manifests,push: add support for ReplicateWithCompression

`c/image` recently added support for EnsureCompressionVariantsExist,
following PR exposes the feature to `c/common` manifests so actual users
can use it.

Signed-off-by: Aditya R <arajan@redhat.com>

libimage/manifests/manifests.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containers/image/v5/docker/reference"
 	"github.com/containers/image/v5/image"
 	"github.com/containers/image/v5/manifest"
+	"github.com/containers/image/v5/pkg/compression"
 	"github.com/containers/image/v5/signature"
 	"github.com/containers/image/v5/signature/signer"
 	is "github.com/containers/image/v5/storage"
@@ -70,6 +71,7 @@ type PushOptions struct {
 	RemoveSignatures                 bool                  // true to discard signatures in images
 	ManifestType                     string                // the format to use when saving the list - possible options are oci, v2s1, and v2s2
 	SourceFilter                     LookupReferenceFunc   // filter the list source
+	ReplicateWithCompression         []string              // replicate required imges with requested compression algorithms
 }
 
 // Create creates a new list containing information about the specified image,
@@ -239,6 +241,7 @@ func (l *list) Push(ctx context.Context, dest types.ImageReference, options Push
 			return nil, "", err
 		}
 	}
+	compressionVariant := prepareReplicateWithCompression(option.ReplicateWithCompression)
 	copyOptions := &cp.Options{
 		ImageListSelection:               options.ImageListSelection,
 		Instances:                        options.Instances,
@@ -252,6 +255,7 @@ func (l *list) Push(ctx context.Context, dest types.ImageReference, options Push
 		SignBySigstorePrivateKeyFile:     options.SignBySigstorePrivateKeyFile,
 		SignSigstorePrivateKeyPassphrase: options.SignSigstorePrivateKeyPassphrase,
 		ForceManifestMIMEType:            singleImageManifestType,
+		EnsureCompressionVariantExists:   compressionVariants,
 	}
 
 	// Copy whatever we were asked to copy.
@@ -266,6 +270,19 @@ func (l *list) Push(ctx context.Context, dest types.ImageReference, options Push
 	return nil, manifestDigest, nil
 }
 
+func prepareReplicateWithCompression(variants []string) ([]OptionCompressionVariant, error) {
+	res := []cp.OptionCompressionVariant{}
+	for _, compressionVariant := range variants {
+		algo, err := compression.AlgorithmByName(name)
+		if err != nil {
+			return nil, fmt.Errorf("requested algorithm %s is not supported for replication: %w", err)
+		}
+		variant := cp.CopyOptionCompressionVariant{Algorithm: algo}
+		res = append(res, cp.OptionCompressionVariant{Algorithm: algo})
+	}
+	return res, nil
+}
+
 // Add adds information about the specified image to the list, computing the
 // image's manifest's digest, retrieving OS and architecture information from
 // the image's configuration, and recording the image's reference so that it

libimage/manifests/manifests_test.go

@@ -333,4 +333,8 @@ func TestPush(t *testing.T) {
 	options.Instances = append(options.Instances, otherListDigest)
 	_, _, err = list.Push(ctx, destRef, options)
 	assert.Nilf(t, err, "list.Push(four specified)")
+
+	options.ReplicateWithCompression = []string{"zstd"}
+	_, _, err = list.Push(ctx, destRef, options)
+	assert.Nilf(t, err, "list.Push(with replication for zstd specified)")
 }