refactor: inspectit-gepard-agent/build.gradle

inspectit-gepard-agent/README.md

@@ -1 +1,8 @@
-# TODO
+# inspectIT Gepard - Agent
+
+This project contains the core and actual implementation of the inspectIT Gepard agent extension.
+All logic for runtime instrumentation, configuration processing etc. are located in ths project.
+
+
+To run this extension, u will need to provide it to an 
+[OpenTelemetry Java agent](https://github.com/open-telemetry/opentelemetry-java-instrumentation).

inspectit-gepard-agent/build.gradle

@@ -130,18 +130,51 @@ dependencies {
     add("muzzleTooling", "io.opentelemetry.javaagent:opentelemetry-javaagent-tooling:${versions.opentelemetryJavaagentAlpha}")
 }
 
-// Produces a copy of upstream javaagent with this extension jar included inside it
+/*
+ Since we cannot include additional submodules into the shadowJar that easily, we use the following approach
+ to create one extension-jar, containing all of our submodules:
+
+ 1. Copy the output of all submodules to a temporary directory
+ 2. Unzip the output of the shadowJar task (which includes our core logic)
+ 3. Move the jars of the other submodules into the unzipped directory
+ 4. Re-zip the directory
+ 5. Insert the re-zipped jar into the opentelemetry-javaagent.jar
+ 6. Delete the temporary directory
+ */
+def mergeModules = tasks.register("mergeModules", Zip) {
+    dependsOn(copyModules)
+    from tasks.copyModules.destinationDir
+    destinationDirectory = layout.buildDirectory.dir('libs').get().asFile
+    archiveFileName.set("inspectit-gepard-agent-extension-${version}.jar")
+}
+
+// Copies the output of your submodules to a temporary directory
+def copyModules = tasks.register("copyModules", Copy) {
+    dependsOn(shadowJar)
+    dependsOn(project(":inspectit-gepard-bootstrap").tasks.jar)
+
+    destinationDir = layout.buildDirectory.dir('copy').get().asFile
+
+    from(zipTree(tasks.shadowJar.archiveFile.get()))
+    from(project(":inspectit-gepard-bootstrap").jar.outputs)
+
+    finalizedBy(mergeModules)
+}
+
+shadowJar.finalizedBy(copyModules)
+
+assemble.dependsOn(shadowJar)
+
+// 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
 tasks.register('extendedAgent', Jar) {
     dependsOn(configurations.otel)
+    dependsOn(mergeModules)
+
     archiveFileName = "inspectit-gepard-agent.jar"
     from zipTree(configurations.otel.singleFile)
-//    from(tasks.shadowJar.archiveFile) {
-//        into "extensions"
-//    }
 
-    dependsOn(repack)
-    from(tasks.repack.archiveFile) {
+    from(tasks.mergeModules.archiveFile) {
         into "extensions"
     }
 
@@ -153,41 +186,21 @@ tasks.register('extendedAgent', Jar) {
             }.singleFile
         )
     }
-}
-
-def repack = tasks.register("repack", Zip) {
-    dependsOn(horst)
-    from layout.buildDirectory.dir('bootstrap/tmp').get().asFile
-    destinationDirectory.set(file("${buildDir}/libs"))
-    archiveFileName.set("inspectit-gepard-agent-extension.jar")
-}
 
-def horst = tasks.register("horst", Copy) {
-    dependsOn(shadowJar)
-
-    destinationDir = layout.buildDirectory.dir('bootstrap').get().asFile
-
-    from(zipTree(tasks.shadowJar.archiveFile.get())) {
-        into "tmp"
+    // Remove temporary directory
+    doLast {
+        delete tasks.copyModules.destinationDir
     }
-
-    from(project(":inspectit-gepard-bootstrap").jar.outputs) {
-        into "tmp"
-    }
-
-    finalizedBy(repack)
-}
-
-shadowJar {
-    finalizedBy(horst)
 }
 
 tasks {
     test {
-        dependsOn(extendedAgent)
+        // we need to merge our submodules before running tests,
+        // so all classes are accessible for integration tests
+        dependsOn(mergeModules)
         useJUnitPlatform()
 
-        inputs.files(layout.files(tasks.repack))
+        inputs.files(layout.files(tasks.mergeModules))
         inputs.files(layout.files(tasks.extendedAgent))
 
         // Necessary to use system-lambda in tests
@@ -197,17 +210,17 @@ tasks {
 
         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.repack.archiveFile.get().asFile.absolutePath
+        systemProperty 'io.opentelemetry.smoketest.extensionPath', tasks.mergeModules.archiveFile.get().asFile.absolutePath
 
-        finalizedBy jacocoTestReport
+        finalizedBy(jacocoTestReport)
     }
 
+    jacocoTestReport.dependsOn(test)
+
     compileJava {
         options.release.set(17)
     }
 
-    assemble.dependsOn(shadowJar)
-
     dockerPrepare.dependsOn(extendedAgent)
 
     docker {
@@ -218,6 +231,4 @@ tasks {
         dockerfile file('docker/Dockerfile')
         files 'docker/entrypoint.sh', agentJar.get().asFile
     }
-
-    jacocoTestReport.dependsOn(test)
 }

inspectit-gepard-agent/src/main/java/rocks/inspectit/gepard/agent/bootstrap/InspectitBootstrapManager.java

@@ -15,8 +15,6 @@ public class InspectitBootstrapManager {
 
   private static final Logger log = LoggerFactory.getLogger(InspectitBootstrapManager.class);
 
-  // private static final String INSPECTIT_BOOTSTRAP_JAR_PATH =
-  // "/extensions/inspectit-gepard-bootstrap.jar";
   private static final String INSPECTIT_BOOTSTRAP_JAR_PATH = "/inspectit-gepard-bootstrap.jar";
 
   private static final String INSPECTIT_BOOTSTRAP_JAR_TEMP_PREFIX = "gepard-bootstrap-";
@@ -32,10 +30,10 @@ public static synchronized void appendToBootstrapClassLoader() {
       JarFile bootstrapJar = new JarFile(bootstrapJarPath.toFile());
       instrumentation.appendToBootstrapClassLoaderSearch(bootstrapJar);
     } catch (Exception e) {
-      log.error("Could not add inspectIT Gepard interfaces to bootstrap classloader", e);
+      log.error("Could not append inspectIT Gepard interfaces to bootstrap classloader", e);
       return;
     }
-    log.info("Successfully added inspectIT Gepard interfaces to bootstrap classloader");
+    log.info("Successfully appended inspectIT Gepard interfaces to bootstrap classloader");
   }
 
   /**
@@ -47,7 +45,6 @@ public static synchronized void appendToBootstrapClassLoader() {
    */
   private static Path copyResourceToTempJarFile(String resourcePath, String prefix)
       throws IOException {
-    // try (InputStream inputStream = OpenTelemetryAgent.class.getResourceAsStream(resourcePath)) {
     try (InputStream inputStream =
         InspectitBootstrapManager.class.getResourceAsStream(resourcePath)) {
       Path targetFile = Files.createTempFile(prefix, ".jar");

inspectit-gepard-bootstrap/README.md

@@ -1 +1,9 @@
-# TODO
+# inspectIT Gepard - Bootstrap
+
+This project contains interfaces which have to be implemented by inspectIT Gepard Java agents and
+are injected into the user application.
+
+The resulting Jar file of this package will be pushed to the JVM's bootstrap class loader.
+This is necessary in order to create a bridge between the user (application) classes 
+and the classes which will be loaded by the OpenTelemetry extension class loader 
+(classes of the inspectIT Gepard Java agent).