Remove the deprecated WithRouteTag option in otelhttp

CHANGELOG.md

@@ -18,6 +18,9 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
   Use a custom `*http.Client` with `otelhttp.NewTransport(http.DefaultTransport)` instead. (#8266)
 - The deprecated `WithPublicEndpoint` in `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp`.
   Use `WithPublicEndpointFn` instead. (#8267)
+- The deprecated `WithRouteTag` in `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp`.
+  The route is already added automatically for spans.
+  For metrics, the alternative is to use the `WithMetricAttributesFn` option. (#8268)
 
 <!-- Released section -->
 <!-- Don't change this section unless doing release -->

instrumentation/net/http/otelhttp/handler.go

@@ -219,21 +219,3 @@ func (h *middleware) metricAttributesFromRequest(r *http.Request) []attribute.Ke
 	}
 	return attributeForRequest
 }
-
-// WithRouteTag annotates spans and metrics with the provided route name
-// with HTTP route attribute.
-//
-// Deprecated: spans are automatically annotated with the route attribute.
-// To annotate metrics, use the [WithMetricAttributesFn] option.
-func WithRouteTag(route string, h http.Handler) http.Handler {
-	attr := semconv.NewHTTPServer(nil).Route(route)
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		span := trace.SpanFromContext(r.Context())
-		span.SetAttributes(attr)
-
-		labeler, _ := LabelerFromContext(r.Context())
-		labeler.Add(attr)
-
-		h.ServeHTTP(w, r)
-	})
-}

instrumentation/net/http/otelhttp/handler_test.go

@@ -24,7 +24,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/metricdata/metricdatatest"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/sdk/trace/tracetest"
-	semconv "go.opentelemetry.io/otel/semconv/v1.37.0"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -608,74 +607,6 @@ func TestSpanStatus(t *testing.T) {
 	}
 }
 
-func TestWithRouteTag(t *testing.T) {
-	t.Setenv("OTEL_METRICS_EXEMPLAR_FILTER", "always_off")
-	route := "/some/route"
-
-	spanRecorder := tracetest.NewSpanRecorder()
-	tracerProvider := sdktrace.NewTracerProvider()
-	tracerProvider.RegisterSpanProcessor(spanRecorder)
-
-	metricReader := sdkmetric.NewManualReader()
-	meterProvider := sdkmetric.NewMeterProvider(sdkmetric.WithReader(metricReader))
-
-	h := NewHandler(
-		WithRouteTag(
-			route,
-			http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-				w.WriteHeader(http.StatusTeapot)
-			}),
-		),
-		"test_handler",
-		WithTracerProvider(tracerProvider),
-		WithMeterProvider(meterProvider),
-	)
-
-	h.ServeHTTP(httptest.NewRecorder(), httptest.NewRequest(http.MethodGet, "/", http.NoBody))
-	want := semconv.HTTPRouteKey.String(route)
-
-	require.Len(t, spanRecorder.Ended(), 1, "should emit a span")
-	gotSpan := spanRecorder.Ended()[0]
-	require.Contains(t, gotSpan.Attributes(), want, "should add route to span attributes")
-
-	rm := metricdata.ResourceMetrics{}
-	err := metricReader.Collect(t.Context(), &rm)
-	require.NoError(t, err)
-	require.Len(t, rm.ScopeMetrics, 1, "should emit metrics for one scope")
-	gotMetrics := rm.ScopeMetrics[0].Metrics
-
-	for _, m := range gotMetrics {
-		switch d := m.Data.(type) {
-		case metricdata.Sum[int64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		case metricdata.Sum[float64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		case metricdata.Histogram[int64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		case metricdata.Histogram[float64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		case metricdata.Gauge[int64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		case metricdata.Gauge[float64]:
-			require.Len(t, d.DataPoints, 1, "metric '%v' should have exactly one data point", m.Name)
-			require.Contains(t, d.DataPoints[0].Attributes.ToSlice(), want, "should add route to attributes for metric '%v'", m.Name)
-
-		default:
-			require.Fail(t, "metric has unexpected data type", "metric '%v' has unexpected data type %T", m.Name, m.Data)
-		}
-	}
-}
-
 func TestHandlerWithMetricAttributesFn(t *testing.T) {
 	const (
 		serverRequestSize  = "http.server.request.size"