Add http.route to HTTP client requests and extract from Spring WebClient

docs/apidiffs/current_vs_latest/opentelemetry-instrumentation-api.txt

@@ -1,2 +1,6 @@
 Comparing source compatibility of  against 
-No changes.
+***! MODIFIED INTERFACE: PUBLIC ABSTRACT io.opentelemetry.instrumentation.api.semconv.http.HttpClientAttributesGetter  (not serializable)
+	===  CLASS FILE FORMAT VERSION: 52.0 <- 52.0
+	GENERIC TEMPLATES: === REQUEST:java.lang.Object, === RESPONSE:java.lang.Object
+	+++! NEW METHOD: PUBLIC(+) java.lang.String getHttpRoute(java.lang.Object)
+		+++  NEW ANNOTATION: javax.annotation.Nullable

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/semconv/http/HttpClientAttributesExtractor.java

@@ -75,6 +75,11 @@ public void onStart(AttributesBuilder attributes, Context parentContext, REQUEST
     String fullUrl = stripSensitiveData(getter.getUrlFull(request));
     internalSet(attributes, SemanticAttributes.URL_FULL, fullUrl);
 
+    String httpRoute = getter.getHttpRoute(request);
+    if (httpRoute != null && !httpRoute.isEmpty()) {
+      internalSet(attributes, SemanticAttributes.HTTP_ROUTE, httpRoute);
+    }
+
     int resendCount = resendCountIncrementer.applyAsInt(parentContext);
     if (resendCount > 0) {
       attributes.put(SemanticAttributes.HTTP_REQUEST_RESEND_COUNT, resendCount);

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/semconv/http/HttpClientAttributesGetter.java

@@ -32,6 +32,16 @@ public interface HttpClientAttributesGetter<REQUEST, RESPONSE>
   @Nullable
   String getUrlFull(REQUEST request);
 
+  /**
+   * Returns the path template in the format used by the respective client framework.
+   *
+   * <p>Examples: <code>/foo/{bar}</code>
+   */
+  @Nullable
+  default String getHttpRoute(REQUEST request) {
+    return null;
+  }
+
   /** {@inheritDoc} */
   @Nullable
   @Override

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/semconv/http/HttpMetricsAdvice.java

@@ -26,6 +26,7 @@ static void applyClientDurationAdvice(DoubleHistogramBuilder builder) {
     ((ExtendedDoubleHistogramBuilder) builder)
         .setAttributesAdvice(
             asList(
+                SemanticAttributes.HTTP_ROUTE,
                 SemanticAttributes.HTTP_REQUEST_METHOD,
                 SemanticAttributes.HTTP_RESPONSE_STATUS_CODE,
                 SemanticAttributes.ERROR_TYPE,

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/semconv/http/HttpClientAttributesExtractorTest.java

@@ -42,6 +42,12 @@ public String getUrlFull(Map<String, String> request) {
       return request.get("urlFull");
     }
 
+    @Nullable
+    @Override
+    public String getHttpRoute(Map<String, String> request) {
+      return request.get("httpRoute");
+    }
+
     @Override
     public String getHttpRequestMethod(Map<String, String> request) {
       return request.get("method");
@@ -138,6 +144,7 @@ void normal() {
     Map<String, String> request = new HashMap<>();
     request.put("method", "POST");
     request.put("urlFull", "http://github.com");
+    request.put("httpRoute", "/api");
     request.put("header.content-length", "10");
     request.put("header.user-agent", "okhttp 3.x");
     request.put("header.custom-request-header", "123,456");
@@ -170,6 +177,7 @@ void normal() {
         .containsOnly(
             entry(SemanticAttributes.HTTP_REQUEST_METHOD, "POST"),
             entry(SemanticAttributes.URL_FULL, "http://github.com"),
+            entry(SemanticAttributes.HTTP_ROUTE, "/api"),
             entry(
                 AttributeKey.stringArrayKey("http.request.header.custom-request-header"),
                 asList("123", "456")),

instrumentation/spring/spring-webflux/spring-webflux-5.3/library/src/main/java/io/opentelemetry/instrumentation/spring/webflux/v5_3/internal/WebClientHttpAttributesGetter.java

@@ -9,9 +9,12 @@
 
 import io.opentelemetry.instrumentation.api.semconv.http.HttpClientAttributesGetter;
 import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
 import javax.annotation.Nullable;
 import org.springframework.web.reactive.function.client.ClientRequest;
 import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.reactive.function.client.WebClient;
 
 /**
  * This class is internal and is hence not for public use. Its APIs are unstable and can change at
@@ -21,11 +24,27 @@ public enum WebClientHttpAttributesGetter
     implements HttpClientAttributesGetter<ClientRequest, ClientResponse> {
   INSTANCE;
 
+  private static final String URI_TEMPLATE_ATTRIBUTE = WebClient.class.getName() + ".uriTemplate";
+  private static final Pattern PATTERN_BEFORE_PATH = Pattern.compile("^https?://[^/]+/");
+
   @Override
   public String getUrlFull(ClientRequest request) {
     return request.url().toString();
   }
 
+  @Nullable
+  @Override
+  public String getHttpRoute(ClientRequest clientRequest) {
+    Map<String, Object> attributes = clientRequest.attributes();
+    Object value = attributes.get(URI_TEMPLATE_ATTRIBUTE);
+    if (value instanceof String) {
+      String uriTemplate = (String) value;
+      String path = PATTERN_BEFORE_PATH.matcher(uriTemplate).replaceFirst("");
+      return path.startsWith("/") ? path : "/" + path;
+    }
+    return null;
+  }
+
   @Override
   public String getHttpRequestMethod(ClientRequest request) {
     return request.method().name();

instrumentation/spring/spring-webflux/spring-webflux-5.3/testing/src/main/java/io/opentelemetry/instrumentation/spring/webflux/client/AbstractSpringWebfluxClientInstrumentationTest.java

@@ -23,6 +23,7 @@
 import java.lang.invoke.MethodType;
 import java.net.URI;
 import java.time.Duration;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
@@ -44,7 +45,7 @@ public WebClient.RequestBodySpec buildRequest(
 
     return webClient
         .method(HttpMethod.valueOf(method))
-        .uri(uri)
+        .uri(uri.toString(), Collections.emptyMap())
         .headers(h -> headers.forEach(h::add));
   }
 
@@ -182,6 +183,7 @@ void shouldEndSpanOnMonoTimeout() {
                         .hasAttributesSatisfyingExactly(
                             equalTo(SemanticAttributes.HTTP_REQUEST_METHOD, "GET"),
                             equalTo(SemanticAttributes.URL_FULL, uri.toString()),
+                            equalTo(SemanticAttributes.HTTP_ROUTE, uri.getPath()),
                             equalTo(SemanticAttributes.SERVER_ADDRESS, "localhost"),
                             equalTo(SemanticAttributes.SERVER_PORT, uri.getPort()),
                             equalTo(SemanticAttributes.ERROR_TYPE, "cancelled")),