StorageDriver: Test case for #1698

Signed-off-by: Arthur Baars <arthur@semmle.com>

docs/handlers/api_test.go

@@ -29,7 +29,7 @@ import (
 	"github.com/docker/distribution/reference"
 	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/docker/distribution/registry/api/v2"
-	_ "github.com/docker/distribution/registry/storage/driver/inmemory"
+	_ "github.com/docker/distribution/registry/storage/driver/testdriver"
 	"github.com/docker/distribution/testutil"
 	"github.com/docker/libtrust"
 	"github.com/gorilla/handlers"
@@ -219,7 +219,7 @@ func contains(elems []string, e string) bool {
 func TestURLPrefix(t *testing.T) {
 	config := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
+			"testdriver": configuration.Parameters{},
 		},
 	}
 	config.HTTP.Prefix = "/test/"
@@ -296,7 +296,7 @@ func TestBlobDelete(t *testing.T) {
 func TestRelativeURL(t *testing.T) {
 	config := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
+			"testdriver": configuration.Parameters{},
 		},
 	}
 	config.HTTP.Headers = headerConfig
@@ -1884,8 +1884,8 @@ type testEnv struct {
 func newTestEnvMirror(t *testing.T, deleteEnabled bool) *testEnv {
 	config := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
-			"delete":   configuration.Parameters{"enabled": deleteEnabled},
+			"testdriver": configuration.Parameters{},
+			"delete":     configuration.Parameters{"enabled": deleteEnabled},
 		},
 		Proxy: configuration.Proxy{
 			RemoteURL: "http://example.com",
@@ -1899,8 +1899,8 @@ func newTestEnvMirror(t *testing.T, deleteEnabled bool) *testEnv {
 func newTestEnv(t *testing.T, deleteEnabled bool) *testEnv {
 	config := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
-			"delete":   configuration.Parameters{"enabled": deleteEnabled},
+			"testdriver": configuration.Parameters{},
+			"delete":     configuration.Parameters{"enabled": deleteEnabled},
 		},
 	}
 
@@ -2413,7 +2413,7 @@ func TestCheckContextNotifier(t *testing.T) {
 func TestProxyManifestGetByTag(t *testing.T) {
 	truthConfig := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
+			"testdriver": configuration.Parameters{},
 		},
 	}
 	truthConfig.HTTP.Headers = headerConfig
@@ -2427,7 +2427,7 @@ func TestProxyManifestGetByTag(t *testing.T) {
 
 	proxyConfig := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": configuration.Parameters{},
+			"testdriver": configuration.Parameters{},
 		},
 		Proxy: configuration.Proxy{
 			RemoteURL: truthEnv.server.URL,

docs/handlers/app_test.go

@@ -16,7 +16,7 @@ import (
 	_ "github.com/docker/distribution/registry/auth/silly"
 	"github.com/docker/distribution/registry/storage"
 	memorycache "github.com/docker/distribution/registry/storage/cache/memory"
-	"github.com/docker/distribution/registry/storage/driver/inmemory"
+	"github.com/docker/distribution/registry/storage/driver/testdriver"
 )
 
 // TestAppDispatcher builds an application with a test dispatcher and ensures
@@ -24,7 +24,7 @@ import (
 // This only tests the dispatch mechanism. The underlying dispatchers must be
 // tested individually.
 func TestAppDispatcher(t *testing.T) {
-	driver := inmemory.New()
+	driver := testdriver.New()
 	ctx := context.Background()
 	registry, err := storage.NewRegistry(ctx, driver, storage.BlobDescriptorCacheProvider(memorycache.NewInMemoryBlobDescriptorCacheProvider()), storage.EnableDelete, storage.EnableRedirect)
 	if err != nil {
@@ -142,7 +142,7 @@ func TestNewApp(t *testing.T) {
 	ctx := context.Background()
 	config := configuration.Configuration{
 		Storage: configuration.Storage{
-			"inmemory": nil,
+			"testdriver": nil,
 		},
 		Auth: configuration.Auth{
 			// For now, we simply test that new auth results in a viable

docs/storage/blob_test.go

@@ -14,7 +14,7 @@ import (
 	"github.com/docker/distribution/digest"
 	"github.com/docker/distribution/reference"
 	"github.com/docker/distribution/registry/storage/cache/memory"
-	"github.com/docker/distribution/registry/storage/driver/inmemory"
+	"github.com/docker/distribution/registry/storage/driver/testdriver"
 	"github.com/docker/distribution/testutil"
 	"path"
 )
@@ -24,7 +24,7 @@ import (
 func TestWriteSeek(t *testing.T) {
 	ctx := context.Background()
 	imageName, _ := reference.ParseNamed("foo/bar")
-	driver := inmemory.New()
+	driver := testdriver.New()
 	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)
@@ -42,6 +42,7 @@ func TestWriteSeek(t *testing.T) {
 	}
 	contents := []byte{1, 2, 3}
 	blobUpload.Write(contents)
+	blobUpload.Close()
 	offset := blobUpload.Size()
 	if offset != int64(len(contents)) {
 		t.Fatalf("unexpected value for blobUpload offset:  %v != %v", offset, len(contents))
@@ -59,7 +60,7 @@ func TestSimpleBlobUpload(t *testing.T) {
 
 	ctx := context.Background()
 	imageName, _ := reference.ParseNamed("foo/bar")
-	driver := inmemory.New()
+	driver := testdriver.New()
 	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)
@@ -120,11 +121,12 @@ func TestSimpleBlobUpload(t *testing.T) {
 		t.Fatalf("layer data write incomplete")
 	}
 
+	blobUpload.Close()
+
 	offset := blobUpload.Size()
 	if offset != nn {
 		t.Fatalf("blobUpload not updated with correct offset: %v != %v", offset, nn)
 	}
-	blobUpload.Close()
 
 	// Do a resume, for good fun
 	blobUpload, err = bs.Resume(ctx, blobUpload.ID())
@@ -253,7 +255,7 @@ func TestSimpleBlobUpload(t *testing.T) {
 func TestSimpleBlobRead(t *testing.T) {
 	ctx := context.Background()
 	imageName, _ := reference.ParseNamed("foo/bar")
-	driver := inmemory.New()
+	driver := testdriver.New()
 	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)
@@ -365,7 +367,7 @@ func TestBlobMount(t *testing.T) {
 	ctx := context.Background()
 	imageName, _ := reference.ParseNamed("foo/bar")
 	sourceImageName, _ := reference.ParseNamed("foo/source")
-	driver := inmemory.New()
+	driver := testdriver.New()
 	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)
@@ -516,7 +518,7 @@ func TestBlobMount(t *testing.T) {
 func TestLayerUploadZeroLength(t *testing.T) {
 	ctx := context.Background()
 	imageName, _ := reference.ParseNamed("foo/bar")
-	driver := inmemory.New()
+	driver := testdriver.New()
 	registry, err := NewRegistry(ctx, driver, BlobDescriptorCacheProvider(memory.NewInMemoryBlobDescriptorCacheProvider()), EnableDelete, EnableRedirect)
 	if err != nil {
 		t.Fatalf("error creating registry: %v", err)

docs/storage/driver/testdriver/testdriver.go

@@ -0,0 +1,71 @@
+package testdriver
+
+import (
+	"github.com/docker/distribution/context"
+	storagedriver "github.com/docker/distribution/registry/storage/driver"
+	"github.com/docker/distribution/registry/storage/driver/factory"
+	"github.com/docker/distribution/registry/storage/driver/inmemory"
+)
+
+const driverName = "testdriver"
+
+func init() {
+	factory.Register(driverName, &testDriverFactory{})
+}
+
+// testDriverFactory implements the factory.StorageDriverFactory interface.
+type testDriverFactory struct{}
+
+func (factory *testDriverFactory) Create(parameters map[string]interface{}) (storagedriver.StorageDriver, error) {
+	return New(), nil
+}
+
+// TestDriver is a StorageDriver for testing purposes. The Writer returned by this driver
+// simulates the case where Write operations are buffered. This causes the value returned by Size to lag
+// behind until Close (or Commit, or Cancel) is called.
+type TestDriver struct {
+	storagedriver.StorageDriver
+}
+
+type testFileWriter struct {
+	storagedriver.FileWriter
+	prevchunk []byte
+}
+
+var _ storagedriver.StorageDriver = &TestDriver{}
+
+// New constructs a new StorageDriver for testing purposes. The Writer returned by this driver
+// simulates the case where Write operations are buffered. This causes the value returned by Size to lag
+// behind until Close (or Commit, or Cancel) is called.
+func New() *TestDriver {
+	return &TestDriver{StorageDriver: inmemory.New()}
+}
+
+// Writer returns a FileWriter which will store the content written to it
+// at the location designated by "path" after the call to Commit.
+func (td *TestDriver) Writer(ctx context.Context, path string, append bool) (storagedriver.FileWriter, error) {
+	fw, err := td.StorageDriver.Writer(ctx, path, append)
+	return &testFileWriter{FileWriter: fw}, err
+}
+
+func (tfw *testFileWriter) Write(p []byte) (int, error) {
+	_, err := tfw.FileWriter.Write(tfw.prevchunk)
+	tfw.prevchunk = make([]byte, len(p))
+	copy(tfw.prevchunk, p)
+	return len(p), err
+}
+
+func (tfw *testFileWriter) Close() error {
+	tfw.Write(nil)
+	return tfw.FileWriter.Close()
+}
+
+func (tfw *testFileWriter) Cancel() error {
+	tfw.Write(nil)
+	return tfw.FileWriter.Cancel()
+}
+
+func (tfw *testFileWriter) Commit() error {
+	tfw.Write(nil)
+	return tfw.FileWriter.Commit()
+}