exporter: Add exptypes with Common exporter keys

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

exporter/containerimage/exptypes/keys.go

@@ -1,5 +1,7 @@
 package exptypes
 
+import commonexptypes "github.com/moby/buildkit/exporter/exptypes"
+
 type ImageExporterOptKey string
 
 // Options keys supported by the image exporter output.
@@ -55,7 +57,7 @@ var (
 	// Clamp produced timestamps. For more information see the
 	// SOURCE_DATE_EPOCH specification.
 	// Value: int (number of seconds since Unix epoch)
-	OptKeySourceDateEpoch ImageExporterOptKey = "source-date-epoch"
+	OptKeySourceDateEpoch ImageExporterOptKey = ImageExporterOptKey(commonexptypes.OptKeySourceDateEpoch)
 
 	// Compression type for newly created and cached layers.
 	// estargz should be used with OptKeyOCITypes set to true.

exporter/containerimage/exptypes/types.go

@@ -12,7 +12,6 @@ const (
 	ExporterImageDescriptorKey   = "containerimage.descriptor"
 	ExporterInlineCache          = "containerimage.inlinecache"
 	ExporterPlatformsKey         = "refs.platforms"
-	ExporterEpochKey             = "source.date.epoch"
 )
 
 // KnownRefMetadataKeys are the subset of exporter keys that can be suffixed by

exporter/exptypes/keys.go

@@ -0,0 +1,15 @@
+package exptypes
+
+const (
+	ExporterEpochKey = "source.date.epoch"
+)
+
+type ExporterOptKey string
+
+// Options keys supported by all exporters.
+var (
+	// Clamp produced timestamps. For more information see the
+	// SOURCE_DATE_EPOCH specification.
+	// Value: int (number of seconds since Unix epoch)
+	OptKeySourceDateEpoch ExporterOptKey = "source-date-epoch"
+)

exporter/util/epoch/parse.go

@@ -5,7 +5,7 @@ import (
 	"time"
 
 	"github.com/moby/buildkit/exporter"
-	"github.com/moby/buildkit/exporter/containerimage/exptypes"
+	commonexptypes "github.com/moby/buildkit/exporter/exptypes"
 	"github.com/pkg/errors"
 )
 
@@ -25,7 +25,7 @@ func ParseExporterAttrs(opt map[string]string) (*time.Time, map[string]string, e
 
 	for k, v := range opt {
 		switch k {
-		case string(exptypes.OptKeySourceDateEpoch):
+		case string(commonexptypes.OptKeySourceDateEpoch):
 			var err error
 			tm, err = parseTime(k, v)
 			if err != nil {
@@ -40,7 +40,7 @@ func ParseExporterAttrs(opt map[string]string) (*time.Time, map[string]string, e
 }
 
 func ParseSource(inp *exporter.Source) (*time.Time, bool, error) {
-	if v, ok := inp.Metadata[exptypes.ExporterEpochKey]; ok {
+	if v, ok := inp.Metadata[commonexptypes.ExporterEpochKey]; ok {
 		epoch, err := parseTime("", string(v))
 		if err != nil {
 			return nil, false, errors.Wrapf(err, "invalid SOURCE_DATE_EPOCH from frontend: %q", v)