
+
+	if err := cmd.Run(); err != nil {
+		tmp.Close()
+		return nil, err
+	}
+
+	if _, err := tmp.Seek(0, io.SeekStart); err != nil {
+		tmp.Close()
+		return nil, err
+	}
+
+	return tmp, nil
+}

cmd/dist/main.go

@@ -106,6 +106,7 @@ var contentCommand = cli.Command{
 		ingestCommand,
 		activeCommand,
 		getCommand,
+		editCommand,
 		deleteCommand,
 	},
 }

services/content/ingester.go

@@ -127,6 +127,9 @@ func (rw *remoteWriter) Write(p []byte) (n int, err error) {
 	}
 
 	rw.offset += int64(n)
+	if resp.Digest != "" {
+		rw.digest = resp.Digest
+	}
 	return
 }
 
@@ -149,6 +152,8 @@ func (rw *remoteWriter) Commit(size int64, expected digest.Digest) error {
 		return errors.Errorf("unexpected digest: %v != %v", resp.Digest, expected)
 	}
 
+	rw.digest = resp.Digest
+	rw.offset = resp.Offset
 	return nil
 }
 

services/content/service.go

@@ -304,9 +304,9 @@ func (s *Service) Write(session api.Content_WriteServer) (err error) {
 				if err := wr.Commit(total, expected); err != nil {
 					return err
 				}
-
-				msg.Digest = wr.Digest()
 			}
+
+			msg.Digest = wr.Digest()
 		case api.WriteActionAbort:
 			return s.store.Abort(ref)
 		}