Publish features as pre-packaged opentelemetry agent extension (#205)

Author: JonasKunz

.github/workflows/build.yml

@@ -50,6 +50,13 @@ jobs:
           path: |
             ./agent/build/libs/elastic-otel-javaagent-*.jar
 
+      - name: Agent extension artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: elastic-otel-agentextension
+          path: |
+            ./agentextension/build/libs/elastic-otel-agentextension-*.jar
+
   test:
     runs-on: ubuntu-latest
     needs:

agentextension/build.gradle.kts

@@ -0,0 +1,40 @@
+plugins {
+  id("java")
+  id("elastic-otel.sign-and-publish-conventions")
+  id("com.github.johnrengelman.shadow")
+}
+
+description = "Bundles all elastic extensions in a fat-jar to be used" +
+    " with the vanilla agent via the otel.javaagent.extensions config option"
+base.archivesName.set("elastic-otel-agentextension")
+
+val shadowDependencies: Configuration by configurations.creating
+
+dependencies {
+  shadowDependencies(project(":custom"))
+}
+
+
+tasks {
+
+  jar {
+    enabled = false
+    dependsOn(shadowJar)
+  }
+
+  shadowJar {
+    configurations = listOf(shadowDependencies)
+    mergeServiceFiles()
+    archiveClassifier.set("")
+
+    // include licenses and notices in jar
+    dependsOn(project(":agent").tasks.named("updateLicensesAndNotice"))
+    from(rootDir) {
+      into("META-INF")
+
+      include("LICENSE")
+      include("NOTICE")
+      include("licenses/**")
+    }
+  }
+}

custom/src/test/java/co/elastic/otel/ElasticDistroResourceProviderTest.java renamed to agentextension/src/main/java/co/elastic/otel/JavadocPlaceholder.java

@@ -18,21 +18,5 @@
  */
 package co.elastic.otel;
 
-import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
-
-import io.opentelemetry.sdk.resources.Resource;
-import org.junit.jupiter.api.Test;
-
-class ElasticDistroResourceProviderTest {
-
-  @Test
-  void elasticDistroNameAndVersion() {
-    ElasticDistroResourceProvider provider = new ElasticDistroResourceProvider();
-    Resource resource = provider.createResource(null);
-
-    assertThat(resource.getAttributes())
-        .hasSize(2)
-        .containsEntry("telemetry.distro.name", "elastic")
-        .containsKey("telemetry.distro.version");
-  }
-}
+/** This class is here as a placeholder so that the sources and javadoc are not empty. */
+public class JavadocPlaceholder {}

buildSrc/src/main/kotlin/elastic-otel.test-with-agent-conventions.gradle.kts

@@ -2,15 +2,41 @@ plugins {
   id("elastic-otel.java-conventions")
 }
 
-val agentForTesting: Configuration by configurations.creating
+val agentDistroForTesting: Configuration by configurations.creating
+val upstreamAgentForTesting: Configuration by configurations.creating
+val agentExtension: Configuration by configurations.creating
+
+
+//https://github.com/gradle/gradle/issues/15383
+val catalog = extensions.getByType<VersionCatalogsExtension>().named("catalog")
 
 dependencies {
-  agentForTesting(project(":testing:agent-for-testing"))
+  agentDistroForTesting(project(":testing:agent-for-testing"))
   testImplementation("io.opentelemetry.javaagent:opentelemetry-testing-common")
+
+  catalog.findLibrary("opentelemetryInstrumentationAlphaBom").ifPresent {
+    upstreamAgentForTesting(platform(it))
+  }
+  upstreamAgentForTesting("io.opentelemetry.javaagent:opentelemetry-agent-for-testing")
+  agentExtension(project(":agentextension"))
 }
 
-tasks.withType<Test>() {
-  dependsOn(agentForTesting)
-  useJUnitPlatform()
-  jvmArgs("-javaagent:${agentForTesting.singleFile.absoluteFile}")
+tasks {
+
+  val testWithVanillaAgentAndExtension by registering( Test::class) {
+    dependsOn(upstreamAgentForTesting, agentExtension)
+    group = "verification"
+    useJUnitPlatform()
+    jvmArgs("-javaagent:${upstreamAgentForTesting.singleFile.absoluteFile}")
+    jvmArgs("-Dotel.javaagent.extensions=${agentExtension.singleFile.absoluteFile}")
+  }
+  test {
+    dependsOn(testWithVanillaAgentAndExtension)
+  }
+
+  test {
+    dependsOn(agentDistroForTesting)
+    useJUnitPlatform()
+    jvmArgs("-javaagent:${agentDistroForTesting.singleFile.absoluteFile}")
+  }
 }

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

@@ -31,13 +31,21 @@ public class ElasticDistroResourceProvider implements ResourceProvider {
 
   @Override
   public Resource createResource(ConfigProperties configProperties) {
-    return AgentVersion.VERSION == null
-        ? Resource.empty()
-        : Resource.create(
-            Attributes.of(
-                ElasticAttributes.TELEMETRY_DISTRO_NAME,
-                "elastic",
-                ElasticAttributes.TELEMETRY_DISTRO_VERSION,
-                AgentVersion.VERSION));
+    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(
+            ElasticAttributes.TELEMETRY_DISTRO_NAME,
+            "elastic",
+            ElasticAttributes.TELEMETRY_DISTRO_VERSION,
+            AgentVersion.VERSION));
   }
 }

gradle/libs.versions.toml

@@ -72,3 +72,4 @@ jmh = {id = "me.champeau.jmh", version = "0.7.2"}
 nexusPublish = { id = "io.github.gradle-nexus.publish-plugin", version = '2.0.0' }
 licenseReport = { id = "com.github.jk1.dependency-license-report", version = "2.6" }
 dockerJavaApplication = { id = "com.bmuschko.docker-java-application", version = "9.4.0" }
+shadow = { id = "com.github.johnrengelman.shadow", version.ref = "shadow" }

settings.gradle.kts

@@ -13,6 +13,7 @@ rootProject.name = "elastic-otel-java"
 
 include("agent")
 include("agent:entrypoint")
+include("agentextension")
 include("bootstrap")
 include("custom")
 include("instrumentation")

testing/integration-tests/agent-internals/src/test/java/DistroResourceAttributesTest.java

@@ -0,0 +1,53 @@
+/*
+ * 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.
+ */
+import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
+
+import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.instrumentation.testing.junit.AgentInstrumentationExtension;
+import io.opentelemetry.sdk.resources.Resource;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+public class DistroResourceAttributesTest {
+
+  @RegisterExtension
+  static final AgentInstrumentationExtension testing = AgentInstrumentationExtension.create();
+
+  @Test
+  public void checkDistroName() {
+    Span testSpan =
+        GlobalOpenTelemetry.get().getTracer("dummy-tracer").spanBuilder("testSpan").startSpan();
+    testSpan.end();
+    assertThat(testing.spans()).hasSize(1);
+    Resource resource = testing.spans().get(0).getResource();
+
+    boolean isRunningDistro = System.getProperty("otel.javaagent.extensions") == null;
+
+    if (isRunningDistro) {
+      assertThat(resource.getAttributes()).containsEntry("telemetry.distro.name", "elastic");
+      assertThat(resource.getAttributes()).containsKey("telemetry.distro.version");
+    } else {
+      // we are running with the vanilla agent as extension: we should not be setting the distro
+      // name
+      assertThat(resource.getAttributes()).doesNotContainKey("telemetry.distro.name");
+      assertThat(resource.getAttributes()).doesNotContainKey("telemetry.distro.version");
+    }
+  }
+}

testing/integration-tests/agent-internals/src/test/java/SpanValueTest.java

@@ -24,7 +24,13 @@
 import java.lang.reflect.Field;
 import java.util.concurrent.atomic.AtomicReferenceArray;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledIfSystemProperty;
 
+@DisabledIfSystemProperty(
+    named = "otel.javaagent.extensions",
+    matches = ".+",
+    disabledReason =
+        "When running with the vanilla agent, span values won't be able to use the field backed storage")
 public class SpanValueTest {
   @Test
   @SuppressWarnings("unchecked")

testing/integration-tests/inferred-spans-test/build.gradle.kts

@@ -8,7 +8,7 @@ dependencies {
   testImplementation("io.opentelemetry.instrumentation:opentelemetry-instrumentation-annotations")
 }
 
-tasks.test {
+tasks.withType<Test>() {
   jvmArgs(
     //"-Dotel.javaagent.debug=true",
     "-Delastic.otel.inferred.spans.enabled=true",