add declarative config span logger

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/SpanLoggingCustomizerProvider.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.tooling;
+
+import com.google.auto.service.AutoService;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfigurationCustomizer;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfigurationCustomizerProvider;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.ConsoleExporterModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OpenTelemetryConfigurationModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SimpleSpanProcessorModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SpanExporterModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.SpanProcessorModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.TracerProviderModel;
+
+/** Adds span logging exporter for debug mode */
+@AutoService(DeclarativeConfigurationCustomizerProvider.class)
+public class SpanLoggingCustomizerProvider implements DeclarativeConfigurationCustomizerProvider {
+
+  @Override
+  public void customize(DeclarativeConfigurationCustomizer customizer) {
+    customizer.addModelCustomizer(
+        model -> {
+          maybeEnableLoggingExporter(model);
+          return model;
+        });
+  }
+
+  private static void maybeEnableLoggingExporter(OpenTelemetryConfigurationModel model) {
+    // read from system properties as it's an early init property and the config bridge is not
+    // available here
+    if (!"true".equals(System.getProperty("otel.javaagent.debug"))) {
+      return;
+    }
+    // don't install another instance if the user has already explicitly requested it.
+    if (loggingExporterIsAlreadyConfigured(model)) {
+      return;
+    }
+    TracerProviderModel tracerProvider = model.getTracerProvider();
+    if (tracerProvider == null) {
+      tracerProvider = new TracerProviderModel();
+      model.withTracerProvider(tracerProvider);
+    }
+    SpanProcessorModel processor =
+        new SpanProcessorModel()
+            .withSimple(
+                new SimpleSpanProcessorModel()
+                    .withExporter(new SpanExporterModel().withConsole(new ConsoleExporterModel())));
+    tracerProvider.getProcessors().add(processor);
+  }
+
+  private static boolean loggingExporterIsAlreadyConfigured(OpenTelemetryConfigurationModel model) {
+    TracerProviderModel tracerProvider = model.getTracerProvider();
+    if (tracerProvider == null) {
+      return false;
+    }
+    for (SpanProcessorModel processor : tracerProvider.getProcessors()) {
+      SimpleSpanProcessorModel simple = processor.getSimple();
+      if (simple == null) {
+        continue;
+      }
+      SpanExporterModel exporter = simple.getExporter();
+      if (exporter == null) {
+        continue;
+      }
+      if (exporter.getConsole() != null) {
+        return true;
+      }
+    }
+    return false;
+  }
+}

javaagent-tooling/src/test/java/io/opentelemetry/javaagent/tooling/SpanLoggingCustomizerProviderTest.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.tooling;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.sdk.extension.incubator.fileconfig.DeclarativeConfiguration;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OpenTelemetryConfigurationModel;
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Function;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.junitpioneer.jupiter.ClearSystemProperty;
+
+class SpanLoggingCustomizerProviderTest {
+
+  @ParameterizedTest
+  @CsvSource({
+    "true, true, false",
+    "false, false, false",
+    ", false, false", // empty value means property is not set
+    "invalid, false, false",
+    "true, true, true",
+  })
+  @ClearSystemProperty(key = "otel.javaagent.debug")
+  void addSpanLoggingExporter(String propertyValue, boolean expected, boolean alreadyAdded) {
+    if (propertyValue != null) {
+      System.setProperty("otel.javaagent.debug", propertyValue);
+    }
+    String yaml =
+        alreadyAdded
+            ? "file_format: \"1.0-rc.1\"\n"
+                + "tracer_provider:\n"
+                + "  processors:\n"
+                + "    - simple:\n"
+                + "        exporter:\n"
+                + "          console: {}\n"
+            : "file_format: \"1.0-rc.1\"\n";
+
+    OpenTelemetryConfigurationModel model =
+        applyCustomizer(
+            DeclarativeConfiguration.parse(
+                new ByteArrayInputStream(yaml.getBytes(StandardCharsets.UTF_8))),
+            new SpanLoggingCustomizerProvider());
+
+    String console = "ConsoleExporterModel";
+    if (expected) {
+      assertThat(model.toString()).containsOnlyOnce(console);
+    } else {
+      assertThat(model.toString()).doesNotContain(console);
+    }
+  }
+
+  private static OpenTelemetryConfigurationModel applyCustomizer(
+      OpenTelemetryConfigurationModel model, SpanLoggingCustomizerProvider provider) {
+    List<Function<OpenTelemetryConfigurationModel, OpenTelemetryConfigurationModel>> customizers =
+        new ArrayList<>();
+    provider.customize(c -> customizers.add(c));
+    for (Function<OpenTelemetryConfigurationModel, OpenTelemetryConfigurationModel> customizer :
+        customizers) {
+      model = customizer.apply(model);
+    }
+    return model;
+  }
+}

testing-common/src/main/java/io/opentelemetry/instrumentation/testing/provider/TestExporterCustomizerProvider.java

@@ -26,6 +26,12 @@
 import java.util.List;
 
 public class TestExporterCustomizerProvider implements DeclarativeConfigurationCustomizerProvider {
+
+  @Override
+  public int order() {
+    return Integer.MIN_VALUE; // run before other customizers that might add exporters
+  }
+
   @Override
   public void customize(DeclarativeConfigurationCustomizer customizer) {
     if (TestSpanExporterComponentProvider.getSpanExporter() == null) {

testing/agent-exporter/src/main/java/io/opentelemetry/javaagent/testing/provider/AgentTestExporterCustomizerProvider.java

@@ -30,6 +30,12 @@
 @AutoService(DeclarativeConfigurationCustomizerProvider.class)
 public class AgentTestExporterCustomizerProvider
     implements DeclarativeConfigurationCustomizerProvider {
+
+  @Override
+  public int order() {
+    return Integer.MIN_VALUE; // run before other customizers that might add exporters
+  }
+
   @Override
   public void customize(DeclarativeConfigurationCustomizer customizer) {
     TestExportersUtil.initTestExporters();