Apply reproducible builds to plugins (#4746)

As per gradle [docs] add support to remove timestamps and package with
same order which is required from [reproducible] builds

This is a result of the discussion in
opensearch-project/opensearch-plugin-template-java#38
to apply for all plugins going forward.

[docs]:
https://docs.gradle.org/current/userguide/working_with_files.html#sec:reproducible_archives
[reproducible]: https://reproducible-builds.org/

Signed-off-by: Leonidas Spyropoulos <artafinde@archlinux.org>

Signed-off-by: Leonidas Spyropoulos <artafinde@archlinux.org>
Co-authored-by: Daniel (dB.) Doubrovkine <dblock@amazon.com>

CHANGELOG.md

@@ -32,6 +32,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Introduce experimental searchable snapshot API ([#4680](https://github.com/opensearch-project/OpenSearch/pull/4680))
 - Recommissioning of zone. REST layer support. ([#4624](https://github.com/opensearch-project/OpenSearch/pull/4604))
 - Added in-flight cancellation of SearchShardTask based on resource consumption ([#4565](https://github.com/opensearch-project/OpenSearch/pull/4565))
+- Apply reproducible builds configuration for OpenSearch plugins through gradle plugin ([#4746](https://github.com/opensearch-project/OpenSearch/pull/4746))
 
 ### Dependencies
 - Bumps `log4j-core` from 2.18.0 to 2.19.0

buildSrc/src/main/groovy/org/opensearch/gradle/plugin/PluginBuildPlugin.groovy

@@ -29,13 +29,13 @@
 package org.opensearch.gradle.plugin
 
 import com.github.jengelman.gradle.plugins.shadow.ShadowPlugin
+import org.gradle.api.tasks.bundling.AbstractArchiveTask
 import org.opensearch.gradle.BuildPlugin
 import org.opensearch.gradle.NoticeTask
 import org.opensearch.gradle.Version
 import org.opensearch.gradle.VersionProperties
 import org.opensearch.gradle.dependencies.CompileOnlyResolvePlugin
 import org.opensearch.gradle.info.BuildParams
-import org.opensearch.gradle.plugin.PluginPropertiesExtension
 import org.opensearch.gradle.test.RestTestBasePlugin
 import org.opensearch.gradle.testclusters.RunTask
 import org.opensearch.gradle.util.Util
@@ -134,6 +134,12 @@ class PluginBuildPlugin implements Plugin<Project> {
         }
         project.configurations.getByName('default')
                 .extendsFrom(project.configurations.getByName('runtimeClasspath'))
+        project.tasks.withType(AbstractArchiveTask.class).configureEach { task ->
+            // ignore file timestamps
+            // be consistent in archive file order
+            task.preserveFileTimestamps = false
+            task.reproducibleFileOrder = true
+        }
         // allow running ES with this plugin in the foreground of a build
         project.tasks.register('run', RunTask) {
             dependsOn(project.tasks.bundlePlugin)

buildSrc/src/test/java/org/opensearch/gradle/plugin/PluginBuildPluginTests.java

@@ -31,6 +31,7 @@
 
 package org.opensearch.gradle.plugin;
 
+import org.gradle.api.tasks.bundling.AbstractArchiveTask;
 import org.opensearch.gradle.BwcVersions;
 import org.opensearch.gradle.test.GradleUnitTestCase;
 import org.gradle.api.Project;
@@ -64,6 +65,10 @@ public void testApply() {
         assertNotNull("plugin extensions has the right type", project.getExtensions().findByType(PluginPropertiesExtension.class));
 
         assertNull("plugin should not create the integTest task", project.getTasks().findByName("integTest"));
+        project.getTasks().withType(AbstractArchiveTask.class).forEach(t -> {
+            assertFalse(String.format("task '%s' should not preserve timestamps", t.getName()), t.isPreserveFileTimestamps());
+            assertTrue(String.format("task '%s' should have reproducible file order", t.getName()), t.isReproducibleFileOrder());
+        });
     }
 
     @Ignore("https://github.com/elastic/elasticsearch/issues/47123")