Enable selecting compression on remote cache export

Signed-off-by: Kohei Tokunaga <[email protected]>

README.md

@@ -360,6 +360,9 @@ buildctl build ... \
 * `mode=max`: export all the layers of all intermediate steps.
 * `ref=docker.io/user/image:tag`: reference
 * `oci-mediatypes=true|false`: whether to use OCI mediatypes in exported manifests. Since BuildKit `v0.8` defaults to true.
+* `compression=[uncompressed,gzip,estargz,zstd]`: choose compression type for layers newly created and cached, gzip is default value. estargz and zstd should be used with `oci-mediatypes=true`.
+* `compression-level=[value]`: compression level for gzip, estargz (0-9) and zstd (0-22)
+* `force-compression=true`: forcibly apply `compression` option to all layers.
 
 `--import-cache` options:
 * `type=registry`
@@ -380,6 +383,9 @@ The directory layout conforms to OCI Image Spec v1.0.
 * `mode=max`: export all the layers of all intermediate steps.
 * `dest=path/to/output-dir`: destination directory for cache exporter
 * `oci-mediatypes=true|false`: whether to use OCI mediatypes in exported manifests. Since BuildKit `v0.8` defaults to true.
+* `compression=[uncompressed,gzip,estargz,zstd]`: choose compression type for layers newly created and cached, gzip is default value. estargz and zstd should be used with `oci-mediatypes=true`.
+* `compression-level=[value]`: compression level for gzip, estargz (0-9) and zstd (0-22)
+* `force-compression=true`: forcibly apply `compression` option to all layers.
 
 `--import-cache` options:
 * `type=local`

cache/remotecache/export.go

@@ -47,6 +47,14 @@ type Exporter interface {
 	Finalize(ctx context.Context) (map[string]string, error)
 }
 
+type ExporterConfig interface {
+	Config() Config
+}
+
+type Config struct {
+	Compression compression.Config
+}
+
 const (
 	// ExportResponseManifestDesc is a key for the map returned from Exporter.Finalize.
 	// The map value is a JSON string of an OCI desciptor of a manifest.
@@ -59,11 +67,18 @@ type contentCacheExporter struct {
 	ingester content.Ingester
 	oci      bool
 	ref      string
+	comp     compression.Config
 }
 
-func NewExporter(ingester content.Ingester, ref string, oci bool) Exporter {
+func NewExporter(ingester content.Ingester, ref string, oci bool, compressionConfig compression.Config) Exporter {
 	cc := v1.NewCacheChains()
-	return &contentCacheExporter{CacheExporterTarget: cc, chains: cc, ingester: ingester, oci: oci, ref: ref}
+	return &contentCacheExporter{CacheExporterTarget: cc, chains: cc, ingester: ingester, oci: oci, ref: ref, comp: compressionConfig}
+}
+
+func (ce *contentCacheExporter) Config() Config {
+	return Config{
+		Compression: ce.comp,
+	}
 }
 
 func (ce *contentCacheExporter) Finalize(ctx context.Context) (map[string]string, error) {

cache/remotecache/local/local.go

@@ -9,6 +9,7 @@ import (
 	"github.com/moby/buildkit/cache/remotecache"
 	"github.com/moby/buildkit/session"
 	sessioncontent "github.com/moby/buildkit/session/content"
+	"github.com/moby/buildkit/util/compression"
 	digest "github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
@@ -20,6 +21,9 @@ const (
 	attrDest             = "dest"
 	attrOCIMediatypes    = "oci-mediatypes"
 	contentStoreIDPrefix = "local:"
+	attrLayerCompression = "compression"
+	attrForceCompression = "force-compression"
+	attrCompressionLevel = "compression-level"
 )
 
 // ResolveCacheExporterFunc for "local" cache exporter.
@@ -29,6 +33,10 @@ func ResolveCacheExporterFunc(sm *session.Manager) remotecache.ResolveCacheExpor
 		if store == "" {
 			return nil, errors.New("local cache exporter requires dest")
 		}
+		compressionConfig, err := attrsToCompression(attrs)
+		if err != nil {
+			return nil, err
+		}
 		ociMediatypes := true
 		if v, ok := attrs[attrOCIMediatypes]; ok {
 			b, err := strconv.ParseBool(v)
@@ -42,7 +50,7 @@ func ResolveCacheExporterFunc(sm *session.Manager) remotecache.ResolveCacheExpor
 		if err != nil {
 			return nil, err
 		}
-		return remotecache.NewExporter(cs, "", ociMediatypes), nil
+		return remotecache.NewExporter(cs, "", ociMediatypes, *compressionConfig), nil
 	}
 }
 
@@ -92,3 +100,34 @@ func getContentStore(ctx context.Context, sm *session.Manager, g session.Group,
 	}
 	return sessioncontent.NewCallerStore(caller, storeID), nil
 }
+
+func attrsToCompression(attrs map[string]string) (*compression.Config, error) {
+	compressionType := compression.Default
+	if v, ok := attrs[attrLayerCompression]; ok {
+		if c := compression.Parse(v); c != compression.UnknownCompression {
+			compressionType = c
+		}
+	}
+	compressionConfig := compression.New(compressionType)
+	if v, ok := attrs[attrForceCompression]; ok {
+		var force bool
+		if v == "" {
+			force = true
+		} else {
+			b, err := strconv.ParseBool(v)
+			if err != nil {
+				return nil, errors.Wrapf(err, "non-bool value %s specified for %s", v, attrForceCompression)
+			}
+			force = b
+		}
+		compressionConfig = compressionConfig.SetForce(force)
+	}
+	if v, ok := attrs[attrCompressionLevel]; ok {
+		ii, err := strconv.ParseInt(v, 10, 64)
+		if err != nil {
+			return nil, errors.Wrapf(err, "non-integer value %s specified for %s", v, attrCompressionLevel)
+		}
+		compressionConfig = compressionConfig.SetLevel(int(ii))
+	}
+	return &compressionConfig, nil
+}

cache/remotecache/registry/registry.go

@@ -10,6 +10,7 @@ import (
 	"github.com/docker/distribution/reference"
 	"github.com/moby/buildkit/cache/remotecache"
 	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/util/compression"
 	"github.com/moby/buildkit/util/contentutil"
 	"github.com/moby/buildkit/util/estargz"
 	"github.com/moby/buildkit/util/push"
@@ -32,12 +33,19 @@ func canonicalizeRef(rawRef string) (string, error) {
 }
 
 const (
-	attrRef           = "ref"
-	attrOCIMediatypes = "oci-mediatypes"
+	attrRef              = "ref"
+	attrOCIMediatypes    = "oci-mediatypes"
+	attrLayerCompression = "compression"
+	attrForceCompression = "force-compression"
+	attrCompressionLevel = "compression-level"
 )
 
 func ResolveCacheExporterFunc(sm *session.Manager, hosts docker.RegistryHosts) remotecache.ResolveCacheExporterFunc {
 	return func(ctx context.Context, g session.Group, attrs map[string]string) (remotecache.Exporter, error) {
+		compressionConfig, err := attrsToCompression(attrs)
+		if err != nil {
+			return nil, err
+		}
 		ref, err := canonicalizeRef(attrs[attrRef])
 		if err != nil {
 			return nil, err
@@ -55,7 +63,7 @@ func ResolveCacheExporterFunc(sm *session.Manager, hosts docker.RegistryHosts) r
 		if err != nil {
 			return nil, err
 		}
-		return remotecache.NewExporter(contentutil.FromPusher(pusher), ref, ociMediatypes), nil
+		return remotecache.NewExporter(contentutil.FromPusher(pusher), ref, ociMediatypes, *compressionConfig), nil
 	}
 }
 
@@ -121,3 +129,34 @@ func (dsl *withDistributionSourceLabel) SnapshotLabels(descs []ocispecs.Descript
 	}
 	return labels
 }
+
+func attrsToCompression(attrs map[string]string) (*compression.Config, error) {
+	compressionType := compression.Default
+	if v, ok := attrs[attrLayerCompression]; ok {
+		if c := compression.Parse(v); c != compression.UnknownCompression {
+			compressionType = c
+		}
+	}
+	compressionConfig := compression.New(compressionType)
+	if v, ok := attrs[attrForceCompression]; ok {
+		var force bool
+		if v == "" {
+			force = true
+		} else {
+			b, err := strconv.ParseBool(v)
+			if err != nil {
+				return nil, errors.Wrapf(err, "non-bool value %s specified for %s", v, attrForceCompression)
+			}
+			force = b
+		}
+		compressionConfig = compressionConfig.SetForce(force)
+	}
+	if v, ok := attrs[attrCompressionLevel]; ok {
+		ii, err := strconv.ParseInt(v, 10, 64)
+		if err != nil {
+			return nil, errors.Wrapf(err, "non-integer value %s specified for %s", v, attrCompressionLevel)
+		}
+		compressionConfig = compressionConfig.SetLevel(int(ii))
+	}
+	return &compressionConfig, nil
+}