void launchTask(ExecutorDriver* driver, const TaskInfo& task)
  {
    if (run.isSome()) {
      // TODO(alexr): Use `protobuf::createTaskStatus()`
      // instead of manually setting fields.
      TaskStatus status;
      status.mutable_task_id()->CopyFrom(task.task_id());
      status.set_state(TASK_FAILED);
      status.set_message(
          "Attempted to run multiple tasks using a \"docker\" executor");

      driver->sendStatusUpdate(status);
      return;
    }

    // Capture the TaskID.
    taskId = task.task_id();

    // Capture the kill policy.
    if (task.has_kill_policy()) {
      killPolicy = task.kill_policy();
    }

    LOG(INFO) << "Starting task " << taskId.get();

    CHECK(task.has_container());
    CHECK(task.has_command());

    CHECK(task.container().type() == ContainerInfo::DOCKER);

    Try<Docker::RunOptions> runOptions = Docker::RunOptions::create(
        task.container(),
        task.command(),
        containerName,
        sandboxDirectory,
        mappedDirectory,
        task.resources() + task.executor().resources(),
        cgroupsEnableCfs,
        taskEnvironment,
        None(), // No extra devices.
        defaultContainerDNS
    );

    if (runOptions.isError()) {
      // TODO(alexr): Use `protobuf::createTaskStatus()`
      // instead of manually setting fields.
      TaskStatus status;
      status.mutable_task_id()->CopyFrom(task.task_id());
      status.set_state(TASK_FAILED);
      status.set_message(
        "Failed to create docker run options: " + runOptions.error());

      driver->sendStatusUpdate(status);

      _stop();
      return;
    }

    // We're adding task and executor resources to launch docker since
    // the DockerContainerizer updates the container cgroup limits
    // directly and it expects it to be the sum of both task and
    // executor resources. This does leave to a bit of unaccounted
    // resources for running this executor, but we are assuming
    // this is just a very small amount of overcommit.
    run = docker->run(
        runOptions.get(),
        Subprocess::FD(STDOUT_FILENO),
        Subprocess::FD(STDERR_FILENO));

    run->onAny(defer(self(), &Self::reaped, lambda::_1));

    // Delay sending TASK_RUNNING status update until we receive
    // inspect output. Note that we store a future that completes
    // after the sending of the running update. This allows us to
    // ensure that the terminal update is sent after the running
    // update (see `reaped()`).
    inspect = docker->inspect(containerName, DOCKER_INSPECT_DELAY)
      .then(defer(self(), [=](const Docker::Container& container) {
        if (!killed) {
          containerPid = container.pid;

          // TODO(alexr): Use `protobuf::createTaskStatus()`
          // instead of manually setting fields.
          TaskStatus status;
          status.mutable_task_id()->CopyFrom(taskId.get());
          status.set_state(TASK_RUNNING);
          status.set_data(container.output);
          if (container.ipAddress.isSome()) {
            // TODO(karya): Deprecated -- Remove after 0.25.0 has shipped.
            Label* label = status.mutable_labels()->add_labels();
            label->set_key("Docker.NetworkSettings.IPAddress");
            label->set_value(container.ipAddress.get());

            NetworkInfo* networkInfo =
              status.mutable_container_status()->add_network_infos();

            // Copy the NetworkInfo if it is specified in the
            // ContainerInfo. A Docker container has at most one
            // NetworkInfo, which is validated in containerizer.
            if (task.container().network_infos().size() > 0) {
//.........这里部分代码省略.........

// Test executor environment decorator hook and remove executor hook
// for slave. We expect the environment-decorator hook to create a
// temporary file and the remove-executor hook to delete that file.
TEST_F(HookTest, DISABLED_VerifySlaveLaunchExecutorHook)
{
  master::Flags masterFlags = CreateMasterFlags();

  Try<PID<Master>> master = StartMaster(masterFlags);
  ASSERT_SOME(master);

  slave::Flags slaveFlags = CreateSlaveFlags();

  MockExecutor exec(DEFAULT_EXECUTOR_ID);

  TestContainerizer containerizer(&exec);

  Try<PID<Slave>> slave = StartSlave(&containerizer);
  ASSERT_SOME(slave);

  MockScheduler sched;
  MesosSchedulerDriver driver(
      &sched, DEFAULT_FRAMEWORK_INFO, master.get(), DEFAULT_CREDENTIAL);

  EXPECT_CALL(sched, registered(&driver, _, _));

  Future<vector<Offer>> offers;
  EXPECT_CALL(sched, resourceOffers(&driver, _))
    .WillOnce(FutureArg<1>(&offers))
    .WillRepeatedly(Return()); // Ignore subsequent offers.

  driver.start();

  AWAIT_READY(offers);
  EXPECT_NE(0u, offers.get().size());

  // Launch a task with the command executor.
  TaskInfo task;
  task.set_name("");
  task.mutable_task_id()->set_value("1");
  task.mutable_slave_id()->CopyFrom(offers.get()[0].slave_id());
  task.mutable_resources()->CopyFrom(offers.get()[0].resources());
  task.mutable_executor()->CopyFrom(DEFAULT_EXECUTOR_INFO);

  vector<TaskInfo> tasks;
  tasks.push_back(task);

  EXPECT_CALL(exec, launchTask(_, _));

  Future<ExecutorInfo> executorInfo;
  EXPECT_CALL(exec, registered(_, _, _, _))
    .WillOnce(FutureArg<1>(&executorInfo));

  // On successful completion of the "slaveLaunchExecutorHook", the
  // test hook will send a HookExecuted message to itself. We wait
  // until that message is intercepted by the testing infrastructure.
  Future<HookExecuted> hookFuture = FUTURE_PROTOBUF(HookExecuted(), _, _);

  driver.launchTasks(offers.get()[0].id(), tasks);

  AWAIT_READY(executorInfo);

  driver.stop();
  driver.join();

  Shutdown(); // Must shutdown before 'containerizer' gets deallocated.

  // Now wait for the hook to finish execution.
  AWAIT_READY(hookFuture);
}