Allow overriding image creation time

local/local.go

@@ -11,6 +11,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -789,12 +790,27 @@ func defaultPlatform(dockerClient client.CommonAPIClient) (imgutil.Platform, err
 	}, nil
 }
 
+func getCreationTimeFromEnv() v1.Time {
+	epoch := os.Getenv("SOURCE_DATE_EPOCH")
+	if epoch == "" {
+		return v1.Time{Time: imgutil.NormalizedDateTime}
+	}
+
+	seconds, err := strconv.ParseInt(epoch, 10, 64)
+	if err != nil {
+		return v1.Time{Time: imgutil.NormalizedDateTime}
+	}
+	return v1.Time{Time: time.Unix(seconds, 0)}
+}
+
 func v1Config(inspect types.ImageInspect) (v1.ConfigFile, error) {
+	creationTime := getCreationTimeFromEnv()
+
 	history := make([]v1.History, len(inspect.RootFS.Layers))
 	for i := range history {
 		// zero history
 		history[i] = v1.History{
-			Created: v1.Time{Time: imgutil.NormalizedDateTime},
+			Created: creationTime,
 		}
 	}
 	diffIDs := make([]v1.Hash, len(inspect.RootFS.Layers))
@@ -850,7 +866,7 @@ func v1Config(inspect types.ImageInspect) (v1.ConfigFile, error) {
 	}
 	return v1.ConfigFile{
 		Architecture: inspect.Architecture,
-		Created:      v1.Time{Time: imgutil.NormalizedDateTime},
+		Created:      creationTime,
 		History:      history,
 		OS:           inspect.Os,
 		OSVersion:    inspect.OsVersion,

remote/remote.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -629,12 +631,26 @@ func findLayerWithSha(layers []v1.Layer, diffID string) (v1.Layer, error) {
 	return nil, fmt.Errorf("previous image did not have layer with diff id %q", diffID)
 }
 
+func getCreationTimeFromEnv() v1.Time {
+	epoch := os.Getenv("SOURCE_DATE_EPOCH")
+	if epoch == "" {
+		return v1.Time{Time: imgutil.NormalizedDateTime}
+	}
+
+	seconds, err := strconv.ParseInt(epoch, 10, 64)
+	if err != nil {
+		return v1.Time{Time: imgutil.NormalizedDateTime}
+	}
+	return v1.Time{Time: time.Unix(seconds, 0)}
+}
+
 func (i *Image) Save(additionalNames ...string) error {
 	var err error
 
 	allNames := append([]string{i.repoName}, additionalNames...)
 
-	i.image, err = mutate.CreatedAt(i.image, v1.Time{Time: imgutil.NormalizedDateTime})
+	creationTime := getCreationTimeFromEnv()
+	i.image, err = mutate.CreatedAt(i.image, creationTime)
 	if err != nil {
 		return errors.Wrap(err, "set creation time")
 	}
@@ -652,7 +668,7 @@ func (i *Image) Save(additionalNames ...string) error {
 	cfg.History = make([]v1.History, len(layers))
 	for i := range cfg.History {
 		cfg.History[i] = v1.History{
-			Created: v1.Time{Time: imgutil.NormalizedDateTime},
+			Created: creationTime,
 		}
 	}
 

remote/remote_test.go

@@ -1404,6 +1404,30 @@ func testImage(t *testing.T, when spec.G, it spec.S) {
 					h.AssertEq(t, item.Created.Unix(), imgutil.NormalizedDateTime.Unix())
 				}
 			})
+
+			it("can override creation time", func() {
+				img, err := remote.NewImage(repoName, authn.DefaultKeychain)
+				h.AssertNil(t, err)
+
+				tarPath, err := h.CreateSingleFileLayerTar("/new-layer.txt", "new-layer", "linux")
+				h.AssertNil(t, err)
+				defer os.Remove(tarPath)
+
+				h.AssertNil(t, img.AddLayer(tarPath))
+
+				epoch := time.Now().Unix()
+				os.Setenv("SOURCE_DATE_EPOCH", fmt.Sprintf("%d", epoch))
+				h.AssertNil(t, img.Save())
+
+				configFile := h.FetchManifestImageConfigFile(t, repoName)
+
+				h.AssertEq(t, configFile.Created.Time.Unix(), epoch)
+
+				h.AssertEq(t, len(configFile.History), len(configFile.RootFS.DiffIDs))
+				for _, item := range configFile.History {
+					h.AssertEq(t, item.Created.Unix(), epoch)
+				}
+			})
 		})
 
 		when("additional names are provided", func() {