SPARK-1384 - fix spark-shell on yarn access to secure HDFS

Author: tgravescs

repl/src/main/scala/org/apache/spark/repl/SparkILoop.scala

@@ -880,6 +880,7 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
 
   def process(settings: Settings): Boolean = savingContextLoader {
     this.settings = settings
+    if (getMaster() == "yarn-client") System.setProperty("SPARK_YARN_MODE", "true")
     createInterpreter()
 
     // sets in to some kind of reader depending on environmental cues
@@ -937,16 +938,9 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
 
   def createSparkContext(): SparkContext = {
     val execUri = System.getenv("SPARK_EXECUTOR_URI")
-    val master = this.master match {
-      case Some(m) => m
-      case None => {
-        val prop = System.getenv("MASTER")
-        if (prop != null) prop else "local"
-      }
-    }
     val jars = SparkILoop.getAddedJars.map(new java.io.File(_).getAbsolutePath)
     val conf = new SparkConf()
-      .setMaster(master)
+      .setMaster(getMaster())
       .setAppName("Spark shell")
       .setJars(jars)
       .set("spark.repl.class.uri", intp.classServer.uri)
@@ -961,6 +955,17 @@ class SparkILoop(in0: Option[BufferedReader], protected val out: JPrintWriter,
     sparkContext
   }
 
+  private def getMaster(): String = {
+     val master = this.master match {
+       case Some(m) => m
+       case None => {
+         val prop = System.getenv("MASTER")
+         if (prop != null) prop else "local"
+       }
+     }
+     master
+   }
+
   /** process command-line arguments and do as they request */
   def process(args: Array[String]): Boolean = {
     val command = new SparkCommandLine(args.toList, msg => echo(msg))