Add EventToSpanEventBridge

processors/README.md

@@ -1,6 +1,34 @@
 # Processors
 
-This module provides tools to intercept and process signals globally.
+## Interceptable exporters
+
+This module provides tools to intercept and process signals globally:
+
+* `InterceptableSpanExporter`
+* `InterceptableMetricExporter`
+* `InterceptableLogRecordExporter`
+
+## Event to SpanEvent Bridge
+
+`EventToSpanEventBridge` is a `LogRecordProcessor` which records events (i.e. log records with an `event.name` attribute) as span events for the current span if:
+
+* The log record has a valid span context
+* `Span.current()` returns a span where `Span.isRecording()` is true
+
+For details of how the event log record is translated to span event, see [EventToSpanEventBridge Javadoc](./src/main/java/io/opentelemetry/contrib/eventbridge/EventToSpanEventBridge.java).
+
+`EventToSpanEventBridge` can be referenced in [declarative configuration](https://opentelemetry.io/docs/languages/java/configuration/#declarative-configuration) as follows:
+
+```yaml
+// Configure tracer provider as usual, omitted for brevity
+tracer_provider: ...
+
+logger_provider:
+  processors:
+    - event_to_span_event_bridge: {}
+```
+
+// TODO(jack-berg): remove "{}" after merging / rle https://github.com/open-telemetry/opentelemetry-java/pull/6891/files
 
 ## Component owners
 

processors/build.gradle.kts

@@ -13,5 +13,13 @@ java {
 
 dependencies {
   api("io.opentelemetry:opentelemetry-sdk")
+  compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+
+  // For EventToSpanEventBridge
+  implementation("io.opentelemetry:opentelemetry-exporter-otlp-common")
+  implementation("com.fasterxml.jackson.core:jackson-core")
+
   testImplementation("io.opentelemetry:opentelemetry-sdk-testing")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-incubator")
 }

processors/src/main/java/io/opentelemetry/contrib/eventbridge/EventToSpanEventBridge.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.eventbridge;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.api.common.Value;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.exporter.internal.marshal.MarshalerWithSize;
+import io.opentelemetry.exporter.internal.otlp.AnyValueMarshaler;
+import io.opentelemetry.sdk.logs.LogRecordProcessor;
+import io.opentelemetry.sdk.logs.ReadWriteLogRecord;
+import io.opentelemetry.sdk.logs.data.LogRecordData;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A processor that records events (i.e. log records with an {@code event.name} attribute) as span
+ * events for the current span if:
+ *
+ * <ul>
+ *   <li>The log record has a valid span context
+ *   <li>{@link Span#current()} returns a span where {@link Span#isRecording()} is true
+ * </ul>
+ *
+ * <p>The event {@link LogRecordData} is converted to attributes on the span event as follows:
+ *
+ * <ul>
+ *   <li>{@code event.name} attribute is mapped to span event name
+ *   <li>{@link LogRecordData#getTimestampEpochNanos()} is mapped to span event timestamp
+ *   <li>{@link LogRecordData#getAttributes()} are mapped to span event attributes, excluding {@code
+ *       event.name}
+ *   <li>{@link LogRecordData#getObservedTimestampEpochNanos()} is mapped to span event attribute
+ *       with key {@code log.record.observed_timestamp}
+ *   <li>{@link LogRecordData#getSeverity()} is mapped to span event attribute with key {@code
+ *       log.record.severity_number}
+ *   <li>{@link LogRecordData#getBodyValue()} is mapped to span event attribute with key {@code
+ *       log.record.body}, as an escaped JSON string following the standard protobuf JSON encoding
+ *   <li>{@link LogRecordData#getTotalAttributeCount()} - {@link
+ *       LogRecordData#getAttributes()}.size() is mapped to span event attribute with key {@code
+ *       log.record.dropped_attributes_count}
+ * </ul>
+ */
+public final class EventToSpanEventBridge implements LogRecordProcessor {
+
+  private static final Logger LOGGER = Logger.getLogger(EventToSpanEventBridge.class.getName());
+
+  private static final AttributeKey<String> EVENT_NAME = AttributeKey.stringKey("event.name");
+  private static final AttributeKey<Long> LOG_RECORD_OBSERVED_TIME_UNIX_NANO =
+      AttributeKey.longKey("log.record.observed_time_unix_nano");
+  private static final AttributeKey<Long> LOG_RECORD_SEVERITY_NUMBER =
+      AttributeKey.longKey("log.record.severity_number");
+  private static final AttributeKey<String> LOG_RECORD_BODY =
+      AttributeKey.stringKey("log.record.body");
+  private static final AttributeKey<Long> LOG_RECORD_DROPPED_ATTRIBUTES_COUNT =
+      AttributeKey.longKey("log.record.dropped_attributes_count");
+
+  private EventToSpanEventBridge() {}
+
+  /** Create an instance. */
+  public static EventToSpanEventBridge create() {
+    return new EventToSpanEventBridge();
+  }
+
+  @Override
+  public void onEmit(Context context, ReadWriteLogRecord logRecord) {
+    LogRecordData logRecordData = logRecord.toLogRecordData();
+    String eventName = logRecordData.getAttributes().get(EVENT_NAME);
+    if (eventName == null) {
+      return;
+    }
+    if (!logRecordData.getSpanContext().isValid()) {
+      return;
+    }
+    Span currentSpan = Span.current();
+    if (!currentSpan.isRecording()) {
+      return;
+    }
+    currentSpan.addEvent(
+        eventName,
+        toSpanEventAttributes(logRecordData),
+        logRecordData.getTimestampEpochNanos(),
+        TimeUnit.NANOSECONDS);
+  }
+
+  private static Attributes toSpanEventAttributes(LogRecordData logRecord) {
+    AttributesBuilder builder =
+        logRecord.getAttributes().toBuilder().removeIf(key -> key.equals(EVENT_NAME));
+
+    builder.put(LOG_RECORD_OBSERVED_TIME_UNIX_NANO, logRecord.getObservedTimestampEpochNanos());
+
+    builder.put(LOG_RECORD_SEVERITY_NUMBER, logRecord.getSeverity().getSeverityNumber());
+
+    // Add bridging for logRecord.getSeverityText() if EventBuilder adds severity text setter
+
+    Value<?> body = logRecord.getBodyValue();
+    if (body != null) {
+      MarshalerWithSize marshaler = AnyValueMarshaler.create(body);
+      ByteArrayOutputStream baos = new ByteArrayOutputStream();
+      try {
+        marshaler.writeJsonTo(baos);
+      } catch (IOException e) {
+        LOGGER.log(Level.WARNING, "Error converting log record body to JSON", e);
+      }
+      builder.put(LOG_RECORD_BODY, new String(baos.toByteArray(), StandardCharsets.UTF_8));
+    }
+
+    int droppedAttributesCount =
+        logRecord.getTotalAttributeCount() - logRecord.getAttributes().size();
+    if (droppedAttributesCount > 0) {
+      builder.put(LOG_RECORD_DROPPED_ATTRIBUTES_COUNT, droppedAttributesCount);
+    }
+
+    return builder.build();
+  }
+
+  @Override
+  public String toString() {
+    return "EventToSpanEventBridge{}";
+  }
+}

processors/src/main/java/io/opentelemetry/contrib/eventbridge/internal/EventToSpanEventBridgeComponentProvider.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.eventbridge.internal;
+
+import io.opentelemetry.contrib.eventbridge.EventToSpanEventBridge;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.StructuredConfigProperties;
+import io.opentelemetry.sdk.logs.LogRecordProcessor;
+
+/**
+ * Declarative configuration SPI implementation for {@link EventToSpanEventBridge}.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+public class EventToSpanEventBridgeComponentProvider
+    implements ComponentProvider<LogRecordProcessor> {
+
+  @Override
+  public Class<LogRecordProcessor> getType() {
+    return LogRecordProcessor.class;
+  }
+
+  @Override
+  public String getName() {
+    return "event_to_span_event_bridge";
+  }
+
+  @Override
+  public LogRecordProcessor create(StructuredConfigProperties config) {
+    return EventToSpanEventBridge.create();
+  }
+}

processors/src/main/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider

@@ -0,0 +1 @@
+io.opentelemetry.contrib.eventbridge.internal.EventToSpanEventBridgeComponentProvider

processors/src/test/java/io/opentelemetry/contrib/eventbridge/EventToSpanEventBridgeTest.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.eventbridge;
+
+import static io.opentelemetry.api.common.AttributeKey.longKey;
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
+import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.Value;
+import io.opentelemetry.api.incubator.events.EventLogger;
+import io.opentelemetry.api.logs.Severity;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanKind;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.context.Scope;
+import io.opentelemetry.sdk.logs.SdkLoggerProvider;
+import io.opentelemetry.sdk.logs.internal.SdkEventLoggerProvider;
+import io.opentelemetry.sdk.testing.exporter.InMemorySpanExporter;
+import io.opentelemetry.sdk.testing.time.TestClock;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.data.LinkData;
+import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
+import io.opentelemetry.sdk.trace.samplers.Sampler;
+import io.opentelemetry.sdk.trace.samplers.SamplingResult;
+import java.time.Instant;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import org.junit.jupiter.api.Test;
+
+class EventToSpanEventBridgeTest {
+
+  private final InMemorySpanExporter spanExporter = InMemorySpanExporter.create();
+  private final SdkTracerProvider tracerProvider =
+      SdkTracerProvider.builder()
+          .setSampler(onlyServerSpans())
+          .addSpanProcessor(SimpleSpanProcessor.create(spanExporter))
+          .build();
+  private final TestClock testClock = TestClock.create();
+  private final SdkEventLoggerProvider eventLoggerProvider =
+      SdkEventLoggerProvider.create(
+          SdkLoggerProvider.builder()
+              .setClock(testClock)
+              .addLogRecordProcessor(EventToSpanEventBridge.create())
+              .build());
+  private final Tracer tracer = tracerProvider.get("tracer");
+  private final EventLogger eventLogger = eventLoggerProvider.get("event-logger");
+
+  private static Sampler onlyServerSpans() {
+    return new Sampler() {
+      @Override
+      public SamplingResult shouldSample(
+          Context parentContext,
+          String traceId,
+          String name,
+          SpanKind spanKind,
+          Attributes attributes,
+          List<LinkData> parentLinks) {
+        return SpanKind.SERVER.equals(spanKind)
+            ? SamplingResult.recordAndSample()
+            : SamplingResult.drop();
+      }
+
+      @Override
+      public String getDescription() {
+        return "description";
+      }
+    };
+  }
+
+  @Test
+  void withRecordingSpan_BridgesEvent() {
+    testClock.setTime(Instant.ofEpochMilli(1));
+
+    Span span = tracer.spanBuilder("span").setSpanKind(SpanKind.SERVER).startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      eventLogger
+          .builder("my.event-name")
+          .setTimestamp(100, TimeUnit.NANOSECONDS)
+          .setSeverity(Severity.DEBUG)
+          .put("foo", "bar")
+          .put("number", 1)
+          .put("map", Value.of(Collections.singletonMap("key", Value.of("value"))))
+          .setAttributes(Attributes.builder().put("color", "red").build())
+          .setAttributes(Attributes.builder().put("shape", "square").build())
+          .emit();
+    } finally {
+      span.end();
+    }
+
+    assertThat(spanExporter.getFinishedSpanItems())
+        .satisfiesExactly(
+            spanData ->
+                assertThat(spanData)
+                    .hasName("span")
+                    .hasEventsSatisfyingExactly(
+                        spanEvent ->
+                            spanEvent
+                                .hasName("my.event-name")
+                                .hasTimestamp(100, TimeUnit.NANOSECONDS)
+                                .hasAttributesSatisfying(
+                                    attributes -> {
+                                      assertThat(attributes.get(stringKey("color")))
+                                          .isEqualTo("red");
+                                      assertThat(attributes.get(stringKey("shape")))
+                                          .isEqualTo("square");
+                                      assertThat(
+                                              attributes.get(
+                                                  longKey("log.record.observed_time_unix_nano")))
+                                          .isEqualTo(1000000L);
+                                      assertThat(
+                                              attributes.get(longKey("log.record.severity_number")))
+                                          .isEqualTo(Severity.DEBUG.getSeverityNumber());
+                                      assertThat(attributes.get(stringKey("log.record.body")))
+                                          .isEqualTo(
+                                              "{\"kvlistValue\":{\"values\":[{\"key\":\"number\",\"value\":{\"intValue\":\"1\"}},{\"key\":\"foo\",\"value\":{\"stringValue\":\"bar\"}},{\"key\":\"map\",\"value\":{\"kvlistValue\":{\"values\":[{\"key\":\"key\",\"value\":{\"stringValue\":\"value\"}}]}}}]}}");
+                                    })));
+  }
+
+  @Test
+  void noSpan_doesNotBridgeEvent() {
+    eventLogger
+        .builder("my.event-name")
+        .setTimestamp(100, TimeUnit.NANOSECONDS)
+        .setSeverity(Severity.DEBUG)
+        .put("foo", "bar")
+        .put("number", 1)
+        .put("map", Value.of(Collections.singletonMap("key", Value.of("value"))))
+        .setAttributes(Attributes.builder().put("color", "red").build())
+        .setAttributes(Attributes.builder().put("shape", "square").build())
+        .emit();
+
+    assertThat(spanExporter.getFinishedSpanItems()).isEmpty();
+  }
+
+  @Test
+  void nonRecordingSpan_doesNotBridgeEvent() {
+    Span span = tracer.spanBuilder("span").setSpanKind(SpanKind.INTERNAL).startSpan();
+    try (Scope unused = span.makeCurrent()) {
+      eventLogger
+          .builder("my.event-name")
+          .setTimestamp(100, TimeUnit.NANOSECONDS)
+          .setSeverity(Severity.DEBUG)
+          .put("foo", "bar")
+          .put("number", 1)
+          .put("map", Value.of(Collections.singletonMap("key", Value.of("value"))))
+          .setAttributes(Attributes.builder().put("color", "red").build())
+          .setAttributes(Attributes.builder().put("shape", "square").build())
+          .emit();
+    } finally {
+      span.end();
+    }
+
+    assertThat(spanExporter.getFinishedSpanItems()).isEmpty();
+  }
+}