Raises an error when RabbitMQ regex matches more than 1 page (#2103)

Signed-off-by: jorturfer <jorge_turrado@hotmail.es>

pkg/scalers/rabbitmq_scaler.go

@@ -80,7 +80,8 @@ type queueInfo struct {
 }
 
 type regexQueueInfo struct {
-	Queues []queueInfo `json:"items"`
+	Queues     []queueInfo `json:"items"`
+	TotalPages int         `json:"page_count"`
 }
 
 type messageStat struct {
@@ -375,6 +376,9 @@ func getJSON(s *rabbitMQScaler, url string) (queueInfo, error) {
 			if err != nil {
 				return queueInfo{}, err
 			}
+			if queues.TotalPages > 1 {
+				return queueInfo{}, fmt.Errorf("regex matches more queues than can be recovered at once")
+			}
 			result, err := getComposedQueue(s, queues.Queues)
 			return result, err
 		}

pkg/scalers/rabbitmq_scaler_test.go

@@ -437,3 +437,62 @@ func TestRabbitMQAnonimizeRabbitMQError(t *testing.T) {
 		assert.Equal(t, fmt.Sprint(err), testData.message)
 	}
 }
+
+type getQueueInfoNavigationTestData struct {
+	response string
+	isError  bool
+}
+
+var testRegexQueueInfoNavigationTestData = []getQueueInfoNavigationTestData{
+	// sum queue length
+	{`{"items":[], "filtered_count": 250, "page": 1, "page_count": 3}`, true},
+	{`{"items":[], "filtered_count": 250, "page": 1, "page_count": 1}`, false},
+}
+
+func TestRegexQueueMissingError(t *testing.T) {
+	for _, testData := range testRegexQueueInfoNavigationTestData {
+		var apiStub = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			expectedPath := "/api/queues?page=1&use_regex=true&pagination=false&name=evaluate_trials"
+			if r.RequestURI != expectedPath {
+				t.Error("Expect request path to =", expectedPath, "but it is", r.RequestURI)
+			}
+
+			w.WriteHeader(http.StatusOK)
+			_, err := w.Write([]byte(testData.response))
+			if err != nil {
+				t.Error("Expect request path to =", testData.response, "but it is", err)
+			}
+		}))
+
+		resolvedEnv := map[string]string{host: apiStub.URL, "plainHost": apiStub.URL}
+
+		metadata := map[string]string{
+			"queueName":   "evaluate_trials",
+			"hostFromEnv": host,
+			"protocol":    "http",
+			"useRegex":    "true",
+		}
+
+		s, err := NewRabbitMQScaler(
+			&ScalerConfig{
+				ResolvedEnv:       resolvedEnv,
+				TriggerMetadata:   metadata,
+				AuthParams:        map[string]string{},
+				GlobalHTTPTimeout: 1000 * time.Millisecond,
+			},
+		)
+
+		if err != nil {
+			t.Error("Expect success", err)
+		}
+
+		ctx := context.TODO()
+		_, err = s.IsActive(ctx)
+		if err != nil && !testData.isError {
+			t.Error("Expected success but got error", err)
+		}
+		if testData.isError && err == nil {
+			t.Error("Expected error but got success")
+		}
+	}
+}