From f6dd4ab6c8de2168600aa7e2d7a833e1d46e2d4e Mon Sep 17 00:00:00 2001
From: Sydney Munro <97561403+sydney-munro@users.noreply.github.com>
Date: Thu, 17 Oct 2024 10:51:57 -0700
Subject: [PATCH] feat: Instrument HTTP with OpenTelemetry (#2780)

---
 .../clirr-ignored-differences.xml             |  13 ++
 google-cloud-storage/pom.xml                  |   9 +
 .../cloud/storage/GrpcStorageOptions.java     |  11 +
 .../cloud/storage/HttpStorageOptions.java     |  26 +++
 .../google/cloud/storage/StorageOptions.java  |   6 +
 .../otel/NoOpOpenTelemetryInstance.java       |  96 +++++++++
 .../storage/otel/OpenTelemetryInstance.java   | 191 ++++++++++++++++++
 .../storage/otel/OpenTelemetryTraceUtil.java  |  94 +++++++++
 .../cloud/storage/spi/v1/HttpStorageRpc.java  |  11 +-
 .../cloud/storage/ITOpenTelemetryTest.java    | 105 ++++++++++
 10 files changed, 561 insertions(+), 1 deletion(-)
 create mode 100644 google-cloud-storage/src/main/java/com/google/cloud/storage/otel/NoOpOpenTelemetryInstance.java
 create mode 100644 google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryInstance.java
 create mode 100644 google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryTraceUtil.java
 create mode 100644 google-cloud-storage/src/test/java/com/google/cloud/storage/ITOpenTelemetryTest.java

diff --git a/google-cloud-storage/clirr-ignored-differences.xml b/google-cloud-storage/clirr-ignored-differences.xml
index d81c37bb24..03e37c174e 100644
--- a/google-cloud-storage/clirr-ignored-differences.xml
+++ b/google-cloud-storage/clirr-ignored-differences.xml
@@ -96,4 +96,17 @@
     <method>boolean equals(java.lang.Object)</method>
   </difference>
 
+  <difference>
+    <differenceType>7013</differenceType>
+    <className>com/google/cloud/storage/StorageOptions$Builder</className>
+    <method>com.google.cloud.storage.StorageOptions$Builder setOpenTelemetrySdk(io.opentelemetry.sdk.OpenTelemetrySdk)</method>
+  </difference>
+
+  <difference>
+    <differenceType>7013</differenceType>
+    <className>com/google/cloud/storage/StorageOptions</className>
+    <method>io.opentelemetry.sdk.OpenTelemetrySdk getOpenTelemetrySdk()</method>
+  </difference>
+
+
 </differences>
diff --git a/google-cloud-storage/pom.xml b/google-cloud-storage/pom.xml
index 2b3413e7f3..02ef4f2611 100644
--- a/google-cloud-storage/pom.xml
+++ b/google-cloud-storage/pom.xml
@@ -83,6 +83,10 @@
       <groupId>io.opencensus</groupId>
       <artifactId>opencensus-api</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-context</artifactId>
+    </dependency>
     <dependency>
       <groupId>com.google.api.grpc</groupId>
       <artifactId>proto-google-iam-v1</artifactId>
@@ -205,6 +209,11 @@
       <artifactId>grpc-googleapis</artifactId>
       <scope>runtime</scope>
     </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk-trace</artifactId>
+      <scope>test</scope>
+    </dependency>
 
     <!--
     We're not using this directly, however there appears to be some resolution
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/GrpcStorageOptions.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/GrpcStorageOptions.java
index 10d7066987..cd574e97bc 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/GrpcStorageOptions.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/GrpcStorageOptions.java
@@ -78,6 +78,7 @@
 import io.grpc.MethodDescriptor;
 import io.grpc.Status;
 import io.grpc.protobuf.ProtoUtils;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
 import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
@@ -347,6 +348,11 @@ private Tuple<StorageSettings, Opts<UserProject>> resolveSettingsAndOpts() throw
     return Tuple.of(builder.build(), defaultOpts);
   }
 
+  @Override
+  public OpenTelemetrySdk getOpenTelemetrySdk() {
+    return null;
+  }
+
   /** @since 2.14.0 This new api is in preview and is subject to breaking changes. */
   @BetaApi
   @Override
@@ -628,6 +634,11 @@ public GrpcStorageOptions.Builder setBlobWriteSessionConfig(
       return this;
     }
 
+    @Override
+    public StorageOptions.Builder setOpenTelemetrySdk(@NonNull OpenTelemetrySdk openTelemetrySdk) {
+      return null;
+    }
+
     /** @since 2.14.0 This new api is in preview and is subject to breaking changes. */
     @BetaApi
     @Override
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/HttpStorageOptions.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/HttpStorageOptions.java
index 9f6781f6c4..f58da29e18 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/HttpStorageOptions.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/HttpStorageOptions.java
@@ -38,6 +38,7 @@
 import com.google.cloud.storage.spi.v1.StorageRpc;
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ImmutableSet;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.Serializable;
@@ -60,6 +61,8 @@ public class HttpStorageOptions extends StorageOptions {
   private transient RetryDependenciesAdapter retryDepsAdapter;
   private final BlobWriteSessionConfig blobWriteSessionConfig;
 
+  private OpenTelemetrySdk openTelemetrySdk;
+
   private HttpStorageOptions(Builder builder, StorageDefaults serviceDefaults) {
     super(builder, serviceDefaults);
     this.retryAlgorithmManager =
@@ -68,6 +71,7 @@ private HttpStorageOptions(Builder builder, StorageDefaults serviceDefaults) {
                 builder.storageRetryStrategy, defaults().getStorageRetryStrategy()));
     retryDepsAdapter = new RetryDependenciesAdapter();
     blobWriteSessionConfig = builder.blobWriteSessionConfig;
+    openTelemetrySdk = builder.openTelemetrySdk;
   }
 
   @Override
@@ -85,6 +89,11 @@ StorageRpc getStorageRpcV1() {
     return (StorageRpc) getRpc();
   }
 
+  @Override
+  public OpenTelemetrySdk getOpenTelemetrySdk() {
+    return openTelemetrySdk;
+  }
+
   @Override
   public HttpStorageOptions.Builder toBuilder() {
     return new HttpStorageOptions.Builder(this);
@@ -131,11 +140,16 @@ RetryingDependencies asRetryDependencies() {
     return retryDepsAdapter;
   }
 
+  public void setOpenTelemetrySdk(OpenTelemetrySdk openTelemetrySdk) {
+    this.openTelemetrySdk = openTelemetrySdk;
+  }
+
   public static class Builder extends StorageOptions.Builder {
 
     private StorageRetryStrategy storageRetryStrategy;
     private BlobWriteSessionConfig blobWriteSessionConfig =
         HttpStorageDefaults.INSTANCE.getDefaultStorageWriterConfig();
+    private OpenTelemetrySdk openTelemetrySdk;
 
     Builder() {}
 
@@ -144,6 +158,7 @@ public static class Builder extends StorageOptions.Builder {
       HttpStorageOptions hso = (HttpStorageOptions) options;
       this.storageRetryStrategy = hso.retryAlgorithmManager.retryStrategy;
       this.blobWriteSessionConfig = hso.blobWriteSessionConfig;
+      this.openTelemetrySdk = hso.getOpenTelemetrySdk();
     }
 
     @Override
@@ -269,6 +284,17 @@ public HttpStorageOptions build() {
       }
       return options;
     }
+
+    /**
+     * Enable OpenTelemetry Tracing and provide an instance for the client to use.
+     *
+     * @param openTelemetrySdk
+     */
+    public HttpStorageOptions.Builder setOpenTelemetrySdk(OpenTelemetrySdk openTelemetrySdk) {
+      requireNonNull(openTelemetrySdk, "openTelemetry must be non null");
+      this.openTelemetrySdk = openTelemetrySdk;
+      return this;
+    }
   }
 
   public static final class HttpStorageDefaults extends StorageDefaults {
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/StorageOptions.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/StorageOptions.java
index ab32532ae1..703f927509 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/StorageOptions.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/StorageOptions.java
@@ -29,6 +29,7 @@
 import com.google.cloud.storage.Storage.BlobWriteOption;
 import com.google.cloud.storage.TransportCompatibility.Transport;
 import com.google.cloud.storage.spi.StorageRpcFactory;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Properties;
@@ -110,6 +111,9 @@ public abstract static class Builder
     public abstract StorageOptions.Builder setBlobWriteSessionConfig(
         @NonNull BlobWriteSessionConfig blobWriteSessionConfig);
 
+    public abstract StorageOptions.Builder setOpenTelemetrySdk(
+        @NonNull OpenTelemetrySdk openTelemetrySdk);
+
     @Override
     public abstract StorageOptions build();
   }
@@ -144,6 +148,8 @@ public static String version() {
     return VERSION;
   }
 
+  public abstract OpenTelemetrySdk getOpenTelemetrySdk();
+
   @SuppressWarnings("unchecked")
   @Override
   public abstract StorageOptions.Builder toBuilder();
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/NoOpOpenTelemetryInstance.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/NoOpOpenTelemetryInstance.java
new file mode 100644
index 0000000000..814dbafdc4
--- /dev/null
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/NoOpOpenTelemetryInstance.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage.otel;
+
+import com.google.api.core.ApiFuture;
+import io.opentelemetry.api.trace.StatusCode;
+import java.util.Map;
+import javax.annotation.Nonnull;
+
+class NoOpOpenTelemetryInstance implements OpenTelemetryTraceUtil {
+
+  @Override
+  public OpenTelemetryTraceUtil.Span startSpan(String spanName) {
+    return new Span();
+  }
+
+  @Override
+  public OpenTelemetryTraceUtil.Span startSpan(
+      String spanName, OpenTelemetryTraceUtil.Context parent) {
+    return new Span();
+  }
+
+  @Nonnull
+  @Override
+  public Span currentSpan() {
+    return new Span();
+  }
+
+  @Nonnull
+  @Override
+  public Context currentContext() {
+    return new Context();
+  }
+
+  static class Span implements OpenTelemetryTraceUtil.Span {
+    @Override
+    public void end() {}
+
+    @Override
+    public void end(Throwable error) {}
+
+    @Override
+    public <T> void endAtFuture(ApiFuture<T> futureValue) {}
+
+    @Override
+    public OpenTelemetryTraceUtil.Span recordException(Throwable error) {
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span setStatus(StatusCode status, String name) {
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span addEvent(String name) {
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span addEvent(String name, Map<String, Object> attributes) {
+      return this;
+    }
+
+    @Override
+    public Scope makeCurrent() {
+      return new Scope();
+    }
+  }
+
+  static class Context implements OpenTelemetryTraceUtil.Context {
+    @Override
+    public Scope makeCurrent() {
+      return new Scope();
+    }
+  }
+
+  static class Scope implements OpenTelemetryTraceUtil.Scope {
+    @Override
+    public void close() {}
+  }
+}
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryInstance.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryInstance.java
new file mode 100644
index 0000000000..4fd1f0b6ff
--- /dev/null
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryInstance.java
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage.otel;
+
+import com.google.api.core.ApiFuture;
+import com.google.api.gax.core.GaxProperties;
+import com.google.cloud.storage.StorageOptions;
+import com.google.cloud.storage.otel.OpenTelemetryTraceUtil.Context;
+import com.google.cloud.storage.otel.OpenTelemetryTraceUtil.Span;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.api.trace.SpanBuilder;
+import io.opentelemetry.api.trace.SpanKind;
+import io.opentelemetry.api.trace.StatusCode;
+import io.opentelemetry.api.trace.Tracer;
+import java.util.Map;
+import javax.annotation.Nonnull;
+
+class OpenTelemetryInstance implements OpenTelemetryTraceUtil {
+  private final Tracer tracer;
+  private final OpenTelemetry openTelemetry;
+  private final StorageOptions storageOptions;
+
+  private static final String LIBRARY_NAME = "cloud.google.com/java/storage";
+
+  public OpenTelemetryInstance(StorageOptions storageOptions) {
+    this.storageOptions = storageOptions;
+    this.openTelemetry = storageOptions.getOpenTelemetrySdk();
+    this.tracer =
+        openTelemetry.getTracer(LIBRARY_NAME, GaxProperties.getLibraryVersion(this.getClass()));
+  }
+
+  static class Span implements OpenTelemetryTraceUtil.Span {
+    private final io.opentelemetry.api.trace.Span span;
+    private final String spanName;
+
+    Span(io.opentelemetry.api.trace.Span span, String spanName) {
+      this.span = span;
+      this.spanName = spanName;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span recordException(Throwable error) {
+      span.recordException(error);
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span setStatus(StatusCode status, String name) {
+      span.setStatus(status, name);
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span addEvent(String name) {
+      span.addEvent(name);
+      return this;
+    }
+
+    @Override
+    public OpenTelemetryTraceUtil.Span addEvent(String name, Map<String, Object> attributes) {
+      AttributesBuilder attributesBuilder = Attributes.builder();
+      attributes.forEach(
+          (key, value) -> {
+            if (value instanceof Integer) {
+              attributesBuilder.put(key, (int) value);
+            } else if (value instanceof Long) {
+              attributesBuilder.put(key, (long) value);
+            } else if (value instanceof Double) {
+              attributesBuilder.put(key, (double) value);
+            } else if (value instanceof Float) {
+              attributesBuilder.put(key, (float) value);
+            } else if (value instanceof Boolean) {
+              attributesBuilder.put(key, (boolean) value);
+            } else if (value instanceof String) {
+              attributesBuilder.put(key, (String) value);
+            } else {
+              // OpenTelemetry APIs do not support any other type.
+              throw new IllegalArgumentException(
+                  "Unknown attribute type:" + value.getClass().getSimpleName());
+            }
+          });
+      span.addEvent(name, attributesBuilder.build());
+      return this;
+    }
+
+    @Override
+    public Scope makeCurrent() {
+      return new Scope(span.makeCurrent());
+    }
+
+    @Override
+    public void end() {
+      span.end();
+    }
+
+    @Override
+    public void end(Throwable error) {}
+
+    @Override
+    public <T> void endAtFuture(ApiFuture<T> futureValue) {}
+  }
+
+  static class Scope implements OpenTelemetryTraceUtil.Scope {
+    private final io.opentelemetry.context.Scope scope;
+
+    Scope(io.opentelemetry.context.Scope scope) {
+      this.scope = scope;
+    }
+
+    @Override
+    public void close() {
+      scope.close();
+    }
+  }
+
+  static class Context implements OpenTelemetryTraceUtil.Context {
+    private final io.opentelemetry.context.Context context;
+
+    Context(io.opentelemetry.context.Context context) {
+      this.context = context;
+    }
+
+    @Override
+    public Scope makeCurrent() {
+      return new Scope(context.makeCurrent());
+    }
+  }
+
+  @Override
+  public OpenTelemetryTraceUtil.Span startSpan(String methodName) {
+    String formatSpanName = String.format("%s.%s/%s", "storage", "client", methodName);
+    SpanBuilder spanBuilder = tracer.spanBuilder(formatSpanName).setSpanKind(SpanKind.CLIENT);
+    io.opentelemetry.api.trace.Span span =
+        addSettingsAttributesToCurrentSpan(spanBuilder).startSpan();
+    return new Span(span, formatSpanName);
+  }
+
+  @Override
+  public OpenTelemetryTraceUtil.Span startSpan(
+      String spanName, OpenTelemetryTraceUtil.Context parent) {
+    assert (parent instanceof OpenTelemetryInstance.Context);
+    SpanBuilder spanBuilder =
+        tracer
+            .spanBuilder(spanName)
+            .setSpanKind(SpanKind.CLIENT)
+            .setParent(((OpenTelemetryInstance.Context) parent).context);
+    io.opentelemetry.api.trace.Span span =
+        addSettingsAttributesToCurrentSpan(spanBuilder).startSpan();
+    return new Span(span, spanName);
+  }
+
+  @Nonnull
+  @Override
+  public OpenTelemetryTraceUtil.Span currentSpan() {
+    return new Span(io.opentelemetry.api.trace.Span.current(), "");
+  }
+
+  @Nonnull
+  @Override
+  public OpenTelemetryTraceUtil.Context currentContext() {
+    return new Context(io.opentelemetry.context.Context.current());
+  }
+
+  private SpanBuilder addSettingsAttributesToCurrentSpan(SpanBuilder spanBuilder) {
+    spanBuilder = spanBuilder.setAttribute("gcp.client.service", "Storage");
+    spanBuilder =
+        spanBuilder.setAllAttributes(
+            Attributes.builder()
+                .put("gcp.client.version", GaxProperties.getLibraryVersion(this.getClass()))
+                .put("gcp.client.repo", "googleapis/java-storage")
+                .put("gcp.client.artifact", "com.google.cloud.google-cloud-storage")
+                .build());
+    return spanBuilder;
+  }
+}
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryTraceUtil.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryTraceUtil.java
new file mode 100644
index 0000000000..932457d05e
--- /dev/null
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/otel/OpenTelemetryTraceUtil.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage.otel;
+
+import com.google.api.core.ApiFuture;
+import com.google.cloud.storage.StorageOptions;
+import io.opentelemetry.api.trace.StatusCode;
+import java.util.Map;
+import javax.annotation.Nonnull;
+
+public interface OpenTelemetryTraceUtil {
+
+  static OpenTelemetryTraceUtil getInstance(@Nonnull StorageOptions storageOptions) {
+    boolean createNoOp = storageOptions.getOpenTelemetrySdk() == null;
+
+    if (createNoOp) {
+      return new NoOpOpenTelemetryInstance();
+    } else {
+      return new OpenTelemetryInstance(storageOptions);
+    }
+  }
+
+  /** Represents a trace span. */
+  interface Span {
+    Span recordException(Throwable error);
+
+    Span setStatus(StatusCode status, String name);
+    /** Adds the given event to this span. */
+    Span addEvent(String name);
+
+    /** Adds the given event with the given attributes to this span. */
+    Span addEvent(String name, Map<String, Object> attributes);
+
+    /** Marks this span as the current span. */
+    Scope makeCurrent();
+
+    /** Ends this span. */
+    void end();
+
+    /** Ends this span in an error. */
+    void end(Throwable error);
+
+    /**
+     * If an operation ends in the future, its relevant span should end _after_ the future has been
+     * completed. This method "appends" the span completion code at the completion of the given
+     * future. In order for telemetry info to be recorded, the future returned by this method should
+     * be completed.
+     */
+    <T> void endAtFuture(ApiFuture<T> futureValue);
+  }
+
+  /** Represents a trace context. */
+  interface Context {
+    /** Makes this context the current context. */
+    Scope makeCurrent();
+  }
+
+  /** Represents a trace scope. */
+  interface Scope extends AutoCloseable {
+    /** Closes the current scope. */
+    void close();
+  }
+
+  /** Starts a new span with the given name, sets it as the current span, and returns it. */
+  Span startSpan(String spanName);
+
+  /**
+   * Starts a new span with the given name and the given context as its parent, sets it as the
+   * current span, and returns it.
+   */
+  Span startSpan(String spanName, Context parent);
+
+  /** Returns the current span. */
+  @Nonnull
+  Span currentSpan();
+
+  /** Returns the current Context. */
+  @Nonnull
+  Context currentContext();
+}
diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/spi/v1/HttpStorageRpc.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/spi/v1/HttpStorageRpc.java
index 5341051a25..fdfec46199 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/spi/v1/HttpStorageRpc.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/spi/v1/HttpStorageRpc.java
@@ -67,6 +67,7 @@
 import com.google.cloud.http.HttpTransportOptions;
 import com.google.cloud.storage.StorageException;
 import com.google.cloud.storage.StorageOptions;
+import com.google.cloud.storage.otel.OpenTelemetryTraceUtil;
 import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
@@ -80,6 +81,7 @@
 import io.opencensus.trace.Status;
 import io.opencensus.trace.Tracer;
 import io.opencensus.trace.Tracing;
+import io.opentelemetry.api.trace.StatusCode;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -113,6 +115,7 @@ public class HttpStorageRpc implements StorageRpc {
   private final Storage storage;
   private final Tracer tracer = Tracing.getTracer();
   private final HttpRequestInitializer batchRequestInitializer;
+  private final OpenTelemetryTraceUtil openTelemetryTraceUtil;
 
   private static final long MEGABYTE = 1024L * 1024L;
   private static final FileNameMap FILE_NAME_MAP = URLConnection.getFileNameMap();
@@ -144,6 +147,8 @@ public HttpStorageRpc(StorageOptions options, JsonFactory jsonFactory) {
             .setRootUrl(options.getHost())
             .setApplicationName(applicationName)
             .build();
+    // Get instance of OpenTelemetry
+    openTelemetryTraceUtil = OpenTelemetryTraceUtil.getInstance(options);
   }
 
   public Storage getStorage() {
@@ -355,9 +360,10 @@ private Span startSpan(String spanName) {
 
   @Override
   public Bucket create(Bucket bucket, Map<Option, ?> options) {
+    OpenTelemetryTraceUtil.Span otelSpan = openTelemetryTraceUtil.startSpan("create(Bucket,Map)");
     Span span = startSpan(HttpStorageRpcSpans.SPAN_NAME_CREATE_BUCKET);
     Scope scope = tracer.withSpan(span);
-    try {
+    try (OpenTelemetryTraceUtil.Scope unused = otelSpan.makeCurrent()) {
       return storage
           .buckets()
           .insert(this.options.getProjectId(), bucket)
@@ -368,9 +374,12 @@ public Bucket create(Bucket bucket, Map<Option, ?> options) {
           .setEnableObjectRetention(Option.ENABLE_OBJECT_RETENTION.getBoolean(options))
           .execute();
     } catch (IOException ex) {
+      otelSpan.recordException(ex);
+      otelSpan.setStatus(StatusCode.ERROR, ex.getClass().getSimpleName());
       span.setStatus(Status.UNKNOWN.withDescription(ex.getMessage()));
       throw translate(ex);
     } finally {
+      otelSpan.end();
       scope.close();
       span.end(HttpStorageRpcSpans.END_SPAN_OPTIONS);
     }
diff --git a/google-cloud-storage/src/test/java/com/google/cloud/storage/ITOpenTelemetryTest.java b/google-cloud-storage/src/test/java/com/google/cloud/storage/ITOpenTelemetryTest.java
new file mode 100644
index 0000000000..e07cf659cc
--- /dev/null
+++ b/google-cloud-storage/src/test/java/com/google/cloud/storage/ITOpenTelemetryTest.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.storage;
+
+import com.google.cloud.storage.TransportCompatibility.Transport;
+import com.google.cloud.storage.it.runner.StorageITRunner;
+import com.google.cloud.storage.it.runner.annotations.Backend;
+import com.google.cloud.storage.it.runner.annotations.CrossRun;
+import com.google.cloud.storage.it.runner.annotations.Inject;
+import com.google.cloud.storage.it.runner.registry.Generator;
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(StorageITRunner.class)
+@CrossRun(
+    backends = {Backend.PROD},
+    transports = {Transport.HTTP})
+public final class ITOpenTelemetryTest {
+  @Inject public Generator generator;
+
+  @Test
+  public void checkInstrumentation() {
+    SpanExporter exporter = new TestExporter();
+
+    OpenTelemetrySdk openTelemetrySdk =
+        OpenTelemetrySdk.builder()
+            .setTracerProvider(
+                SdkTracerProvider.builder()
+                    .addSpanProcessor(SimpleSpanProcessor.create(exporter))
+                    .build())
+            .build();
+    StorageOptions storageOptions =
+        StorageOptions.http().setOpenTelemetrySdk(openTelemetrySdk).build();
+    Storage storage = storageOptions.getService();
+    storage.create(BucketInfo.of(generator.randomBucketName()));
+    TestExporter testExported = (TestExporter) exporter;
+    SpanData spanData = testExported.getExportedSpans().get(0);
+    Assert.assertEquals("Storage", getAttributeValue(spanData, "gcp.client.service"));
+    Assert.assertEquals("googleapis/java-storage", getAttributeValue(spanData, "gcp.client.repo"));
+    Assert.assertEquals(
+        "com.google.cloud.google-cloud-storage",
+        getAttributeValue(spanData, "gcp.client.artifact"));
+  }
+
+  @Test
+  public void noOpDoesNothing() {
+    StorageOptions storageOptions = StorageOptions.http().build();
+    Storage storage = storageOptions.getService();
+    storage.create(BucketInfo.of(generator.randomBucketName()));
+  }
+
+  private String getAttributeValue(SpanData spanData, String key) {
+    return spanData.getAttributes().get(AttributeKey.stringKey(key)).toString();
+  }
+}
+
+class TestExporter implements SpanExporter {
+  public final List<SpanData> exportedSpans = Collections.synchronizedList(new ArrayList<>());
+
+  @Override
+  public CompletableResultCode export(Collection<SpanData> spans) {
+    exportedSpans.addAll(spans);
+    return CompletableResultCode.ofSuccess();
+  }
+
+  @Override
+  public CompletableResultCode flush() {
+    return null;
+  }
+
+  @Override
+  public CompletableResultCode shutdown() {
+    return null;
+  }
+
+  public List<SpanData> getExportedSpans() {
+    return exportedSpans;
+  }
+}