podman-remote save [image]

Add the ability to save an image from the remote-host to the
remote-client.

Signed-off-by: baude <bbaude@redhat.com>

4 files changed, 183 insertions, 17 deletions

diff --git a/libpod/adapter/runtime.go b/libpod/adapter/runtime.go
index 02ef9af07..b12f63cdc 100644
--- a/libpod/adapter/runtime.go
+++ b/libpod/adapter/runtime.go
@@ -310,3 +310,15 @@ func (r *LocalRuntime) Build(ctx context.Context, c *cliconfig.BuildValues, opti
 func (r *LocalRuntime) PruneVolumes(ctx context.Context) ([]string, []error) {
 	return r.Runtime.PruneVolumes(ctx)
 }
+
+// SaveImage is a wrapper function for saving an image to the local filesystem
+func (r *LocalRuntime) SaveImage(ctx context.Context, c *cliconfig.SaveValues) error {
+	source := c.InputArgs[0]
+	additionalTags := c.InputArgs[1:]
+
+	newImage, err := r.Runtime.ImageRuntime().NewFromLocal(source)
+	if err != nil {
+		return err
+	}
+	return newImage.Save(ctx, source, c.Format, c.Output, additionalTags, c.Quiet, c.Compress)
+}
diff --git a/libpod/adapter/runtime_remote.go b/libpod/adapter/runtime_remote.go
index b1d4d4d25..a79f93079 100644
--- a/libpod/adapter/runtime_remote.go
+++ b/libpod/adapter/runtime_remote.go
@@ -20,6 +20,7 @@ import (
 	"github.com/containers/libpod/cmd/podman/varlink"
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/libpod/image"
+	"github.com/containers/libpod/utils"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
@@ -385,8 +386,11 @@ func (r *LocalRuntime) Export(name string, path string) error {
 	if err != nil {
 		return err
 	}
+	return r.GetFileFromRemoteHost(tempPath, path, true)
+}
 
-	outputFile, err := os.Create(path)
+func (r *LocalRuntime) GetFileFromRemoteHost(remoteFilePath, outputPath string, delete bool) error {
+	outputFile, err := os.Create(outputPath)
 	if err != nil {
 		return err
 	}
@@ -395,7 +399,7 @@ func (r *LocalRuntime) Export(name string, path string) error {
 	writer := bufio.NewWriter(outputFile)
 	defer writer.Flush()
 
-	reply, err := iopodman.ReceiveFile().Send(r.Conn, varlink.Upgrade, tempPath, true)
+	reply, err := iopodman.ReceiveFile().Send(r.Conn, varlink.Upgrade, remoteFilePath, delete)
 	if err != nil {
 		return err
 	}
@@ -409,7 +413,6 @@ func (r *LocalRuntime) Export(name string, path string) error {
 	if _, err := io.CopyN(writer, reader, length); err != nil {
 		return errors.Wrap(err, "file transer failed")
 	}
-
 	return nil
 }
 
@@ -467,28 +470,17 @@ func (r *LocalRuntime) Build(ctx context.Context, c *cliconfig.BuildValues, opti
 		Squash:              options.Squash,
 	}
 	// tar the file
-	logrus.Debugf("creating tarball of context dir %s", options.ContextDirectory)
-	input, err := archive.Tar(options.ContextDirectory, archive.Uncompressed)
-	if err != nil {
-		return errors.Wrapf(err, "unable to create tarball of context dir %s", options.ContextDirectory)
-	}
-
-	// Write the tarball to the fs
-	// TODO we might considering sending this without writing to the fs for the sake of performance
-	// under given conditions like memory availability.
 	outputFile, err := ioutil.TempFile("", "varlink_tar_send")
 	if err != nil {
 		return err
 	}
 	defer outputFile.Close()
-	logrus.Debugf("writing context dir tarball to %s", outputFile.Name())
+	defer os.Remove(outputFile.Name())
 
-	_, err = io.Copy(outputFile, input)
-	if err != nil {
+	// Create the tarball of the context dir to a tempfile
+	if err := utils.TarToFilesystem(options.ContextDirectory, outputFile); err != nil {
 		return err
 	}
-
-	logrus.Debugf("completed writing context dir tarball %s", outputFile.Name())
 	// Send the context dir tarball over varlink.
 	tempFile, err := r.SendFileOverVarlink(outputFile.Name())
 	if err != nil {
@@ -702,3 +694,72 @@ func (r *LocalRuntime) PruneVolumes(ctx context.Context) ([]string, []error) {
 	}
 	return prunedNames, errs
 }
+
+// SaveImage is a wrapper function for saving an image to the local filesystem
+func (r *LocalRuntime) SaveImage(ctx context.Context, c *cliconfig.SaveValues) error {
+	source := c.InputArgs[0]
+	additionalTags := c.InputArgs[1:]
+
+	options := iopodman.ImageSaveOptions{
+		Name:     source,
+		Format:   c.Format,
+		Output:   c.Output,
+		MoreTags: additionalTags,
+		Quiet:    c.Quiet,
+		Compress: c.Compress,
+	}
+	reply, err := iopodman.ImageSave().Send(r.Conn, varlink.More, options)
+	if err != nil {
+		return err
+	}
+
+	var fetchfile string
+	for {
+		responses, flags, err := reply()
+		if err != nil {
+			return err
+		}
+		if len(responses.Id) > 0 {
+			fetchfile = responses.Id
+		}
+		for _, line := range responses.Logs {
+			fmt.Print(line)
+		}
+		if flags&varlink.Continues == 0 {
+			break
+		}
+
+	}
+	if err != nil {
+		return err
+	}
+
+	outputToDir := false
+	outfile := c.Output
+	var outputFile *os.File
+	// If the result is supposed to be a dir, then we need to put the tarfile
+	// from the host in a temporary file
+	if options.Format != "oci-archive" && options.Format != "docker-archive" {
+		outputToDir = true
+		outputFile, err = ioutil.TempFile("", "saveimage_tempfile")
+		if err != nil {
+			return err
+		}
+		outfile = outputFile.Name()
+		defer outputFile.Close()
+		defer os.Remove(outputFile.Name())
+	}
+	// We now need to fetch the tarball result back to the more system
+	if err := r.GetFileFromRemoteHost(fetchfile, outfile, true); err != nil {
+		return err
+	}
+
+	// If the result is a tarball, we're done
+	// If it is a dir, we need to untar the temporary file into the dir
+	if outputToDir {
+		if err := utils.UntarToFileSystem(c.Output, outputFile, &archive.TarOptions{}); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/libpod/image/image.go b/libpod/image/image.go
index 028a795ea..547fb8994 100644
--- a/libpod/image/image.go
+++ b/libpod/image/image.go
@@ -5,14 +5,18 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"os"
 	"strings"
 	"syscall"
 	"time"
 
 	types2 "github.com/containernetworking/cni/pkg/types"
 	cp "github.com/containers/image/copy"
+	"github.com/containers/image/directory"
+	dockerarchive "github.com/containers/image/docker/archive"
 	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/manifest"
+	ociarchive "github.com/containers/image/oci/archive"
 	is "github.com/containers/image/storage"
 	"github.com/containers/image/tarball"
 	"github.com/containers/image/transports"
@@ -26,6 +30,7 @@ import (
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/reexec"
 	digest "github.com/opencontainers/go-digest"
+	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
 	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/pkg/errors"
@@ -1084,3 +1089,65 @@ func (i *Image) Comment(ctx context.Context, manifestType string) (string, error
 	}
 	return ociv1Img.History[0].Comment, nil
 }
+
+// Save writes a container image to the filesystem
+func (i *Image) Save(ctx context.Context, source, format, output string, moreTags []string, quiet, compress bool) error {
+	var (
+		writer       io.Writer
+		destRef      types.ImageReference
+		manifestType string
+		err          error
+	)
+
+	if quiet {
+		writer = os.Stderr
+	}
+	switch format {
+	case "oci-archive":
+		destImageName := imageNameForSaveDestination(i, source)
+		destRef, err = ociarchive.NewReference(output, destImageName) // destImageName may be ""
+		if err != nil {
+			return errors.Wrapf(err, "error getting OCI archive ImageReference for (%q, %q)", output, destImageName)
+		}
+	case "oci-dir":
+		destRef, err = directory.NewReference(output)
+		if err != nil {
+			return errors.Wrapf(err, "error getting directory ImageReference for %q", output)
+		}
+		manifestType = imgspecv1.MediaTypeImageManifest
+	case "docker-dir":
+		destRef, err = directory.NewReference(output)
+		if err != nil {
+			return errors.Wrapf(err, "error getting directory ImageReference for %q", output)
+		}
+		manifestType = manifest.DockerV2Schema2MediaType
+	case "docker-archive", "":
+		dst := output
+		destImageName := imageNameForSaveDestination(i, source)
+		if destImageName != "" {
+			dst = fmt.Sprintf("%s:%s", dst, destImageName)
+		}
+		destRef, err = dockerarchive.ParseReference(dst) // FIXME? Add dockerarchive.NewReference
+		if err != nil {
+			return errors.Wrapf(err, "error getting Docker archive ImageReference for %q", dst)
+		}
+	default:
+		return errors.Errorf("unknown format option %q", format)
+	}
+	// supports saving multiple tags to the same tar archive
+	var additionaltags []reference.NamedTagged
+	if len(moreTags) > 0 {
+		additionaltags, err = GetAdditionalTags(moreTags)
+		if err != nil {
+			return err
+		}
+	}
+	if err := i.PushImageToReference(ctx, destRef, manifestType, "", "", writer, compress, SigningOptions{}, &DockerRegistryOptions{}, additionaltags); err != nil {
+		if err2 := os.Remove(output); err2 != nil {
+			logrus.Errorf("error deleting %q: %v", output, err)
+		}
+		return errors.Wrapf(err, "unable to save %q", source)
+	}
+
+	return nil
+}
diff --git a/libpod/image/utils.go b/libpod/image/utils.go
index 3585428ad..544796a4b 100644
--- a/libpod/image/utils.go
+++ b/libpod/image/utils.go
@@ -1,6 +1,7 @@
 package image
 
 import (
+	"fmt"
 	"io"
 	"net/url"
 	"regexp"
@@ -148,3 +149,28 @@ func IsValidImageURI(imguri string) (bool, error) {
 	}
 	return true, nil
 }
+
+// imageNameForSaveDestination returns a Docker-like reference appropriate for saving img,
+// which the user referred to as imgUserInput; or an empty string, if there is no appropriate
+// reference.
+func imageNameForSaveDestination(img *Image, imgUserInput string) string {
+	if strings.Contains(img.ID(), imgUserInput) {
+		return ""
+	}
+
+	prepend := ""
+	localRegistryPrefix := fmt.Sprintf("%s/", DefaultLocalRegistry)
+	if !strings.HasPrefix(imgUserInput, localRegistryPrefix) {
+		// we need to check if localhost was added to the image name in NewFromLocal
+		for _, name := range img.Names() {
+			// If the user is saving an image in the localhost registry,  getLocalImage need
+			// a name that matches the format localhost/<tag1>:<tag2> or localhost/<tag>:latest to correctly
+			// set up the manifest and save.
+			if strings.HasPrefix(name, localRegistryPrefix) && (strings.HasSuffix(name, imgUserInput) || strings.HasSuffix(name, fmt.Sprintf("%s:latest", imgUserInput))) {
+				prepend = localRegistryPrefix
+				break
+			}
+		}
+	}
+	return fmt.Sprintf("%s%s", prepend, imgUserInput)
+}