Enabling testing against an external cluster

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

@@ -70,31 +70,44 @@ public class RestIntegTestTask extends DefaultTask {
         runner.parallelism = '1'
         runner.include('**/*IT.class')
         runner.systemProperty('tests.rest.load_packaged', 'false')
-        // we pass all nodes to the rest cluster to allow the clients to round-robin between them
-        // this is more realistic than just talking to a single node
-        runner.systemProperty('tests.rest.cluster', "${-> nodes.collect{it.httpUri()}.join(",")}")
-        runner.systemProperty('tests.config.dir', "${-> nodes[0].pathConf}")
-        // TODO: our "client" qa tests currently use the rest-test plugin. instead they should have their own plugin
-        // that sets up the test cluster and passes this transport uri instead of http uri. Until then, we pass
-        // both as separate sysprops
-        runner.systemProperty('tests.cluster', "${-> nodes[0].transportUri()}")
-
-        // dump errors and warnings from cluster log on failure
-        TaskExecutionAdapter logDumpListener = new TaskExecutionAdapter() {
-            @Override
-            void afterExecute(Task task, TaskState state) {
-                if (state.failure != null) {
-                    for (NodeInfo nodeInfo : nodes) {
-                        printLogExcerpt(nodeInfo)
+
+        if (System.getProperty("tests.rest.cluster") == null) {
+            if (System.getProperty("tests.cluster") != null) {
+                throw new IllegalArgumentException("tests.rest.cluster and tests.cluster must both be null or non-null")
+            }
+            // we pass all nodes to the rest cluster to allow the clients to round-robin between them
+            // this is more realistic than just talking to a single node
+            runner.systemProperty('tests.rest.cluster', "${-> nodes.collect{it.httpUri()}.join(",")}")
+            runner.systemProperty('tests.config.dir', "${-> nodes[0].pathConf}")
+            // TODO: our "client" qa tests currently use the rest-test plugin. instead they should have their own plugin
+            // that sets up the test cluster and passes this transport uri instead of http uri. Until then, we pass
+            // both as separate sysprops
+            runner.systemProperty('tests.cluster', "${-> nodes[0].transportUri()}")
+
+            // dump errors and warnings from cluster log on failure
+            TaskExecutionAdapter logDumpListener = new TaskExecutionAdapter() {
+                @Override
+                void afterExecute(Task task, TaskState state) {
+                    if (state.failure != null) {
+                        for (NodeInfo nodeInfo : nodes) {
+                            printLogExcerpt(nodeInfo)
+                        }
                     }
                 }
             }
-        }
-        runner.doFirst {
-            project.gradle.addListener(logDumpListener)
-        }
-        runner.doLast {
-            project.gradle.removeListener(logDumpListener)
+            runner.doFirst {
+                project.gradle.addListener(logDumpListener)
+            }
+            runner.doLast {
+                project.gradle.removeListener(logDumpListener)
+            }
+        } else {
+            if (System.getProperty("tests.cluster") == null) {
+                throw new IllegalArgumentException("tests.rest.cluster and tests.cluster must both be null or non-null")
+            }
+            // an external cluster was specified and all responsibility for cluster configuration is taken by the user
+            runner.systemProperty('tests.rest.cluster', System.getProperty("tests.rest.cluster"))
+            runner.systemProperty('test.cluster', System.getProperty("tests.cluster"))
         }
 
         // copy the rest spec/tests into the test resources
@@ -109,7 +122,10 @@ public class RestIntegTestTask extends DefaultTask {
                 clusterInit.enabled = false
                 return // no need to add cluster formation tasks if the task won't run!
             }
-            nodes = ClusterFormationTasks.setup(project, "${name}Cluster", runner, clusterConfig)
+            // only create the cluster if needed as otherwise an external cluster to use was specified
+            if (System.getProperty("tests.rest.cluster") == null) {
+                nodes = ClusterFormationTasks.setup(project, "${name}Cluster", runner, clusterConfig)
+            }
             super.dependsOn(runner.finalizedBy)
         }
     }