feat(inputs.prometheus): Always apply kubernetes label and field selectors (#13624)

plugins/inputs/prometheus/prometheus.go

@@ -166,24 +166,22 @@ func (p *Prometheus) Init() error {
 		p.MonitorKubernetesPodsMethod = MonitorMethodAnnotations
 	}
 
-	if p.isNodeScrapeScope || p.MonitorKubernetesPodsMethod != MonitorMethodAnnotations {
+	// Parse label and field selectors - will be used to filter pods after cAdvisor call
-		// Parse label and field selectors - will be used to filter pods after cAdvisor call
+	var err error
-		var err error
+	p.podLabelSelector, err = labels.Parse(p.KubernetesLabelSelector)
-		p.podLabelSelector, err = labels.Parse(p.KubernetesLabelSelector)
+	if err != nil {
-		if err != nil {
+		return fmt.Errorf("error parsing the specified label selector(s): %w", err)
-			return fmt.Errorf("error parsing the specified label selector(s): %w", err)
-		}
-		p.podFieldSelector, err = fields.ParseSelector(p.KubernetesFieldSelector)
-		if err != nil {
-			return fmt.Errorf("error parsing the specified field selector(s): %w", err)
-		}
-		isValid, invalidSelector := fieldSelectorIsSupported(p.podFieldSelector)
-		if !isValid {
-			return fmt.Errorf("the field selector %q is not supported for pods", invalidSelector)
-		}
-
-		p.Log.Infof("Using the label selector: %v and field selector: %v", p.podLabelSelector, p.podFieldSelector)
 	}
+	p.podFieldSelector, err = fields.ParseSelector(p.KubernetesFieldSelector)
+	if err != nil {
+		return fmt.Errorf("error parsing the specified field selector(s): %w", err)
+	}
+	isValid, invalidSelector := fieldSelectorIsSupported(p.podFieldSelector)
+	if !isValid {
+		return fmt.Errorf("the field selector %q is not supported for pods", invalidSelector)
+	}
+
+	p.Log.Infof("Using the label selector: %v and field selector: %v", p.podLabelSelector, p.podFieldSelector)
 
 	for k, vs := range p.NamespaceAnnotationPass {
 		tagFilter := models.TagFilter{}

plugins/inputs/prometheus/prometheus_test.go

@@ -352,6 +352,7 @@ func TestPrometheusGeneratesSummaryMetricsV2(t *testing.T) {
 	defer ts.Close()
 
 	p := &Prometheus{
+		Log:           &testutil.Logger{},
 		URLs:          []string{ts.URL},
 		URLTag:        "url",
 		MetricVersion: 2,
@@ -385,6 +386,7 @@ go_gc_duration_seconds_count 42`
 	defer ts.Close()
 
 	p := &Prometheus{
+		Log:           &testutil.Logger{},
 		URLs:          []string{ts.URL},
 		URLTag:        "",
 		MetricVersion: 2,
@@ -444,6 +446,7 @@ func TestPrometheusGeneratesGaugeMetricsV2(t *testing.T) {
 	defer ts.Close()
 
 	p := &Prometheus{
+		Log:           &testutil.Logger{},
 		URLs:          []string{ts.URL},
 		URLTag:        "url",
 		MetricVersion: 2,

plugins/outputs/prometheus_client/prometheus_client_v1_test.go

@@ -389,6 +389,7 @@ rpc_duration_seconds_count 2693
 			})
 
 			input := &inputs.Prometheus{
+				Log:           logger,
 				URLs:          []string{address},
 				URLTag:        "",
 				MetricVersion: 1,

plugins/outputs/prometheus_client/prometheus_client_v2_test.go

@@ -420,6 +420,7 @@ rpc_duration_seconds_count 2693
 			})
 
 			input := &inputs.Prometheus{
+				Log:           logger,
 				URLs:          []string{url},
 				URLTag:        "",
 				MetricVersion: 2,