feature: add custom HTTP client timeout to Metrics API scaler

CHANGELOG.md

@@ -78,6 +78,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 
 - **General**: Add CRD-level validation markers (Minimum, MinLength, MinItems, Enum) for ScaledObject, ScaledJob, ScaleTriggers, and TriggerAuthentication API types ([#7533](https://github.com/kedacore/keda/pull/7533))
 - **Elasticsearch Scaler**: Add HTTP status check for Elasticsearch errors ([#7480](https://github.com/kedacore/keda/pull/7480))
+- **Metrics API Scaler**: Add custom HTTP client timeout ([#7549](https://github.com/kedacore/keda/issues/7549))
 
 ### Fixes
 

pkg/scalers/metrics_api_scaler.go

@@ -12,6 +12,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/go-logr/logr"
 	"github.com/prometheus/common/expfmt"
@@ -48,6 +49,7 @@ type metricsAPIScalerMetadata struct {
 	UnsafeSsl                         bool            `keda:"name=unsafeSsl,order=triggerMetadata,default=false"`
 	AggregateFromKubeServiceEndpoints bool            `keda:"name=aggregateFromKubeServiceEndpoints,order=triggerMetadata,default=false"`
 	AggregationType                   AggregationType `keda:"name=aggregationType,order=triggerMetadata,default=average,enum=average;sum;max;min"`
+	Timeout                           time.Duration   `keda:"name=timeout, order=triggerMetadata, optional"`
 	// Authentication parameters for connecting to the metrics API
 	MetricsAPIAuth *authentication.Config `keda:"optional"`
 
@@ -93,7 +95,13 @@ func NewMetricsAPIScaler(config *scalersconfig.ScalerConfig, kubeClient client.C
 		return nil, fmt.Errorf("error parsing metric API metadata: %w", err)
 	}
 
-	httpClient := kedautil.CreateHTTPClient(config.GlobalHTTPTimeout, meta.UnsafeSsl)
+	// handle HTTP client timeout
+	httpClientTimeout := config.GlobalHTTPTimeout
+	if meta.Timeout > 0 {
+		httpClientTimeout = time.Duration(meta.Timeout) * time.Millisecond
+	}
+
+	httpClient := kedautil.CreateHTTPClient(httpClientTimeout, meta.UnsafeSsl)
 
 	// Handle TLS configuration with authentication config
 	if meta.MetricsAPIAuth != nil && meta.MetricsAPIAuth.EnabledTLS() {
@@ -126,6 +134,13 @@ func parseMetricsAPIMetadata(config *scalersconfig.ScalerConfig) (*metricsAPISca
 		return nil, fmt.Errorf("no targetValue given in metadata")
 	}
 
+	// Resolve HTTP client timeout
+	meta.Timeout = config.GlobalHTTPTimeout
+	// validate the timeout
+	if meta.Timeout < 0 {
+		return nil, fmt.Errorf("timeout must be greater than 0: %d", meta.Timeout)
+	}
+
 	return meta, nil
 }
 

pkg/scalers/metrics_api_scaler_test.go

@@ -34,6 +34,12 @@ var testMetricsAPIMetadata = []metricsAPIMetadataTestData{
 	{metadata: map[string]string{"valueLocation": "metric", "targetValue": "aa"}, raisesError: true},
 	// Missing targetValue
 	{metadata: map[string]string{"url": "http://dummy:1230/api/v1/", "valueLocation": "metric"}, raisesError: true},
+	// Valid HTTP timeout
+	{metadata: map[string]string{"url": "http://dummy:1230/api/v1/", "valueLocation": "metric", "targetValue": "42", "timeout": "1000"}, raisesError: false},
+	// Invalid - negative - HTTP timeout
+	{metadata: map[string]string{"url": "http://dummy:1230/api/v1/", "valueLocation": "metric", "targetValue": "42", "timeout": "-1"}, raisesError: true},
+	// Invalid - not a number - HTTP timeout
+	{metadata: map[string]string{"url": "http://dummy:1230/api/v1/", "valueLocation": "metric", "targetValue": "42", "timeout": "a"}, raisesError: true},
 }
 
 type metricAPIAuthMetadataTestData struct {