Build: Copy rest specs for plugins that are added to integ test cluster

This change allows having rest tests using the api spec of plugins that
the rest test is testing against.

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

@@ -105,9 +105,7 @@ class ClusterFormationTasks {
 
         // install plugins
         for (Map.Entry<String, Object> plugin : node.config.plugins.entrySet()) {
-            // replace every dash followed by a character with just the uppercase character
+            String actionName = pluginTaskName('install', plugin.getKey(), 'Plugin')
-            String camelName = plugin.getKey().replaceAll(/-(\w)/) { _, c -> c.toUpperCase(Locale.ROOT) }
-            String actionName = "install${camelName[0].toUpperCase(Locale.ROOT) + camelName.substring(1)}Plugin"
             setup = configureInstallPluginTask(taskName(task, node, actionName), project, setup, node, plugin.getValue())
         }
 
@@ -176,16 +174,23 @@ class ClusterFormationTasks {
         }
     }
 
-    /** Adds a task to copy plugins to a temp dir, which they will later be installed from. */
+    /**
+     * Adds a task to copy plugins to a temp dir, which they will later be installed from.
+     *
+     * For each plugin, if the plugin has rest spec apis in its tests, those api files are also copied
+     * to the test resources for this project.
+     */
     static Task configureCopyPluginsTask(String name, Project project, Task setup, NodeInfo node) {
         if (node.config.plugins.isEmpty()) {
             return setup
         }
+        Copy copyPlugins = project.tasks.create(name: name, type: Copy, dependsOn: setup)
 
         List<FileCollection> pluginFiles = []
-        for (Object plugin : node.config.plugins.values()) {
+        for (Map.Entry<String, Object> plugin : node.config.plugins.entrySet()) {
-            if (plugin instanceof Project) {
+            FileCollection pluginZip
-                Project pluginProject = plugin
+            if (plugin.getValue() instanceof Project) {
+                Project pluginProject = plugin.getValue()
                 if (pluginProject.plugins.hasPlugin(PluginBuildPlugin) == false) {
                     throw new GradleException("Task ${name} cannot project ${pluginProject.path} which is not an esplugin")
                 }
@@ -196,15 +201,29 @@ class ClusterFormationTasks {
                 }
                 project.dependencies.add(configurationName, pluginProject)
                 setup.dependsOn(pluginProject.tasks.bundlePlugin)
-                plugin = configuration
+                pluginZip = configuration
+
+                // also allow rest tests to use the rest spec from the plugin
+                Copy copyRestSpec = null
+                for (File resourceDir : pluginProject.sourceSets.test.resources.srcDirs) {
+                    File restApiDir = new File(resourceDir, 'rest-api-spec/api')
+                    if (restApiDir.exists() == false) continue
+                    if (copyRestSpec == null) {
+                        copyRestSpec = project.tasks.create(name: pluginTaskName('copy', plugin.getKey(), 'PluginRestSpec'), type: Copy)
+                        copyPlugins.dependsOn(copyRestSpec)
+                        copyRestSpec.into(project.sourceSets.test.output.resourcesDir)
+                    }
+                    copyRestSpec.from(resourceDir).include('rest-api-spec/api/**')
+                }
+            } else {
+                pluginZip = plugin.getValue()
             }
-            pluginFiles.add(plugin)
+            pluginFiles.add(pluginZip)
         }
 
-        return project.tasks.create(name: name, type: Copy, dependsOn: setup) {
+        copyPlugins.into(node.pluginsTmpDir)
-            into node.pluginsTmpDir
+        copyPlugins.from(pluginFiles)
-            from(pluginFiles)
+        return copyPlugins
-        }
     }
 
     static Task configureInstallPluginTask(String name, Project project, Task setup, NodeInfo node, Object plugin) {
@@ -449,6 +468,12 @@ class ClusterFormationTasks {
         }
     }
 
+    static String pluginTaskName(String action, String name, String suffix) {
+        // replace every dash followed by a character with just the uppercase character
+        String camelName = name.replaceAll(/-(\w)/) { _, c -> c.toUpperCase(Locale.ROOT) }
+        return action + camelName[0].toUpperCase(Locale.ROOT) + camelName.substring(1) + suffix
+    }
+
     /** Runs an ant command, sending output to the given out and error streams */
     static Object runAntCommand(Project project, Closure command, PrintStream outputStream, PrintStream errorStream) {
         DefaultLogger listener = new DefaultLogger(