Add Vagrant Gradle plugin (elastic/elasticsearch#3993)

This commit adds a new Gradle sub project that makes use of the VagrantTestPlugin in order to test the installation of X-Pack.

Original commit: elastic/x-pack-elasticsearch@e09db6602c

qa/vagrant/build.gradle

@@ -0,0 +1,12 @@
+apply plugin: 'elasticsearch.vagrant'
+
+esvagrant {
+    inheritTestUtils true
+}
+
+dependencies {
+    bats project(path: ':x-plugins:elasticsearch', configuration: 'zip')
+
+    // Inherit Bats test utils from :qa:vagrant project
+    bats project(path: ':qa:vagrant', configuration: 'bats')
+}

qa/vagrant/src/test/resources/packaging/tests/10_basic.bats

@@ -0,0 +1,52 @@
+#!/usr/bin/env bats
+
+# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+# or more contributor license agreements. Licensed under the Elastic License;
+# you may not use this file except in compliance with the Elastic License.
+
+# This file is used to test the X-Pack package.
+
+# WARNING: This testing file must be executed as root and can
+# dramatically change your system. It removes the 'elasticsearch'
+# user/group and also many directories. Do not execute this file
+# unless you know exactly what you are doing.
+
+load $BATS_UTILS/utils.bash
+load $BATS_UTILS/tar.bash
+load $BATS_UTILS/plugins.bash
+
+setup() {
+    skip_not_tar_gz
+    export ESHOME=/tmp/elasticsearch
+    export_elasticsearch_paths
+    export ESPLUGIN_COMMAND_USER=elasticsearch
+}
+
+@test "[X-PACK] install x-pack" {
+    # Cleans everything for the 1st execution
+    clean_before_test
+
+    # Install the archive
+    install_archive
+
+    count=$(find . -type f -name 'x-pack*.zip' | wc -l)
+    [ "$count" -eq 1 ]
+
+    install_and_check_plugin x pack x-pack-*.jar
+}
+
+@test "[X-PACK] verify x-pack installation" {
+    assert_file "$ESHOME/bin/x-pack" d elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/certgen" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/croneval" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/extension" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/migrate" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/syskeygen" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/x-pack/users" f elasticsearch elasticsearch 755
+    assert_file "$ESCONFIG/x-pack" d elasticsearch elasticsearch 750
+    assert_file "$ESCONFIG/x-pack/users" f elasticsearch elasticsearch 660
+    assert_file "$ESCONFIG/x-pack/users_roles" f elasticsearch elasticsearch 660
+    assert_file "$ESCONFIG/x-pack/roles.yml" f elasticsearch elasticsearch 660
+    assert_file "$ESCONFIG/x-pack/role_mapping.yml" f elasticsearch elasticsearch 660
+    assert_file "$ESCONFIG/x-pack/log4j2.properties" f elasticsearch elasticsearch 660
+}