From 6918f0bfa4cc44517a48c20d2b5cbd127542a6f9 Mon Sep 17 00:00:00 2001
From: Bryan Cutler <cutlerb@gmail.com>
Date: Fri, 29 Jan 2016 14:40:21 -0800
Subject: [PATCH] Added UIRoot redirection from Master to Application

---
 .../spark/deploy/master/ui/MasterWebUI.scala  | 67 +++++++++++++++++++
 .../api/v1/ApplicationListResource.scala      | 23 +++++++
 2 files changed, 90 insertions(+)

diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
index 5feccf09757ee..ae9cdcaad5454 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterWebUI.scala
@@ -17,8 +17,15 @@
 
 package org.apache.spark.deploy.master.ui
 
+import java.net.URL
+import java.util.regex.Pattern
+import javax.servlet.http.{HttpServlet, HttpServletRequest, HttpServletResponse}
+
+import org.eclipse.jetty.servlet.ServletContextHandler
+
 import org.apache.spark.Logging
 import org.apache.spark.deploy.master.Master
+import org.apache.spark.status.api.v1.{ApplicationsListResource, ApplicationInfo}
 import org.apache.spark.ui.{SparkUI, WebUI}
 import org.apache.spark.ui.JettyUtils._
 
@@ -50,6 +57,66 @@ class MasterWebUI(
       "/app/kill", "/", masterPage.handleAppKillRequest, httpMethods = Set("POST")))
     attachHandler(createRedirectHandler(
       "/driver/kill", "/", masterPage.handleDriverKillRequest, httpMethods = Set("POST")))
+    attachHandler(createApiRootHandler())
+  }
+
+  def createApiRootHandler(): ServletContextHandler = {
+
+    val servlet = new HttpServlet {
+      private lazy val appIdPattern = Pattern.compile("\\/api\\/v\\d+\\/applications\\/([^\\/]+).*")
+
+      override def doGet(request: HttpServletRequest, response: HttpServletResponse): Unit = {
+        doRequest(request, response)
+      }
+      override def doPost(request: HttpServletRequest, response: HttpServletResponse): Unit = {
+        doRequest(request, response)
+      }
+      private def doRequest(request: HttpServletRequest, response: HttpServletResponse): Unit = {
+        val requestURI = request.getRequestURI
+
+        // requesting an application info list
+        if (requestURI == "applications") {
+          // TODO - Should send ApplicationList response ???
+        } else {
+          // forward request to app if it is active, otherwise send error
+          getAppId(request) match {
+            case Some(appId) =>
+              val state = masterPage.getMasterState
+              state.activeApps.find(appInfo => appInfo.id == appId) match {
+                case Some(appInfo) =>
+                  val prefixedDestPath = appInfo.desc.appUiUrl + requestURI
+                  val newUrl = new URL(new URL(request.getRequestURL.toString), prefixedDestPath).toString
+                  response.sendRedirect(newUrl)
+                  request.getPathInfo
+                case None =>
+                  response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE)
+              }
+            case None =>
+              response.sendError(HttpServletResponse.SC_BAD_REQUEST)
+          }
+        }
+      }
+
+      private def getAppId(request: HttpServletRequest): Option[String] = {
+        val m = appIdPattern.matcher(request.getRequestURI)
+        if (m.matches) Some(m.group(1)) else None
+      }
+
+      // SPARK-5983 ensure TRACE is not supported
+      protected override def doTrace(req: HttpServletRequest, res: HttpServletResponse): Unit = {
+        res.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED)
+      }
+    }
+
+    createServletHandler("/api", servlet, "")
+  }
+
+  def getApplicationInfoList: Iterator[ApplicationInfo] = {
+    val state = masterPage.getMasterState
+    val activeApps = state.activeApps.sortBy(_.startTime).reverse
+    val completedApps = state.completedApps.sortBy(_.endTime).reverse
+    activeApps.iterator.map { ApplicationsListResource.convertApplicationInfo(_, false) } ++
+      completedApps.iterator.map { ApplicationsListResource.convertApplicationInfo(_, true) }
   }
 }
 
diff --git a/core/src/main/scala/org/apache/spark/status/api/v1/ApplicationListResource.scala b/core/src/main/scala/org/apache/spark/status/api/v1/ApplicationListResource.scala
index f7e1a58079ff3..0fc0fb59d861f 100644
--- a/core/src/main/scala/org/apache/spark/status/api/v1/ApplicationListResource.scala
+++ b/core/src/main/scala/org/apache/spark/status/api/v1/ApplicationListResource.scala
@@ -21,6 +21,7 @@ import javax.ws.rs.{DefaultValue, GET, Produces, QueryParam}
 import javax.ws.rs.core.MediaType
 
 import org.apache.spark.deploy.history.ApplicationHistoryInfo
+import org.apache.spark.deploy.master.{ApplicationInfo => InternalApplicationInfo}
 
 @Produces(Array(MediaType.APPLICATION_JSON))
 private[v1] class ApplicationListResource(uiRoot: UIRoot) {
@@ -76,4 +77,26 @@ private[spark] object ApplicationsListResource {
       }
     )
   }
+
+  def convertApplicationInfo(
+      internal: InternalApplicationInfo,
+      completed: Boolean): ApplicationInfo = {
+    // standalone application info always has just one attempt
+    new ApplicationInfo(
+      id = internal.id,
+      name = internal.desc.name,
+      coresGranted = Some(internal.coresGranted),
+      maxCores = internal.desc.maxCores,
+      coresPerExecutor = internal.desc.coresPerExecutor,
+      memoryPerExecutorMB = Some(internal.desc.memoryPerExecutorMB),
+      attempts = Seq(new ApplicationAttemptInfo(
+        attemptId = None,
+        startTime = new Date(internal.startTime),
+        endTime = new Date(internal.endTime),
+        sparkUser = internal.desc.user,
+        completed = completed
+      ))
+    )
+  }
+
 }