Keep instrumenting classes decorated by another agent's synthetic types

When the OpenTelemetry agent is loaded before Zen, it injects synthetic
supertypes (its VirtualField markers) onto core types such as java.sql.*,
jakarta.servlet.* and java.lang.Runnable. Those types have no .class resource,
so resolving the hierarchy of any class implementing one threw
NoSuchTypeException and the transform was skipped — silently turning off SQL
injection, request-context/route and executor instrumentation.

Add a lenient type pool that degrades an unresolvable type to an empty
interface so resolution completes, and skip OpenTelemetry's own classes.

Author: Mishenevd

.github/workflows/opentel.yml

@@ -80,3 +80,52 @@ jobs:
       - name: Run End-to-End tests
         working-directory: ./
         run: tail -f ./sample-apps/JavalinPostgres/output.log & sleep 20 && python end2end/javalin_postgres.py
+
+  opentel_test_spring:
+    runs-on: ubuntu-latest
+    needs: build
+    continue-on-error: true
+    strategy:
+      matrix:
+        java-version: [17, 18, 19, 20, 21]
+    steps:
+      - name: Download build artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: pkg-build
+
+      - name: Set up JDK
+        uses: actions/setup-java@v2
+        with:
+          java-version: ${{ matrix.java-version }}
+          distribution: 'adopt'
+
+      - name: Start mock server
+        working-directory: ./end2end/server
+        run: |
+          docker build -t mock_core .
+          docker run --name mock_core -d -p 5000:5000 mock_core
+      - name: Start databases
+        working-directory: ./sample-apps/databases
+        run: |
+          docker compose down --volumes
+          docker compose up --build -d postgres_database
+      - name: Install Python dependencies
+        run: python -m pip install -r end2end/requirements.txt
+      - name: Cleanup application
+        working-directory: ./sample-apps/SpringBootPostgres
+        run: chmod +x ./gradlew && make clean
+
+      - name: Build application
+        working-directory: ./sample-apps/SpringBootPostgres
+        run: make build
+
+      - name: Start Application (with and without Zen)
+        working-directory: ./sample-apps/SpringBootPostgres
+        run: |
+          nohup make runWithoutZen > output_without_zen.log & sleep 5
+          nohup make runWithOpentel > output.log & sleep 5
+
+      - name: Run End-to-End tests
+        working-directory: ./
+        run: tail -f ./sample-apps/SpringBootPostgres/output.log & sleep 20 && python end2end/spring_boot_postgres.py

agent/build.gradle

@@ -12,6 +12,18 @@ dependencies {
     compileOnly 'io.projectreactor.netty:reactor-netty-http:1.2.1' // For Spring Webflux
     compileOnly 'io.javalin:javalin:6.4.0'
     compileOnly 'org.springframework:spring-web:5.3.20'
+
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.2'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.9.2'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher:1.9.2'
+}
+
+test {
+    useJUnitPlatform()
+    // The root `test --tests <name>` smoke run targets a test in another module; don't fail here on no match.
+    filter {
+        setFailOnNoMatchingTests(false)
+    }
 }
 
 shadowJar {

agent/src/main/java/dev/aikido/agent/ByteBuddyInitializer.java

@@ -28,6 +28,8 @@ public static AgentBuilder createAgentBuilder(boolean debugMode) {
                         .with(InstrumentedType.Factory.Default.FROZEN)
         );
 
+        agentBuilder = agentBuilder.with(LenientPoolStrategy.INSTANCE);
+
         //  Disables all implicit changes on a class file that Byte Buddy would apply for certain instrumentation's.
         agentBuilder = agentBuilder.disableClassFormatChanges();
 
@@ -39,10 +41,10 @@ public static AgentBuilder createAgentBuilder(boolean debugMode) {
                     .with(AgentBuilder.InstallationListener.StreamWriting.toSystemError());
         }
 
-        // Ignore Byte Buddy and Aikido's internal code:
         agentBuilder = agentBuilder.ignore(
                 ElementMatchers.nameContains("bytebuddy")
                 .or(ElementMatchers.nameContains("dev.aikido.agent"))
+                .or(ElementMatchers.nameStartsWith("io.opentelemetry.javaagent"))
         );
 
         agentBuilder = agentBuilder.with(AgentBuilder.TypeStrategy.Default.DECORATE);

agent/src/main/java/dev/aikido/agent/LenientPoolStrategy.java

@@ -0,0 +1,71 @@
+package dev.aikido.agent;
+
+import net.bytebuddy.agent.builder.AgentBuilder;
+import net.bytebuddy.description.annotation.AnnotationList;
+import net.bytebuddy.description.field.FieldDescription;
+import net.bytebuddy.description.field.FieldList;
+import net.bytebuddy.description.method.MethodDescription;
+import net.bytebuddy.description.method.MethodList;
+import net.bytebuddy.description.type.RecordComponentDescription;
+import net.bytebuddy.description.type.RecordComponentList;
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.ClassFileLocator;
+import net.bytebuddy.pool.TypePool;
+
+import java.lang.reflect.Modifier;
+import java.util.Collections;
+
+// Another agent (e.g. OpenTelemetry) can add synthetic supertypes with no .class resource to core types;
+// the default pool then throws while resolving the hierarchy. Unresolvable types degrade to an empty interface.
+public enum LenientPoolStrategy implements AgentBuilder.PoolStrategy {
+    INSTANCE;
+
+    @Override
+    public TypePool typePool(ClassFileLocator classFileLocator, ClassLoader classLoader) {
+        return new LenientPool(new TypePool.CacheProvider.Simple(), classFileLocator, TypePool.Default.ReaderMode.FAST);
+    }
+
+    @Override
+    public TypePool typePool(ClassFileLocator classFileLocator, ClassLoader classLoader, String name) {
+        return typePool(classFileLocator, classLoader);
+    }
+
+    private static final class LenientPool extends TypePool.Default {
+        LenientPool(CacheProvider cacheProvider, ClassFileLocator classFileLocator, ReaderMode readerMode) {
+            super(cacheProvider, classFileLocator, readerMode);
+        }
+
+        @Override
+        protected Resolution doDescribe(String name) {
+            Resolution resolution = super.doDescribe(name);
+            return resolution.isResolved() ? resolution : new Resolution.Simple(new EmptyStubType(name));
+        }
+    }
+
+    private static final class EmptyStubType extends TypeDescription.Latent {
+        EmptyStubType(String name) {
+            super(name, Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.INTERFACE,
+                    TypeDescription.Generic.OBJECT, Collections.<TypeDescription.Generic>emptyList());
+        }
+
+        @Override
+        public MethodList<MethodDescription.InDefinedShape> getDeclaredMethods() {
+            return new MethodList.Empty<MethodDescription.InDefinedShape>();
+        }
+
+        @Override
+        public FieldList<FieldDescription.InDefinedShape> getDeclaredFields() {
+            return new FieldList.Empty<FieldDescription.InDefinedShape>();
+        }
+
+        @Override
+        public AnnotationList getDeclaredAnnotations() {
+            return new AnnotationList.Empty();
+        }
+
+        @Override
+        public RecordComponentList<RecordComponentDescription.InDefinedShape> getRecordComponents() {
+            return new RecordComponentList.Empty<RecordComponentDescription.InDefinedShape>();
+        }
+    }
+}

agent/src/test/java/dev/aikido/agent/LenientPoolStrategyTest.java

@@ -0,0 +1,38 @@
+package dev.aikido.agent;
+
+import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.dynamic.ClassFileLocator;
+import net.bytebuddy.pool.TypePool;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class LenientPoolStrategyTest {
+    private TypePool pool() {
+        ClassLoader classLoader = getClass().getClassLoader();
+        return LenientPoolStrategy.INSTANCE.typePool(ClassFileLocator.ForClassLoader.of(classLoader), classLoader);
+    }
+
+    @Test
+    void resolvableTypeIsDescribedNormally() {
+        TypeDescription type = pool().describe("java.util.ArrayList").resolve();
+
+        assertEquals("java.util.ArrayList", type.getName());
+        assertFalse(type.isInterface());
+        assertFalse(type.getDeclaredMethods().isEmpty());
+    }
+
+    @Test
+    void unresolvableTypeDegradesToEmptyInterface() {
+        TypeDescription type = pool().describe("com.acme.Injected$VirtualField$Absent").resolve();
+
+        assertEquals("com.acme.Injected$VirtualField$Absent", type.getName());
+        assertTrue(type.isInterface());
+        assertTrue(type.getDeclaredMethods().isEmpty());
+        assertTrue(type.getDeclaredFields().isEmpty());
+        assertTrue(type.getInterfaces().isEmpty());
+        assertEquals(Object.class.getName(), type.getSuperClass().asErasure().getName());
+    }
+}

sample-apps/SpringBootPostgres/Makefile

@@ -37,6 +37,19 @@ runWithDdTrace: build
 		-javaagent:dd-java-agent.jar -Ddd.profiling.enabled=true -Ddd.logs.injection=true -Ddd.service=my-app -Ddd.env=staging -Ddd.version=1.0 \
 		-javaagent:$(JAVA_AGENT) -jar $(JAR_FILE) --server.port=8080
 
+# Run with the OpenTelemetry agent loaded before Zen (the order that broke Zen instrumentation)
+.PHONY: runWithOpentel
+runWithOpentel: build
+	@echo "Running SpringBootPostgres with OpenTelemetry (first) & Zen (http://localhost:8080)"
+	wget -O opentelemetry-javaagent.jar 'https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar'
+	AIKIDO_LOG_LEVEL="error" \
+	AIKIDO_TOKEN="token" \
+	AIKIDO_REALTIME_ENDPOINT="http://localhost:5000/realtime" \
+	AIKIDO_ENDPOINT="http://localhost:5000" \
+	AIKIDO_BLOCK=1 java \
+		-javaagent:opentelemetry-javaagent.jar -Dotel.service.name=service -Dotel.traces.exporter=none -Dotel.metrics.exporter=none -Dotel.logs.exporter=none \
+		-javaagent:$(JAVA_AGENT) -jar $(JAR_FILE) --server.port=8080
+
 # Run the application without Zen
 .PHONY: runWithoutZen
 runWithoutZen: build