Use proper Java version for BWC builds

buildSrc/src/main/groovy/org/elasticsearch/gradle/BuildPlugin.groovy

@@ -97,6 +97,12 @@ class BuildPlugin implements Plugin<Project> {
             String compilerJavaHome = findCompilerJavaHome()
             String runtimeJavaHome = findRuntimeJavaHome(compilerJavaHome)
             File gradleJavaHome = Jvm.current().javaHome
+
+            final Map<Integer, String> javaVersions = [:]
+            for (int version = 7; version <= Integer.parseInt(minimumCompilerVersion.majorVersion); version++) {
+                javaVersions.put(version, findJavaHome(version));
+            }
+
             String javaVendor = System.getProperty('java.vendor')
             String javaVersion = System.getProperty('java.version')
             String gradleJavaVersionDetails = "${javaVendor} ${javaVersion}" +
@@ -158,10 +164,32 @@ class BuildPlugin implements Plugin<Project> {
                 throw new GradleException(message)
             }
 
+            for (final Map.Entry<Integer, String> javaVersionEntry : javaVersions.entrySet()) {
+                final String javaHome = javaVersionEntry.getValue()
+                if (javaHome == null) {
+                    continue
+                }
+                JavaVersion javaVersionEnum = JavaVersion.toVersion(findJavaSpecificationVersion(project, javaHome))
+                final JavaVersion expectedJavaVersionEnum
+                final int version = javaVersionEntry.getKey()
+                if (version < 9) {
+                    expectedJavaVersionEnum = JavaVersion.toVersion("1." + version)
+                } else {
+                    expectedJavaVersionEnum = JavaVersion.toVersion(Integer.toString(version))
+                }
+                if (javaVersionEnum != expectedJavaVersionEnum) {
+                    final String message =
+                            "the environment variable JAVA" + version + "_HOME must be set to a JDK installation directory for Java" +
+                                    " ${expectedJavaVersionEnum} but is [${javaHome}] corresponding to [${javaVersionEnum}]"
+                    throw new GradleException(message)
+                }
+            }
+
             project.rootProject.ext.compilerJavaHome = compilerJavaHome
             project.rootProject.ext.runtimeJavaHome = runtimeJavaHome
             project.rootProject.ext.compilerJavaVersion = compilerJavaVersionEnum
             project.rootProject.ext.runtimeJavaVersion = runtimeJavaVersionEnum
+            project.rootProject.ext.javaVersions = javaVersions
             project.rootProject.ext.buildChecksDone = true
         }
 
@@ -173,6 +201,7 @@ class BuildPlugin implements Plugin<Project> {
         project.ext.runtimeJavaHome = project.rootProject.ext.runtimeJavaHome
         project.ext.compilerJavaVersion = project.rootProject.ext.compilerJavaVersion
         project.ext.runtimeJavaVersion = project.rootProject.ext.runtimeJavaVersion
+        project.ext.javaVersions = project.rootProject.ext.javaVersions
     }
 
     private static String findCompilerJavaHome() {
@@ -188,6 +217,10 @@ class BuildPlugin implements Plugin<Project> {
         return javaHome
     }
 
+    private static String findJavaHome(int version) {
+        return System.getenv('JAVA' + version + '_HOME')
+    }
+
     private static String findRuntimeJavaHome(final String compilerJavaHome) {
         assert compilerJavaHome != null
         return System.getenv('RUNTIME_JAVA_HOME') ?: compilerJavaHome

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

@@ -22,7 +22,9 @@ import com.sun.jna.Native
 import com.sun.jna.WString
 import org.apache.tools.ant.taskdefs.condition.Os
 import org.elasticsearch.gradle.Version
+import org.gradle.api.GradleException
 import org.gradle.api.InvalidUserDataException
+import org.gradle.api.JavaVersion
 import org.gradle.api.Project
 
 import java.nio.file.Files
@@ -162,7 +164,25 @@ class NodeInfo {
             args.add("${esScript}")
         }
 
-        env = ['JAVA_HOME': project.runtimeJavaHome]
+        final String javaHome
+        final Map<Integer, JavaVersion> javaVersions = project.javaVersions
+        if (Version.fromString(nodeVersion).before("6.2.0")) {
+            final String java8Home = javaVersions.get(8)
+            if (java8Home == null) {
+                throw new GradleException("JAVA8_HOME must be set to run BWC tests against [" + nodeVersion + "]")
+            }
+            javaHome = java8Home
+        } else if (Version.fromString(nodeVersion).onOrAfter("6.2.0") && Version.fromString(nodeVersion).before("6.3.0")) {
+            final String java9Home = javaVersions.get(9)
+            if (java9Home == null) {
+                throw new GradleException("JAVA9_HOME must be set to run BWC tests against [" + nodeVersion + "]")
+            }
+            javaHome = java9Home
+        } else {
+            javaHome = project.compilerJavaHome
+        }
+
+        env = ['JAVA_HOME':javaHome]
         args.addAll("-E", "node.portsfile=true")
         String collectedSystemProperties = config.systemProperties.collect { key, value -> "-D${key}=${value}" }.join(" ")
         String esJavaOpts = config.jvmArgs.isEmpty() ? collectedSystemProperties : collectedSystemProperties + " " + config.jvmArgs

distribution/bwc/build.gradle

@@ -144,12 +144,19 @@ subprojects {
   task buildBwcVersion(type: Exec) {
     dependsOn checkoutBwcBranch, writeBuildMetadata
     workingDir = checkoutDir
-    if (project.rootProject.ext.runtimeJavaVersion == JavaVersion.VERSION_1_8 && ["5.6", "6.0", "6.1"].contains(bwcBranch)) {
-      /*
-       * If runtime Java home is set to JDK 8 and we are building branches that are officially built with JDK 8, push this to JAVA_HOME for
-       * these builds.
-       */
-      environment('JAVA_HOME', System.getenv('RUNTIME_JAVA_HOME'))
+    if (["5.6", "6.0", "6.1"].contains(bwcBranch)) {
+      // we are building branches that are officially built with JDK 8, push JAVA8_HOME to JAVA_HOME for these builds
+      if (project.javaVersions.get(8) == null) {
+        throw new GradleException("JAVA8_HOME is required to build BWC versions for BWC branch [" + bwcBranch + "]")
+      }
+      environment('JAVA_HOME', project.javaVersions.get(8))
+    } else if ("6.2".equals(bwcBranch)) {
+      if (project.javaVersions.get(9) == null) {
+        throw new GradleException("JAVA9_HOME is required to build BWC versions for BWC branch [" + bwcBranch + "]")
+      }
+      environment('JAVA_HOME', project.javaVersions.get(9))
+    } else {
+      environment('JAVA_HOME', project.compilerJavaHome)
     }
     if (Os.isFamily(Os.FAMILY_WINDOWS)) {
       executable 'cmd'

qa/reindex-from-old/build.gradle

@@ -51,11 +51,13 @@ dependencies {
   es090 'org.elasticsearch:elasticsearch:0.90.13@zip'
 }
 
-if (project.runtimeJavaVersion >= JavaVersion.VERSION_1_9 || Os.isFamily(Os.FAMILY_WINDOWS)) {
-  /* We can't run the dependencies with Java 9 so for now we'll skip the whole
-   * thing. We can't get the pid files in windows so we skip that as well.... */
+if (Os.isFamily(Os.FAMILY_WINDOWS)) {
+  // we can't get the pid files in windows so we skip that
   integTest.enabled = false
 } else {
+  if (project.javaVersions.get(7) == null) {
+    throw new GradleException("JAVA7_HOME must be set to run reindex-from-old")
+  }
   /* Set up tasks to unzip and run the old versions of ES before running the
    * integration tests. */
   for (String version : ['2', '1', '090']) {
@@ -75,7 +77,7 @@ if (project.runtimeJavaVersion >= JavaVersion.VERSION_1_9 || Os.isFamily(Os.FAMI
       dependsOn unzip
       executable = new File(project.runtimeJavaHome, 'bin/java')
       env 'CLASSPATH', "${ -> project.configurations.oldesFixture.asPath }"
-      env 'JAVA_HOME', project.runtimeJavaHome
+      env 'JAVA_HOME', project.javaVersions.get(7)
       args 'oldes.OldElasticsearch',
            baseDir,
            unzip.temporaryDir,