Refactoring

Makefile

@@ -15,9 +15,9 @@ check-counterfeiter:
 gen-mocks: check-counterfeiter
 	counterfeiter -o pkg/registry/ggcrfakes/fake_image.go github.com/google/go-containerregistry/pkg/v1.Image
 	counterfeiter -o pkg/registry/ggcrfakes/fake_image_index.go github.com/google/go-containerregistry/pkg/v1.ImageIndex
-	counterfeiter pkg/registry LayoutPath
+	counterfeiter pkg/registry/ggcr/path LayoutPath
 	counterfeiter pkg/registry Image
-	counterfeiter pkg/registry/ggcr RegistryClient
+	counterfeiter -o pkg/registry/ggcr/registryclientfakes/fake_registry_client.go ./pkg/registry/ggcr RegistryClient
 
 irel: $(GO_SOURCES)
 	GO111MODULE=on go build -o $(OUTPUT) cmd/irel/main.go

pkg/registry/ggcr/client.go

@@ -18,13 +18,30 @@ package ggcr
 
 import (
 	"fmt"
+	"os"
 
 	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/empty"
+	"github.com/google/go-containerregistry/pkg/v1/layout"
 
 	"github.com/pivotal/image-relocation/pkg/image"
 	"github.com/pivotal/image-relocation/pkg/registry"
 )
 
+const outputDirPermissions = 0755
+
+// RegistryClient provides methods for building abstract images.
+type RegistryClient interface {
+	// ReadRemoteImage builds an abstract image from a repository.
+	ReadRemoteImage(n image.Name) (registry.Image, error)
+
+	// NewImageFromManifest builds an abstract image from an image manifest.
+	NewImageFromManifest(img v1.Image) registry.Image
+
+	// NewImageFromIndex builds an abstract image from an image index.
+	NewImageFromIndex(img v1.ImageIndex) registry.Image
+}
+
 type manifestWriter func(i v1.Image, n image.Name) error
 type indexWriter func(i v1.ImageIndex, n image.Name) error
 
@@ -34,6 +51,8 @@ type client struct {
 	writeRemoteIndex indexWriter
 }
 
+var _ RegistryClient = &client{}
+
 // NewRegistryClient returns a new Client.
 func NewRegistryClient() *client {
 	return &client{
@@ -44,7 +63,7 @@ func NewRegistryClient() *client {
 }
 
 func (r *client) Digest(n image.Name) (image.Digest, error) {
-	img, err := r.readRemoteImage(n)
+	img, err := r.ReadRemoteImage(n)
 	if err != nil {
 		return image.EmptyDigest, err
 	}
@@ -58,7 +77,7 @@ func (r *client) Digest(n image.Name) (image.Digest, error) {
 }
 
 func (r *client) Copy(source image.Name, target image.Name) (image.Digest, int64, error) {
-	img, err := r.readRemoteImage(source)
+	img, err := r.ReadRemoteImage(source)
 	if err != nil {
 		return image.EmptyDigest, 0, fmt.Errorf("failed to read image %v: %v", source, err)
 	}
@@ -70,22 +89,48 @@ func (r *client) Copy(source image.Name, target image.Name) (image.Digest, int64
 
 	targetDigest, s, err := img.Write(target)
 	if err != nil {
-		return image.EmptyDigest, 0, fmt.Errorf("failed to write image %v: %v", target, err)
+		return image.EmptyDigest, 0, fmt.Errorf("failed to write image %v to %v: %v", source, target, err)
 	}
 	if sourceDigest != targetDigest {
 		return image.EmptyDigest, 0, fmt.Errorf("failed to preserve digest of image %v: source digest %v, target digest %v", source, sourceDigest, targetDigest)
 	}
 	return targetDigest, s, err
 }
 
+func (r *client) NewLayout(path string) (registry.Layout, error) {
+	if _, err := os.Stat(path); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+		if err := os.MkdirAll(path, outputDirPermissions); err != nil {
+			return nil, err
+		}
+	}
+
+	lp, err := layout.Write(path, empty.Index)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewImageLayout(r, lp), nil
+}
+
+func (r *client) ReadLayout(path string) (registry.Layout, error) {
+	lp, err := layout.FromPath(path)
+	if err != nil {
+		return nil, err
+	}
+	return NewImageLayout(r, lp), nil
+}
+
 func (r *client) ReadRemoteImage(n image.Name) (registry.Image, error) {
 	return r.readRemoteImage(n)
 }
 
-func (r *client) WriteRemoteImage(i v1.Image, n image.Name) error {
-	return r.writeRemoteImage(i, n)
+func (r *client) NewImageFromManifest(img v1.Image) registry.Image {
+	return newImageFromManifest(img, r.writeRemoteImage)
 }
 
-func (r *client) WriteRemoteIndex(i v1.ImageIndex, n image.Name) error {
-	return r.writeRemoteIndex(i, n)
+func (r *client) NewImageFromIndex(idx v1.ImageIndex) registry.Image {
+	return newImageFromIndex(idx, r.writeRemoteIndex)
 }

pkg/registry/ggcr/client_test.go

@@ -115,7 +115,7 @@ var _ = Describe("Client", func() {
 			})
 
 			It("should return a corresponding error", func() {
-				Expect(err).To(MatchError("failed to write image docker.io/library/target: something bad happened"))
+				Expect(err).To(MatchError("failed to write image docker.io/library/source to docker.io/library/target: something bad happened"))
 			})
 		})
 

pkg/registry/ggcr/registry_suite_test.go → pkg/registry/ggcr/ggcr_suite_test.go

@@ -23,7 +23,7 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-func TestRegistry(t *testing.T) {
+func TestGgcr(t *testing.T) {
 	RegisterFailHandler(Fail)
-	RunSpecs(t, "Registry Suite")
+	RunSpecs(t, "ggcr Suite")
 }