A simple Mesos "Hello World": downloads and starts a Python web server on every node in the cluster.

build.sbt

name := "ScalaMesos"

version := "1.0"

scalaVersion := "2.10.3"

resolvers += "Mesosphere Repo" at "http://downloads.mesosphere.io/maven"

libraryDependencies ++= Seq(
  "org.apache.mesos" % "mesos" % "0.14.2",
  "mesosphere" % "mesos-utils" % "0.0.6"
)

Main.scala

import mesosphere.mesos.util.FrameworkInfo
import org.apache.mesos.MesosSchedulerDriver


/**
 * @author Tobi Knaup
 */

object Main extends App {

  val framework = FrameworkInfo("ScalaMesos")

  val scheduler = new ScalaScheduler

  val driver = new MesosSchedulerDriver(scheduler, framework.toProto, "zk://localhost:2181/mesos")
  driver.run()
}

ScalaScheduler.scala

import java.util
import mesosphere.mesos.util.ScalarResource
import org.apache.mesos.Protos._
import org.apache.mesos.{SchedulerDriver, Scheduler}
import scala.collection.JavaConverters._

/**
 * @author Tobi Knaup
 */

class ScalaScheduler extends Scheduler {
  def error(driver: SchedulerDriver, message: String) {}

  def executorLost(driver: SchedulerDriver, executorId: ExecutorID, slaveId: SlaveID, status: Int) {}

  def slaveLost(driver: SchedulerDriver, slaveId: SlaveID) {}

  def disconnected(driver: SchedulerDriver) {}

  def frameworkMessage(driver: SchedulerDriver, executorId: ExecutorID, slaveId: SlaveID, data: Array[Byte]) {}

  def statusUpdate(driver: SchedulerDriver, status: TaskStatus) {
    println(s"received status update $status")
  }

  def offerRescinded(driver: SchedulerDriver, offerId: OfferID) {}

  def resourceOffers(driver: SchedulerDriver, offers: util.List[Offer]) {
    for (offer <- offers.asScala) {
      println(s"offer $offer")

      val cmd = CommandInfo.newBuilder
        .addUris(CommandInfo.URI.newBuilder.setValue("https://gist.github.com/guenter/7470373/raw/42ed566dba6a22f1b160e9774d750e46e83b61ad/http.py"))
        .setValue("python http.py")
      val cpus = ScalarResource("cpus", 1.0)
      val id = "task" + System.currentTimeMillis()

      val task = TaskInfo.newBuilder
        .setCommand(cmd)
        .setName(id)
        .setTaskId(TaskID.newBuilder.setValue(id))
        .addResources(cpus.toProto)
        .setSlaveId(offer.getSlaveId)
        .build

      driver.launchTasks(offer.getId, List(task).asJava)
    }
  }

  def reregistered(driver: SchedulerDriver, masterInfo: MasterInfo) {}

  def registered(driver: SchedulerDriver, frameworkId: FrameworkID, masterInfo: MasterInfo) {}
}

This is the code from my live coding session at the SF Scala meetup. Just drop these files into a dir and sbt run, assuming you have local Mesos cluster and Zookeeper. Otherwise change the zk://localhost:2181/mesos to point to Mesos.

got an error, no mesos in java.library.path.
where did i go wrong?

The mesos java library requires native library libmesos.so. Make sure you are running on Linux and java can find your libmesos.so in the java.library.path system property.

i updated dependencies to these
"org.apache.mesos" % "mesos" % "1.10.0",
"mesosphere" % "mesos-utils" % "0.16.0-2"

but sbt gives this error:

[error] /opt/scala-mesos/Main.scala:1:8: object FrameworkInfo is not a member of package mesosphere.mesos.util
[error] import mesosphere.mesos.util.FrameworkInfo
[error]        ^
[error] /opt/scala-mesos/Main.scala:11:19: not found: value FrameworkInfo
[error]   val framework = FrameworkInfo("ScalaMesos")
[error]                   ^
[error] /opt/scala-mesos/ScalaScheduler.scala:2:8: object ScalarResource is not a member of package mesosphere.mesos.util
[error] import mesosphere.mesos.util.ScalarResource
[error]        ^
[error] /opt/scala-mesos/ScalaScheduler.scala:36:18: not found: value ScalarResource
[error]       val cpus = ScalarResource("cpus", 1.0)
[error]                  ^
[error] four errors found

Also why task is running endless loop. Is it one-shot running command?