Add JSON path to master index page

core/src/main/scala/spark/deploy/master/ui/IndexPage.scala

@@ -25,15 +25,22 @@ import javax.servlet.http.HttpServletRequest
 
 import scala.xml.Node
 
-import spark.deploy.{RequestMasterState, DeployWebUI, MasterState}
+import spark.deploy.{JsonProtocol, RequestMasterState, DeployWebUI, MasterState}
 import spark.Utils
 import spark.ui.UIUtils
 import spark.deploy.master.{ApplicationInfo, WorkerInfo}
+import net.liftweb.json.JsonAST.JValue
 
 private[spark] class IndexPage(parent: MasterWebUI) {
   val master = parent.master
   implicit val timeout = parent.timeout
 
+  def renderJson(request: HttpServletRequest): JValue = {
+    val stateFuture = (master ? RequestMasterState)(timeout).mapTo[MasterState]
+    val state = Await.result(stateFuture, 30 seconds)
+    JsonProtocol.writeMasterState(state)
+  }
+
   /** Index view listing applications and executors */
   def render(request: HttpServletRequest): Seq[Node] = {
     val stateFuture = (master ? RequestMasterState)(timeout).mapTo[MasterState]

core/src/main/scala/spark/deploy/master/ui/MasterWebUI.scala

@@ -61,6 +61,7 @@ class MasterWebUI(val master: ActorRef, requestedPort: Int) extends Logging {
     ("/static", createStaticHandler(MasterWebUI.STATIC_RESOURCE_DIR)),
     ("/app/json", (request: HttpServletRequest) => applicationPage.renderJson(request)),
     ("/app", (request: HttpServletRequest) => applicationPage.render(request)),
+    ("/json", (request: HttpServletRequest) => indexPage.renderJson(request)),
     ("*", (request: HttpServletRequest) => indexPage.render(request))
   )