Add RemoteAttributesSpanProcessor component to awsxray

aws-xray/src/main/java/io/opentelemetry/contrib/awsxray/RemoteAttributesSpanProcessor.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.awsxray;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.trace.ReadWriteSpan;
+import io.opentelemetry.sdk.trace.ReadableSpan;
+import io.opentelemetry.sdk.trace.SpanProcessor;
+
+/**
+ * RemoteAttributesSpanProcessor copies attributes aws.remote.application and aws.remote.operation
+ * from the parent span to children after receiving them. These two attributes will be used as
+ * RemoteApplication and RemoteOperation dimension values in dependency metrics generation.
+ */
+public class RemoteAttributesSpanProcessor implements SpanProcessor {
+
+  private static final AttributeKey<String> REMOTE_APPLICATION =
+      AttributeKey.stringKey("aws.remote.application");
+  private static final AttributeKey<String> REMOTE_OPERATION =
+      AttributeKey.stringKey("aws.remote.operation");
+
+  @Override
+  public void onStart(Context parentContext, ReadWriteSpan span) {
+    Span parentSpan = Span.fromContextOrNull(parentContext);
+    if (!(parentSpan instanceof ReadableSpan)) {
+      return;
+    }
+    ReadableSpan parentReadableSpan = (ReadableSpan) parentSpan;
+
+    String remoteApplication = parentReadableSpan.getAttribute(REMOTE_APPLICATION);
+    if (remoteApplication != null) {
+      span.setAttribute(REMOTE_APPLICATION, remoteApplication);
+    }
+
+    String remoteOperation = parentReadableSpan.getAttribute(REMOTE_OPERATION);
+    if (remoteOperation != null) {
+      span.setAttribute(REMOTE_OPERATION, remoteOperation);
+    }
+  }
+
+  @Override
+  public boolean isStartRequired() {
+    return true;
+  }
+
+  @Override
+  public void onEnd(ReadableSpan span) {}
+
+  @Override
+  public boolean isEndRequired() {
+    return false;
+  }
+}

aws-xray/src/test/java/io/opentelemetry/contrib/awsxray/RemoteAttributesSpanProcessorTest.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.awsxray;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.trace.ReadableSpan;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class RemoteAttributesSpanProcessorTest {
+
+  private static final String REMOTE_APPLICATION = "aws.remote.application";
+  private static final String REMOTE_OPERATION = "aws.remote.operation";
+
+  private Tracer tracer;
+
+  @BeforeEach
+  public void setup() {
+    tracer =
+        SdkTracerProvider.builder()
+            .addSpanProcessor(new RemoteAttributesSpanProcessor())
+            .build()
+            .get("awsxray");
+  }
+
+  @Test
+  public void testRemoteAttributesInheritance() {
+    Span span = tracer.spanBuilder("parent").startSpan();
+
+    span.setAttribute(REMOTE_APPLICATION, "testApplication");
+    span.setAttribute(REMOTE_OPERATION, "testOperation");
+
+    ReadableSpan leafSpan = (ReadableSpan) createNestedSpan(span, 10);
+
+    assertThat(leafSpan.getParentSpanContext()).isNotNull();
+    assertThat(leafSpan.getName()).isEqualTo("child:1");
+    assertThat(leafSpan.getAttribute(AttributeKey.stringKey(REMOTE_APPLICATION)))
+        .isEqualTo("testApplication");
+    assertThat(leafSpan.getAttribute(AttributeKey.stringKey(REMOTE_OPERATION)))
+        .isEqualTo("testOperation");
+  }
+
+  private Span createNestedSpan(Span parentSpan, int depth) {
+    if (depth == 0) {
+      return parentSpan;
+    }
+    Span childSpan =
+        tracer
+            .spanBuilder("child:" + depth)
+            .setParent(Context.current().with(parentSpan))
+            .startSpan();
+    try {
+      return createNestedSpan(childSpan, depth - 1);
+    } finally {
+      childSpan.end();
+    }
+  }
+}