remove time from random.Image history (#1678)

ktarplee · web-flow · commit d64f9e0e999f · 2023-04-27T09:55:16.000-07:00
This makes the images non-reproducible which defeats the purpose of setting the random source.
diff --git a/pkg/v1/random/image.go b/pkg/v1/random/image.go
@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"io"
 	"math/rand"
-	"time"
 
 	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/empty"
@@ -69,7 +68,6 @@ func Image(byteSize, layers int64, options ...Option) (v1.Image, error) {
 				Author:    "random.Image",
 				Comment:   fmt.Sprintf("this is a random history %d of %d", i, layers),
 				CreatedBy: "random",
-				Created:   v1.Time{Time: time.Now()},
 			},
 		})
 	}
diff --git a/pkg/v1/random/image_test.go b/pkg/v1/random/image_test.go
@@ -22,6 +22,7 @@ import (
 	"math/rand"
 	"testing"
 
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/types"
 	"github.com/google/go-containerregistry/pkg/v1/validate"
 )
@@ -169,3 +170,37 @@ func TestRandomLayerSource(t *testing.T) {
 		t.Error("Expected the layer data to be different with different random seeds")
 	}
 }
+
+func TestRandomImageSource(t *testing.T) {
+	imageDigest := func(o ...Option) v1.Hash {
+		img, err := Image(1024, 2, o...)
+		if err != nil {
+			t.Fatalf("Image: %v", err)
+		}
+
+		h, err := img.Digest()
+		if err != nil {
+			t.Fatalf("Digest(): %v", err)
+		}
+		return h
+	}
+
+	digest0a := imageDigest(WithSource(rand.NewSource(0)))
+	digest0b := imageDigest(WithSource(rand.NewSource(0)))
+	digest1 := imageDigest(WithSource(rand.NewSource(1)))
+
+	if digest0a != digest0b {
+		t.Error("Expected the image digest to be the same with the same seed")
+	}
+
+	if digest0a == digest1 {
+		t.Error("Expected the image digest to be different with different seeds")
+	}
+
+	digestA := imageDigest()
+	digestB := imageDigest()
+
+	if digestA == digestB {
+		t.Error("Expected the image digest to be different with different random seeds")
+	}
+}
diff --git a/pkg/v1/random/index_test.go b/pkg/v1/random/index_test.go
@@ -15,8 +15,10 @@
 package random
 
 import (
+	"math/rand"
 	"testing"
 
+	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/types"
 	"github.com/google/go-containerregistry/pkg/v1/validate"
 )
@@ -62,3 +64,37 @@ func TestRandomIndex(t *testing.T) {
 		t.Errorf("MediaType: got: %v, want: %v", got, want)
 	}
 }
+
+func TestRandomIndexSource(t *testing.T) {
+	indexDigest := func(o ...Option) v1.Hash {
+		img, err := Index(1024, 2, 2, o...)
+		if err != nil {
+			t.Fatalf("Image: %v", err)
+		}
+
+		h, err := img.Digest()
+		if err != nil {
+			t.Fatalf("Digest(): %v", err)
+		}
+		return h
+	}
+
+	digest0a := indexDigest(WithSource(rand.NewSource(0)))
+	digest0b := indexDigest(WithSource(rand.NewSource(0)))
+	digest1 := indexDigest(WithSource(rand.NewSource(1)))
+
+	if digest0a != digest0b {
+		t.Error("Expected the index digest to be the same with the same seed")
+	}
+
+	if digest0a == digest1 {
+		t.Error("Expected the index digest to be different with different seeds")
+	}
+
+	digestA := indexDigest()
+	digestB := indexDigest()
+
+	if digestA == digestB {
+		t.Error("Expected the index digest to be different with different random seeds")
+	}
+}
