browser: Add user-agent header filter to gorilla mux route (#8040)

When a peer client which higher version sends a request to a peer
server with lower version, the returned status code is 200 OK instead
of 405 code. The reason is that the peer client request reaches the
browser handler, which registers itself by '/minio' route but without
any other constraints. Adding filtering by user agent header to the
browser route so internal requests to old endpoints versions return
405 error code.

cmd/test-utils_test.go

@@ -1232,6 +1232,7 @@ func newWebRPCRequest(methodRPC, authorization string, body io.ReadSeeker) (*htt
 	if err != nil {
 		return nil, err
 	}
+	req.Header.Set("User-Agent", "Mozilla")
 	req.Header.Set("Content-Type", "application/json")
 	if authorization != "" {
 		req.Header.Set("Authorization", "Bearer "+authorization)

cmd/web-handlers_test.go

@@ -831,6 +831,7 @@ func testUploadWebHandler(obj ObjectLayer, instanceType string, t TestErrHandler
 
 		req.Header.Set("x-amz-date", "20160814T114029Z")
 		req.Header.Set("Accept", "*/*")
+		req.Header.Set("User-Agent", "Mozilla")
 
 		req.Body = ioutil.NopCloser(bytes.NewReader(content))
 
@@ -937,6 +938,8 @@ func testDownloadWebHandler(obj ObjectLayer, instanceType string, t TestErrHandl
 			t.Fatalf("Cannot create upload request, %v", err)
 		}
 
+		req.Header.Set("User-Agent", "Mozilla")
+
 		apiRouter.ServeHTTP(rec, req)
 		return rec.Code, rec.Body.Bytes()
 	}
@@ -1081,6 +1084,8 @@ func testWebHandlerDownloadZip(obj ObjectLayer, instanceType string, t TestErrHa
 			t.Fatalf("Cannot create upload request, %v", err)
 		}
 
+		req.Header.Set("User-Agent", "Mozilla")
+
 		apiRouter.ServeHTTP(rec, req)
 		return rec.Code, rec.Body.Bytes()
 	}
@@ -1515,6 +1520,7 @@ func TestWebCheckAuthorization(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Cannot create upload request, %v", err)
 	}
+	req.Header.Set("User-Agent", "Mozilla")
 	apiRouter.ServeHTTP(rec, req)
 	if rec.Code != http.StatusForbidden {
 		t.Fatalf("Expected the response status to be 403, but instead found `%d`", rec.Code)
@@ -1529,6 +1535,7 @@ func TestWebCheckAuthorization(t *testing.T) {
 	content := []byte("temporary file's content")
 	req, err = http.NewRequest("PUT", "/minio/upload/bucket/object", nil)
 	req.Header.Set("Authorization", "Bearer foo-authorization")
+	req.Header.Set("User-Agent", "Mozilla")
 	req.Header.Set("Content-Length", strconv.Itoa(len(content)))
 	req.Header.Set("x-amz-date", "20160814T114029Z")
 	req.Header.Set("Accept", "*/*")

cmd/web-router.go

@@ -70,7 +70,7 @@ func registerWebRouter(router *mux.Router) error {
 	codec := json2.NewCodec()
 
 	// MinIO browser router.
-	webBrowserRouter := router.PathPrefix(minioReservedBucketPath).Subrouter()
+	webBrowserRouter := router.PathPrefix(minioReservedBucketPath).HeadersRegexp("User-Agent", ".*Mozilla.*").Subrouter()
 
 	// Initialize json rpc handlers.
 	webRPC := jsonrpc.NewServer()