From c5cc7cf49ef9ea0c68948df6bd3d3697d79e8ef3 Mon Sep 17 00:00:00 2001
From: Wenkai Yin <yinw@vmware.com>
Date: Mon, 13 Jan 2020 19:27:00 +0800
Subject: [PATCH] Provide a util function to apply middlewares to handler

Provide a util function to apply middlewares to handler

Signed-off-by: Wenkai Yin <yinw@vmware.com>
---
 src/server/middleware/middleware.go      | 13 +++++-
 src/server/middleware/middleware_test.go | 51 ++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 2 deletions(-)
 create mode 100644 src/server/middleware/middleware_test.go

diff --git a/src/server/middleware/middleware.go b/src/server/middleware/middleware.go
index dfbe1714c..fb8669082 100644
--- a/src/server/middleware/middleware.go
+++ b/src/server/middleware/middleware.go
@@ -16,7 +16,16 @@ package middleware
 
 import "net/http"
 
-// Middleware receives a handler and returns another handler
-// the returned handler can do some customized task according to
+// Middleware receives a handler and returns another handler.
+// The returned handler can do some customized task according to
 // the requirement
 type Middleware func(http.Handler) http.Handler
+
+// WithMiddlewares apply the middlewares to the handler.
+// The middlewares are executed in the order that they are applied
+func WithMiddlewares(handler http.Handler, middlewares ...Middleware) http.Handler {
+	for i := len(middlewares) - 1; i >= 0; i-- {
+		handler = middlewares[i](handler)
+	}
+	return handler
+}
diff --git a/src/server/middleware/middleware_test.go b/src/server/middleware/middleware_test.go
new file mode 100644
index 000000000..6f85ac653
--- /dev/null
+++ b/src/server/middleware/middleware_test.go
@@ -0,0 +1,51 @@
+// Copyright Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package middleware
+
+import (
+	"github.com/stretchr/testify/suite"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+type middlewareTestSuite struct {
+	suite.Suite
+}
+
+func (m *middlewareTestSuite) TestWithMiddlewares() {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("key", w.Header().Get("key")+"handler")
+	})
+	middleware1 := func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("key", w.Header().Get("key")+"middleware1")
+			h.ServeHTTP(w, r)
+		})
+	}
+	middleware2 := func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("key", w.Header().Get("key")+"middleware2")
+			h.ServeHTTP(w, r)
+		})
+	}
+	record := &httptest.ResponseRecorder{}
+	WithMiddlewares(handler, middleware1, middleware2).ServeHTTP(record, nil)
+	m.Equal("middleware1middleware2handler", record.Header().Get("key"))
+}
+
+func TestMiddlewareTestSuite(t *testing.T) {
+	suite.Run(t, &middlewareTestSuite{})
+}