code review fixes

Get windows box IDs from environment variables in static context instead
of on plugin application

Clarify how the plugin determines the environment variables to run
vagrant with

Author: andyb-elastic

buildSrc/src/main/groovy/org/elasticsearch/gradle/vagrant/VagrantTestPlugin.groovy

@@ -32,7 +32,7 @@ class VagrantTestPlugin implements Plugin<Project> {
     ]
 
     /** Windows boxes that are available - map of box names to image IDs **/
-    static Map<String, String> WINDOWS_BOXES = [:]
+    static List<String> WINDOWS_BOXES = []
 
     /** All available boxes **/
     static List<String> BOXES
@@ -44,7 +44,7 @@ class VagrantTestPlugin implements Plugin<Project> {
     ]
 
     /** extra env vars to pass to vagrant for box configuration **/
-    static Map<String, String> VAGRANT_ENV_VARS = [:]
+    static Map<String, String> VAGRANT_BOX_ENV_VARS = [:]
 
     /** All distributions to bring into test VM, whether or not they are used **/
     static List<String> DISTRIBUTIONS = [
@@ -65,11 +65,13 @@ class VagrantTestPlugin implements Plugin<Project> {
     private static final String BATS_TEST_COMMAND ="cd \$PACKAGING_ARCHIVES && sudo bats --tap \$BATS_TESTS/*.$BATS"
     private static final String PLATFORM_TEST_COMMAND ="rm -rf ~/elasticsearch && rsync -r /elasticsearch/ ~/elasticsearch && cd ~/elasticsearch && ./gradlew test integTest"
 
+    static {
+        collectAvailableBoxes()
+    }
+
     @Override
     void apply(Project project) {
 
-        collectAvailableBoxes(project)
-
         // Creates the Vagrant extension for the project
         project.extensions.create('esvagrant', VagrantPropertiesExtension, listSelectedBoxes(project))
 
@@ -100,20 +102,20 @@ class VagrantTestPlugin implements Plugin<Project> {
     /**
      * Enumerate all the boxes that we know about and could possibly choose to test
      */
-    private static void collectAvailableBoxes(Project project) {
+    private static void collectAvailableBoxes() {
         String windows_2012r2_box = System.getenv('VAGRANT_WINDOWS_2012R2_BOX')
         if (windows_2012r2_box != null && windows_2012r2_box.isEmpty() == false) {
-            WINDOWS_BOXES['windows-2012r2'] = windows_2012r2_box
-            VAGRANT_ENV_VARS['VAGRANT_WINDOWS_2012R2_BOX'] = windows_2012r2_box
+            WINDOWS_BOXES.add('windows-2012r2')
+            VAGRANT_BOX_ENV_VARS['VAGRANT_WINDOWS_2012R2_BOX'] = windows_2012r2_box
         }
 
         String windows_2016_box = System.getenv('VAGRANT_WINDOWS_2016_BOX')
         if (windows_2016_box != null && windows_2016_box.isEmpty() == false) {
-            WINDOWS_BOXES['windows-2016'] = windows_2016_box
-            VAGRANT_ENV_VARS['VAGRANT_WINDOWS_2016_BOX'] = windows_2016_box
+            WINDOWS_BOXES.add('windows-2016')
+            VAGRANT_BOX_ENV_VARS['VAGRANT_WINDOWS_2016_BOX'] = windows_2016_box
         }
 
-        BOXES = LINUX_BOXES + WINDOWS_BOXES.keySet()
+        BOXES = LINUX_BOXES + WINDOWS_BOXES
     }
 
     /**
@@ -127,7 +129,7 @@ class VagrantTestPlugin implements Plugin<Project> {
             case 'linux-all':
                 return LINUX_BOXES
             case 'windows-all':
-                return WINDOWS_BOXES.keySet().toList()
+                return WINDOWS_BOXES
             case 'all':
                 return BOXES
             default:
@@ -341,20 +343,6 @@ class VagrantTestPlugin implements Plugin<Project> {
         createPlatformTestTask(project)
     }
 
-    private static Map<String, String> vagrantEnvVars(Project project) {
-        /*
-         * We always use the main project.rootDir as Vagrant's current working directory (VAGRANT_CWD)
-         * so that boxes are not duplicated for every Gradle project that use this VagrantTestPlugin.
-         */
-        def vagrantEnvVars = [
-                'VAGRANT_CWD'        : "${project.rootDir.absolutePath}",
-                'VAGRANT_VAGRANTFILE': 'Vagrantfile',
-                'VAGRANT_PROJECT_DIR': "${project.projectDir.absolutePath}"
-        ]
-        vagrantEnvVars.putAll(VAGRANT_ENV_VARS)
-        return vagrantEnvVars
-    }
-
     private static void createVagrantBoxesTasks(Project project) {
         assert project.extensions.esvagrant.boxes != null
 
@@ -379,7 +367,15 @@ class VagrantTestPlugin implements Plugin<Project> {
         assert project.tasks.platformTest != null
         Task platformTest = project.tasks.platformTest
 
-        def vagrantEnvVars = vagrantEnvVars(project)
+        /*
+         * We always use the main project.rootDir as Vagrant's current working directory (VAGRANT_CWD)
+         * so that boxes are not duplicated for every Gradle project that use this VagrantTestPlugin.
+         */
+        def vagrantEnvVars = [
+                'VAGRANT_CWD'           : "${project.rootDir.absolutePath}",
+                'VAGRANT_VAGRANTFILE'   : 'Vagrantfile',
+                'VAGRANT_PROJECT_DIR'   : "${project.projectDir.absolutePath}"
+        ] + VAGRANT_BOX_ENV_VARS
 
         // Each box gets it own set of tasks
         for (String box : BOXES) {