Make bootstrap instrumentation available in JDK9 - 11 (#3194)

* Make JDK9-11 available for bootstrap instrumentation

* Remove temp folder of old bootstrap instrumentation requirement.

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java

@@ -19,7 +19,6 @@
 package org.apache.skywalking.apm.agent.core.plugin.bootstrap;
 
 import java.io.ByteArrayOutputStream;
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.instrument.Instrumentation;
@@ -33,8 +32,6 @@ import net.bytebuddy.dynamic.ClassFileLocator;
 import net.bytebuddy.dynamic.DynamicType;
 import net.bytebuddy.dynamic.loading.ClassInjector;
 import net.bytebuddy.pool.TypePool;
-import org.apache.skywalking.apm.agent.core.boot.AgentPackageNotFoundException;
-import org.apache.skywalking.apm.agent.core.boot.AgentPackagePath;
 import org.apache.skywalking.apm.agent.core.logging.api.ILog;
 import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
 import org.apache.skywalking.apm.agent.core.plugin.AbstractClassEnhancePluginDefine;
@@ -82,7 +79,6 @@ public class BootstrapInstrumentBoost {
 
     public static AgentBuilder inject(PluginFinder pluginFinder, AgentBuilder agentBuilder,
         Instrumentation instrumentation) throws PluginException {
-
         Map<String, byte[]> classesTypeMap = new HashMap<String, byte[]>();
 
         if (!prepareJREInstrumentation(pluginFinder, classesTypeMap)) {
@@ -93,17 +89,36 @@ public class BootstrapInstrumentBoost {
             loadHighPriorityClass(classesTypeMap, highPriorityClass);
         }
 
-        File temp = null;
-        try {
-            temp = new File(AgentPackagePath.getPath(), "bootstrapJarTmp");
-        } catch (AgentPackageNotFoundException e) {
-            logger.error(e, "Bootstrap plugin exist, but SkyWalking agent can't create bootstrapJarTmp folder. Shutting down.");
-            throw new UnsupportedOperationException("Bootstrap plugin exist, but SkyWalking agent can't create bootstrapJarTmp folder. Shutting down.", e);
+        /**
+         * This strategy is no longer available after Java 11.
+         * Inject the classes into bootstrap class loader.
+         */
+        ClassInjector.UsingUnsafe.ofBootLoader().injectRaw(classesTypeMap);
+        agentBuilder = agentBuilder.enableUnsafeBootstrapInjection();
+
+        /**
+         * Assures that all modules of the supplied types are read by the module of any instrumented type.
+         * JDK Module system was introduced since JDK9.
+         *
+         * The following codes work only JDK Module system exist.
+         */
+        for (String highPriorityClass : HIGH_PRIORITY_CLASSES) {
+            try {
+                agentBuilder = agentBuilder.assureReadEdgeTo(instrumentation, Class.forName(highPriorityClass));
+            } catch (ClassNotFoundException e) {
+                logger.error(e, "Fail to open the high priority class " + highPriorityClass + " to public access in JDK9+");
+                throw new UnsupportedOperationException("Fail to open the high priority class " + highPriorityClass + " to public access in JDK9+", e);
+            }
+        }
+        for (String generatedClass : classesTypeMap.keySet()) {
+            try {
+                agentBuilder = agentBuilder.assureReadEdgeTo(instrumentation, Class.forName(generatedClass));
+            } catch (ClassNotFoundException e) {
+                logger.error(e, "Fail to open the high generated class " + generatedClass + " to public access in JDK9+");
+                throw new UnsupportedOperationException("Fail to open the high generated class " + generatedClass + " to public access in JDK9+", e);
+            }
         }
 
-        ClassInjector.UsingInstrumentation.of(temp, ClassInjector.UsingInstrumentation.Target.BOOTSTRAP, instrumentation).injectRaw(classesTypeMap);
-
-        agentBuilder = agentBuilder.enableBootstrapInjection(instrumentation, temp);
         return agentBuilder;
     }
 
@@ -206,12 +221,17 @@ public class BootstrapInstrumentBoost {
      * @param loadedTypeMap hosts all injected class
      * @param className to load
      */
-    private static void loadHighPriorityClass(Map<String, byte[]> loadedTypeMap, String className) {
+    private static void loadHighPriorityClass(Map<String, byte[]> loadedTypeMap,
+        String className) throws PluginException {
         byte[] enhancedInstanceClassFile;
         try {
             String classResourceName = className.replaceAll("\\.", "/") + ".class";
             InputStream resourceAsStream = AgentClassLoader.getDefault().getResourceAsStream(classResourceName);
 
+            if (resourceAsStream == null) {
+                throw new PluginException("High priority class " + className + " not found.");
+            }
+
             ByteArrayOutputStream os = new ByteArrayOutputStream();
 
             byte[] buffer = new byte[1024];

apm-sniffer/apm-agent/pom.xml

@@ -136,7 +136,6 @@
                                 <mkdir dir="${project.basedir}/../../skywalking-agent/logs"/>
                                 <copydir src="${project.basedir}/../config"
                                          dest="${project.basedir}/../../skywalking-agent/config" forceoverwrite="true"/>
-                                <mkdir dir="${project.basedir}/../../skywalking-agent/bootstrapJarTmp"/>
                             </tasks>
                         </configuration>
                     </execution>

apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java

@@ -100,7 +100,7 @@ public class SkyWalkingAgent {
         try {
             agentBuilder = BootstrapInstrumentBoost.inject(pluginFinder, agentBuilder, instrumentation);
         } catch (Exception e) {
-            logger.error(e, "SkyWalking agent inject boostrap instrumentation failure. Shutting down.");
+            logger.error(e, "SkyWalking agent inject bootstrap instrumentation failure. Shutting down.");
             return;
         }
 

docs/en/setup/service-agent/java-agent/README.md

 # Setup java agent
+1. Agent is available for JDK 1.6 - 11.
 1. Find `agent` folder in SkyWalking release package
 1. Set `agent.service_name` in `config/agent.config`. Could be any String in English.
 1. Set `collector.backend_service` in `config/agent.config`. Default point to `127.0.0.1:11800`, only works for local backend.
@@ -19,7 +20,6 @@ The agent release dist is included in Apache [official release](http://skywalkin
          apm-feign-default-http-9.x.jar
          apm-httpClient-4.x-plugin.jar
          .....
-    +--- bootstrapJarTmp
     +--- logs
     skywalking-agent.jar
 ```
@@ -108,8 +108,6 @@ Now, we have the following known optional plugins.
 ## Bootstrap class plugins
 All bootstrap plugins are optional, due to unexpected risk. Bootstrap plugins are provided in `bootstrap-plugins` folder.
 
-**Make sure `bootstrapJarTmp` writable by agent, which is required by bootstrap instrumentation. New temp jar files will be generated there.**.
-
 ## Advanced Features
 * Set the settings through system properties for config file override. Read [setting override](Setting-override.md).
 * Use gRPC TLS to link backend. See [open TLS](TLS.md)