Embedded extension

examples/extension/build.gradle

@@ -49,7 +49,7 @@ configurations {
 dependencies {
   /*
   Interfaces and SPIs that we implement. We use `compileOnly` dependency because during
-  runtime all neccessary classes are provided by javaagent itself.
+  runtime all necessary classes are provided by javaagent itself.
    */
   compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:${versions.opentelemetryAlpha}")
   compileOnly("io.opentelemetry.javaagent:opentelemetry-javaagent-api:${versions.opentelemetryJavaagentAlpha}")
@@ -92,19 +92,36 @@ dependencies {
   otel("io.opentelemetry.javaagent:opentelemetry-javaagent:${versions.opentelemetryJavaagent}:all")
 }
 
+//Extracts manifest from OpenTelemetry Java agent to reuse it later
+task agentManifest(type: Copy) {
+  from zipTree(configurations.otel.singleFile).matching {
+    include 'META-INF/MANIFEST.MF'
+  }
+  into buildDir
+}
+
+//Produces a copy of upstream javaagent with this extension jar included inside it
+//The location of extension directory inside agent jar is hard-coded in the agent source code
+task extendedAgent(type: Jar) {
+  dependsOn agentManifest
+  archiveFileName = "opentelemetry-javaagent-all.jar"
+  manifest.from "$buildDir/META-INF/MANIFEST.MF"
+  from zipTree(configurations.otel.singleFile)
+  from(tasks.shadowJar.archiveFile) {
+    into "extensions"
+  }
+}
+
 tasks {
   test {
     useJUnitPlatform()
 
-    def extensionJar = tasks.shadowJar
-    inputs.files(layout.files(extensionJar))
+    inputs.files(layout.files(tasks.shadowJar))
+    inputs.files(layout.files(tasks.extendedAgent))
 
-    doFirst {
-      //To run our tests with the javaagent published by OpenTelemetry Java instrumentation project
-      jvmArgs("-Dio.opentelemetry.smoketest.agentPath=${configurations.getByName("otel").resolve().find().absolutePath}")
-      //Instructs our integration test where to find our extension archive
-      jvmArgs("-Dio.opentelemetry.smoketest.extensionPath=${extensionJar.archiveFile.get()}")
-    }
+    systemProperty 'io.opentelemetry.smoketest.agentPath', configurations.otel.singleFile.absolutePath
+    systemProperty 'io.opentelemetry.smoketest.extendedAgentPath', tasks.extendedAgent.archiveFile.get().asFile.absolutePath
+    systemProperty 'io.opentelemetry.smoketest.extensionPath', tasks.shadowJar.archiveFile.get().asFile.absolutePath
   }
 
   compileJava {

examples/extension/src/test/java/com/example/javaagent/smoketest/IntegrationTest.java

@@ -38,6 +38,9 @@ abstract class IntegrationTest {
   private static final Network network = Network.newNetwork();
   protected static final String agentPath =
       System.getProperty("io.opentelemetry.smoketest.agentPath");
+  //Javaagent with extensions embedded inside it
+  protected static final String extendedAgentPath =
+      System.getProperty("io.opentelemetry.smoketest.extendedAgentPath");
   protected static final String extensionPath =
       System.getProperty("io.opentelemetry.smoketest.extensionPath");
 
@@ -80,25 +83,38 @@ static void setupSpec() {
   protected GenericContainer<?> target;
 
   void startTarget(String extensionLocation) {
-    target =
+    target = buildTargetContainer(agentPath, extensionLocation);
+    target.start();
+  }
+
+  void startTargetWithExtendedAgent() {
+    target = buildTargetContainer(extendedAgentPath, null);
+    target.start();
+  }
+
+  private GenericContainer<?> buildTargetContainer(String agentPath, String extensionLocation) {
+    GenericContainer<?> result =
         new GenericContainer<>(getTargetImage(11))
             .withExposedPorts(8080)
             .withNetwork(network)
             .withLogConsumer(new Slf4jLogConsumer(logger))
             .withCopyFileToContainer(
                 MountableFile.forHostPath(agentPath), "/opentelemetry-javaagent.jar")
-            .withCopyFileToContainer(
-                MountableFile.forHostPath(extensionPath), "/opentelemetry-extensions.jar")
-            //Adds instrumentation agent with debug configuration to the targe application
+            //Adds instrumentation agent with debug configuration to the target application
             .withEnv("JAVA_TOOL_OPTIONS",
                 "-javaagent:/opentelemetry-javaagent.jar -Dotel.javaagent.debug=true")
-            //Asks instrumentation agent to include this extension archive into its runtime
-            .withEnv("OTEL_JAVAAGENT_EXPERIMENTAL_EXTENSIONS", extensionLocation)
             .withEnv("OTEL_BSP_MAX_EXPORT_BATCH", "1")
             .withEnv("OTEL_BSP_SCHEDULE_DELAY", "10")
             .withEnv("OTEL_PROPAGATORS", "tracecontext,baggage,demo")
             .withEnv(getExtraEnv());
-    target.start();
+    //If external extensions are requested
+    if (extensionLocation != null) {
+      //Asks instrumentation agent to include extensions from given location into its runtime
+      result = result.withCopyFileToContainer(
+          MountableFile.forHostPath(extensionPath), "/opentelemetry-extensions.jar")
+          .withEnv("OTEL_JAVAAGENT_EXPERIMENTAL_EXTENSIONS", extensionLocation);
+    }
+    return result;
   }
 
   @AfterEach
@@ -108,7 +124,7 @@ void cleanup() throws IOException {
             new Request.Builder()
                 .url(
                     String.format(
-                        "http://localhost:%d/clear-requests", backend.getMappedPort(8080)))
+                        "http://localhost:%d/clear", backend.getMappedPort(8080)))
                 .build())
         .execute()
         .close();

examples/extension/src/test/java/com/example/javaagent/smoketest/SpringBootIntegrationTest.java

@@ -36,6 +36,14 @@ public void extensionsAreLoadedFromFolder() throws IOException, InterruptedExcep
     stopTarget();
   }
 
+  @Test
+  public void extensionsAreLoadedFromJavaagent() throws IOException, InterruptedException {
+    startTargetWithExtendedAgent();
+
+    testAndVerify();
+
+    stopTarget();
+  }
 
   private void testAndVerify() throws IOException, InterruptedException {
     String url = String.format("http://localhost:%d/greeting", target.getMappedPort(8080));

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/OpenTelemetryAgent.java

@@ -5,14 +5,13 @@
 
 package io.opentelemetry.javaagent;
 
+import io.opentelemetry.javaagent.bootstrap.AgentInitializer;
 import java.io.File;
 import java.io.IOException;
 import java.lang.instrument.Instrumentation;
 import java.lang.management.ManagementFactory;
 import java.lang.reflect.Field;
-import java.lang.reflect.Method;
 import java.net.URISyntaxException;
-import java.net.URL;
 import java.security.CodeSource;
 import java.util.Arrays;
 import java.util.List;
@@ -53,38 +52,29 @@ public static void premain(String agentArgs, Instrumentation inst) {
 
   public static void agentmain(String agentArgs, Instrumentation inst) {
     try {
-
-      URL bootstrapUrl = installBootstrapJar(inst);
-
-      Class<?> agentInitializerClass =
-          ClassLoader.getSystemClassLoader()
-              .loadClass("io.opentelemetry.javaagent.bootstrap.AgentInitializer");
-      Method startMethod =
-          agentInitializerClass.getMethod("initialize", Instrumentation.class, URL.class);
-      startMethod.invoke(null, inst, bootstrapUrl);
+      File javaagentFile = installBootstrapJar(inst);
+      AgentInitializer.initialize(inst, javaagentFile);
     } catch (Throwable ex) {
       // Don't rethrow.  We don't have a log manager here, so just print.
       System.err.println("ERROR " + thisClass.getName());
       ex.printStackTrace();
     }
   }
 
-  private static synchronized URL installBootstrapJar(Instrumentation inst)
+  private static synchronized File installBootstrapJar(Instrumentation inst)
       throws IOException, URISyntaxException {
-    URL javaAgentJarUrl = null;
 
     // First try Code Source
     CodeSource codeSource = thisClass.getProtectionDomain().getCodeSource();
 
     if (codeSource != null) {
-      javaAgentJarUrl = codeSource.getLocation();
-      File bootstrapFile = new File(javaAgentJarUrl.toURI());
+      File javaagentFile = new File(codeSource.getLocation().toURI());
 
-      if (!bootstrapFile.isDirectory()) {
-        JarFile agentJar = new JarFile(bootstrapFile, false);
-        verifyJarManifestMainClassIsThis(javaAgentJarUrl, agentJar);
+      if (javaagentFile.isFile()) {
+        JarFile agentJar = new JarFile(javaagentFile, false);
+        verifyJarManifestMainClassIsThis(javaagentFile, agentJar);
         inst.appendToBootstrapClassLoaderSearch(agentJar);
-        return javaAgentJarUrl;
+        return javaagentFile;
       }
     }
 
@@ -124,15 +114,14 @@ private static synchronized URL installBootstrapJar(Instrumentation inst)
     }
 
     File javaagentFile = new File(matcher.group(1));
-    if (!(javaagentFile.exists() || javaagentFile.isFile())) {
+    if (!javaagentFile.isFile()) {
       throw new IllegalStateException("Unable to find javaagent file: " + javaagentFile);
     }
-    javaAgentJarUrl = javaagentFile.toURI().toURL();
+
     JarFile agentJar = new JarFile(javaagentFile, false);
-    verifyJarManifestMainClassIsThis(javaAgentJarUrl, agentJar);
+    verifyJarManifestMainClassIsThis(javaagentFile, agentJar);
     inst.appendToBootstrapClassLoaderSearch(agentJar);
-
-    return javaAgentJarUrl;
+    return javaagentFile;
   }
 
   private static List<String> getVmArgumentsThroughReflection() {
@@ -175,7 +164,7 @@ private static List<String> getVmArgumentsThroughReflection() {
     }
   }
 
-  private static void verifyJarManifestMainClassIsThis(URL jarUrl, JarFile agentJar)
+  private static void verifyJarManifestMainClassIsThis(File jarFile, JarFile agentJar)
       throws IOException {
     Manifest manifest = agentJar.getManifest();
     String mainClass = manifest.getMainAttributes().getValue("Main-Class");
@@ -184,7 +173,7 @@ private static void verifyJarManifestMainClassIsThis(URL jarUrl, JarFile agentJa
           "opentelemetry-javaagent is not installed, because class '"
               + thisClass.getCanonicalName()
               + "' is located in '"
-              + jarUrl
+              + jarFile
               + "'. Make sure you don't have this .class file anywhere, "
               + "besides opentelemetry-javaagent.jar");
     }

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentClassLoader.java

@@ -10,7 +10,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
-import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.net.URLConnection;
@@ -69,15 +68,13 @@ public class AgentClassLoader extends URLClassLoader {
   /**
    * Construct a new AgentClassLoader.
    *
-   * @param bootstrapJarLocation Used for resource lookups.
+   * @param javaagentFile Used for resource lookups.
    * @param internalJarFileName File name of the internal jar
    * @param parent Classloader parent. Should null (bootstrap), or the platform classloader for java
-   *     9+.
    */
-  public AgentClassLoader(
-      URL bootstrapJarLocation, String internalJarFileName, ClassLoader parent) {
+  public AgentClassLoader(File javaagentFile, String internalJarFileName, ClassLoader parent) {
     super(new URL[] {}, parent);
-    if (bootstrapJarLocation == null) {
+    if (javaagentFile == null) {
       throw new IllegalArgumentException("Agent jar location should be set");
     }
     if (internalJarFileName == null) {
@@ -90,18 +87,17 @@ public AgentClassLoader(
         internalJarFileName
             + (internalJarFileName.isEmpty() || internalJarFileName.endsWith("/") ? "" : "/");
     try {
-      // open jar with verification disabled
-      jarFile = new JarFile(new File(bootstrapJarLocation.toURI()), false);
+      jarFile = new JarFile(javaagentFile, false);
       // base url for constructing jar entry urls
       // we use a custom protocol instead of typical jar:file: because we don't want to be affected
       // by user code disabling URLConnection caching for jar protocol e.g. tomcat does this
       jarBase =
           new URL("x-internal-jar", null, 0, "/", new AgentClassLoaderUrlStreamHandler(jarFile));
-    } catch (URISyntaxException | IOException e) {
+      codeSource = new CodeSource(javaagentFile.toURI().toURL(), (Certificate[]) null);
+      manifest = getManifest(jarFile, jarEntryPrefix + META_INF_MANIFEST_MF);
+    } catch (IOException e) {
       throw new IllegalStateException("Unable to open agent jar", e);
     }
-    codeSource = new CodeSource(bootstrapJarLocation, (Certificate[]) null);
-    manifest = getManifest(jarFile, jarEntryPrefix + META_INF_MANIFEST_MF);
 
     if (!AGENT_INITIALIZER_JAR.isEmpty()) {
       URL url;

javaagent-bootstrap/src/main/java/io/opentelemetry/javaagent/bootstrap/AgentInitializer.java

@@ -5,11 +5,10 @@
 
 package io.opentelemetry.javaagent.bootstrap;
 
+import java.io.File;
 import java.lang.instrument.Instrumentation;
-import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.net.URL;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -27,14 +26,9 @@ public final class AgentInitializer {
   @Nullable private static ClassLoader agentClassLoader = null;
 
   // called via reflection in the OpenTelemetryAgent class
-  public static void initialize(Instrumentation inst, URL bootstrapUrl) throws Exception {
-    startAgent(inst, bootstrapUrl);
-  }
-
-  private static synchronized void startAgent(Instrumentation inst, URL bootstrapUrl)
-      throws Exception {
+  public static void initialize(Instrumentation inst, File javaagentFile) throws Exception {
     if (agentClassLoader == null) {
-      agentClassLoader = createAgentClassLoader("inst", bootstrapUrl);
+      agentClassLoader = createAgentClassLoader("inst", javaagentFile);
 
       Class<?> agentInstallerClass =
           agentClassLoader.loadClass("io.opentelemetry.javaagent.tooling.AgentInstaller");
@@ -63,8 +57,7 @@ public static synchronized ClassLoader getAgentClassLoader() {
    *     classloader
    * @return Agent Classloader
    */
-  @SuppressWarnings("unchecked")
-  private static ClassLoader createAgentClassLoader(String innerJarFilename, URL bootstrapUrl)
+  private static ClassLoader createAgentClassLoader(String innerJarFilename, File javaagentFile)
       throws Exception {
     ClassLoader agentParent;
     if (isJavaBefore9()) {
@@ -74,21 +67,15 @@ private static ClassLoader createAgentClassLoader(String innerJarFilename, URL b
       agentParent = getPlatformClassLoader();
     }
 
-    Class<?> loaderClass =
-        ClassLoader.getSystemClassLoader()
-            .loadClass("io.opentelemetry.javaagent.bootstrap.AgentClassLoader");
-    Constructor<ClassLoader> constructor =
-        (Constructor<ClassLoader>)
-            loaderClass.getDeclaredConstructor(URL.class, String.class, ClassLoader.class);
     ClassLoader agentClassLoader =
-        constructor.newInstance(bootstrapUrl, innerJarFilename, agentParent);
+        new AgentClassLoader(javaagentFile, innerJarFilename, agentParent);
 
     Class<?> extensionClassLoaderClass =
         agentClassLoader.loadClass("io.opentelemetry.javaagent.tooling.ExtensionClassLoader");
     return (ClassLoader)
         extensionClassLoaderClass
-            .getDeclaredMethod("getInstance", ClassLoader.class)
-            .invoke(null, agentClassLoader);
+            .getDeclaredMethod("getInstance", ClassLoader.class, File.class)
+            .invoke(null, agentClassLoader, javaagentFile);
   }
 
   private static ClassLoader getPlatformClassLoader()

javaagent-bootstrap/src/test/groovy/io/opentelemetry/javaagent/bootstrap/AgentClassLoaderTest.groovy

@@ -18,7 +18,7 @@ class AgentClassLoaderTest extends Specification {
     def className2 = 'some/class/Name2'
     // any jar would do, use opentelemety sdk
     URL testJarLocation = JavaVersionSpecific.getProtectionDomain().getCodeSource().getLocation()
-    AgentClassLoader loader = new AgentClassLoader(testJarLocation, "", null)
+    AgentClassLoader loader = new AgentClassLoader(new File(testJarLocation.toURI()), "", null)
     Phaser threadHoldLockPhase = new Phaser(2)
     Phaser acquireLockFromMainThreadPhase = new Phaser(2)
 
@@ -57,7 +57,7 @@ class AgentClassLoaderTest extends Specification {
     boolean jdk8 = "1.8" == System.getProperty("java.specification.version")
     // sdk is a multi release jar
     URL multiReleaseJar = JavaVersionSpecific.getProtectionDomain().getCodeSource().getLocation()
-    AgentClassLoader loader = new AgentClassLoader(multiReleaseJar, "", null) {
+    AgentClassLoader loader = new AgentClassLoader(new File(multiReleaseJar.toURI()), "", null) {
       @Override
       protected String getClassSuffix() {
         return ""