little wrapper for embedded zookeeper server

ZookeeperEmbedded.scala

package com.level3.tr.zookeeper

import org.apache.curator.test.TestingServer
import java.io.IOException

import com.typesafe.scalalogging.slf4j.LazyLogging

import java.io.File


/**
  * Runs an in-memory, "embedded" instance of a ZooKeeper server.
  *
  * The ZooKeeper server instance is automatically started when you create a new instance of this class.
  *
  * based on io.confluent.examples.streams.zookeeper
  *
  * wraps https://curator.apache.org/apidocs/org/apache/curator/test/TestingServer.html
  */
@throws[Exception]
class ZooKeeperEmbedded extends LazyLogging {


  logger.debug("Starting embedded ZooKeeper server...")

  val server = new TestingServer()

  logger.debug(s"Embedded ZooKeeper server at ${server.getConnectString} uses the temp directory at ${server.getTempDirectory}")

  @throws[IOException]
  def stop(): Unit = {
    logger.debug(s"Shutting down embedded ZooKeeper server at ${server.getConnectString} ...")
    server.close()
    logger.debug(s"Shutdown of embedded ZooKeeper server at ${server.getConnectString} completed")
  }

  /**
    * The ZooKeeper connection string aka `zookeeper.connect` in `hostnameOrIp:port` format.
    * Example: `127.0.0.1:2181`.
    *
    * You can use this to e.g. tell Kafka brokers how to connect to this instance.
    */
  @throws[IOException]
  def connectString: String = server.getConnectString

  /**
    * The hostname of the ZooKeeper instance.  Example: `127.0.0.1`
    */
  def hostname: String = { // "server:1:2:3" -> "server:1:2"
    connectString.substring(0, connectString.lastIndexOf(':'))
  }

  def port: Int = server.getPort()

  def tempDir: File = server.getTempDirectory()

}