support multi-image (docker) archives

Support loading and saving tarballs with more than one image.
Add a new `/libpod/images/export` endpoint to the rest API to
allow for exporting/saving multiple images into an archive.

Note that a non-release version of containers/image is vendored.
A release version must be vendored before cutting a new Podman
release.  We force the containers/image version via a replace in
the go.mod file; this way go won't try to match the versions.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

3 files changed, 35 insertions, 19 deletions

diff --git a/pkg/domain/entities/images.go b/pkg/domain/entities/images.go
index 3a12a4e22..2a8133680 100644
--- a/pkg/domain/entities/images.go
+++ b/pkg/domain/entities/images.go
@@ -271,11 +271,22 @@ type ImageImportReport struct {
 	Id string //nolint
 }
 
+// ImageSaveOptions provide options for saving images.
 type ImageSaveOptions struct {
+	// Compress layers when saving to a directory.
 	Compress bool
-	Format   string
-	Output   string
-	Quiet    bool
+	// Format of saving the image: oci-archive, oci-dir (directory with oci
+	// manifest type), docker-archive, docker-dir (directory with v2s2
+	// manifest type).
+	Format string
+	// MultiImageArchive denotes if the created archive shall include more
+	// than one image.  Additional tags will be interpreted as references
+	// to images which are added to the archive.
+	MultiImageArchive bool
+	// Output - write image to the specified path.
+	Output string
+	// Quiet - suppress output when copying images
+	Quiet bool
 }
 
 // ImageTreeOptions provides options for ImageEngine.Tree()
diff --git a/pkg/domain/infra/abi/images.go b/pkg/domain/infra/abi/images.go
index 6b94ca9c0..33060b34b 100644
--- a/pkg/domain/infra/abi/images.go
+++ b/pkg/domain/infra/abi/images.go
@@ -14,7 +14,6 @@ import (
 
 	"github.com/containers/common/pkg/config"
 	"github.com/containers/image/v5/docker"
-	dockerarchive "github.com/containers/image/v5/docker/archive"
 	"github.com/containers/image/v5/docker/reference"
 	"github.com/containers/image/v5/manifest"
 	"github.com/containers/image/v5/signature"
@@ -230,15 +229,6 @@ func (ir *ImageEngine) Pull(ctx context.Context, rawImage string, options entiti
 		}
 	}
 
-	// Special-case for docker-archive which allows multiple tags.
-	if imageRef.Transport().Name() == dockerarchive.Transport.Name() {
-		newImage, err := ir.Libpod.ImageRuntime().LoadFromArchiveReference(ctx, imageRef, options.SignaturePolicy, writer)
-		if err != nil {
-			return nil, err
-		}
-		return &entities.ImagePullReport{Images: []string{newImage[0].ID()}}, nil
-	}
-
 	var registryCreds *types.DockerAuthConfig
 	if len(options.Username) > 0 && len(options.Password) > 0 {
 		registryCreds = &types.DockerAuthConfig{
@@ -481,6 +471,10 @@ func (ir *ImageEngine) Import(ctx context.Context, opts entities.ImageImportOpti
 }
 
 func (ir *ImageEngine) Save(ctx context.Context, nameOrID string, tags []string, options entities.ImageSaveOptions) error {
+	if options.MultiImageArchive {
+		nameOrIDs := append([]string{nameOrID}, tags...)
+		return ir.Libpod.ImageRuntime().SaveImages(ctx, nameOrIDs, options.Format, options.Output, options.Quiet)
+	}
 	newImage, err := ir.Libpod.ImageRuntime().NewFromLocal(nameOrID)
 	if err != nil {
 		return err
diff --git a/pkg/domain/infra/tunnel/images.go b/pkg/domain/infra/tunnel/images.go
index b255c5da4..185cc2f9a 100644
--- a/pkg/domain/infra/tunnel/images.go
+++ b/pkg/domain/infra/tunnel/images.go
@@ -251,12 +251,23 @@ func (ir *ImageEngine) Save(ctx context.Context, nameOrID string, tags []string,
 		return err
 	}
 
-	exErr := images.Export(ir.ClientCxt, nameOrID, f, &options.Format, &options.Compress)
-	if err := f.Close(); err != nil {
-		return err
-	}
-	if exErr != nil {
-		return exErr
+	if options.MultiImageArchive {
+		exErr := images.MultiExport(ir.ClientCxt, append([]string{nameOrID}, tags...), f, &options.Format, &options.Compress)
+		if err := f.Close(); err != nil {
+			return err
+		}
+		if exErr != nil {
+			return exErr
+		}
+	} else {
+		// FIXME: tags are entirely ignored here but shouldn't.
+		exErr := images.Export(ir.ClientCxt, nameOrID, f, &options.Format, &options.Compress)
+		if err := f.Close(); err != nil {
+			return err
+		}
+		if exErr != nil {
+			return exErr
+		}
 	}
 
 	if options.Format != "oci-dir" && options.Format != "docker-dir" {