docs: Create OpenTelemetry Quickstart Sample (#2861)

Author: sydney-munro

samples/install-without-bom/pom.xml

@@ -76,6 +76,16 @@
       <classifier>tests</classifier>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>exporter-trace</artifactId>
+      <version>0.31.0</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>propagators-gcp</artifactId>
+      <version>0.33.0-alpha</version>
+    </dependency>
   </dependencies>
 
   <!-- compile and run all snippet tests -->

samples/snapshot/pom.xml

@@ -68,6 +68,16 @@
       <classifier>tests</classifier>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>exporter-trace</artifactId>
+      <version>0.31.0</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>propagators-gcp</artifactId>
+      <version>0.33.0-alpha</version>
+    </dependency>
   </dependencies>
 
   <!-- compile and run all snippet tests -->

samples/snippets/pom.xml

@@ -79,6 +79,16 @@
       <version>1.136.0</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>exporter-trace</artifactId>
+      <version>0.31.0</version>
+    </dependency>
+    <dependency>
+      <groupId>com.google.cloud.opentelemetry</groupId>
+      <artifactId>propagators-gcp</artifactId>
+      <version>0.33.0-alpha</version>
+    </dependency>
     <dependency>
       <!-- tests jars aren't in the bom, manually include the version here -->
       <groupId>com.google.cloud</groupId>

samples/snippets/src/main/java/com/example/storage/QuickstartOpenTelemetrySample.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 Google Inc.
+ *
+ * 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.example.storage;
+
+
+
+import com.google.cloud.opentelemetry.propagators.XCloudTraceContextPropagator;
+import com.google.cloud.opentelemetry.trace.TraceExporter;
+import com.google.cloud.storage.Storage;
+import com.google.cloud.storage.StorageOptions;
+import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;
+import io.opentelemetry.context.propagation.ContextPropagators;
+import io.opentelemetry.context.propagation.TextMapPropagator;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+
+// [START storage_enable_otel_tracing]
+public class QuickstartOpenTelemetrySample {
+  public static void main(String... args) throws Exception {
+    SpanExporter spanExporter = TraceExporter.createWithDefaultConfiguration();
+    TextMapPropagator propagators = TextMapPropagator.composite(
+        W3CTraceContextPropagator.getInstance(),
+        new XCloudTraceContextPropagator(/*oneway=*/true));
+
+    OpenTelemetrySdk openTelemetry =
+        OpenTelemetrySdk.builder()
+            .setPropagators(ContextPropagators.create(propagators))
+            .setTracerProvider(
+                SdkTracerProvider.builder()
+                    // Sample Rate is set to alwaysOn
+                    // It is recommended to sample based on a ratio for standard use ie.
+                    // .setSampler(Sampler.traceIdRatioBased(0.2)) // sample only 20% of trace ids
+                    .setSampler(Sampler.alwaysOn())
+                    .addSpanProcessor(BatchSpanProcessor.builder(spanExporter).build())
+                    .build())
+            .build();
+    StorageOptions options = StorageOptions.newBuilder().setOpenTelemetry(openTelemetry).build();
+    Storage storage = options.getService();
+    System.out.println("Created an instance of storage with OpenTelemetry configured");
+
+  }
+}
+// [END storage_enable_otel_tracing]

samples/snippets/src/test/java/com/example/storage/QuickstartSampleIT.java

@@ -86,4 +86,12 @@ public void testQuickstartStorageControl() throws Exception {
                 "Performed getStorageLayout request for %s",
                 StorageLayoutName.format("_", bucketName)));
   }
+
+  @Test
+  public void testQuickstartOpenTelemetry() throws Exception {
+    QuickstartOpenTelemetrySample.main();
+    String got = stdOutCaptureRule.getCapturedOutputAsUtf8String();
+    assertThat(got)
+        .contains("Created an instance of storage with OpenTelemetry configured");
+  }
 }