Add Cors and OPTIONS route unit tests

Move creating the router and populating the
routes to a separate function outside of
ListenAndServe to allow unit tests to make
assertions on the configured routes and handler
funcs.

api.go

@@ -709,9 +709,8 @@ func writeCorsHeaders(w http.ResponseWriter, r *http.Request) {
 	w.Header().Add("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT, OPTIONS")
 }
 
-func ListenAndServe(addr string, srv *Server, logging bool) error {
+func createRouter(srv *Server, logging bool) (*mux.Router, error) {
 	r := mux.NewRouter()
-	log.Printf("Listening for HTTP on %s\n", addr)
 
 	m := map[string]map[string]func(*Server, float64, http.ResponseWriter, *http.Request, map[string]string) error{
 		"GET": {
@@ -788,12 +787,22 @@ func ListenAndServe(addr string, srv *Server, logging bool) error {
 			}
 			r.Path("/v{version:[0-9.]+}" + localRoute).Methods(localMethod).HandlerFunc(f)
 			r.Path(localRoute).Methods(localMethod).HandlerFunc(f)
-			r.Methods("OPTIONS").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				if srv.enableCors {
-					writeCorsHeaders(w, r)
-				}
-			})
 		}
 	}
+	r.Methods("OPTIONS").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if srv.enableCors {
+			writeCorsHeaders(w, r)
+		}
+	})
+	return r, nil
+}
+
+func ListenAndServe(addr string, srv *Server, logging bool) error {
+	log.Printf("Listening for HTTP on %s\n", addr)
+
+	r, err := createRouter(srv, logging)
+	if err != nil {
+		return err
+	}
 	return http.ListenAndServe(addr, r)
 }

api_test.go

@@ -1239,6 +1239,32 @@ func TestDeleteContainers(t *testing.T) {
 	}
 }
 
+func TestOptionsRoute(t *testing.T) {
+	runtime, err := newTestRuntime()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer nuke(runtime)
+
+	srv := &Server{runtime: runtime, enableCors: true}
+
+	r := httptest.NewRecorder()
+	router, err := createRouter(srv, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	req, err := http.NewRequest("OPTIONS", "/", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	router.ServeHTTP(r, req)
+	if r.Code != 200 {
+		t.Errorf("Expected response for OPTIONS request to be \"200\", %v found.", r.Code)
+	}
+}
+
 func TestGetEnabledCors(t *testing.T) {
 	runtime, err := newTestRuntime()
 	if err != nil {
@@ -1250,12 +1276,24 @@ func TestGetEnabledCors(t *testing.T) {
 
 	r := httptest.NewRecorder()
 
-	if err := getVersion(srv, API_VERSION, r, nil, nil); err != nil {
+	router, err := createRouter(srv, false)
+	if err != nil {
 		t.Fatal(err)
 	}
 
+	req, err := http.NewRequest("GET", "/version", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	router.ServeHTTP(r, req)
+	if r.Code != 200 {
+		t.Errorf("Expected response for OPTIONS request to be \"200\", %v found.", r.Code)
+	}
+
 	allowOrigin := r.Header().Get("Access-Control-Allow-Origin")
 	allowHeaders := r.Header().Get("Access-Control-Allow-Headers")
+	allowMethods := r.Header().Get("Access-Control-Allow-Methods")
 
 	if allowOrigin != "*" {
 		t.Errorf("Expected header Access-Control-Allow-Origin to be \"*\", %s found.", allowOrigin)
@@ -1263,6 +1301,9 @@ func TestGetEnabledCors(t *testing.T) {
 	if allowHeaders != "Origin, X-Requested-With, Content-Type, Accept" {
 		t.Errorf("Expected header Access-Control-Allow-Headers to be \"Origin, X-Requested-With, Content-Type, Accept\", %s found.", allowHeaders)
 	}
+	if allowMethods != "GET, POST, DELETE, PUT, OPTIONS" {
+		t.Errorf("Expected hearder Access-Control-Allow-Methods to be \"GET, POST, DELETE, PUT, OPTIONS\", %s found.", allowMethods)
+	}
 }
 
 func TestDeleteImages(t *testing.T) {