Respect SPARK_*_MEMORY for cluster mode

Author: andrewor14

core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala

@@ -75,6 +75,10 @@ private[spark] class SparkSubmitArguments(args: Seq[String]) {
     defaultProperties
   }
 
+  // Respect SPARK_*_MEMORY for cluster mode
+  driverMemory = sys.env.get("SPARK_DRIVER_MEMORY").orNull
+  executorMemory = sys.env.get("SPARK_EXECUTOR_MEMORY").orNull
+
   parseOpts(args.toList)
   mergeSparkProperties()
   checkRequiredArguments()