feat: introduce url.template

Author: diegomarquezp

gax-java/gax/src/main/java/com/google/api/gax/tracing/ApiTracerContext.java

@@ -182,8 +182,13 @@ public Map<String, Object> getAttemptAttributes() {
     if (transport() == Transport.GRPC && !Strings.isNullOrEmpty(fullMethodName())) {
       attributes.put(ObservabilityAttributes.GRPC_RPC_METHOD_ATTRIBUTE, fullMethodName());
     }
-    if (transport() == Transport.HTTP && !Strings.isNullOrEmpty(httpMethod())) {
-      attributes.put(ObservabilityAttributes.HTTP_METHOD_ATTRIBUTE, httpMethod());
+    if (transport() == Transport.HTTP) {
+      if (!Strings.isNullOrEmpty(httpMethod())) {
+        attributes.put(ObservabilityAttributes.HTTP_METHOD_ATTRIBUTE, httpMethod());
+      }
+      if (!Strings.isNullOrEmpty(httpPathTemplate())) {
+        attributes.put(ObservabilityAttributes.HTTP_URL_TEMPLATE_ATTRIBUTE, httpPathTemplate());
+      }
     }
     return attributes;
   }

gax-java/gax/src/main/java/com/google/api/gax/tracing/ObservabilityAttributes.java

@@ -62,6 +62,9 @@ public class ObservabilityAttributes {
   /** The HTTP method of the request (e.g., "GET"). Only used in HTTP transport. */
   public static final String HTTP_METHOD_ATTRIBUTE = "http.request.method";
 
+  /** The HTTP method of the request (e.g., "GET"). Only used in HTTP transport. */
+  public static final String HTTP_URL_TEMPLATE_ATTRIBUTE = "url.template";
+
   /**
    * The error codes of the request. The value will be the string representation of the canonical
    * gRPC status code (e.g., "OK", "INTERNAL").

gax-java/gax/src/test/java/com/google/api/gax/tracing/ApiTracerContextTest.java

@@ -140,6 +140,20 @@ void testGetAttemptAttributes_rpcSystemName() {
     assertThat(attributes).containsEntry(ObservabilityAttributes.RPC_SYSTEM_NAME_ATTRIBUTE, "grpc");
   }
 
+  @Test
+  void testGetAttemptAttributes_httpPathTemplate() {
+    ApiTracerContext context =
+        ApiTracerContext.newBuilder()
+            .setLibraryMetadata(LibraryMetadata.empty())
+            .setTransport(ApiTracerContext.Transport.HTTP)
+            .setHttpPathTemplate("the-template")
+            .build();
+    Map<String, Object> attributes = context.getAttemptAttributes();
+
+    assertThat(attributes)
+        .containsEntry(ObservabilityAttributes.HTTP_URL_TEMPLATE_ATTRIBUTE, "the-template");
+  }
+
   @Test
   void testGetAttemptAttributes_empty() {
     ApiTracerContext context = ApiTracerContext.empty();

gax-java/gax/src/test/java/com/google/api/gax/tracing/ObservabilityUtilsTest.java

@@ -84,6 +84,20 @@ void testToOtelAttributes_correctConversion() {
         .isEqualTo(attribute2Value);
   }
 
+  @Test
+  void testToOtelAttributes_urlTemplateAttribute() {
+    String urlTemplateValue = "/blogs/{blog}/posts/{post}";
+    Map<String, String> attributes =
+        ImmutableMap.of(ObservabilityAttributes.HTTP_URL_TEMPLATE_ATTRIBUTE, urlTemplateValue);
+
+    Attributes otelAttributes = ObservabilityUtils.toOtelAttributes(attributes);
+
+    Truth.assertThat(
+            otelAttributes.get(
+                AttributeKey.stringKey(ObservabilityAttributes.HTTP_URL_TEMPLATE_ATTRIBUTE)))
+        .isEqualTo(urlTemplateValue);
+  }
+
   @Test
   void testToOtelAttributes_nullInput() {
     Throwable thrown =

java-showcase/gapic-showcase/src/test/java/com/google/showcase/v1beta1/it/ITOtelTracing.java

@@ -189,6 +189,11 @@ void testTracing_successfulEcho_httpjson() throws Exception {
                   .getAttributes()
                   .get(AttributeKey.stringKey(ObservabilityAttributes.HTTP_METHOD_ATTRIBUTE)))
           .isEqualTo("POST");
+      assertThat(
+              attemptSpan
+                  .getAttributes()
+                  .get(AttributeKey.stringKey(ObservabilityAttributes.HTTP_URL_TEMPLATE_ATTRIBUTE)))
+          .isEqualTo("v1beta1/echo:echo");
     }
   }
 }