[SW-690] Log Sparkling Water version during startup of Sparkling Water

.gitignore

@@ -1,6 +1,7 @@
 # generated resource file containing Spark version for which Sparkling Water was built
 /core/src/main/resources/spark.version
 /core/src/main/resources/h2o.version
+/core/src/main/resources/sw.version
 *.class
 
 # Mobile Tools for Java (J2ME)

bin/sparkling-env.sh

@@ -106,6 +106,7 @@ cat <<EOF
   Spark master (MASTER)     : $MASTER
   Spark home   (SPARK_HOME) : $SPARK_HOME
   H2O build version         : ${H2O_VERSION}.${H2O_BUILD} ($H2O_NAME)
+  Sparkling Water version   : ${VERSION}
   Spark build version       : ${SPARK_VERSION}
   Scala version             : ${SCALA_VERSION}
 ----

core/build.gradle

@@ -97,9 +97,18 @@ task createH2OVersionFile {
     }
 }
 
+task createSparklingWaterVersionFile {
+    doLast {
+        File version_file = file("src/main/resources/sw.version")
+        // Create parent directories if not created yet
+        version_file.getParentFile().mkdirs()
+        version_file.write(version)
+    }
+}
 test.dependsOn testJar
 processResources.dependsOn createSparkVersionFile
 processResources.dependsOn createH2OVersionFile
+processResources.dependsOn createSparklingWaterVersionFile
 
 integTest {
     // Pass references to libraries to test launcher

core/src/main/scala/org/apache/spark/h2o/BuildInfo.scala

@@ -65,6 +65,22 @@ object BuildInfo {
         case x: Exception => throw new WrongSparkVersion(s"Failed to read H2O version from  $VERSION_FILE: ${x.getMessage}")
       }
     }
+  }
+
+  /**
+    * Returns Sparkling Water version
+    */
+  def SWVersion = {
+    val VERSION_FILE: String = "/sw.version"
+    val stream = getClass.getResourceAsStream(VERSION_FILE)
 
+    stream match {
+      case null => throw new RuntimeException(s"Unknown Sparkling Water version: $VERSION_FILE missing")
+      case s => try {
+        scala.io.Source.fromInputStream(s).mkString
+      } catch {
+        case x: Exception => throw new WrongSparkVersion(s"Failed to read Sparkling Water version from  $VERSION_FILE: ${x.getMessage}")
+      }
+    }
   }
 }

core/src/main/scala/org/apache/spark/h2o/H2OContext.scala

@@ -20,6 +20,7 @@ package org.apache.spark.h2o
 import java.util.concurrent.atomic.AtomicReference
 
 import org.apache.spark._
+import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.h2o.backends.SparklingBackend
 import org.apache.spark.h2o.backends.external.ExternalH2OBackend
 import org.apache.spark.h2o.backends.internal.InternalH2OBackend
@@ -96,8 +97,11 @@ class H2OContext private(val sparkSession: SparkSession, conf: H2OConf) extends
   def init(): H2OContext = {
 
     // Use H2O's logging as H2O info log level is default
-    Log.info("The following Spark configuration is used: " + _conf.getAll.mkString(", "))
-
+    Log.info("Sparkling Water version: " + BuildInfo.SWVersion)
+    Log.info("Spark version: " + sparkContext.version)
+    Log.info("Integrated H2O version: " + BuildInfo.H2OVersion)
+    Log.info("The following Spark configuration is used: \n    " + _conf.getAll.mkString("\n    "))
+    Log.info("")
     if (!isRunningOnCorrectSpark(sparkContext)) {
       throw new WrongSparkVersion(s"You are trying to use Sparkling Water built for Spark ${BuildInfo.buildSparkMajorVersion}," +
         s" but your $$SPARK_HOME(=${sparkContext.getSparkHome().getOrElse("SPARK_HOME is not defined!")}) property" +