Add TestWithDependenciesPlugin to build (#22646)

This commit adds a MessyRestTestPlugin to the gradle build. It extends 
StandaloneRestTestPlugin. The main piece of functionality that it adds 
is to copy plugin-metadata from dependencies into the 
generated-resources for the current test source. This is necessary to 
ensure that permissions for dependencies are applied when running the 
tests.

A current limitation is that the permissions are applied differently 
than in the distribution sources. When permissions are granted to all 
depedencies for a module or plugin, the permissions are granted to all 
dependencies on the classpath for tests besides a few hardcoded 
exclusions:
- es core
- es test framework
- lucene test framework
- randomized runner
- junit library

buildSrc/src/main/groovy/org/elasticsearch/gradle/test/MessyTestPlugin.groovy

@@ -48,7 +48,7 @@ class MessyTestPlugin extends StandaloneTestPlugin {
     }
 
     private static addPluginResources(Project project, Project pluginProject) {
-        String outputDir = "generated-resources/${pluginProject.name}"
+        String outputDir = "${project.buildDir}/generated-resources/${pluginProject.name}"
         String taskName = ClusterFormationTasks.pluginTaskName("copy", pluginProject.name, "Metadata")
         Copy copyPluginMetadata = project.tasks.create(taskName, Copy.class)
         copyPluginMetadata.into(outputDir)

buildSrc/src/main/groovy/org/elasticsearch/gradle/test/TestWithDependenciesPlugin.groovy

@@ -0,0 +1,58 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.gradle.test
+
+import org.elasticsearch.gradle.plugin.PluginBuildPlugin
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.artifacts.Dependency
+import org.gradle.api.artifacts.ProjectDependency
+import org.gradle.api.tasks.Copy
+
+/**
+ * A plugin to run tests that depend on other plugins or modules.
+ *
+ * This plugin will add the plugin-metadata and properties files for each 
+ * dependency to the test source set.
+ */
+class TestWithDependenciesPlugin implements Plugin<Project> {
+
+    @Override
+    void apply(Project project) {
+        project.configurations.testCompile.dependencies.all { Dependency dep ->
+            // this closure is run every time a compile dependency is added
+            if (dep instanceof ProjectDependency && dep.dependencyProject.plugins.hasPlugin(PluginBuildPlugin)) {
+                project.gradle.projectsEvaluated {
+                    addPluginResources(project, dep.dependencyProject)
+                }
+            }
+        }
+    }
+
+    private static addPluginResources(Project project, Project pluginProject) {
+        String outputDir = "${project.buildDir}/generated-resources/${pluginProject.name}"
+        String taskName = ClusterFormationTasks.pluginTaskName("copy", pluginProject.name, "Metadata")
+        Copy copyPluginMetadata = project.tasks.create(taskName, Copy.class)
+        copyPluginMetadata.into(outputDir)
+        copyPluginMetadata.from(pluginProject.tasks.pluginProperties)
+        copyPluginMetadata.from(pluginProject.file('src/main/plugin-metadata'))
+        project.sourceSets.test.output.dir(outputDir, builtBy: taskName)
+    }
+}

buildSrc/src/main/resources/META-INF/gradle-plugins/elasticsearch.test-with-dependencies.properties

@@ -0,0 +1,20 @@
+#
+# Licensed to Elasticsearch under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+implementation-class=org.elasticsearch.gradle.test.TestWithDependenciesPlugin

modules/reindex/build.gradle

@@ -17,6 +17,8 @@
  * under the License.
  */
 
+apply plugin: 'elasticsearch.test-with-dependencies'
+
 esplugin {
   description 'The Reindex module adds APIs to reindex from one index to another or update documents in place.'
   classname 'org.elasticsearch.index.reindex.ReindexPlugin'

qa/smoke-test-http/build.gradle

@@ -19,6 +19,7 @@
 
 apply plugin: 'elasticsearch.standalone-rest-test'
 apply plugin: 'elasticsearch.rest-test'
+apply plugin: 'elasticsearch.test-with-dependencies'
 
 dependencies {
     testCompile project(path: ':modules:transport-netty4', configuration: 'runtime') // for http