fix(firestore): support opentelemetry-instrumentation-grpc 2.25.0+

Author: exoego

java-firestore/google-cloud-firestore/pom.xml

@@ -363,6 +363,36 @@
         </dependency>
       </dependencies>
     </profile>
+    <!--
+      Matrix-test profiles for opentelemetry-instrumentation-grpc-1.6.
+      GrpcTelemetry.newClientInterceptor() was renamed createClientInterceptor();
+      these profiles run tests under both APIs to verify the reflection-based fallback.
+      See https://github.com/googleapis/google-cloud-java/issues/13095
+    -->
+    <profile>
+      <id>otel-grpc-old</id>
+      <dependencyManagement>
+        <dependencies>
+          <dependency>
+            <groupId>io.opentelemetry.instrumentation</groupId>
+            <artifactId>opentelemetry-grpc-1.6</artifactId>
+            <version>2.1.0-alpha</version>
+          </dependency>
+        </dependencies>
+      </dependencyManagement>
+    </profile>
+    <profile>
+      <id>otel-grpc-new</id>
+      <dependencyManagement>
+        <dependencies>
+          <dependency>
+            <groupId>io.opentelemetry.instrumentation</groupId>
+            <artifactId>opentelemetry-grpc-1.6</artifactId>
+            <version>2.25.0-alpha</version>
+          </dependency>
+        </dependencies>
+      </dependencyManagement>
+    </profile>
     <profile>
       <!-- JDK17 set up for tests in src/test-jdk17 -->
       <id>java17-test</id>

java-firestore/google-cloud-firestore/src/main/java/com/google/cloud/firestore/telemetry/EnabledTraceUtil.java

@@ -23,6 +23,7 @@
 import com.google.api.core.InternalApi;
 import com.google.cloud.firestore.FirestoreOptions;
 import com.google.common.base.Throwables;
+import io.grpc.ClientInterceptor;
 import io.grpc.ManagedChannelBuilder;
 import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.api.OpenTelemetry;
@@ -34,6 +35,8 @@
 import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.api.trace.TracerProvider;
 import io.opentelemetry.instrumentation.grpc.v1_6.GrpcTelemetry;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.Map;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -73,13 +76,44 @@ public OpenTelemetry getOpenTelemetry() {
     return openTelemetry;
   }
 
+  // See https://github.com/googleapis/google-cloud-java/issues/13095
+  private static final Method GRPC_CLIENT_INTERCEPTOR_METHOD = resolveGrpcClientInterceptorMethod();
+
+  private static Method resolveGrpcClientInterceptorMethod() {
+    try {
+      return GrpcTelemetry.class.getMethod("createClientInterceptor");
+    } catch (NoSuchMethodException ignored) {
+      // Fall back to the pre-2.25.0 method name.
+    }
+    try {
+      return GrpcTelemetry.class.getMethod("newClientInterceptor");
+    } catch (NoSuchMethodException e) {
+      throw new IllegalStateException(
+          "Neither GrpcTelemetry#createClientInterceptor nor GrpcTelemetry#newClientInterceptor"
+              + " is available on the classpath. Incompatible"
+              + " opentelemetry-instrumentation-grpc-1.6 version.",
+          e);
+    }
+  }
+
+  private static ClientInterceptor newGrpcClientInterceptor(GrpcTelemetry grpcTelemetry) {
+    try {
+      return (ClientInterceptor) GRPC_CLIENT_INTERCEPTOR_METHOD.invoke(grpcTelemetry);
+    } catch (IllegalAccessException e) {
+      throw new IllegalStateException(e);
+    } catch (InvocationTargetException e) {
+      Throwables.throwIfUnchecked(e.getCause());
+      throw new RuntimeException(e.getCause());
+    }
+  }
+
   // The gRPC channel configurator that intercepts gRPC calls for tracing purposes.
   public class OpenTelemetryGrpcChannelConfigurator
       implements ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> {
     @Override
     public ManagedChannelBuilder apply(ManagedChannelBuilder managedChannelBuilder) {
       GrpcTelemetry grpcTelemetry = GrpcTelemetry.create(getOpenTelemetry());
-      return managedChannelBuilder.intercept(grpcTelemetry.newClientInterceptor());
+      return managedChannelBuilder.intercept(newGrpcClientInterceptor(grpcTelemetry));
     }
   }
 

java-firestore/google-cloud-firestore/src/test/java/com/google/cloud/firestore/telemetry/EnabledTraceUtilTest.java

@@ -17,8 +17,10 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.api.core.ApiFunction;
 import com.google.cloud.firestore.FirestoreOpenTelemetryOptions;
 import com.google.cloud.firestore.FirestoreOptions;
+import io.grpc.ManagedChannelBuilder;
 import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.api.trace.TracerProvider;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
@@ -111,6 +113,28 @@ public void openTelemetryInstanceRegistersGrpcChannelConfigurator() {
     assertThat(traceUtil.getChannelConfigurator()).isNotNull();
   }
 
+  // Exercises the reflection fallback that resolves either
+  // GrpcTelemetry#createClientInterceptor (>= 2.25.0) or #newClientInterceptor (< 2.25.0).
+  // See https://github.com/googleapis/google-cloud-java/issues/13095
+  @Test
+  public void channelConfiguratorAppliesInterceptorAcrossOtelGrpcVersions() {
+    OpenTelemetrySdk myOpenTelemetrySdk = OpenTelemetrySdk.builder().build();
+    FirestoreOptions firestoreOptions =
+        getBaseOptions()
+            .setOpenTelemetryOptions(
+                FirestoreOpenTelemetryOptions.newBuilder()
+                    .setOpenTelemetry(myOpenTelemetrySdk)
+                    .build())
+            .build();
+    EnabledTraceUtil traceUtil = new EnabledTraceUtil(firestoreOptions);
+    ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> configurator =
+        traceUtil.getChannelConfigurator();
+    assertThat(configurator).isNotNull();
+
+    ManagedChannelBuilder<?> builder = ManagedChannelBuilder.forAddress("localhost", 9999);
+    assertThat(configurator.apply(builder)).isNotNull();
+  }
+
   @Test
   public void usesEnabledContext() {
     assertThat(defaultEnabledTraceUtil().currentContext() instanceof EnabledTraceUtil.Context)