🐛 Fix bug with consuming OTel extensions

example-projects/app/build.gradle.kts

@@ -6,7 +6,11 @@ plugins {
 
 dependencies {
   otel("io.opentelemetry.javaagent:opentelemetry-javaagent:2.8.0")
-  otelExtension("io.opentelemetry.contrib:opentelemetry-samplers:1.32.0-alpha")
+  otelExtension("com.google.cloud.opentelemetry:exporter-auto:0.33.0-alpha") {
+      artifact {
+          classifier = "shaded"
+      }
+  }
   otelInstrumentation(project(":custom-instrumentation", "shadow"))
 }
 

example-projects/buildSrc/build.gradle.kts

@@ -6,9 +6,11 @@ repositories {
     gradlePluginPortal()
     mavenLocal()
 }
-/* uncomment when doing local testing on this project, leave commented out for functional test to resolve latest plugin
 dependencies {
-  implementation("com.ryandens:otel:0.4.2")
-  implementation("com.ryandens:plugin:0.4.2")
+    /* uncomment when doing local testing on this project, leave commented out for functional test to resolve latest plugin
+    implementation("com.ryandens:otel:0.6.1")
+    implementation("com.ryandens:plugin:0.6.1")
+    */
+    implementation("io.opentelemetry.instrumentation.muzzle-generation:io.opentelemetry.instrumentation.muzzle-generation.gradle.plugin:2.8.0-alpha")
+    implementation("io.opentelemetry.instrumentation.muzzle-check:io.opentelemetry.instrumentation.muzzle-check.gradle.plugin:2.8.0-alpha")
 }
-*/

example-projects/custom-instrumentation/build.gradle.kts

@@ -1,8 +1,8 @@
 plugins {
   id("com.ryandens.javaagent.example.java-library-conventions")
-  id("io.opentelemetry.instrumentation.muzzle-check") version "1.13.1-alpha"
-  id("io.opentelemetry.instrumentation.muzzle-generation") version "1.13.1-alpha"
-  id("com.github.johnrengelman.shadow")
+  id("io.opentelemetry.instrumentation.muzzle-check")
+  id("io.opentelemetry.instrumentation.muzzle-generation")
+  id("com.gradleup.shadow")
 }
 
 tasks.shadowJar {

example-projects/custom-instrumentation/src/main/java/io/opentelemetry/javaagent/instrumentation/ryandens/SampleInstrumentation.java → example-projects/custom-instrumentation/src/main/java/com/ryandens/example/SampleInstrumentation.java

@@ -1,4 +1,4 @@
-package io.opentelemetry.javaagent.instrumentation.ryandens;
+package com.ryandens.example;
 
 
 import io.opentelemetry.api.trace.Span;
@@ -39,7 +39,6 @@ public static void onEnter(@Advice.Local("otelSpan") Span span,
                                @Advice.Local("otelContext") Context context,
                                @Advice.Local("otelScope") Scope scope) {
       Context parentContext = Context.current();
-      // TODO helper classes don't seem to work for some reaso
       span = Singletons.INSTANCE.tracer.spanBuilder("iterative").setSpanKind(SpanKind.INTERNAL).setParent(parentContext).startSpan();
       context = parentContext.with(span);
       scope = context.makeCurrent();

example-projects/custom-instrumentation/src/main/java/io/opentelemetry/javaagent/instrumentation/ryandens/SampleInstrumentationModule.java → example-projects/custom-instrumentation/src/main/java/com/ryandens/example/SampleInstrumentationModule.java

@@ -1,4 +1,4 @@
-package io.opentelemetry.javaagent.instrumentation.ryandens;
+package com.ryandens.example;
 
 import com.google.auto.service.AutoService;
 import io.opentelemetry.javaagent.extension.instrumentation.InstrumentationModule;
@@ -17,4 +17,9 @@ public SampleInstrumentationModule() {
   public List<TypeInstrumentation> typeInstrumentations() {
     return Collections.singletonList(new SampleInstrumentation());
   }
+
+  @Override
+  public boolean isHelperClass(String className) {
+    return className.contains("ryandens");
+  }
 }

example-projects/custom-instrumentation/src/main/java/io/opentelemetry/javaagent/instrumentation/ryandens/Singletons.java → example-projects/custom-instrumentation/src/main/java/com/ryandens/example/Singletons.java

@@ -1,4 +1,4 @@
-package io.opentelemetry.javaagent.instrumentation.ryandens;
+package com.ryandens.example;
 
 import io.opentelemetry.api.GlobalOpenTelemetry;
 import io.opentelemetry.api.trace.Tracer;

gradle.properties

@@ -5,5 +5,5 @@ org.gradle.jvmargs=--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAME
   --add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
 org.gradle.configuration-cache=true
 org.gradle.caching=true
-version=0.6.1
+version=0.7.0
 group=com.ryandens

otel/build.gradle.kts

@@ -4,7 +4,6 @@ plugins {
 
 dependencies {
     implementation(project(":plugin"))
-    implementation("gradle.plugin.com.github.johnrengelman:shadow:8.0.0")
     testImplementation(platform("org.junit:junit-bom:5.11.2"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     testImplementation("org.junit.jupiter:junit-jupiter-params")

otel/src/functionalTest/kotlin/com/ryandens/javaagent/otel/OTelJavaagentPluginFunctionalTest.kt

@@ -17,15 +17,18 @@ class OTelJavaagentPluginFunctionalTest {
         val runner = GradleRunner.create()
         runner.forwardOutput()
         runner.withPluginClasspath()
-        runner.withArguments("extendedAgent", "run")
+        runner.withArguments("mergeInstrumentationServiceFiles", "extendedAgent", "run")
         runner.withProjectDir(projectDir)
+        runner.withDebug(true)
         val result = runner.build()
 
         // Verify the result
         // TODO use testcontainers to start an otel fake backend and retrieve spans from it here to verify instrumentation worked
+        assertTrue(result.output.contains("AgentInstaller - Installed 1 extension(s)"))
+        assertTrue(result.output.contains("InstrumentationLoader - Installed 254 instrumenter(s)"))
         assertTrue(
             result.output.contains(
-                "Applying instrumentation: sample [class io.opentelemetry.javaagent.instrumentation.ryandens.SampleInstrumentationModule]",
+                "Applying instrumentation: sample [class com.ryandens.example.SampleInstrumentationModule]",
             ),
         )
         assertTrue(result.output.contains("LoggingSpanExporter - 'iterative'")) // span name

otel/src/main/kotlin/com/ryandens/javaagent/otel/JavaagentOTelModificationPlugin.kt

@@ -1,10 +1,10 @@
 package com.ryandens.javaagent.otel
 
-import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import com.ryandens.javaagent.JavaagentBasePlugin
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.file.DuplicatesStrategy
+import org.gradle.jvm.tasks.Jar
 
 /**
  * Enables easy consumption of external extensions and instrumentation libraries by creating a new jar with extra
@@ -37,17 +37,24 @@ class JavaagentOTelModificationPlugin : Plugin<Project> {
                 it.isTransitive = false
             }
 
+        val mergeServiceFiles =
+            project.tasks.register("mergeInstrumentationServiceFiles", MergeServiceFiles::class.java) { mergeServiceFiles ->
+                mergeServiceFiles.dependsOn(otelInstrumentation)
+                mergeServiceFiles.inputFiles.from(project.files(otelInstrumentation, otel).map { jar -> project.zipTree(jar) })
+                mergeServiceFiles.outputDirectory.set(project.layout.buildDirectory.dir("merged-instrumentation-services"))
+            }
+
         project.plugins.apply(JavaagentBasePlugin::class.java)
         val extendedAgent =
-            project.tasks.register("extendedAgent", ShadowJar::class.java) { jar ->
+            project.tasks.register("extendedAgent", Jar::class.java) { jar ->
                 jar.inputs.files(otelInstrumentation)
+                jar.dependsOn(mergeServiceFiles)
                 jar.archiveFileName.set("extended-opentelemetry-javaagent.jar")
                 jar.destinationDirectory.set(project.layout.buildDirectory.dir("agents"))
-                jar.mergeServiceFiles {
-                    it.include("inst/META-INF/services/*")
+                jar.from(otel.map { project.zipTree(it.singleFile) }) {
+                    it.exclude("inst/META-INF/services/**")
                 }
-                jar.from(otel.map { project.zipTree(it.singleFile) })
-                jar.from(otelExtension) {
+                jar.from(otelExtension.map { it.singleFile }) {
                     it.into("extensions")
                 }
                 jar.manifest {
@@ -69,7 +76,12 @@ class JavaagentOTelModificationPlugin : Plugin<Project> {
                     it.into("inst")
                     it.exclude("META-INF/MANIFEST.MF")
                     it.rename("(^.*)\\.class\$", "\$1.classdata")
-                    it.duplicatesStrategy = DuplicatesStrategy.INCLUDE
+                    it.exclude("META-INF/services/**")
+                    it.exclude("inst/META-INF/services/**")
+                    it.duplicatesStrategy = DuplicatesStrategy.FAIL
+                }
+                jar.from(mergeServiceFiles.map { it.outputDirectory }) {
+                    it.into("inst")
                 }
             }
         project.dependencies.add("javaagent", extendedAgent.map { project.files(it.outputs.files.singleFile) })

otel/src/main/kotlin/com/ryandens/javaagent/otel/MergeServiceFiles.kt

@@ -0,0 +1,72 @@
+package com.ryandens.javaagent.otel
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.file.FileSystemOperations
+import org.gradle.api.tasks.CacheableTask
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.OutputDirectory
+import org.gradle.api.tasks.PathSensitive
+import org.gradle.api.tasks.PathSensitivity
+import org.gradle.api.tasks.TaskAction
+import java.io.File
+import java.io.FileOutputStream
+import java.io.OutputStreamWriter
+import java.io.PrintWriter
+import java.nio.charset.StandardCharsets
+import java.nio.file.Files
+import java.util.stream.Collectors
+import javax.inject.Inject
+
+/**
+ * Internal task to merge service files between custom instrumentation JArs and the OpenTelemetry Javaagent.
+ *
+ * Inspired by
+ * [Micronaut](https://github.com/micronaut-projects/micronaut-gradle-plugin/blob/eb9d2b3ab4b3fc71379fc3c1c6df30de761576be/aot-plugin/src/main/java/io/micronaut/gradle/aot/MergeServiceFiles.java#L42)
+ * in lieu of a built-in solution in Gradle as referenced [here](https://github.com/gradle/gradle/issues/18751).
+ */
+@CacheableTask
+abstract class MergeServiceFiles
+    @Inject
+    constructor(private val fileSystemOperations: FileSystemOperations) :
+    DefaultTask() {
+        @get:InputFiles
+        @get:PathSensitive(PathSensitivity.RELATIVE)
+        abstract val inputFiles: ConfigurableFileCollection
+
+        @get:OutputDirectory
+        abstract val outputDirectory: DirectoryProperty
+
+        @TaskAction
+        fun execute() {
+            val serviceFiles: Set<File> =
+                inputFiles.asFileTree.matching { f -> f.include("META-INF/services/**").include("inst/META-INF/services/**") }
+                    .files
+            val outputDir: File = outputDirectory.get().dir("META-INF/services").asFile
+            fileSystemOperations.delete {
+                it.delete(outputDir)
+            }
+            outputDir.mkdirs()
+            val perService: Map<String, List<File>> =
+                serviceFiles.stream()
+                    .collect(Collectors.groupingBy(File::getName))
+            for ((serviceType, files) in perService) {
+                val mergedServiceFile = File(outputDir, serviceType)
+                try {
+                    PrintWriter(
+                        OutputStreamWriter(
+                            FileOutputStream(mergedServiceFile),
+                            StandardCharsets.UTF_8,
+                        ),
+                    ).use { wrt ->
+                        for (file in files) {
+                            Files.readAllLines(file.toPath()).forEach(wrt::println)
+                        }
+                    }
+                } catch (e: Exception) {
+                    throw RuntimeException(e)
+                }
+            }
+        }
+    }