Adding UdpExporter for Otlp spans

awsagentprovider/build.gradle.kts

@@ -40,6 +40,9 @@ dependencies {
   implementation("com.amazonaws:aws-java-sdk-core:1.12.773")
   // Export configuration
   compileOnly("io.opentelemetry:opentelemetry-exporter-otlp")
+  // For Udp emitter
+  implementation("io.opentelemetry:opentelemetry-exporter-otlp-common")
+  implementation("io.opentelemetry:opentelemetry-exporter-common")
 
   testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")

awsagentprovider/src/main/java/software/amazon/opentelemetry/javaagent/providers/OtlpUdpSpanExporter.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.opentelemetry.javaagent.providers;
+
+import io.opentelemetry.exporter.internal.otlp.traces.TraceRequestMarshaler;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.Collection;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+public class OtlpUdpSpanExporter implements SpanExporter {
+
+  private static final Logger logger = Logger.getLogger(OtlpUdpSpanExporter.class.getName());
+  private static final String PROTOCOL_HEADER = "{\"format\": \"json\", \"version\": 1}";
+  private static final char PROTOCOL_DELIMITER = '\n';
+  private static final String FORMAT_OTEL_SAMPLED_TRACES_BINARY_PREFIX = "T1S";
+  private static final String FORMAT_OTEL_UNSAMPLED_TRACES_BINARY_PREFIX = "T1U";
+
+  private final AtomicBoolean isShutdown = new AtomicBoolean();
+
+  private final UdpSender sender;
+  private final boolean sampled;
+
+  OtlpUdpSpanExporter(UdpSender sender, boolean sampled) {
+    this.sender = sender;
+    this.sampled = sampled;
+  }
+
+  @Override
+  public CompletableResultCode export(Collection<SpanData> spans) {
+    if (isShutdown.get()) {
+      return CompletableResultCode.ofFailure();
+    }
+
+    TraceRequestMarshaler exportRequest = TraceRequestMarshaler.create(spans);
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    try {
+      exportRequest.writeBinaryTo(baos);
+      String payload =
+          PROTOCOL_HEADER
+              + PROTOCOL_DELIMITER
+              + (sampled
+                  ? FORMAT_OTEL_SAMPLED_TRACES_BINARY_PREFIX
+                  : FORMAT_OTEL_UNSAMPLED_TRACES_BINARY_PREFIX)
+              + Base64.getEncoder().encodeToString(baos.toByteArray());
+      sender.send(payload.getBytes(StandardCharsets.UTF_8));
+      return CompletableResultCode.ofSuccess();
+    } catch (Exception e) {
+      logger.log(Level.SEVERE, "Failed to export spans. Error: " + e.getMessage(), e);
+      return CompletableResultCode.ofFailure();
+    }
+  }
+
+  @Override
+  public CompletableResultCode flush() {
+    // TODO: implement
+    return CompletableResultCode.ofSuccess();
+  }
+
+  @Override
+  public CompletableResultCode shutdown() {
+    if (!isShutdown.compareAndSet(false, true)) {
+      logger.log(Level.INFO, "Calling shutdown() multiple times.");
+      return CompletableResultCode.ofSuccess();
+    }
+    return sender.shutdown();
+  }
+
+  // Visible for testing
+  UdpSender getSender() {
+    return sender;
+  }
+
+  // Visible for testing
+  boolean isSampled() {
+    return sampled;
+  }
+}

awsagentprovider/src/main/java/software/amazon/opentelemetry/javaagent/providers/OtlpUdpSpanExporterBuilder.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.opentelemetry.javaagent.providers;
+
+import static java.util.Objects.requireNonNull;
+
+import java.net.SocketException;
+
+public final class OtlpUdpSpanExporterBuilder {
+
+  private static final String DEFAULT_HOST = "127.0.0.1";
+  private static final int DEFAULT_PORT = 2000;
+
+  private UdpSender sender;
+  private boolean sampled = true;
+
+  public OtlpUdpSpanExporterBuilder setEndpoint(String endpoint) {
+    requireNonNull(endpoint, "endpoint must not be null");
+    try {
+      String[] parts = endpoint.split(":");
+      String host = parts[0];
+      int port = Integer.parseInt(parts[1]);
+      this.sender = new UdpSender(host, port);
+    } catch (Exception e) {
+      throw new IllegalArgumentException("Invalid endpoint, must be a valid URL: " + endpoint, e);
+    }
+    return this;
+  }
+
+  public OtlpUdpSpanExporterBuilder setSampled(boolean sampled) {
+    this.sampled = sampled;
+    return this;
+  }
+
+  public OtlpUdpSpanExporter build() {
+    if (sender == null) {
+      try {
+        this.sender = new UdpSender(DEFAULT_HOST, DEFAULT_PORT);
+      } catch (SocketException e) {
+        throw new IllegalStateException("Failed to create OtlpUdpSpanExporter", e);
+      }
+    }
+    return new OtlpUdpSpanExporter(this.sender, this.sampled);
+  }
+
+  // Only for testing
+  OtlpUdpSpanExporterBuilder setSender(UdpSender sender) {
+    this.sender = sender;
+    return this;
+  }
+}

awsagentprovider/src/main/java/software/amazon/opentelemetry/javaagent/providers/UdpSender.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.opentelemetry.javaagent.providers;
+
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+import java.net.SocketException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class UdpSender {
+  private static final Logger logger = Logger.getLogger(UdpSender.class.getName());
+
+  private final DatagramSocket socket;
+  private final InetSocketAddress endpoint;
+
+  public UdpSender(String host, int port) throws SocketException {
+    this.endpoint = new InetSocketAddress(host, port);
+    try {
+      socket = new DatagramSocket();
+    } catch (SocketException e) {
+      logger.log(Level.SEVERE, "Exception while instantiating UdpSender socket.", e);
+      throw e;
+    }
+  }
+
+  public CompletableResultCode shutdown() {
+    try {
+      socket.close();
+      return CompletableResultCode.ofSuccess();
+    } catch (Exception e) {
+      logger.log(Level.SEVERE, "Exception while closing UdpSender socket.", e);
+      return CompletableResultCode.ofFailure();
+    }
+  }
+
+  public void send(byte[] data) {
+    DatagramPacket packet = new DatagramPacket(data, data.length, endpoint);
+    try {
+      socket.send(packet);
+    } catch (IOException e) {
+      logger.log(Level.SEVERE, "Exception while sending data.", e);
+    }
+  }
+
+  // Visible for testing
+  InetSocketAddress getEndpoint() {
+    return endpoint;
+  }
+}

awsagentprovider/src/test/java/software/amazon/opentelemetry/javaagent/providers/UdpExporterTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.opentelemetry.javaagent.providers;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.*;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.trace.*;
+import io.opentelemetry.sdk.common.InstrumentationScopeInfo;
+import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.data.StatusData;
+import java.util.Collections;
+import org.junit.jupiter.api.Test;
+
+public class UdpExporterTest {
+
+  @Test
+  public void testUdpExporterWithDefaults() {
+    OtlpUdpSpanExporter exporter = new OtlpUdpSpanExporterBuilder().build();
+    UdpSender sender = exporter.getSender();
+    assertThat(sender.getEndpoint().getHostName())
+        .isEqualTo("localhost"); // getHostName implicitly converts 127.0.0.1 to localhost
+    assertThat(sender.getEndpoint().getPort()).isEqualTo(2000);
+    assertThat(exporter.isSampled()).isTrue();
+  }
+
+  @Test
+  public void testUdpExporterWithCustomEndpointAndSample() {
+    OtlpUdpSpanExporter exporter =
+        new OtlpUdpSpanExporterBuilder().setEndpoint("somehost:1000").setSampled(false).build();
+    UdpSender sender = exporter.getSender();
+    assertThat(sender.getEndpoint().getHostName()).isEqualTo("somehost");
+    assertThat(sender.getEndpoint().getPort()).isEqualTo(1000);
+    assertThat(exporter.isSampled()).isFalse();
+  }
+
+  @Test
+  public void testUdpExporterWithInvalidEndpoint() {
+    assertThatThrownBy(
+            () -> {
+              new OtlpUdpSpanExporterBuilder().setEndpoint("invalidhost");
+            })
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Invalid endpoint, must be a valid URL: invalidhost");
+  }
+
+  @Test
+  public void testExport() {
+    UdpSender senderMock = mock(UdpSender.class);
+
+    // mock SpanData
+    SpanData spanData = buildSpanDataMock();
+
+    OtlpUdpSpanExporter exporter = new OtlpUdpSpanExporterBuilder().setSender(senderMock).build();
+    exporter.export(Collections.singletonList(spanData));
+
+    // assert that the senderMock.send is called once
+    verify(senderMock, times(1)).send(any(byte[].class));
+  }
+
+  private static SpanData buildSpanDataMock() {
+    SpanData mockSpanData = mock(SpanData.class);
+
+    Attributes spanAttributes =
+        Attributes.of(AttributeKey.stringKey("original key"), "original value");
+    when(mockSpanData.getAttributes()).thenReturn(spanAttributes);
+    when(mockSpanData.getTotalAttributeCount()).thenReturn(spanAttributes.size());
+    when(mockSpanData.getKind()).thenReturn(SpanKind.SERVER);
+
+    SpanContext parentSpanContextMock = mock(SpanContext.class);
+    when(mockSpanData.getParentSpanContext()).thenReturn(parentSpanContextMock);
+
+    SpanContext spanContextMock = mock(SpanContext.class);
+    when(spanContextMock.isValid()).thenReturn(true);
+    when(mockSpanData.getSpanContext()).thenReturn(spanContextMock);
+
+    TraceState traceState = TraceState.builder().build();
+    when(spanContextMock.getTraceState()).thenReturn(traceState);
+
+    when(mockSpanData.getStatus()).thenReturn(StatusData.unset());
+    when(mockSpanData.getInstrumentationScopeInfo())
+        .thenReturn(InstrumentationScopeInfo.create("Dummy Scope"));
+
+    Resource testResource = Resource.empty();
+    when(mockSpanData.getResource()).thenReturn(testResource);
+
+    return mockSpanData;
+  }
+}