[SPARK-14738][BUILD] Separate docker integration tests from main build

## What changes were proposed in this pull request?

Create a maven profile for executing the docker integration tests using maven
Remove docker integration tests from main sbt build
Update documentation on how to run docker integration tests from sbt

## How was this patch tested?

Manual test of the docker integration tests as in :
mvn -Pdocker-integration-tests -pl :spark-docker-integration-tests_2.11 compile test

## Other comments

Note that the the DB2 Docker Tests are still disabled as there is a kernel version issue on the AMPLab Jenkins slaves and we would need to get them on the right level before enabling those tests. They do run ok locally with the updates from PR #12348

Author: Luciano Resende <lresende@apache.org>

Closes #12508 from lresende/docker.

docs/building-spark.md

@@ -190,6 +190,18 @@ or
 Java 8 tests are automatically enabled when a Java 8 JDK is detected.
 If you have JDK 8 installed but it is not the system default, you can set JAVA_HOME to point to JDK 8 before running the tests.
 
+# Running Docker based Integration Test Suites
+
+Running only docker based integration tests and nothing else.
+
+    mvn install -DskipTests
+    mvn -Pdocker-integration-tests -pl :spark-docker-integration-tests_2.11
+
+or
+
+    sbt docker-integration-tests/test
+
+
 # Packaging without Hadoop Dependencies for YARN
 
 The assembly directory produced by `mvn package` will, by default, include all of Spark's dependencies, including Hadoop and some of its ecosystem projects. On YARN deployments, this causes multiple versions of these to appear on executor classpaths: the version packaged in the Spark assembly and the version on each node, included with `yarn.application.classpath`.  The `hadoop-provided` profile builds the assembly without including Hadoop-ecosystem projects, like ZooKeeper and Hadoop itself.

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/MySQLIntegrationSuite.scala

@@ -21,12 +21,9 @@ import java.math.BigDecimal
 import java.sql.{Connection, Date, Timestamp}
 import java.util.Properties
 
-import org.scalatest.Ignore
-
 import org.apache.spark.tags.DockerTest
 
 @DockerTest
-@Ignore
 class MySQLIntegrationSuite extends DockerJDBCIntegrationSuite {
   override val db = new DatabaseOnDocker {
     override val imageName = "mysql:5.7.9"

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/OracleIntegrationSuite.scala

@@ -20,8 +20,6 @@ package org.apache.spark.sql.jdbc
 import java.sql.Connection
 import java.util.Properties
 
-import org.scalatest.Ignore
-
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.tags.DockerTest
 
@@ -46,12 +44,11 @@ import org.apache.spark.tags.DockerTest
  * repository.
  */
 @DockerTest
-@Ignore
 class OracleIntegrationSuite extends DockerJDBCIntegrationSuite with SharedSQLContext {
   import testImplicits._
 
   override val db = new DatabaseOnDocker {
-    override val imageName = "wnameless/oracle-xe-11g:latest"
+    override val imageName = "wnameless/oracle-xe-11g:14.04.4"
     override val env = Map(
       "ORACLE_ROOT_PASSWORD" -> "oracle"
     )

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/PostgresIntegrationSuite.scala

@@ -20,15 +20,12 @@ package org.apache.spark.sql.jdbc
 import java.sql.Connection
 import java.util.Properties
 
-import org.scalatest.Ignore
-
 import org.apache.spark.sql.Column
 import org.apache.spark.sql.catalyst.expressions.Literal
 import org.apache.spark.sql.types.{ArrayType, DecimalType}
 import org.apache.spark.tags.DockerTest
 
 @DockerTest
-@Ignore
 class PostgresIntegrationSuite extends DockerJDBCIntegrationSuite {
   override val db = new DatabaseOnDocker {
     override val imageName = "postgres:9.4.5"

pom.xml

@@ -101,7 +101,6 @@
     <module>sql/core</module>
     <module>sql/hive</module>
     <module>sql/hivecontext-compatibility</module>
-    <module>external/docker-integration-tests</module>
     <module>assembly</module>
     <module>external/flume</module>
     <module>external/flume-sink</module>
@@ -2469,6 +2468,13 @@
       </build>
     </profile>
 
+    <profile>
+      <id>docker-integration-tests</id>
+      <modules>
+        <module>external/docker-integration-tests</module>
+      </modules>
+    </profile>
+
     <!-- A series of build profiles where customizations for particular Hadoop releases can be made -->
 
     <!-- Hadoop-a.b.c dependencies can be found at

project/SparkBuild.scala

@@ -382,7 +382,8 @@ object SparkBuild extends PomBuild {
 
   enable(Java8TestSettings.settings)(java8Tests)
 
-  enable(DockerIntegrationTests.settings)(dockerIntegrationTests)
+  // SPARK-14738 - Remove docker tests from main Spark build
+  // enable(DockerIntegrationTests.settings)(dockerIntegrationTests)
 
   /**
    * Adds the ability to run the spark shell directly from SBT without building an assembly