[SPARK-8015] [FLUME] Remove Guava dependency from flume-sink.

The minimal change would be to disable shading of Guava in the module,
and rely on the transitive dependency from other libraries instead. But
since Guava's use is so localized, I think it's better to just not use
it instead, so I replaced that code and removed all traces of Guava from
the module's build.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #6555 from vanzin/SPARK-8015 and squashes the following commits:

c0ceea8 [Marcelo Vanzin] Add comments about dependency management.
c38228d [Marcelo Vanzin] Add guava dep in test scope.
b7a0349 [Marcelo Vanzin] Add libthrift exclusion.
6e0942d [Marcelo Vanzin] Add comment in pom.
2d79260 [Marcelo Vanzin] [SPARK-8015] [flume] Remove Guava dependency from flume-sink.

1 files changed, 39 insertions, 0 deletions

diff --git a/external/flume-sink/pom.xml b/external/flume-sink/pom.xml
index 1f3e619d97..71f2b6fe18 100644
--- a/external/flume-sink/pom.xml
+++ b/external/flume-sink/pom.xml
@@ -42,16 +42,47 @@
     <dependency>
       <groupId>org.apache.flume</groupId>
       <artifactId>flume-ng-sdk</artifactId>
+      <exclusions>
+        <!-- Guava is excluded to avoid its use in this module. -->
+        <exclusion>
+          <groupId>com.google.guava</groupId>
+          <artifactId>guava</artifactId>
+        </exclusion>
+        <!--
+          Exclude libthrift since the flume poms seem to confuse sbt, which fails to find the
+          dependency.
+        -->
+        <exclusion>
+          <groupId>org.apache.thrift</groupId>
+          <artifactId>libthrift</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
     <dependency>
       <groupId>org.apache.flume</groupId>
       <artifactId>flume-ng-core</artifactId>
+      <exclusions>
+        <exclusion>
+          <groupId>com.google.guava</groupId>
+          <artifactId>guava</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>org.apache.thrift</groupId>
+          <artifactId>libthrift</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
     <dependency>
       <groupId>org.scala-lang</groupId>
       <artifactId>scala-library</artifactId>
     </dependency>
     <dependency>
+      <!-- Add Guava in test scope since flume actually needs it. -->
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
       <!--
         Netty explicitly added in test as it has been excluded from
         Flume dependency (to avoid runtime problems when running with
@@ -85,6 +116,14 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-shade-plugin</artifactId>
+        <configuration>
+          <!-- Disable all relocations defined in the parent pom. -->
+          <relocations combine.self="override" />
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 </project>