[SPARK-15887][SQL] Bring back the hive-site.xml support for Spark 2.0

## What changes were proposed in this pull request?

Right now, Spark 2.0 does not load hive-site.xml. Based on users' feedback, it seems make sense to still load this conf file.

This PR adds a `hadoopConf` API in `SharedState`, which is `sparkContext.hadoopConfiguration` by default. When users are under hive context, `SharedState.hadoopConf` will load hive-site.xml and append its configs to `sparkContext.hadoopConfiguration`.

When we need to read hadoop config in spark sql, we should call `SessionState.newHadoopConf`, which contains `sparkContext.hadoopConfiguration`, hive-site.xml and sql configs.

## How was this patch tested?

new test in `HiveDataFrameSuite`

Author: Wenchen Fan <wenchen@databricks.com>

Closes #13611 from cloud-fan/hive-site.

3 files changed, 33 insertions, 3 deletions

diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSharedState.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSharedState.scala
index a0106ee882..78b1ecbbea 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSharedState.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSharedState.scala
@@ -45,12 +45,11 @@ private[hive] class HiveSharedState(override val sparkContext: SparkContext)
    */
   // This needs to be a lazy val at here because TestHiveSharedState is overriding it.
   lazy val metadataHive: HiveClient = {
-    HiveUtils.newClientForMetadata(sparkContext.conf, sparkContext.hadoopConfiguration)
+    HiveUtils.newClientForMetadata(sparkContext.conf, hadoopConf)
   }
 
   /**
    * A catalog that interacts with the Hive metastore.
    */
-  override lazy val externalCatalog =
-    new HiveExternalCatalog(metadataHive, sparkContext.hadoopConfiguration)
+  override lazy val externalCatalog = new HiveExternalCatalog(metadataHive, hadoopConf)
 }
diff --git a/sql/hive/src/test/resources/hive-site.xml b/sql/hive/src/test/resources/hive-site.xml
new file mode 100644
index 0000000000..17297b3e22
--- /dev/null
+++ b/sql/hive/src/test/resources/hive-site.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0"?>
+<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
+<!--
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+-->
+
+<configuration>
+  <property>
+    <name>hive.in.test</name>
+      <value>true</value>
+      <description>Internal marker for test.</description>
+  </property>
+</configuration>
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveDataFrameSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveDataFrameSuite.scala
index 1b31caa76d..23798431e6 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveDataFrameSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveDataFrameSuite.scala
@@ -29,4 +29,9 @@ class HiveDataFrameSuite extends QueryTest with TestHiveSingleton {
     spark.sql("drop table usrdb.test")
     spark.sql("drop schema usrdb")
   }
+
+  test("SPARK-15887: hive-site.xml should be loaded") {
+    val hiveClient = spark.sharedState.asInstanceOf[HiveSharedState].metadataHive
+    assert(hiveClient.getConf("hive.in.test", "") == "true")
+  }
 }