Disambiguate routing for multi-level repository names

To be able to support multi-level repository names, the API has been adjusted
to disabiguate routes tagged image manifest routes and tag list routes. With
this effort, the regular expressions have been defined in a single place to
reduce repitition and ensure that validation is consistent across the registry.

The router was also refactored to remove the use of subrouters, simplifying the
route definition code. This also reduces the number of regular expression match
checks during the routing process.

routes_test.go

@@ -10,9 +10,10 @@ import (
 	"github.com/gorilla/mux"
 )
 
-type routeInfo struct {
+type routeTestCase struct {
 	RequestURI string
 	Vars       map[string]string
+	RouteName  string
 }
 
 // TestRouter registers a test handler with all the routes and ensures that
@@ -26,14 +27,15 @@ func TestRouter(t *testing.T) {
 	router := v2APIRouter()
 
 	testHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		routeInfo := routeInfo{
+		testCase := routeTestCase{
 			RequestURI: r.RequestURI,
 			Vars:       mux.Vars(r),
+			RouteName:  mux.CurrentRoute(r).GetName(),
 		}
 
 		enc := json.NewEncoder(w)
 
-		if err := enc.Encode(routeInfo); err != nil {
+		if err := enc.Encode(testCase); err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
@@ -42,64 +44,81 @@ func TestRouter(t *testing.T) {
 	// Startup test server
 	server := httptest.NewServer(router)
 
-	for _, testcase := range []struct {
-		routeName         string
-		expectedRouteInfo routeInfo
-	}{
+	for _, testcase := range []routeTestCase{
 		{
-			routeName: routeNameImageManifest,
-			expectedRouteInfo: routeInfo{
-				RequestURI: "/v2/foo/bar/image/tag",
-				Vars: map[string]string{
-					"name": "foo/bar",
-					"tag":  "tag",
-				},
+			RouteName:  routeNameImageManifest,
+			RequestURI: "/v2/foo/bar/image/tag",
+			Vars: map[string]string{
+				"name": "foo/bar",
+				"tag":  "tag",
 			},
 		},
 		{
-			routeName: routeNameTags,
-			expectedRouteInfo: routeInfo{
-				RequestURI: "/v2/foo/bar/tags",
-				Vars: map[string]string{
-					"name": "foo/bar",
-				},
+			RouteName:  routeNameTags,
+			RequestURI: "/v2/foo/bar/tags/list",
+			Vars: map[string]string{
+				"name": "foo/bar",
 			},
 		},
 		{
-			routeName: routeNameLayer,
-			expectedRouteInfo: routeInfo{
-				RequestURI: "/v2/foo/bar/layer/tarsum",
-				Vars: map[string]string{
-					"name":   "foo/bar",
-					"tarsum": "tarsum",
-				},
+			RouteName:  routeNameLayer,
+			RequestURI: "/v2/foo/bar/layer/tarsum.dev+foo:abcdef0919234",
+			Vars: map[string]string{
+				"name":   "foo/bar",
+				"tarsum": "tarsum.dev+foo:abcdef0919234",
 			},
 		},
 		{
-			routeName: routeNameLayerUpload,
-			expectedRouteInfo: routeInfo{
-				RequestURI: "/v2/foo/bar/layer/tarsum/upload/",
-				Vars: map[string]string{
-					"name":   "foo/bar",
-					"tarsum": "tarsum",
-				},
+			RouteName:  routeNameLayerUpload,
+			RequestURI: "/v2/foo/bar/layer/tarsum.dev+foo:abcdef0919234/upload/",
+			Vars: map[string]string{
+				"name":   "foo/bar",
+				"tarsum": "tarsum.dev+foo:abcdef0919234",
 			},
 		},
 		{
-			routeName: routeNameLayerUploadResume,
-			expectedRouteInfo: routeInfo{
-				RequestURI: "/v2/foo/bar/layer/tarsum/upload/uuid",
-				Vars: map[string]string{
-					"name":   "foo/bar",
-					"tarsum": "tarsum",
-					"uuid":   "uuid",
-				},
+			RouteName:  routeNameLayerUploadResume,
+			RequestURI: "/v2/foo/bar/layer/tarsum.dev+foo:abcdef0919234/upload/uuid",
+			Vars: map[string]string{
+				"name":   "foo/bar",
+				"tarsum": "tarsum.dev+foo:abcdef0919234",
+				"uuid":   "uuid",
+			},
+		},
+		{
+			RouteName:  routeNameLayerUploadResume,
+			RequestURI: "/v2/foo/bar/layer/tarsum.dev+foo:abcdef0919234/upload/D95306FA-FAD3-4E36-8D41-CF1C93EF8286",
+			Vars: map[string]string{
+				"name":   "foo/bar",
+				"tarsum": "tarsum.dev+foo:abcdef0919234",
+				"uuid":   "D95306FA-FAD3-4E36-8D41-CF1C93EF8286",
+			},
+		},
+
+		{
+			// Check ambiguity: ensure we can distinguish between tags for
+			// "foo/bar/image/image" and image for "foo/bar/image" with tag
+			// "tags"
+			RouteName:  routeNameImageManifest,
+			RequestURI: "/v2/foo/bar/image/image/tags",
+			Vars: map[string]string{
+				"name": "foo/bar/image",
+				"tag":  "tags",
+			},
+		},
+		{
+			// This case presents an ambiguity between foo/bar with tag="tags"
+			// and list tags for "foo/bar/image"
+			RouteName:  routeNameTags,
+			RequestURI: "/v2/foo/bar/image/tags/list",
+			Vars: map[string]string{
+				"name": "foo/bar/image",
 			},
 		},
 	} {
 		// Register the endpoint
-		router.GetRoute(testcase.routeName).Handler(testHandler)
-		u := server.URL + testcase.expectedRouteInfo.RequestURI
+		router.GetRoute(testcase.RouteName).Handler(testHandler)
+		u := server.URL + testcase.RequestURI
 
 		resp, err := http.Get(u)
 
@@ -107,15 +126,23 @@ func TestRouter(t *testing.T) {
 			t.Fatalf("error issuing get request: %v", err)
 		}
 
+		if resp.StatusCode != http.StatusOK {
+			t.Fatalf("unexpected status for %s: %v %v", u, resp.Status, resp.StatusCode)
+		}
+
 		dec := json.NewDecoder(resp.Body)
 
-		var actualRouteInfo routeInfo
+		var actualRouteInfo routeTestCase
 		if err := dec.Decode(&actualRouteInfo); err != nil {
 			t.Fatalf("error reading json response: %v", err)
 		}
 
-		if !reflect.DeepEqual(actualRouteInfo, testcase.expectedRouteInfo) {
-			t.Fatalf("actual does not equal expected: %v != %v", actualRouteInfo, testcase.expectedRouteInfo)
+		if actualRouteInfo.RouteName != testcase.RouteName {
+			t.Fatalf("incorrect route %q matched, expected %q", actualRouteInfo.RouteName, testcase.RouteName)
+		}
+
+		if !reflect.DeepEqual(actualRouteInfo, testcase) {
+			t.Fatalf("actual does not equal expected: %#v != %#v", actualRouteInfo, testcase)
 		}
 	}