[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.

1 files changed, 7 insertions, 1 deletions

diff --git a/pom.xml b/pom.xml
index 852136a998..3e783fa56e 100644
--- a/pom.xml
+++ b/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