declarative config part 1

custom/build.gradle.kts

@@ -23,8 +23,10 @@ dependencies {
   }
 
   compileOnly("io.opentelemetry:opentelemetry-sdk")
+  compileOnly("io.opentelemetry:opentelemetry-api-incubator")
   compileOnly("io.opentelemetry:opentelemetry-exporter-otlp")
   compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+  compileOnly("io.opentelemetry:opentelemetry-sdk-extension-incubator")
   compileOnly("io.opentelemetry.javaagent:opentelemetry-javaagent-extension-api")
   compileOnly("io.opentelemetry.javaagent:opentelemetry-javaagent-tooling")
   compileOnly(libs.bundles.semconv)
@@ -54,8 +56,10 @@ dependencies {
   // test dependencies
   testImplementation(project(":testing-common"))
   testImplementation("io.opentelemetry:opentelemetry-sdk")
+  testImplementation("io.opentelemetry:opentelemetry-api-incubator")
   testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
   testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+  testImplementation("io.opentelemetry:opentelemetry-sdk-extension-incubator")
   testImplementation("io.opentelemetry:opentelemetry-exporter-otlp")
   testImplementation("io.opentelemetry.javaagent:opentelemetry-javaagent-tooling") {
     //The following dependency isn't actually needed, but breaks the classpath when testing with Java 8

custom/src/main/java/co/elastic/otel/ElasticDistroResource.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.otel;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.javaagent.tooling.AgentVersion;
+import io.opentelemetry.sdk.resources.Resource;
+import io.opentelemetry.semconv.incubating.TelemetryIncubatingAttributes;
+
+public class ElasticDistroResource {
+
+  private ElasticDistroResource() {}
+
+  public static Resource get() {
+    if (AgentVersion.VERSION == null) {
+      return Resource.empty();
+    }
+    try {
+      Class.forName("co.elastic.otel.agent.ElasticAgent");
+    } catch (ClassNotFoundException e) {
+      // this means that we are running as an extension of the vanilla agent
+      // and not as distro.
+      return Resource.empty();
+    }
+    return Resource.create(
+        Attributes.of(
+            TelemetryIncubatingAttributes.TELEMETRY_DISTRO_NAME,
+            "elastic",
+            TelemetryIncubatingAttributes.TELEMETRY_DISTRO_VERSION,
+            AgentVersion.VERSION));
+  }
+}

custom/src/main/java/co/elastic/otel/ElasticDistroResourceProvider.java

@@ -19,33 +19,19 @@
 package co.elastic.otel;
 
 import com.google.auto.service.AutoService;
-import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.javaagent.tooling.AgentVersion;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ResourceProvider;
 import io.opentelemetry.sdk.resources.Resource;
-import io.opentelemetry.semconv.incubating.TelemetryIncubatingAttributes;
 
+/**
+ * Provides {@code telemetry.distro.name} and {@code telemetry.distro.version} resource attributes
+ * for automatic configuration
+ */
 @AutoService(ResourceProvider.class)
 public class ElasticDistroResourceProvider implements ResourceProvider {
 
   @Override
   public Resource createResource(ConfigProperties configProperties) {
-    if (AgentVersion.VERSION == null) {
-      return Resource.empty();
-    }
-    try {
-      Class.forName("co.elastic.otel.agent.ElasticAgent");
-    } catch (ClassNotFoundException e) {
-      // this means that we are running as an extension of the vanilla agent
-      // and not as distro.
-      return Resource.empty();
-    }
-    return Resource.create(
-        Attributes.of(
-            TelemetryIncubatingAttributes.TELEMETRY_DISTRO_NAME,
-            "elastic",
-            TelemetryIncubatingAttributes.TELEMETRY_DISTRO_VERSION,
-            AgentVersion.VERSION));
+    return ElasticDistroResource.get();
   }
 }

custom/src/main/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizer.java

@@ -0,0 +1,81 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.otel.declarativeconfig;
+
+import static java.util.Objects.requireNonNull;
+import static java.util.stream.Collectors.toSet;
+
+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.ExperimentalResourceDetectionModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.ExperimentalResourceDetectorModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.OpenTelemetryConfigurationModel;
+import io.opentelemetry.sdk.extension.incubator.fileconfig.internal.model.ResourceModel;
+import java.util.List;
+import java.util.Set;
+
+@AutoService(DeclarativeConfigurationCustomizerProvider.class)
+public class ElasticDeclarativeConfigurationCustomizer
+    implements DeclarativeConfigurationCustomizerProvider {
+
+  @Override
+  public void customize(DeclarativeConfigurationCustomizer customizer) {
+    customizer.addModelCustomizer(
+        model -> {
+          customizeResources(model);
+          return model;
+        });
+  }
+
+  private static void customizeResources(OpenTelemetryConfigurationModel model) {
+    // this is equivalent to adding the following explicitly in declarative configuration
+    //
+    //  detection/development:
+    //    detectors:
+    //      - <... other detectors ...>
+    //      - elastic_distribution:
+
+    ResourceModel resource = model.getResource();
+    if (resource == null) {
+      resource = new ResourceModel();
+      model.withResource(resource);
+    }
+
+    ExperimentalResourceDetectionModel detectionDevelopment = resource.getDetectionDevelopment();
+    if (null == detectionDevelopment) {
+      detectionDevelopment = new ExperimentalResourceDetectionModel();
+      resource.withDetectionDevelopment(detectionDevelopment);
+    }
+    List<ExperimentalResourceDetectorModel> detectors =
+        requireNonNull(detectionDevelopment.getDetectors());
+
+    Set<String> names =
+        detectors.stream()
+            .flatMap(detector -> detector.getAdditionalProperties().keySet().stream())
+            .collect(toSet());
+
+    // add at the end to make it have priority over upstream distro provider (which is added 1st)
+    if (!names.contains(ElasticDistroComponentProvider.NAME)) {
+      ExperimentalResourceDetectorModel detector = new ExperimentalResourceDetectorModel();
+      detector.getAdditionalProperties().put(ElasticDistroComponentProvider.NAME, null);
+      detectors.add(detector);
+    }
+  }
+}

custom/src/main/java/co/elastic/otel/declarativeconfig/ElasticDistroComponentProvider.java

@@ -0,0 +1,50 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.otel.declarativeconfig;
+
+import co.elastic.otel.ElasticDistroResource;
+import com.google.auto.service.AutoService;
+import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider;
+import io.opentelemetry.sdk.resources.Resource;
+
+/**
+ * Provides {@code telemetry.distro.name} and {@code telemetry.distro.version} resource attributes
+ * for declarative configuration
+ */
+@AutoService(ComponentProvider.class)
+public class ElasticDistroComponentProvider implements ComponentProvider {
+
+  static final String NAME = "elastic_distribution";
+
+  @Override
+  public Class<?> getType() {
+    return Resource.class;
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+
+  @Override
+  public Object create(DeclarativeConfigProperties config) {
+    return ElasticDistroResource.get();
+  }
+}

custom/src/test/java/co/elastic/otel/declarativeconfig/ElasticDeclarativeConfigurationCustomizerTest.java

@@ -0,0 +1,122 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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 co.elastic.otel.declarativeconfig;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
+import io.opentelemetry.javaagent.tooling.resources.ResourceCustomizerProvider;
+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.OpenTelemetryConfigurationModel;
+import io.opentelemetry.sdk.logs.export.LogRecordExporter;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class ElasticDeclarativeConfigurationCustomizerTest {
+
+  // because declarative config relies on json mapping annotations, we can leverage this for testing
+  // the configuration customization.
+  private final ObjectMapper objectMapper = new ObjectMapper();
+
+  @Test
+  void defaultConfig() {
+    OpenTelemetryConfigurationModel model = new OpenTelemetryConfigurationModel();
+    model = applyConfigCustomize(model, new ElasticDeclarativeConfigurationCustomizer());
+
+    // ensures that we add our resource detector even if the model does not provide any
+    checkJson(
+        model.getResource(),
+        "{\"attributes\":[],\"detection/development\":{\"detectors\":[{\"elastic_distribution\":null}]}}");
+  }
+
+  @ParameterizedTest
+  @ValueSource(booleans = {true, false})
+  void upstreamProvider(boolean elasticFirst) {
+    // upstream provider is always added first in the list, even if we add ours first
+    // this ordering behavior is implemented in upstream provider
+    OpenTelemetryConfigurationModel model = new OpenTelemetryConfigurationModel();
+    DeclarativeConfigurationCustomizerProvider first;
+    DeclarativeConfigurationCustomizerProvider second;
+    if (elasticFirst) {
+      first = new ElasticDeclarativeConfigurationCustomizer();
+      second = new ResourceCustomizerProvider();
+    } else {
+      first = new ElasticDeclarativeConfigurationCustomizer();
+      second = new ResourceCustomizerProvider();
+    }
+
+    model = applyConfigCustomize(model, first);
+    model = applyConfigCustomize(model, second);
+    checkJson(
+        model.getResource(),
+        "{\"attributes\":[],\"detection/development\":{\"detectors\":[{\"opentelemetry_javaagent_distribution\":null},{\"elastic_distribution\":null}]}}");
+  }
+
+  private void checkJson(Object o, String expected) {
+    try {
+      assertThat(objectMapper.writeValueAsString(o)).isEqualTo(expected);
+    } catch (JsonProcessingException e) {
+      throw new IllegalStateException(e);
+    }
+  }
+
+  private OpenTelemetryConfigurationModel applyConfigCustomize(
+      OpenTelemetryConfigurationModel originalModel,
+      DeclarativeConfigurationCustomizerProvider customizerProvider) {
+    AtomicReference<OpenTelemetryConfigurationModel> resultModel = new AtomicReference<>();
+    customizerProvider.customize(
+        new TestCustomizer() {
+          @Override
+          public void addModelCustomizer(
+              Function<OpenTelemetryConfigurationModel, OpenTelemetryConfigurationModel>
+                  customizer) {
+            resultModel.set(customizer.apply(originalModel));
+          }
+        });
+    return resultModel.get();
+  }
+
+  private static class TestCustomizer implements DeclarativeConfigurationCustomizer {
+
+    @Override
+    public void addModelCustomizer(
+        Function<OpenTelemetryConfigurationModel, OpenTelemetryConfigurationModel> customizer) {}
+
+    @Override
+    public <T extends SpanExporter> void addSpanExporterCustomizer(
+        Class<T> exporterType, BiFunction<T, DeclarativeConfigProperties, T> customizer) {}
+
+    @Override
+    public <T extends MetricExporter> void addMetricExporterCustomizer(
+        Class<T> exporterType, BiFunction<T, DeclarativeConfigProperties, T> customizer) {}
+
+    @Override
+    public <T extends LogRecordExporter> void addLogRecordExporterCustomizer(
+        Class<T> exporterType, BiFunction<T, DeclarativeConfigProperties, T> customizer) {}
+  }
+}