Spark 3883: SSL support for HttpServer and Akka

SPARK-3883: SSL support for Akka connections and Jetty based file servers.

This story introduced the following changes:
- Introduced SSLOptions object which holds the SSL configuration and can build the appropriate configuration for Akka or Jetty. SSLOptions can be created by parsing SparkConf entries at a specified namespace.
- SSLOptions is created and kept by SecurityManager
- All Akka actor address creation snippets based on interpolated strings were replaced by a dedicated methods from AkkaUtils. Those methods select the proper Akka protocol - whether akka.tcp or akka.ssl.tcp
- Added tests cases for AkkaUtils, FileServer, SSLOptions and SecurityManager
- Added a way to use node local SSL configuration by executors and driver in standalone mode. It can be done by specifying spark.ssl.useNodeLocalConf in SparkConf.
- Made CoarseGrainedExecutorBackend not overwrite the settings which are executor startup configuration - they are passed anyway from Worker

Refer to https://github.com/apache/spark/pull/3571 for discussion and details

Author: Jacek Lewandowski <lewandowski.jacek@gmail.com>
Author: Jacek Lewandowski <jacek.lewandowski@datastax.com>

Closes #3571 from jacek-lewandowski/SPARK-3883-master and squashes the following commits:

9ef4ed1 [Jacek Lewandowski] Merge pull request #2 from jacek-lewandowski/SPARK-3883-docs2
fb31b49 [Jacek Lewandowski] SPARK-3883: Added SSL setup documentation
2532668 [Jacek Lewandowski] SPARK-3883: Refactored AkkaUtils.protocol method to not use Try
90a8762 [Jacek Lewandowski] SPARK-3883: Refactored methods to resolve Akka address and made it possible to easily configure multiple communication layers for SSL
72b2541 [Jacek Lewandowski] SPARK-3883: A reference to the fallback SSLOptions can be provided when constructing SSLOptions
93050f4 [Jacek Lewandowski] SPARK-3883: SSL support for HttpServer and Akka

1 files changed, 6 insertions, 2 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceiverSupervisorImpl.scala b/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceiverSupervisorImpl.scala
index 716cf2c7f3..7d29ed88cf 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceiverSupervisorImpl.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceiverSupervisorImpl.scala
@@ -67,8 +67,12 @@ private[streaming] class ReceiverSupervisorImpl(
   private val trackerActor = {
     val ip = env.conf.get("spark.driver.host", "localhost")
     val port = env.conf.getInt("spark.driver.port", 7077)
-    val url = "akka.tcp://%s@%s:%s/user/ReceiverTracker".format(
-      SparkEnv.driverActorSystemName, ip, port)
+    val url = AkkaUtils.address(
+      AkkaUtils.protocol(env.actorSystem),
+      SparkEnv.driverActorSystemName,
+      ip,
+      port,
+      "ReceiverTracker")
     env.actorSystem.actorSelection(url)
   }