Attempt to simplify jacoco logic

Simplifies Jacoco logic. From long ago, jacoco support was added through
a series of hacks. Some of these hacks are no longer necessary, so they
were removed to simplify.

Signed-off-by: John Mazanec <jmazane@amazon.com>

build-tools/knnplugin-coverage.gradle

@@ -3,79 +3,47 @@
  *  SPDX-License-Identifier: Apache-2.0
  */
 
+apply plugin: 'jacoco'
+
+jacoco {
+    toolVersion = "0.8.10"
+}
+
 /**
- * ES Plugin build tools don't work with the Gradle Jacoco Plugin to report coverage out of the box.
- * https://github.com/elastic/elasticsearch/issues/28867.
- *
- * This code sets up coverage reporting manually for ES plugin tests. This is complicated because:
- *  1. The ES integTest Task doesn't implement Gradle's JavaForkOptions so we have to manually start the jacoco agent with the test JVM
+ * This code sets up coverage reporting manually for the k-NN plugin tests. This is complicated because:
+ *  1. The OS integTest Task doesn't implement Gradle's JavaForkOptions so we have to manually start the jacoco agent with the test JVM
  *  2. The cluster nodes are stopped using 'kill -9' which means jacoco can't dump it's execution output to a file on VM shutdown
  *  3. The Java Security Manager prevents JMX from writing execution output to the file.
  *
  *  To workaround these we start the cluster with jmx enabled and then use Jacoco's JMX MBean to get the execution data before the
  *  cluster is stopped and dump it to a file. Luckily our current security policy seems to allow this. This will also probably
  *  break if there are multiple nodes in the integTestCluster. But for now... it sorta works.
  */
-
-import org.apache.tools.ant.taskdefs.condition.Os
-apply plugin: 'jacoco'
-
-// Get gradle to generate the required jvm agent arg for us using a dummy tasks of type Test. Unfortunately Elastic's
-// testing tasks don't derive from Test so the jacoco plugin can't do this automatically.
-def jacocoDir = "${buildDir}/jacoco"
-task dummyTest(type: Test) {
-    enabled = false
-    workingDir = file("/") // Force absolute path to jacoco agent jar
-    jacoco {
-        destinationFile = file("${jacocoDir}/test.exec")
-        destinationFile.parentFile.mkdirs()
-        jmx = true
-    }
-}
-
-task dummyIntegTest(type: Test) {
-    enabled = false
-    workingDir = file("/") // Force absolute path to jacoco agent jar
+integTest {
     jacoco {
-        destinationFile = file("${jacocoDir}/integTest.exec")
-        destinationFile.parentFile.mkdirs()
         jmx = true
     }
-}
 
-integTest {
-    systemProperty 'jacoco.dir', "${jacocoDir}"
+    systemProperty 'jacoco.dir', project.layout.buildDirectory.get().file("jacoco").asFile.absolutePath
     systemProperty 'jmx.serviceUrl', "service:jmx:rmi:///jndi/rmi://127.0.0.1:7777/jmxrmi"
 }
 
 jacocoTestReport {
     dependsOn integTest, test
-    executionData.from = [dummyTest.jacoco.destinationFile, dummyIntegTest.jacoco.destinationFile]
-    sourceDirectories.from = sourceSets.main.java.sourceDirectories
-    classDirectories.from = files(sourceSets.main.java.classesDirectory)
-
+    executionData.from = [integTest.jacoco.destinationFile, test.jacoco.destinationFile]
     reports {
         html.getRequired().set(true) // human readable
         csv.getRequired().set(true)
         xml.getRequired().set(true) // for coverlay
     }
 }
 
-afterEvaluate {
-    jacocoTestReport.dependsOn integTest
+testClusters.integTest {
+    jvmArgs " ${integTest.jacoco.getAsJvmArg()}"
 
-    testClusters.integTest {
-        if (Os.isFamily(Os.FAMILY_WINDOWS)) {
-            // Replacing build with absolute path to fix the error "error opening zip file or JAR manifest missing : /build/tmp/expandedArchives/..../jacocoagent.jar"
-            jvmArgs " ${dummyIntegTest.jacoco.getAsJvmArg()}".replace('build',"${buildDir}")
-        } else {
-            jvmArgs " ${dummyIntegTest.jacoco.getAsJvmArg()}".replace('javaagent:','javaagent:/')
-        }
-
-        systemProperty 'com.sun.management.jmxremote', "true"
-        systemProperty 'com.sun.management.jmxremote.authenticate', "false"
-        systemProperty 'com.sun.management.jmxremote.port', "7777"
-        systemProperty 'com.sun.management.jmxremote.ssl', "false"
-        systemProperty 'java.rmi.server.hostname', "127.0.0.1"
-    }
+    systemProperty 'com.sun.management.jmxremote', "true"
+    systemProperty 'com.sun.management.jmxremote.authenticate', "false"
+    systemProperty 'com.sun.management.jmxremote.port', "7777"
+    systemProperty 'com.sun.management.jmxremote.ssl', "false"
+    systemProperty 'java.rmi.server.hostname', "127.0.0.1"
 }

build.gradle

@@ -36,7 +36,6 @@ plugins {
     id 'java-library'
     id 'java-test-fixtures'
     id 'idea'
-    id 'jacoco'
     id "com.diffplug.spotless" version "6.3.0" apply false
     id 'io.freefair.lombok' version '8.4'
 }
@@ -135,10 +134,6 @@ if (!usingRemoteCluster) {
     }
 }
 
-jacoco {
-    toolVersion = "0.8.7"
-}
-
 check.dependsOn spotlessCheck
 check.dependsOn jacocoTestReport
 

src/testFixtures/java/org/opensearch/knn/KNNRestTestCase.java

@@ -10,6 +10,8 @@
 import com.google.common.primitives.Floats;
 import org.apache.commons.lang.StringUtils;
 import org.apache.hc.core5.http.io.entity.EntityUtils;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.core.xcontent.DeprecationHandler;
@@ -52,7 +54,6 @@
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Base64;
@@ -118,6 +119,8 @@ public class KNNRestTestCase extends ODFERestTestCase {
     protected static final int NUM_OF_ATTEMPTS = 30;
     private static final String SYSTEM_INDEX_PREFIX = ".opendistro";
 
+    private static final Logger logger = LogManager.getLogger(KNNRestTestCase.class);
+
     @AfterClass
     public static void dumpCoverage() throws IOException, MalformedObjectNameException {
         // jacoco.dir is set in esplugin-coverage.gradle, if it doesn't exist we don't
@@ -136,9 +139,10 @@ public static void dumpCoverage() throws IOException, MalformedObjectNameExcepti
                 false
             );
 
-            Path path = Paths.get(jacocoBuildPath + "/integTest.exec");
+            Path path = Path.of(jacocoBuildPath, "integTest.exec");
             Files.write(path, proxy.getExecutionData(false));
         } catch (Exception ex) {
+            logger.error("Failed to dump coverage: ", ex);
             throw new RuntimeException("Failed to dump coverage: " + ex);
         }
     }