SPARK-1167: Remove metrics-ganglia from default build due to LGPL issues...

This patch removes Ganglia integration from the default build. It
allows users willing to link against LGPL code to use Ganglia
by adding build flags or linking against a new Spark artifact called
spark-ganglia-lgpl.

This brings Spark in line with the Apache policy on LGPL code
enumerated here:

https://www.apache.org/legal/3party.html#options-optional

Author: Patrick Wendell <pwendell@gmail.com>

Closes #108 from pwendell/ganglia and squashes the following commits:

326712a [Patrick Wendell] Responding to review feedback
5f28ee4 [Patrick Wendell] SPARK-1167: Remove metrics-ganglia from default build due to LGPL issues.

5 files changed, 97 insertions, 3 deletions

diff --git a/dev/audit-release/README.md b/dev/audit-release/README.md
new file mode 100644
index 0000000000..2437a98672
--- /dev/null
+++ b/dev/audit-release/README.md
@@ -0,0 +1,11 @@
+# Test Application Builds
+This directory includes test applications which are built when auditing releases. You can
+run them locally by setting appropriate environment variables.
+
+```
+$ cd sbt_app_core
+$ SCALA_VERSION=2.10.3 \
+  SPARK_VERSION=1.0.0-SNAPSHOT \
+  SPARK_RELEASE_REPOSITORY=file:///home/patrick/.ivy2/local \
+  sbt run
+```
diff --git a/dev/audit-release/sbt_app_core/src/main/scala/SparkApp.scala b/dev/audit-release/sbt_app_core/src/main/scala/SparkApp.scala
index d49de8b73a..53fe43215e 100644
--- a/dev/audit-release/sbt_app_core/src/main/scala/SparkApp.scala
+++ b/dev/audit-release/sbt_app_core/src/main/scala/SparkApp.scala
@@ -17,6 +17,8 @@
 
 package main.scala
 
+import scala.util.Try
+
 import org.apache.spark.SparkContext
 import org.apache.spark.SparkContext._
 
@@ -31,6 +33,17 @@ object SimpleApp {
       println("Failed to parse log files with Spark")
       System.exit(-1)
     }
-    println("Test succeeded")
+
+    // Regression test for SPARK-1167: Remove metrics-ganglia from default build due to LGPL issue
+    val foundConsole = Try(Class.forName("org.apache.spark.metrics.sink.ConsoleSink")).isSuccess
+    val foundGanglia = Try(Class.forName("org.apache.spark.metrics.sink.GangliaSink")).isSuccess
+    if (!foundConsole) {
+      println("Console sink not loaded via spark-core")
+      System.exit(-1)
+    }
+    if (foundGanglia) {
+      println("Ganglia sink was loaded via spark-core")
+      System.exit(-1)
+    }
   }
 }
diff --git a/dev/audit-release/sbt_app_ganglia/build.sbt b/dev/audit-release/sbt_app_ganglia/build.sbt
new file mode 100644
index 0000000000..55db675c72
--- /dev/null
+++ b/dev/audit-release/sbt_app_ganglia/build.sbt
@@ -0,0 +1,31 @@
+//
+// 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.
+//
+
+name := "Ganglia Test"
+
+version := "1.0"
+
+scalaVersion := System.getenv.get("SCALA_VERSION")
+
+libraryDependencies += "org.apache.spark" %% "spark-core" % System.getenv.get("SPARK_VERSION")
+
+libraryDependencies += "org.apache.spark" %% "spark-ganglia-lgpl" % System.getenv.get("SPARK_VERSION")
+
+resolvers ++= Seq(
+  "Spark Release Repository" at System.getenv.get("SPARK_RELEASE_REPOSITORY"),
+  "Akka Repository" at "http://repo.akka.io/releases/",
+  "Spray Repository" at "http://repo.spray.cc/")
diff --git a/dev/audit-release/sbt_app_ganglia/src/main/scala/SparkApp.scala b/dev/audit-release/sbt_app_ganglia/src/main/scala/SparkApp.scala
new file mode 100644
index 0000000000..0be8e64fbf
--- /dev/null
+++ b/dev/audit-release/sbt_app_ganglia/src/main/scala/SparkApp.scala
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+package main.scala
+
+import scala.util.Try
+
+import org.apache.spark.SparkContext
+import org.apache.spark.SparkContext._
+
+object SimpleApp {
+  def main(args: Array[String]) {
+    // Regression test for SPARK-1167: Remove metrics-ganglia from default build due to LGPL issue
+    val foundConsole = Try(Class.forName("org.apache.spark.metrics.sink.ConsoleSink")).isSuccess
+    val foundGanglia = Try(Class.forName("org.apache.spark.metrics.sink.GangliaSink")).isSuccess
+    if (!foundConsole) {
+      println("Console sink not loaded via spark-core")
+      System.exit(-1)
+    }
+    if (!foundGanglia) {
+      println("Ganglia sink not loaded via spark-ganglia-lgpl")
+      System.exit(-1)
+    }
+  }
+}
diff --git a/dev/create-release/create-release.sh b/dev/create-release/create-release.sh
index b9088eac37..995106f111 100755
--- a/dev/create-release/create-release.sh
+++ b/dev/create-release/create-release.sh
@@ -49,14 +49,14 @@ mvn -DskipTests \
   -Darguments="-DskipTests=true -Dhadoop.version=2.2.0 -Dyarn.version=2.2.0 -Dgpg.passphrase=${GPG_PASSPHRASE}" \
   -Dusername=$GIT_USERNAME -Dpassword=$GIT_PASSWORD \
   -Dhadoop.version=2.2.0 -Dyarn.version=2.2.0 \
-  -Pyarn \
+  -Pyarn -Pspark-ganglia-lgpl \
   -Dtag=$GIT_TAG -DautoVersionSubmodules=true \
   --batch-mode release:prepare
 
 mvn -DskipTests \
   -Darguments="-DskipTests=true -Dhadoop.version=2.2.0 -Dyarn.version=2.2.0 -Dgpg.passphrase=${GPG_PASSPHRASE}" \
   -Dhadoop.version=2.2.0 -Dyarn.version=2.2.0 \
-  -Pyarn \
+  -Pyarn -Pspark-ganglia-lgpl\
   release:perform
 
 rm -rf spark