[SPARK-6211][Streaming] Add Python Kafka API unit test

Refactor the Kafka unit test and add Python API support. CC tdas davies please help to review, thanks a lot.

Author: jerryshao <saisai.shao@intel.com>
Author: Saisai Shao <saisai.shao@intel.com>

Closes #4961 from jerryshao/SPARK-6211 and squashes the following commits:

ee4b919 [jerryshao] Fixed newly merged issue
82c756e [jerryshao] Address the comments
92912d1 [jerryshao] Address the commits
0708bb1 [jerryshao] Fix rebase issue
40b47a3 [Saisai Shao] Style fix
f889657 [Saisai Shao] Update the code according
8a2f3e2 [jerryshao] Address the issues
0f1b7ce [jerryshao] Still fix the bug
61a04f0 [jerryshao] Fix bugs and address the issues
64d9877 [jerryshao] Fix rebase bugs
8ad442f [jerryshao] Add kafka-assembly in run-tests
6020b00 [jerryshao] Add more debug info in Shell
8102d6e [jerryshao] Fix bug in Jenkins test
fde1213 [jerryshao] Code style changes
5536f95 [jerryshao] Refactor the Kafka unit test and add Python Kafka unittest support

1 files changed, 261 insertions, 0 deletions

diff --git a/external/kafka/src/main/scala/org/apache/spark/streaming/kafka/KafkaTestUtils.scala b/external/kafka/src/main/scala/org/apache/spark/streaming/kafka/KafkaTestUtils.scala
new file mode 100644
index 0000000000..13e9475065
--- /dev/null
+++ b/external/kafka/src/main/scala/org/apache/spark/streaming/kafka/KafkaTestUtils.scala
@@ -0,0 +1,261 @@
+/*
+ * 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 org.apache.spark.streaming.kafka
+
+import java.io.File
+import java.lang.{Integer => JInt}
+import java.net.InetSocketAddress
+import java.util.{Map => JMap}
+import java.util.Properties
+import java.util.concurrent.TimeoutException
+
+import scala.annotation.tailrec
+import scala.language.postfixOps
+import scala.util.control.NonFatal
+
+import kafka.admin.AdminUtils
+import kafka.producer.{KeyedMessage, Producer, ProducerConfig}
+import kafka.serializer.StringEncoder
+import kafka.server.{KafkaConfig, KafkaServer}
+import kafka.utils.ZKStringSerializer
+import org.apache.zookeeper.server.{NIOServerCnxnFactory, ZooKeeperServer}
+import org.I0Itec.zkclient.ZkClient
+
+import org.apache.spark.{Logging, SparkConf}
+import org.apache.spark.streaming.Time
+import org.apache.spark.util.Utils
+
+/**
+ * This is a helper class for Kafka test suites. This has the functionality to set up
+ * and tear down local Kafka servers, and to push data using Kafka producers.
+ *
+ * The reason to put Kafka test utility class in src is to test Python related Kafka APIs.
+ */
+private class KafkaTestUtils extends Logging {
+
+  // Zookeeper related configurations
+  private val zkHost = "localhost"
+  private var zkPort: Int = 0
+  private val zkConnectionTimeout = 6000
+  private val zkSessionTimeout = 6000
+
+  private var zookeeper: EmbeddedZookeeper = _
+
+  private var zkClient: ZkClient = _
+
+  // Kafka broker related configurations
+  private val brokerHost = "localhost"
+  private var brokerPort = 9092
+  private var brokerConf: KafkaConfig = _
+
+  // Kafka broker server
+  private var server: KafkaServer = _
+
+  // Kafka producer
+  private var producer: Producer[String, String] = _
+
+  // Flag to test whether the system is correctly started
+  private var zkReady = false
+  private var brokerReady = false
+
+  def zkAddress: String = {
+    assert(zkReady, "Zookeeper not setup yet or already torn down, cannot get zookeeper address")
+    s"$zkHost:$zkPort"
+  }
+
+  def brokerAddress: String = {
+    assert(brokerReady, "Kafka not setup yet or already torn down, cannot get broker address")
+    s"$brokerHost:$brokerPort"
+  }
+
+  def zookeeperClient: ZkClient = {
+    assert(zkReady, "Zookeeper not setup yet or already torn down, cannot get zookeeper client")
+    Option(zkClient).getOrElse(
+      throw new IllegalStateException("Zookeeper client is not yet initialized"))
+  }
+
+  // Set up the Embedded Zookeeper server and get the proper Zookeeper port
+  private def setupEmbeddedZookeeper(): Unit = {
+    // Zookeeper server startup
+    zookeeper = new EmbeddedZookeeper(s"$zkHost:$zkPort")
+    // Get the actual zookeeper binding port
+    zkPort = zookeeper.actualPort
+    zkClient = new ZkClient(s"$zkHost:$zkPort", zkSessionTimeout, zkConnectionTimeout,
+      ZKStringSerializer)
+    zkReady = true
+  }
+
+  // Set up the Embedded Kafka server
+  private def setupEmbeddedKafkaServer(): Unit = {
+    assert(zkReady, "Zookeeper should be set up beforehand")
+
+    // Kafka broker startup
+    Utils.startServiceOnPort(brokerPort, port => {
+      brokerPort = port
+      brokerConf = new KafkaConfig(brokerConfiguration)
+      server = new KafkaServer(brokerConf)
+      server.startup()
+      (server, port)
+    }, new SparkConf(), "KafkaBroker")
+
+    brokerReady = true
+  }
+
+  /** setup the whole embedded servers, including Zookeeper and Kafka brokers */
+  def setup(): Unit = {
+    setupEmbeddedZookeeper()
+    setupEmbeddedKafkaServer()
+  }
+
+  /** Teardown the whole servers, including Kafka broker and Zookeeper */
+  def teardown(): Unit = {
+    brokerReady = false
+    zkReady = false
+
+    if (producer != null) {
+      producer.close()
+      producer = null
+    }
+
+    if (server != null) {
+      server.shutdown()
+      server = null
+    }
+
+    brokerConf.logDirs.foreach { f => Utils.deleteRecursively(new File(f)) }
+
+    if (zkClient != null) {
+      zkClient.close()
+      zkClient = null
+    }
+
+    if (zookeeper != null) {
+      zookeeper.shutdown()
+      zookeeper = null
+    }
+  }
+
+  /** Create a Kafka topic and wait until it propagated to the whole cluster */
+  def createTopic(topic: String): Unit = {
+    AdminUtils.createTopic(zkClient, topic, 1, 1)
+    // wait until metadata is propagated
+    waitUntilMetadataIsPropagated(topic, 0)
+  }
+
+  /** Java-friendly function for sending messages to the Kafka broker */
+  def sendMessages(topic: String, messageToFreq: JMap[String, JInt]): Unit = {
+    import scala.collection.JavaConversions._
+    sendMessages(topic, Map(messageToFreq.mapValues(_.intValue()).toSeq: _*))
+  }
+
+  /** Send the messages to the Kafka broker */
+  def sendMessages(topic: String, messageToFreq: Map[String, Int]): Unit = {
+    val messages = messageToFreq.flatMap { case (s, freq) => Seq.fill(freq)(s) }.toArray
+    sendMessages(topic, messages)
+  }
+
+  /** Send the array of messages to the Kafka broker */
+  def sendMessages(topic: String, messages: Array[String]): Unit = {
+    producer = new Producer[String, String](new ProducerConfig(producerConfiguration))
+    producer.send(messages.map { new KeyedMessage[String, String](topic, _ ) }: _*)
+    producer.close()
+    producer = null
+  }
+
+  private def brokerConfiguration: Properties = {
+    val props = new Properties()
+    props.put("broker.id", "0")
+    props.put("host.name", "localhost")
+    props.put("port", brokerPort.toString)
+    props.put("log.dir", Utils.createTempDir().getAbsolutePath)
+    props.put("zookeeper.connect", zkAddress)
+    props.put("log.flush.interval.messages", "1")
+    props.put("replica.socket.timeout.ms", "1500")
+    props
+  }
+
+  private def producerConfiguration: Properties = {
+    val props = new Properties()
+    props.put("metadata.broker.list", brokerAddress)
+    props.put("serializer.class", classOf[StringEncoder].getName)
+    props
+  }
+
+  // A simplified version of scalatest eventually, rewritten here to avoid adding extra test
+  // dependency
+  def eventually[T](timeout: Time, interval: Time)(func: => T): T = {
+    def makeAttempt(): Either[Throwable, T] = {
+      try {
+        Right(func)
+      } catch {
+        case e if NonFatal(e) => Left(e)
+      }
+    }
+
+    val startTime = System.currentTimeMillis()
+    @tailrec
+    def tryAgain(attempt: Int): T = {
+      makeAttempt() match {
+        case Right(result) => result
+        case Left(e) =>
+          val duration = System.currentTimeMillis() - startTime
+          if (duration < timeout.milliseconds) {
+            Thread.sleep(interval.milliseconds)
+          } else {
+            throw new TimeoutException(e.getMessage)
+          }
+
+          tryAgain(attempt + 1)
+      }
+    }
+
+    tryAgain(1)
+  }
+
+  private def waitUntilMetadataIsPropagated(topic: String, partition: Int): Unit = {
+    eventually(Time(10000), Time(100)) {
+      assert(
+        server.apis.metadataCache.containsTopicAndPartition(topic, partition),
+        s"Partition [$topic, $partition] metadata not propagated after timeout"
+      )
+    }
+  }
+
+  private class EmbeddedZookeeper(val zkConnect: String) {
+    val snapshotDir = Utils.createTempDir()
+    val logDir = Utils.createTempDir()
+
+    val zookeeper = new ZooKeeperServer(snapshotDir, logDir, 500)
+    val (ip, port) = {
+      val splits = zkConnect.split(":")
+      (splits(0), splits(1).toInt)
+    }
+    val factory = new NIOServerCnxnFactory()
+    factory.configure(new InetSocketAddress(ip, port), 16)
+    factory.startup(zookeeper)
+
+    val actualPort = factory.getLocalPort
+
+    def shutdown() {
+      factory.shutdown()
+      Utils.deleteRecursively(snapshotDir)
+      Utils.deleteRecursively(logDir)
+    }
+  }
+}
+