DataDog: Check for response object before returning the generic error (…

…#4259)

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

CHANGELOG.md

@@ -79,6 +79,7 @@ Here is an overview of all new **experimental** features:
 - **Azure Service Bus Scaler:** Use correct auth flows with pod identity ([#4026](https://github.com/kedacore/keda/issues/4026)|[#4123](https://github.com/kedacore/keda/issues/4123))
 - **Cassandra Scaler**: Checking whether the port information is entered in the ClusterIPAddres is done correctly. ([#4110](https://github.com/kedacore/keda/issues/4110))
 - **CPU Memory Scaler** Store forgotten logger ([#4022](https://github.com/kedacore/keda/issues/4022))
+- **Datadog Scaler**: Return correct error when getting a 429 error ([#4187](https://github.com/kedacore/keda/issues/4187))
 - **Kafka Scaler**: Return error if the processing of the partition lag fails ([#4098](https://github.com/kedacore/keda/issues/4098))
 - **Kafka Scaler**: Support 0 in activationLagThreshold configuration ([#4137](https://github.com/kedacore/keda/issues/4137))
 - **Prometheus Metrics**: Expose Prometheus Metrics also when getting ScaledObject state ([#4075](https://github.com/kedacore/keda/issues/4075))

pkg/scalers/datadog_scaler.go

@@ -286,19 +286,26 @@ func (s *datadogScaler) getQueryResult(ctx context.Context) (float64, error) {
 	timeWindowTo := time.Now().Unix() - int64(s.metadata.timeWindowOffset)
 	timeWindowFrom := timeWindowTo - int64(s.metadata.age)
 	resp, r, err := s.apiClient.MetricsApi.QueryMetrics(ctx, timeWindowFrom, timeWindowTo, s.metadata.query) //nolint:bodyclose
-	if err != nil {
-		return -1, fmt.Errorf("error when retrieving Datadog metrics: %w", err)
-	}
 
-	if r.StatusCode == 429 {
-		rateLimit := r.Header.Get("X-Ratelimit-Limit")
-		rateLimitReset := r.Header.Get("X-Ratelimit-Reset")
+	if r != nil {
+		if r.StatusCode == 429 {
+			rateLimit := r.Header.Get("X-Ratelimit-Limit")
+			rateLimitReset := r.Header.Get("X-Ratelimit-Reset")
+			rateLimitPeriod := r.Header.Get("X-Ratelimit-Period")
+
+			return -1, fmt.Errorf("your Datadog account reached the %s queries per %s seconds rate limit, next limit reset will happen in %s seconds", rateLimit, rateLimitPeriod, rateLimitReset)
+		}
 
-		return -1, fmt.Errorf("your Datadog account reached the %s queries per hour rate limit, next limit reset will happen in %s seconds", rateLimit, rateLimitReset)
+		if r.StatusCode != 200 {
+			if err != nil {
+				return -1, fmt.Errorf("error when retrieving Datadog metrics: %w", err)
+			}
+			return -1, fmt.Errorf("error when retrieving Datadog metrics")
+		}
 	}
 
-	if r.StatusCode != 200 {
-		return -1, fmt.Errorf("error when retrieving Datadog metrics")
+	if err != nil {
+		return -1, fmt.Errorf("error when retrieving Datadog metrics: %w", err)
 	}
 
 	if resp.GetStatus() == "error" {