fixup! metrics: add exemplar support for counters

Author: rexagod

staging/src/k8s.io/component-base/metrics/counter_test.go

@@ -302,8 +302,9 @@ func TestCounterWithExemplar(t *testing.T) {
 	traceID := trace.TraceID(fn(1))
 	spanID := trace.SpanID(fn(2))
 	ctxForSpanCtx := trace.ContextWithSpanContext(context.Background(), trace.NewSpanContext(trace.SpanContextConfig{
-		TraceID: traceID,
-		SpanID:  spanID,
+		SpanID:     spanID,
+		TraceID:    traceID,
+		TraceFlags: trace.FlagsSampled,
 	}))
 	toAdd := float64(40)
 

staging/src/k8s.io/component-base/metrics/metric.go

@@ -226,7 +226,7 @@ type exemplarMetric struct {
 func (e *exemplarMetric) withExemplar(v float64) {
 	if m, ok := e.CounterMetric.(prometheus.ExemplarAdder); ok {
 		maybeSpanCtx := trace.SpanContextFromContext(e.ctx)
-		if maybeSpanCtx.IsValid() {
+		if maybeSpanCtx.IsValid() && maybeSpanCtx.IsSampled() {
 			exemplarLabels := prometheus.Labels{
 				"trace_id": maybeSpanCtx.TraceID().String(),
 				"span_id":  maybeSpanCtx.SpanID().String(),

staging/src/k8s.io/dynamic-resource-allocation/go.mod

@@ -58,6 +58,8 @@ require (
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stoewer/go-strcase v1.2.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
+	go.opentelemetry.io/otel v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
 	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
 	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/oauth2 v0.23.0 // indirect

staging/src/k8s.io/dynamic-resource-allocation/go.sum

@@ -48,6 +48,8 @@ require (
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
+	go.opentelemetry.io/otel v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
 	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/oauth2 v0.23.0 // indirect
 	golang.org/x/sys v0.26.0 // indirect

staging/src/k8s.io/endpointslice/go.mod

@@ -34,6 +34,8 @@ require (
 	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
+	go.opentelemetry.io/otel v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
 	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/sys v0.26.0 // indirect
 	golang.org/x/text v0.19.0 // indirect

staging/src/k8s.io/endpointslice/go.sum

@@ -47,6 +47,8 @@ require (
 	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
+	go.opentelemetry.io/otel v1.28.0 // indirect
+	go.opentelemetry.io/otel/trace v1.28.0 // indirect
 	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/oauth2 v0.23.0 // indirect
 	golang.org/x/sys v0.26.0 // indirect