Manually call jlink because plugin won't work with our build

dd-smoke-tests/java9-modules/java9-modules.gradle

@@ -1,17 +1,9 @@
-import org.beryx.jlink.BaseTask
-
-plugins {
-  id 'org.beryx.jlink' version '2.1.1' // latest version that doesn't have a Java 11+ warning
-}
-
 ext {
   minJavaVersionForTests = JavaVersion.VERSION_1_9
 }
 
 apply from: "${rootDir}/gradle/java.gradle"
 
-mainClassName = 'datadog.smoketest.moduleapp.ModuleApplication'
-
 jar {
   manifest {
     attributes(
@@ -20,20 +12,32 @@ jar {
   }
 }
 
-jlink {
-  moduleName = 'datadog.smoketest.moduleapp'
-  options = ['--no-man-pages', '--no-header-files', '--add-modules', 'java.instrument']
-}
+/**
+ * For each Test task, creates a jlink image using the java bin directory of the test
+ */
+tasks.withType(Test).each {
+  def javaExecutable = it.executable
+  def javaVersion = getJavaExecutableVersion(javaExecutable)
 
-tasks.withType(BaseTask).each {
-  it.enabled = JavaVersion.VERSION_1_9.compareTo(JavaVersion.current()) <= 0
-}
+  if (JavaVersion.VERSION_1_9.compareTo(javaVersion) > 0) {
+    return
+  }
 
-test {
-  dependsOn tasks.jlink
+  def jlinkExecutable = file(javaExecutable).parent + "/jlink"
+  def generatedImageDir = "${buildDir}/${it.name}image"
+  
+  it.doFirst {
+    exec {
+      commandLine jlinkExecutable, '--no-man-pages', '--no-header-files',
+        '--add-modules', 'java.instrument,datadog.smoketest.moduleapp',
+        "--module-path", jar.archiveFile.get().toString(), "--output", generatedImageDir
+    }
+  }
+
+  it.jvmArgs "-Ddatadog.smoketest.module.image=${generatedImageDir}"
+  it.dependsOn jar
 }
 
 dependencies {
   testCompile project(':dd-smoke-tests')
-}
-
+}

dd-smoke-tests/java9-modules/src/test/groovy/datadog/smoketest/Java9ModulesSmokeTest.groovy

@@ -10,8 +10,12 @@ class Java9ModulesSmokeTest extends AbstractSmokeTest {
 
   @Override
   ProcessBuilder createProcessBuilder() {
+    String imageDir = System.getProperty("datadog.smoketest.module.image")
+
+    assert imageDir != null
+
     List<String> command = new ArrayList<>()
-    command.add(buildDirectory + "/image/bin/java")
+    command.add(imageDir + "/bin/java")
     command.addAll(defaultJavaProperties)
     command.addAll((String[]) ["-m", "datadog.smoketest.moduleapp/datadog.smoketest.moduleapp.ModuleApplication"])
     ProcessBuilder processBuilder = new ProcessBuilder(command)

gradle/java.gradle

@@ -246,6 +246,10 @@ JavaVersion getJavaExecutableVersion(String path) {
   }
 }
 
+ext {
+  getJavaExecutableVersion = this.&getJavaExecutableVersion
+}
+
 def isJavaVersionAllowed(JavaVersion version) {
   if (project.hasProperty('minJavaVersionForTests') && project.getProperty('minJavaVersionForTests').compareTo(version) > 0) {
     return false