diff --git a/configuration/configuration.go b/configuration/configuration.go
index b347d63b..e86b23d6 100644
--- a/configuration/configuration.go
+++ b/configuration/configuration.go
@@ -388,7 +388,7 @@ func (loglevel *Loglevel) UnmarshalYAML(unmarshal func(interface{}) error) error
 	switch loglevelString {
 	case "error", "warn", "info", "debug":
 	default:
-		return fmt.Errorf("Invalid loglevel %s Must be one of [error, warn, info, debug]", loglevelString)
+		return fmt.Errorf("invalid loglevel %s Must be one of [error, warn, info, debug]", loglevelString)
 	}
 
 	*loglevel = Loglevel(loglevelString)
@@ -463,7 +463,7 @@ func (storage *Storage) UnmarshalYAML(unmarshal func(interface{}) error) error {
 			}
 
 			if len(types) > 1 {
-				return fmt.Errorf("Must provide exactly one storage type. Provided: %v", types)
+				return fmt.Errorf("must provide exactly one storage type. Provided: %v", types)
 			}
 		}
 		*storage = storageMap
@@ -665,11 +665,11 @@ func Parse(rd io.Reader) (*Configuration, error) {
 						v0_1.Loglevel = Loglevel("")
 					}
 					if v0_1.Storage.Type() == "" {
-						return nil, errors.New("No storage configuration provided")
+						return nil, errors.New("no storage configuration provided")
 					}
 					return (*Configuration)(v0_1), nil
 				}
-				return nil, fmt.Errorf("Expected *v0_1Configuration, received %#v", c)
+				return nil, fmt.Errorf("expected *v0_1Configuration, received %#v", c)
 			},
 		},
 	})
diff --git a/configuration/configuration_test.go b/configuration/configuration_test.go
index e5f71486..b9ffadb7 100644
--- a/configuration/configuration_test.go
+++ b/configuration/configuration_test.go
@@ -540,9 +540,7 @@ func copyConfig(config Configuration) *Configuration {
 	}
 
 	configCopy.Notifications = Notifications{Endpoints: []Endpoint{}}
-	for _, v := range config.Notifications.Endpoints {
-		configCopy.Notifications.Endpoints = append(configCopy.Notifications.Endpoints, v)
-	}
+	configCopy.Notifications.Endpoints = append(configCopy.Notifications.Endpoints, config.Notifications.Endpoints...)
 
 	configCopy.HTTP.Headers = make(http.Header)
 	for k, v := range config.HTTP.Headers {
diff --git a/configuration/parser.go b/configuration/parser.go
index b46f7326..2bf59d21 100644
--- a/configuration/parser.go
+++ b/configuration/parser.go
@@ -122,7 +122,7 @@ func (p *Parser) Parse(in []byte, v interface{}) error {
 
 	parseInfo, ok := p.mapping[versionedStruct.Version]
 	if !ok {
-		return fmt.Errorf("Unsupported version: %q", versionedStruct.Version)
+		return fmt.Errorf("unsupported version: %q", versionedStruct.Version)
 	}
 
 	parseAs := reflect.New(parseInfo.ParseAs)
diff --git a/health/api/api.go b/health/api/api.go
index 73fcc453..a323a127 100644
--- a/health/api/api.go
+++ b/health/api/api.go
@@ -14,7 +14,7 @@ var (
 // DownHandler registers a manual_http_status that always returns an Error
 func DownHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method == "POST" {
-		updater.Update(errors.New("Manual Check"))
+		updater.Update(errors.New("manual Check"))
 	} else {
 		w.WriteHeader(http.StatusNotFound)
 	}
diff --git a/manifest/manifestlist/manifestlist.go b/manifest/manifestlist/manifestlist.go
index 0dd3c47c..3a1d73e8 100644
--- a/manifest/manifestlist/manifestlist.go
+++ b/manifest/manifestlist/manifestlist.go
@@ -163,7 +163,7 @@ func FromDescriptorsWithMediaType(descriptors []ManifestDescriptor, mediaType st
 		},
 	}
 
-	m.Manifests = make([]ManifestDescriptor, len(descriptors), len(descriptors))
+	m.Manifests = make([]ManifestDescriptor, len(descriptors))
 	copy(m.Manifests, descriptors)
 
 	deserialized := DeserializedManifestList{
@@ -177,7 +177,7 @@ func FromDescriptorsWithMediaType(descriptors []ManifestDescriptor, mediaType st
 
 // UnmarshalJSON populates a new ManifestList struct from JSON data.
 func (m *DeserializedManifestList) UnmarshalJSON(b []byte) error {
-	m.canonical = make([]byte, len(b), len(b))
+	m.canonical = make([]byte, len(b))
 	// store manifest list in canonical
 	copy(m.canonical, b)
 
diff --git a/manifest/ocischema/builder.go b/manifest/ocischema/builder.go
index 14e8eebd..b89bf5b7 100644
--- a/manifest/ocischema/builder.go
+++ b/manifest/ocischema/builder.go
@@ -48,7 +48,7 @@ func NewManifestBuilder(bs distribution.BlobService, configJSON []byte, annotati
 // valid media type for oci image manifests currently: "" or "application/vnd.oci.image.manifest.v1+json"
 func (mb *Builder) SetMediaType(mediaType string) error {
 	if mediaType != "" && mediaType != v1.MediaTypeImageManifest {
-		return errors.New("Invalid media type for OCI image manifest")
+		return errors.New("invalid media type for OCI image manifest")
 	}
 
 	mb.mediaType = mediaType
diff --git a/manifest/ocischema/manifest.go b/manifest/ocischema/manifest.go
index 35135c90..c5e85f28 100644
--- a/manifest/ocischema/manifest.go
+++ b/manifest/ocischema/manifest.go
@@ -87,7 +87,7 @@ func FromStruct(m Manifest) (*DeserializedManifest, error) {
 
 // UnmarshalJSON populates a new Manifest struct from JSON data.
 func (m *DeserializedManifest) UnmarshalJSON(b []byte) error {
-	m.canonical = make([]byte, len(b), len(b))
+	m.canonical = make([]byte, len(b))
 	// store manifest in canonical
 	copy(m.canonical, b)
 
diff --git a/manifest/schema1/manifest.go b/manifest/schema1/manifest.go
index 5a06b54b..9fef4dc7 100644
--- a/manifest/schema1/manifest.go
+++ b/manifest/schema1/manifest.go
@@ -108,7 +108,7 @@ type SignedManifest struct {
 
 // UnmarshalJSON populates a new SignedManifest struct from JSON data.
 func (sm *SignedManifest) UnmarshalJSON(b []byte) error {
-	sm.all = make([]byte, len(b), len(b))
+	sm.all = make([]byte, len(b))
 	// store manifest and signatures in all
 	copy(sm.all, b)
 
@@ -124,7 +124,7 @@ func (sm *SignedManifest) UnmarshalJSON(b []byte) error {
 	}
 
 	// sm.Canonical stores the canonical manifest JSON
-	sm.Canonical = make([]byte, len(bytes), len(bytes))
+	sm.Canonical = make([]byte, len(bytes))
 	copy(sm.Canonical, bytes)
 
 	// Unmarshal canonical JSON into Manifest object
diff --git a/manifest/schema1/reference_builder.go b/manifest/schema1/reference_builder.go
index a4f6032c..0f1d386a 100644
--- a/manifest/schema1/reference_builder.go
+++ b/manifest/schema1/reference_builder.go
@@ -58,7 +58,7 @@ func (mb *referenceManifestBuilder) Build(ctx context.Context) (distribution.Man
 func (mb *referenceManifestBuilder) AppendReference(d distribution.Describable) error {
 	r, ok := d.(Reference)
 	if !ok {
-		return fmt.Errorf("Unable to add non-reference type to v1 builder")
+		return fmt.Errorf("unable to add non-reference type to v1 builder")
 	}
 
 	// Entries need to be prepended
diff --git a/manifest/schema2/manifest.go b/manifest/schema2/manifest.go
index ee29438f..41f48029 100644
--- a/manifest/schema2/manifest.go
+++ b/manifest/schema2/manifest.go
@@ -106,7 +106,7 @@ func FromStruct(m Manifest) (*DeserializedManifest, error) {
 
 // UnmarshalJSON populates a new Manifest struct from JSON data.
 func (m *DeserializedManifest) UnmarshalJSON(b []byte) error {
-	m.canonical = make([]byte, len(b), len(b))
+	m.canonical = make([]byte, len(b))
 	// store manifest in canonical
 	copy(m.canonical, b)
 
diff --git a/manifests.go b/manifests.go
index 1816baea..8f84a220 100644
--- a/manifests.go
+++ b/manifests.go
@@ -87,7 +87,7 @@ func ManifestMediaTypes() (mediaTypes []string) {
 // UnmarshalFunc implements manifest unmarshalling a given MediaType
 type UnmarshalFunc func([]byte) (Manifest, Descriptor, error)
 
-var mappings = make(map[string]UnmarshalFunc, 0)
+var mappings = make(map[string]UnmarshalFunc)
 
 // UnmarshalManifest looks up manifest unmarshal functions based on
 // MediaType
diff --git a/notifications/bridge.go b/notifications/bridge.go
index eb9af41a..86af43f3 100644
--- a/notifications/bridge.go
+++ b/notifications/bridge.go
@@ -125,15 +125,6 @@ func (b *bridge) RepoDeleted(repo reference.Named) error {
 	return b.sink.Write(*event)
 }
 
-func (b *bridge) createManifestEventAndWrite(action string, repo reference.Named, sm distribution.Manifest) error {
-	manifestEvent, err := b.createManifestEvent(action, repo, sm)
-	if err != nil {
-		return err
-	}
-
-	return b.sink.Write(*manifestEvent)
-}
-
 func (b *bridge) createManifestDeleteEventAndWrite(action string, repo reference.Named, dgst digest.Digest) error {
 	event := b.createEvent(action)
 	event.Target.Repository = repo.Name()
diff --git a/notifications/event_test.go b/notifications/event_test.go
index 0981a7ad..2dddf944 100644
--- a/notifications/event_test.go
+++ b/notifications/event_test.go
@@ -114,8 +114,7 @@ func TestEventEnvelopeJSONFormat(t *testing.T) {
 	prototype.Request.UserAgent = "test/0.1"
 	prototype.Source.Addr = "hostname.local:port"
 
-	var manifestPush Event
-	manifestPush = prototype
+	var manifestPush = prototype
 	manifestPush.ID = "asdf-asdf-asdf-asdf-0"
 	manifestPush.Target.Digest = "sha256:0123456789abcdef0"
 	manifestPush.Target.Length = 1
@@ -124,8 +123,7 @@ func TestEventEnvelopeJSONFormat(t *testing.T) {
 	manifestPush.Target.Repository = "library/test"
 	manifestPush.Target.URL = "http://example.com/v2/library/test/manifests/latest"
 
-	var layerPush0 Event
-	layerPush0 = prototype
+	var layerPush0 = prototype
 	layerPush0.ID = "asdf-asdf-asdf-asdf-1"
 	layerPush0.Target.Digest = "sha256:3b3692957d439ac1928219a83fac91e7bf96c153725526874673ae1f2023f8d5"
 	layerPush0.Target.Length = 2
@@ -134,8 +132,7 @@ func TestEventEnvelopeJSONFormat(t *testing.T) {
 	layerPush0.Target.Repository = "library/test"
 	layerPush0.Target.URL = "http://example.com/v2/library/test/manifests/latest"
 
-	var layerPush1 Event
-	layerPush1 = prototype
+	var layerPush1 = prototype
 	layerPush1.ID = "asdf-asdf-asdf-asdf-2"
 	layerPush1.Target.Digest = "sha256:3b3692957d439ac1928219a83fac91e7bf96c153725526874673ae1f2023f8d6"
 	layerPush1.Target.Length = 3
diff --git a/notifications/http.go b/notifications/http.go
index 15751619..46f47af2 100644
--- a/notifications/http.go
+++ b/notifications/http.go
@@ -133,8 +133,7 @@ type headerRoundTripper struct {
 }
 
 func (hrt *headerRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	var nreq http.Request
-	nreq = *req
+	var nreq = *req
 	nreq.Header = make(http.Header)
 
 	merge := func(headers http.Header) {
diff --git a/notifications/listener_test.go b/notifications/listener_test.go
index ff49fd00..dee4dac5 100644
--- a/notifications/listener_test.go
+++ b/notifications/listener_test.go
@@ -136,11 +136,10 @@ func checkExerciseRepository(t *testing.T, repository distribution.Repository, r
 	var blobDigests []digest.Digest
 	blobs := repository.Blobs(ctx)
 	for i := 0; i < 2; i++ {
-		rs, ds, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("error creating test layer: %v", err)
 		}
-		dgst := digest.Digest(ds)
 		blobDigests = append(blobDigests, dgst)
 
 		wr, err := blobs.Create(ctx)
diff --git a/notifications/sinks.go b/notifications/sinks.go
index 14b692a3..816f75d7 100644
--- a/notifications/sinks.go
+++ b/notifications/sinks.go
@@ -284,11 +284,6 @@ type retryingSink struct {
 	}
 }
 
-type retryingSinkListener interface {
-	active(events ...Event)
-	retry(events ...Event)
-}
-
 // TODO(stevvooe): We are using circuit break here, which actually doesn't
 // make a whole lot of sense for this use case, since we always retry. Move
 // this to use bounded exponential backoff.
diff --git a/reference/reference.go b/reference/reference.go
index 2f66cca8..8c0c23b2 100644
--- a/reference/reference.go
+++ b/reference/reference.go
@@ -205,7 +205,7 @@ func Parse(s string) (Reference, error) {
 	var repo repository
 
 	nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1])
-	if nameMatch != nil && len(nameMatch) == 3 {
+	if len(nameMatch) == 3 {
 		repo.domain = nameMatch[1]
 		repo.path = nameMatch[2]
 	} else {
diff --git a/registry/api/errcode/errors.go b/registry/api/errcode/errors.go
index 6d9bb4b6..4c35b879 100644
--- a/registry/api/errcode/errors.go
+++ b/registry/api/errcode/errors.go
@@ -207,11 +207,11 @@ func (errs Errors) MarshalJSON() ([]byte, error) {
 	for _, daErr := range errs {
 		var err Error
 
-		switch daErr.(type) {
+		switch daErr := daErr.(type) {
 		case ErrorCode:
-			err = daErr.(ErrorCode).WithDetail(nil)
+			err = daErr.WithDetail(nil)
 		case Error:
-			err = daErr.(Error)
+			err = daErr
 		default:
 			err = ErrorCodeUnknown.WithDetail(daErr)
 
diff --git a/registry/api/v2/urls.go b/registry/api/v2/urls.go
index 1337bdb1..3c3ec989 100644
--- a/registry/api/v2/urls.go
+++ b/registry/api/v2/urls.go
@@ -252,15 +252,3 @@ func appendValuesURL(u *url.URL, values ...url.Values) *url.URL {
 	u.RawQuery = merged.Encode()
 	return u
 }
-
-// appendValues appends the parameters to the url. Panics if the string is not
-// a url.
-func appendValues(u string, values ...url.Values) string {
-	up, err := url.Parse(u)
-
-	if err != nil {
-		panic(err) // should never happen
-	}
-
-	return appendValuesURL(up, values...).String()
-}
diff --git a/registry/api/v2/urls_test.go b/registry/api/v2/urls_test.go
index 4f854b23..fbf9d0d4 100644
--- a/registry/api/v2/urls_test.go
+++ b/registry/api/v2/urls_test.go
@@ -182,11 +182,6 @@ func TestURLBuilderWithPrefix(t *testing.T) {
 	doTest(false)
 }
 
-type builderFromRequestTestCase struct {
-	request *http.Request
-	base    string
-}
-
 func TestBuilderFromRequest(t *testing.T) {
 	u, err := url.Parse("http://example.com")
 	if err != nil {
diff --git a/registry/client/auth/challenge/authchallenge.go b/registry/client/auth/challenge/authchallenge.go
index 6e3f1ccc..fe238210 100644
--- a/registry/client/auth/challenge/authchallenge.go
+++ b/registry/client/auth/challenge/authchallenge.go
@@ -117,8 +117,8 @@ func init() {
 		var t octetType
 		isCtl := c <= 31 || c == 127
 		isChar := 0 <= c && c <= 127
-		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
-		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+		isSeparator := strings.ContainsRune(" \t\"(),/:;<=>?@[]\\{}", rune(c))
+		if strings.ContainsRune(" \t\r\n", rune(c)) {
 			t |= isSpace
 		}
 		if isChar && !isCtl && !isSeparator {
diff --git a/registry/client/repository_test.go b/registry/client/repository_test.go
index 88e7e4b5..53b53cce 100644
--- a/registry/client/repository_test.go
+++ b/registry/client/repository_test.go
@@ -152,7 +152,7 @@ func TestBlobFetch(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if bytes.Compare(b, b1) != 0 {
+	if !bytes.Equal(b, b1) {
 		t.Fatalf("Wrong bytes values fetched: [%d]byte != [%d]byte", len(b), len(b1))
 	}
 
diff --git a/registry/handlers/api_test.go b/registry/handlers/api_test.go
index 6389253b..2d3edc74 100644
--- a/registry/handlers/api_test.go
+++ b/registry/handlers/api_test.go
@@ -959,7 +959,6 @@ func testManifestWithStorageError(t *testing.T, env *testEnv, imageName referenc
 	defer resp.Body.Close()
 	checkResponse(t, "getting non-existent manifest", resp, expectedStatusCode)
 	checkBodyHasErrorCodes(t, "getting non-existent manifest", resp, expectedErrorCode)
-	return
 }
 
 func testManifestAPISchema1(t *testing.T, env *testEnv, imageName reference.Named) manifestArgs {
@@ -1066,12 +1065,11 @@ func testManifestAPISchema1(t *testing.T, env *testEnv, imageName reference.Name
 	expectedLayers := make(map[digest.Digest]io.ReadSeeker)
 
 	for i := range unsignedManifest.FSLayers {
-		rs, dgstStr, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 
 		if err != nil {
 			t.Fatalf("error creating random layer %d: %v", i, err)
 		}
-		dgst := digest.Digest(dgstStr)
 
 		expectedLayers[dgst] = rs
 		unsignedManifest.FSLayers[i].BlobSum = dgst
@@ -1405,12 +1403,11 @@ func testManifestAPISchema2(t *testing.T, env *testEnv, imageName reference.Name
 	expectedLayers := make(map[digest.Digest]io.ReadSeeker)
 
 	for i := range manifest.Layers {
-		rs, dgstStr, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 
 		if err != nil {
 			t.Fatalf("error creating random layer %d: %v", i, err)
 		}
-		dgst := digest.Digest(dgstStr)
 
 		expectedLayers[dgst] = rs
 		manifest.Layers[i].Digest = dgst
@@ -2432,11 +2429,10 @@ func createRepository(env *testEnv, t *testing.T, imageName string, tag string)
 	expectedLayers := make(map[digest.Digest]io.ReadSeeker)
 
 	for i := range unsignedManifest.FSLayers {
-		rs, dgstStr, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("error creating random layer %d: %v", i, err)
 		}
-		dgst := digest.Digest(dgstStr)
 
 		expectedLayers[dgst] = rs
 		unsignedManifest.FSLayers[i].BlobSum = dgst
diff --git a/registry/handlers/app.go b/registry/handlers/app.go
index a689466b..b9fbf3da 100644
--- a/registry/handlers/app.go
+++ b/registry/handlers/app.go
@@ -753,20 +753,18 @@ func (app *App) logError(ctx context.Context, errors errcode.Errors) {
 	for _, e1 := range errors {
 		var c context.Context
 
-		switch e1.(type) {
+		switch e := e1.(type) {
 		case errcode.Error:
-			e, _ := e1.(errcode.Error)
 			c = context.WithValue(ctx, errCodeKey{}, e.Code)
 			c = context.WithValue(c, errMessageKey{}, e.Message)
 			c = context.WithValue(c, errDetailKey{}, e.Detail)
 		case errcode.ErrorCode:
-			e, _ := e1.(errcode.ErrorCode)
 			c = context.WithValue(ctx, errCodeKey{}, e)
 			c = context.WithValue(c, errMessageKey{}, e.Message())
 		default:
 			// just normal go 'error'
 			c = context.WithValue(ctx, errCodeKey{}, errcode.ErrorCodeUnknown)
-			c = context.WithValue(c, errMessageKey{}, e1.Error())
+			c = context.WithValue(c, errMessageKey{}, e.Error())
 		}
 
 		c = dcontext.WithLogger(c, dcontext.GetLogger(c,
diff --git a/registry/handlers/blobupload.go b/registry/handlers/blobupload.go
index 49ab1aaa..b6bfe302 100644
--- a/registry/handlers/blobupload.go
+++ b/registry/handlers/blobupload.go
@@ -172,7 +172,7 @@ func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Reque
 
 	ct := r.Header.Get("Content-Type")
 	if ct != "" && ct != "application/octet-stream" {
-		buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(fmt.Errorf("Bad Content-Type")))
+		buh.Errors = append(buh.Errors, errcode.ErrorCodeUnknown.WithDetail(fmt.Errorf("bad Content-Type")))
 		// TODO(dmcgowan): encode error
 		return
 	}
diff --git a/registry/handlers/hooks.go b/registry/handlers/hooks.go
index e51df2b7..4a2b1be8 100644
--- a/registry/handlers/hooks.go
+++ b/registry/handlers/hooks.go
@@ -20,7 +20,7 @@ type logHook struct {
 func (hook *logHook) Fire(entry *logrus.Entry) error {
 	addr := strings.Split(hook.Mail.Addr, ":")
 	if len(addr) != 2 {
-		return errors.New("Invalid Mail Address")
+		return errors.New("invalid Mail Address")
 	}
 	host := addr[0]
 	subject := fmt.Sprintf("[%s] %s: %s", entry.Level, host, entry.Message)
@@ -37,7 +37,7 @@ func (hook *logHook) Fire(entry *logrus.Entry) error {
 	if err := t.Execute(b, entry); err != nil {
 		return err
 	}
-	body := fmt.Sprintf("%s", b)
+	body := b.String()
 
 	return hook.Mail.sendMail(subject, body)
 }
diff --git a/registry/handlers/mail.go b/registry/handlers/mail.go
index 9e884265..684b1b34 100644
--- a/registry/handlers/mail.go
+++ b/registry/handlers/mail.go
@@ -17,7 +17,7 @@ type mailer struct {
 func (mail *mailer) sendMail(subject, message string) error {
 	addr := strings.Split(mail.Addr, ":")
 	if len(addr) != 2 {
-		return errors.New("Invalid Mail Address")
+		return errors.New("invalid Mail Address")
 	}
 	host := addr[0]
 	msg := []byte("To:" + strings.Join(mail.To, ";") +
diff --git a/registry/proxy/proxyblobstore.go b/registry/proxy/proxyblobstore.go
index fc59552b..9ca9c968 100644
--- a/registry/proxy/proxyblobstore.go
+++ b/registry/proxy/proxyblobstore.go
@@ -6,7 +6,6 @@ import (
 	"net/http"
 	"strconv"
 	"sync"
-	"time"
 
 	"github.com/docker/distribution"
 	dcontext "github.com/docker/distribution/context"
@@ -15,9 +14,6 @@ import (
 	"github.com/opencontainers/go-digest"
 )
 
-// todo(richardscothern): from cache control header or config file
-const blobTTL = 24 * 7 * time.Hour
-
 type proxyBlobStore struct {
 	localStore     distribution.BlobStore
 	remoteStore    distribution.BlobService
diff --git a/registry/proxy/proxyblobstore_test.go b/registry/proxy/proxyblobstore_test.go
index 4bf4ea8a..6e90dbe5 100644
--- a/registry/proxy/proxyblobstore_test.go
+++ b/registry/proxy/proxyblobstore_test.go
@@ -193,7 +193,7 @@ func makeTestEnv(t *testing.T, name string) *testEnv {
 }
 
 func makeBlob(size int) []byte {
-	blob := make([]byte, size, size)
+	blob := make([]byte, size)
 	for i := 0; i < size; i++ {
 		blob[i] = byte('A' + rand.Int()%48)
 	}
@@ -204,16 +204,6 @@ func init() {
 	rand.Seed(42)
 }
 
-func perm(m []distribution.Descriptor) []distribution.Descriptor {
-	for i := 0; i < len(m); i++ {
-		j := rand.Intn(i + 1)
-		tmp := m[i]
-		m[i] = m[j]
-		m[j] = tmp
-	}
-	return m
-}
-
 func populate(t *testing.T, te *testEnv, blobCount, size, numUnique int) {
 	var inRemote []distribution.Descriptor
 
diff --git a/registry/proxy/proxymanifeststore_test.go b/registry/proxy/proxymanifeststore_test.go
index 99aaed28..82a1a2b7 100644
--- a/registry/proxy/proxymanifeststore_test.go
+++ b/registry/proxy/proxymanifeststore_test.go
@@ -165,11 +165,10 @@ func populateRepo(ctx context.Context, t *testing.T, repository distribution.Rep
 			t.Fatalf("unexpected error creating test upload: %v", err)
 		}
 
-		rs, ts, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("unexpected error generating test layer file")
 		}
-		dgst := digest.Digest(ts)
 		if _, err := io.Copy(wr, rs); err != nil {
 			t.Fatalf("unexpected error copying to upload: %v", err)
 		}
diff --git a/registry/proxy/scheduler/scheduler.go b/registry/proxy/scheduler/scheduler.go
index f8340184..f3c1caa0 100644
--- a/registry/proxy/scheduler/scheduler.go
+++ b/registry/proxy/scheduler/scheduler.go
@@ -118,7 +118,7 @@ func (ttles *TTLExpirationScheduler) Start() error {
 	}
 
 	if !ttles.stopped {
-		return fmt.Errorf("Scheduler already started")
+		return fmt.Errorf("scheduler already started")
 	}
 
 	dcontext.GetLogger(ttles.ctx).Infof("Starting cached object TTL expiration scheduler...")
@@ -126,7 +126,7 @@ func (ttles *TTLExpirationScheduler) Start() error {
 
 	// Start timer for each deserialized entry
 	for _, entry := range ttles.entries {
-		entry.timer = ttles.startTimer(entry, entry.Expiry.Sub(time.Now()))
+		entry.timer = ttles.startTimer(entry, time.Until(entry.Expiry))
 	}
 
 	// Start a ticker to periodically save the entries index
@@ -164,7 +164,7 @@ func (ttles *TTLExpirationScheduler) add(r reference.Reference, ttl time.Duratio
 		Expiry:    time.Now().Add(ttl),
 		EntryType: eType,
 	}
-	dcontext.GetLogger(ttles.ctx).Infof("Adding new scheduler entry for %s with ttl=%s", entry.Key, entry.Expiry.Sub(time.Now()))
+	dcontext.GetLogger(ttles.ctx).Infof("Adding new scheduler entry for %s with ttl=%s", entry.Key, time.Until(entry.Expiry))
 	if oldEntry, present := ttles.entries[entry.Key]; present && oldEntry.timer != nil {
 		oldEntry.timer.Stop()
 	}
diff --git a/registry/registry.go b/registry/registry.go
index a3006079..3cc4c32a 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -186,7 +186,7 @@ func (registry *Registry) ListenAndServe() error {
 				}
 
 				if ok := pool.AppendCertsFromPEM(caPem); !ok {
-					return fmt.Errorf("Could not add CA to pool")
+					return fmt.Errorf("could not add CA to pool")
 				}
 			}
 
diff --git a/registry/storage/blobstore.go b/registry/storage/blobstore.go
index 9fdf5219..1008aad8 100644
--- a/registry/storage/blobstore.go
+++ b/registry/storage/blobstore.go
@@ -152,16 +152,6 @@ func (bs *blobStore) readlink(ctx context.Context, path string) (digest.Digest,
 	return linked, nil
 }
 
-// resolve reads the digest link at path and returns the blob store path.
-func (bs *blobStore) resolve(ctx context.Context, path string) (string, error) {
-	dgst, err := bs.readlink(ctx, path)
-	if err != nil {
-		return "", err
-	}
-
-	return bs.path(dgst)
-}
-
 type blobStatter struct {
 	driver driver.StorageDriver
 }
diff --git a/registry/storage/driver/azure/azure.go b/registry/storage/driver/azure/azure.go
index 906e7792..58c6293b 100644
--- a/registry/storage/driver/azure/azure.go
+++ b/registry/storage/driver/azure/azure.go
@@ -55,17 +55,17 @@ func (factory *azureDriverFactory) Create(parameters map[string]interface{}) (st
 func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	accountName, ok := parameters[paramAccountName]
 	if !ok || fmt.Sprint(accountName) == "" {
-		return nil, fmt.Errorf("No %s parameter provided", paramAccountName)
+		return nil, fmt.Errorf("no %s parameter provided", paramAccountName)
 	}
 
 	accountKey, ok := parameters[paramAccountKey]
 	if !ok || fmt.Sprint(accountKey) == "" {
-		return nil, fmt.Errorf("No %s parameter provided", paramAccountKey)
+		return nil, fmt.Errorf("no %s parameter provided", paramAccountKey)
 	}
 
 	container, ok := parameters[paramContainer]
 	if !ok || fmt.Sprint(container) == "" {
-		return nil, fmt.Errorf("No %s parameter provided", paramContainer)
+		return nil, fmt.Errorf("no %s parameter provided", paramContainer)
 	}
 
 	realm, ok := parameters[paramRealm]
diff --git a/registry/storage/driver/inmemory/mfs.go b/registry/storage/driver/inmemory/mfs.go
index cdefacfd..9a2865f9 100644
--- a/registry/storage/driver/inmemory/mfs.go
+++ b/registry/storage/driver/inmemory/mfs.go
@@ -252,20 +252,6 @@ func (d *dir) delete(p string) error {
 	return nil
 }
 
-// dump outputs a primitive directory structure to stdout.
-func (d *dir) dump(indent string) {
-	fmt.Println(indent, d.name()+"/")
-
-	for _, child := range d.children {
-		if child.isdir() {
-			child.(*dir).dump(indent + "\t")
-		} else {
-			fmt.Println(indent, child.name())
-		}
-
-	}
-}
-
 func (d *dir) String() string {
 	return fmt.Sprintf("&dir{path: %v, children: %v}", d.p, d.children)
 }
diff --git a/registry/storage/driver/s3-aws/s3.go b/registry/storage/driver/s3-aws/s3.go
index f61cfaee..d9c1a826 100644
--- a/registry/storage/driver/s3-aws/s3.go
+++ b/registry/storage/driver/s3-aws/s3.go
@@ -188,19 +188,19 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 
 	regionName := parameters["region"]
 	if regionName == nil || fmt.Sprint(regionName) == "" {
-		return nil, fmt.Errorf("No region parameter provided")
+		return nil, fmt.Errorf("no region parameter provided")
 	}
 	region := fmt.Sprint(regionName)
 	// Don't check the region value if a custom endpoint is provided.
 	if regionEndpoint == "" {
 		if _, ok := validRegions[region]; !ok {
-			return nil, fmt.Errorf("Invalid region provided: %v", region)
+			return nil, fmt.Errorf("invalid region provided: %v", region)
 		}
 	}
 
 	bucket := parameters["bucket"]
 	if bucket == nil || fmt.Sprint(bucket) == "" {
-		return nil, fmt.Errorf("No bucket parameter provided")
+		return nil, fmt.Errorf("no bucket parameter provided")
 	}
 
 	encryptBool := false
@@ -209,7 +209,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case string:
 		b, err := strconv.ParseBool(encrypt)
 		if err != nil {
-			return nil, fmt.Errorf("The encrypt parameter should be a boolean")
+			return nil, fmt.Errorf("the encrypt parameter should be a boolean")
 		}
 		encryptBool = b
 	case bool:
@@ -217,7 +217,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case nil:
 		// do nothing
 	default:
-		return nil, fmt.Errorf("The encrypt parameter should be a boolean")
+		return nil, fmt.Errorf("the encrypt parameter should be a boolean")
 	}
 
 	secureBool := true
@@ -226,7 +226,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case string:
 		b, err := strconv.ParseBool(secure)
 		if err != nil {
-			return nil, fmt.Errorf("The secure parameter should be a boolean")
+			return nil, fmt.Errorf("the secure parameter should be a boolean")
 		}
 		secureBool = b
 	case bool:
@@ -234,7 +234,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case nil:
 		// do nothing
 	default:
-		return nil, fmt.Errorf("The secure parameter should be a boolean")
+		return nil, fmt.Errorf("the secure parameter should be a boolean")
 	}
 
 	skipVerifyBool := false
@@ -243,7 +243,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case string:
 		b, err := strconv.ParseBool(skipVerify)
 		if err != nil {
-			return nil, fmt.Errorf("The skipVerify parameter should be a boolean")
+			return nil, fmt.Errorf("the skipVerify parameter should be a boolean")
 		}
 		skipVerifyBool = b
 	case bool:
@@ -251,7 +251,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case nil:
 		// do nothing
 	default:
-		return nil, fmt.Errorf("The skipVerify parameter should be a boolean")
+		return nil, fmt.Errorf("the skipVerify parameter should be a boolean")
 	}
 
 	v4Bool := true
@@ -260,7 +260,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case string:
 		b, err := strconv.ParseBool(v4auth)
 		if err != nil {
-			return nil, fmt.Errorf("The v4auth parameter should be a boolean")
+			return nil, fmt.Errorf("the v4auth parameter should be a boolean")
 		}
 		v4Bool = b
 	case bool:
@@ -268,7 +268,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	case nil:
 		// do nothing
 	default:
-		return nil, fmt.Errorf("The v4auth parameter should be a boolean")
+		return nil, fmt.Errorf("the v4auth parameter should be a boolean")
 	}
 
 	keyID := parameters["keyid"]
@@ -306,7 +306,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	if storageClassParam != nil {
 		storageClassString, ok := storageClassParam.(string)
 		if !ok {
-			return nil, fmt.Errorf("The storageclass parameter must be one of %v, %v invalid",
+			return nil, fmt.Errorf("the storageclass parameter must be one of %v, %v invalid",
 				[]string{s3.StorageClassStandard, s3.StorageClassReducedRedundancy}, storageClassParam)
 		}
 		// All valid storage class parameters are UPPERCASE, so be a bit more flexible here
@@ -314,7 +314,7 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 		if storageClassString != noStorageClass &&
 			storageClassString != s3.StorageClassStandard &&
 			storageClassString != s3.StorageClassReducedRedundancy {
-			return nil, fmt.Errorf("The storageclass parameter must be one of %v, %v invalid",
+			return nil, fmt.Errorf("the storageclass parameter must be one of %v, %v invalid",
 				[]string{noStorageClass, s3.StorageClassStandard, s3.StorageClassReducedRedundancy}, storageClassParam)
 		}
 		storageClass = storageClassString
@@ -330,11 +330,11 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	if objectACLParam != nil {
 		objectACLString, ok := objectACLParam.(string)
 		if !ok {
-			return nil, fmt.Errorf("Invalid value for objectacl parameter: %v", objectACLParam)
+			return nil, fmt.Errorf("invalid value for objectacl parameter: %v", objectACLParam)
 		}
 
 		if _, ok = validObjectACLs[objectACLString]; !ok {
-			return nil, fmt.Errorf("Invalid value for objectacl parameter: %v", objectACLParam)
+			return nil, fmt.Errorf("invalid value for objectacl parameter: %v", objectACLParam)
 		}
 		objectACL = objectACLString
 	}
@@ -389,7 +389,7 @@ func getParameterAsInt64(parameters map[string]interface{}, name string, default
 	}
 
 	if rv < min || rv > max {
-		return 0, fmt.Errorf("The %s %#v parameter should be a number between %d and %d (inclusive)", name, rv, min, max)
+		return 0, fmt.Errorf("the %s %#v parameter should be a number between %d and %d (inclusive)", name, rv, min, max)
 	}
 
 	return rv, nil
@@ -401,7 +401,7 @@ func New(params DriverParameters) (*Driver, error) {
 	if !params.V4Auth &&
 		(params.RegionEndpoint == "" ||
 			strings.Contains(params.RegionEndpoint, "s3.amazonaws.com")) {
-		return nil, fmt.Errorf("On Amazon S3 this storage driver can only be used with v4 authentication")
+		return nil, fmt.Errorf("on Amazon S3 this storage driver can only be used with v4 authentication")
 	}
 
 	awsConfig := aws.NewConfig()
@@ -878,7 +878,7 @@ func (d *driver) URLFor(ctx context.Context, path string, options map[string]int
 	if ok {
 		et, ok := expires.(time.Time)
 		if ok {
-			expiresIn = et.Sub(time.Now())
+			expiresIn = time.Until(et)
 		}
 	}
 
diff --git a/registry/storage/driver/s3-aws/s3_v2_signer.go b/registry/storage/driver/s3-aws/s3_v2_signer.go
index 29688ae5..9f1e621c 100644
--- a/registry/storage/driver/s3-aws/s3_v2_signer.go
+++ b/registry/storage/driver/s3-aws/s3_v2_signer.go
@@ -39,12 +39,6 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
-const (
-	signatureVersion = "2"
-	signatureMethod  = "HmacSHA1"
-	timeFormat       = "2006-01-02T15:04:05Z"
-)
-
 type signer struct {
 	// Values that must be populated from the request
 	Request      *http.Request
diff --git a/registry/storage/driver/swift/swift.go b/registry/storage/driver/swift/swift.go
index 46201ee7..adbe8aa9 100644
--- a/registry/storage/driver/swift/swift.go
+++ b/registry/storage/driver/swift/swift.go
@@ -160,23 +160,23 @@ func FromParameters(parameters map[string]interface{}) (*Driver, error) {
 	}
 
 	if params.Username == "" {
-		return nil, fmt.Errorf("No username parameter provided")
+		return nil, fmt.Errorf("no username parameter provided")
 	}
 
 	if params.Password == "" {
-		return nil, fmt.Errorf("No password parameter provided")
+		return nil, fmt.Errorf("no password parameter provided")
 	}
 
 	if params.AuthURL == "" {
-		return nil, fmt.Errorf("No authurl parameter provided")
+		return nil, fmt.Errorf("no authurl parameter provided")
 	}
 
 	if params.Container == "" {
-		return nil, fmt.Errorf("No container parameter provided")
+		return nil, fmt.Errorf("no container parameter provided")
 	}
 
 	if params.ChunkSize < minChunkSize {
-		return nil, fmt.Errorf("The chunksize %#v parameter should be a number that is larger than or equal to %d", params.ChunkSize, minChunkSize)
+		return nil, fmt.Errorf("the chunksize %#v parameter should be a number that is larger than or equal to %d", params.ChunkSize, minChunkSize)
 	}
 
 	return New(params)
@@ -211,15 +211,15 @@ func New(params Parameters) (*Driver, error) {
 	}
 	err := ct.Authenticate()
 	if err != nil {
-		return nil, fmt.Errorf("Swift authentication failed: %s", err)
+		return nil, fmt.Errorf("swift authentication failed: %s", err)
 	}
 
 	if _, _, err := ct.Container(params.Container); err == swift.ContainerNotFound {
 		if err := ct.ContainerCreate(params.Container, nil); err != nil {
-			return nil, fmt.Errorf("Failed to create container %s (%s)", params.Container, err)
+			return nil, fmt.Errorf("failed to create container %s (%s)", params.Container, err)
 		}
 	} else if err != nil {
-		return nil, fmt.Errorf("Failed to retrieve info about container %s (%s)", params.Container, err)
+		return nil, fmt.Errorf("failed to retrieve info about container %s (%s)", params.Container, err)
 	}
 
 	d := &driver{
@@ -258,7 +258,7 @@ func New(params Parameters) (*Driver, error) {
 		if d.TempURLContainerKey {
 			_, containerHeaders, err := d.Conn.Container(d.Container)
 			if err != nil {
-				return nil, fmt.Errorf("Failed to fetch container info %s (%s)", d.Container, err)
+				return nil, fmt.Errorf("failed to fetch container info %s (%s)", d.Container, err)
 			}
 
 			d.SecretKey = containerHeaders["X-Container-Meta-Temp-Url-Key"]
@@ -273,7 +273,7 @@ func New(params Parameters) (*Driver, error) {
 			// Use the account secret key
 			_, accountHeaders, err := d.Conn.Account()
 			if err != nil {
-				return nil, fmt.Errorf("Failed to fetch account info (%s)", err)
+				return nil, fmt.Errorf("failed to fetch account info (%s)", err)
 			}
 
 			d.SecretKey = accountHeaders["X-Account-Meta-Temp-Url-Key"]
@@ -350,7 +350,7 @@ func (d *driver) Reader(ctx context.Context, path string, offset int64) (io.Read
 		}
 		if isDLO && size == 0 {
 			if time.Now().Add(waitingTime).After(endTime) {
-				return nil, fmt.Errorf("Timeout expired while waiting for segments of %s to show up", path)
+				return nil, fmt.Errorf("timeout expired while waiting for segments of %s to show up", path)
 			}
 			time.Sleep(waitingTime)
 			waitingTime *= 2
@@ -456,7 +456,7 @@ func (d *driver) Stat(ctx context.Context, path string) (storagedriver.FileInfo,
 		_, isDLO := headers["X-Object-Manifest"]
 		if isDLO && info.Bytes == 0 {
 			if time.Now().Add(waitingTime).After(endTime) {
-				return nil, fmt.Errorf("Timeout expired while waiting for segments of %s to show up", path)
+				return nil, fmt.Errorf("timeout expired while waiting for segments of %s to show up", path)
 			}
 			time.Sleep(waitingTime)
 			waitingTime *= 2
@@ -755,7 +755,7 @@ func chunkFilenames(slice []string, maxSize int) (chunks [][]string, err error)
 			chunks = append(chunks, slice[offset:offset+chunkSize])
 		}
 	} else {
-		return nil, fmt.Errorf("Max chunk size must be > 0")
+		return nil, fmt.Errorf("max chunk size must be > 0")
 	}
 	return
 }
@@ -894,7 +894,7 @@ func (w *writer) waitForSegmentsToShowUp() error {
 			if info.Bytes == w.size {
 				break
 			}
-			err = fmt.Errorf("Timeout expired while waiting for segments of %s to show up", w.path)
+			err = fmt.Errorf("timeout expired while waiting for segments of %s to show up", w.path)
 		}
 		if time.Now().Add(waitingTime).After(endTime) {
 			break
diff --git a/registry/storage/linkedblobstore_test.go b/registry/storage/linkedblobstore_test.go
index e0ffd279..7682b45c 100644
--- a/registry/storage/linkedblobstore_test.go
+++ b/registry/storage/linkedblobstore_test.go
@@ -27,13 +27,12 @@ func TestLinkedBlobStoreCreateWithMountFrom(t *testing.T) {
 	// readseekers for upload later.
 	testLayers := map[digest.Digest]io.ReadSeeker{}
 	for i := 0; i < 2; i++ {
-		rs, ds, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("unexpected error generating test layer file")
 		}
-		dgst := digest.Digest(ds)
 
-		testLayers[digest.Digest(dgst)] = rs
+		testLayers[dgst] = rs
 	}
 
 	// upload the layers to foo/bar
diff --git a/registry/storage/manifeststore_test.go b/registry/storage/manifeststore_test.go
index 864ef38c..54b58ae1 100644
--- a/registry/storage/manifeststore_test.go
+++ b/registry/storage/manifeststore_test.go
@@ -91,13 +91,12 @@ func testManifestStorage(t *testing.T, schema1Enabled bool, options ...RegistryO
 	// readseekers for upload later.
 	testLayers := map[digest.Digest]io.ReadSeeker{}
 	for i := 0; i < 2; i++ {
-		rs, ds, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("unexpected error generating test layer file")
 		}
-		dgst := digest.Digest(ds)
 
-		testLayers[digest.Digest(dgst)] = rs
+		testLayers[dgst] = rs
 		m.FSLayers = append(m.FSLayers, schema1.FSLayer{
 			BlobSum: dgst,
 		})
@@ -414,11 +413,10 @@ func testOCIManifestStorage(t *testing.T, testname string, includeMediaTypes boo
 
 	// Add some layers
 	for i := 0; i < 2; i++ {
-		rs, ds, err := testutil.CreateRandomTarFile()
+		rs, dgst, err := testutil.CreateRandomTarFile()
 		if err != nil {
 			t.Fatalf("%s: unexpected error generating test layer file", testname)
 		}
-		dgst := digest.Digest(ds)
 
 		wr, err := env.repository.Blobs(env.ctx).Create(env.ctx)
 		if err != nil {
diff --git a/registry/storage/paths.go b/registry/storage/paths.go
index b6d9b9b5..2d1f5132 100644
--- a/registry/storage/paths.go
+++ b/registry/storage/paths.go
@@ -133,10 +133,7 @@ func pathFor(spec pathSpec) (string, error) {
 
 		return path.Join(append(append(repoPrefix, v.name, "_manifests", "revisions"), components...)...), nil
 	case manifestRevisionLinkPathSpec:
-		root, err := pathFor(manifestRevisionPathSpec{
-			name:     v.name,
-			revision: v.revision,
-		})
+		root, err := pathFor(manifestRevisionPathSpec(v))
 
 		if err != nil {
 			return "", err
@@ -156,10 +153,7 @@ func pathFor(spec pathSpec) (string, error) {
 
 		return path.Join(root, v.tag), nil
 	case manifestTagCurrentPathSpec:
-		root, err := pathFor(manifestTagPathSpec{
-			name: v.name,
-			tag:  v.tag,
-		})
+		root, err := pathFor(manifestTagPathSpec(v))
 
 		if err != nil {
 			return "", err
@@ -167,10 +161,7 @@ func pathFor(spec pathSpec) (string, error) {
 
 		return path.Join(root, "current", "link"), nil
 	case manifestTagIndexPathSpec:
-		root, err := pathFor(manifestTagPathSpec{
-			name: v.name,
-			tag:  v.tag,
-		})
+		root, err := pathFor(manifestTagPathSpec(v))
 
 		if err != nil {
 			return "", err
@@ -178,11 +169,7 @@ func pathFor(spec pathSpec) (string, error) {
 
 		return path.Join(root, "index"), nil
 	case manifestTagIndexEntryLinkPathSpec:
-		root, err := pathFor(manifestTagIndexEntryPathSpec{
-			name:     v.name,
-			tag:      v.tag,
-			revision: v.revision,
-		})
+		root, err := pathFor(manifestTagIndexEntryPathSpec(v))
 
 		if err != nil {
 			return "", err
diff --git a/registry/storage/paths_test.go b/registry/storage/paths_test.go
index 677a34b9..ab3b8445 100644
--- a/registry/storage/paths_test.go
+++ b/registry/storage/paths_test.go
@@ -10,7 +10,6 @@ func TestPathMapper(t *testing.T) {
 	for _, testcase := range []struct {
 		spec     pathSpec
 		expected string
-		err      error
 	}{
 		{
 			spec: manifestRevisionPathSpec{
diff --git a/registry/storage/purgeuploads.go b/registry/storage/purgeuploads.go
index 7ebd1604..cac92121 100644
--- a/registry/storage/purgeuploads.go
+++ b/registry/storage/purgeuploads.go
@@ -59,7 +59,7 @@ func PurgeUploads(ctx context.Context, driver storageDriver.StorageDriver, older
 // file, so gather files by UUID with a date from startedAt.
 func getOutstandingUploads(ctx context.Context, driver storageDriver.StorageDriver) (map[string]uploadData, []error) {
 	var errors []error
-	uploads := make(map[string]uploadData, 0)
+	uploads := make(map[string]uploadData)
 
 	inUploadDir := false
 	root, err := pathFor(repositoriesRootPathSpec{})
diff --git a/registry/storage/purgeuploads_test.go b/registry/storage/purgeuploads_test.go
index 23c553ba..398df2b6 100644
--- a/registry/storage/purgeuploads_test.go
+++ b/registry/storage/purgeuploads_test.go
@@ -118,7 +118,7 @@ func TestPurgeOnlyUploads(t *testing.T) {
 		t.Fatalf(err.Error())
 	}
 	nonUploadPath := strings.Replace(dataPath, "_upload", "_important", -1)
-	if strings.Index(nonUploadPath, "_upload") != -1 {
+	if strings.Contains(nonUploadPath, "_upload") {
 		t.Fatalf("Non-upload path not created correctly")
 	}
 
@@ -132,7 +132,7 @@ func TestPurgeOnlyUploads(t *testing.T) {
 		t.Error("Unexpected errors", errs)
 	}
 	for _, file := range deleted {
-		if strings.Index(file, "_upload") == -1 {
+		if !strings.Contains(file, "_upload") {
 			t.Errorf("Non-upload file deleted")
 		}
 	}
diff --git a/registry/storage/schema2manifesthandler.go b/registry/storage/schema2manifesthandler.go
index 4b3e7d16..3e32e9f4 100644
--- a/registry/storage/schema2manifesthandler.go
+++ b/registry/storage/schema2manifesthandler.go
@@ -14,9 +14,8 @@ import (
 )
 
 var (
-	errUnexpectedURL = errors.New("unexpected URL on layer")
-	errMissingURL    = errors.New("missing URL on layer")
-	errInvalidURL    = errors.New("invalid URL on layer")
+	errMissingURL = errors.New("missing URL on layer")
+	errInvalidURL = errors.New("invalid URL on layer")
 )
 
 //schema2ManifestHandler is a ManifestHandler that covers schema2 manifests.
diff --git a/registry/storage/tagstore.go b/registry/storage/tagstore.go
index f80b9628..a3c766b4 100644
--- a/registry/storage/tagstore.go
+++ b/registry/storage/tagstore.go
@@ -50,25 +50,6 @@ func (ts *tagStore) All(ctx context.Context) ([]string, error) {
 	return tags, nil
 }
 
-// exists returns true if the specified manifest tag exists in the repository.
-func (ts *tagStore) exists(ctx context.Context, tag string) (bool, error) {
-	tagPath, err := pathFor(manifestTagCurrentPathSpec{
-		name: ts.repository.Named().Name(),
-		tag:  tag,
-	})
-
-	if err != nil {
-		return false, err
-	}
-
-	exists, err := exists(ctx, ts.blobStore.driver, tagPath)
-	if err != nil {
-		return false, err
-	}
-
-	return exists, nil
-}
-
 // Tag tags the digest with the given tag, updating the the store to point at
 // the current tag. The digest must point to a manifest.
 func (ts *tagStore) Tag(ctx context.Context, tag string, desc distribution.Descriptor) error {
diff --git a/registry/storage/util.go b/registry/storage/util.go
deleted file mode 100644
index 8ab235e2..00000000
--- a/registry/storage/util.go
+++ /dev/null
@@ -1,22 +0,0 @@
-package storage
-
-import (
-	"context"
-
-	"github.com/docker/distribution/registry/storage/driver"
-)
-
-// Exists provides a utility method to test whether or not a path exists in
-// the given driver.
-func exists(ctx context.Context, drv driver.StorageDriver, path string) (bool, error) {
-	if _, err := drv.Stat(ctx, path); err != nil {
-		switch err := err.(type) {
-		case driver.PathNotFoundError:
-			return false, nil
-		default:
-			return false, err
-		}
-	}
-
-	return true, nil
-}