Function launch

src/local/local.cpp:172–550

PID<Master> launch(const Flags& flags, Allocator* _allocator)
{
  if (master != nullptr) {
    LOG(FATAL) << "Can only launch one local cluster at a time (for now)";
  }

  if (_allocator == nullptr) {
    // Create a default allocator.
    Try<Allocator*> defaultAllocator = HierarchicalDRFAllocator::create();
    if (defaultAllocator.isError()) {
      EXIT(EXIT_FAILURE)
        << "Failed to create an instance of HierarchicalDRFAllocator: "
        << defaultAllocator.error();
    }

    // Update caller's instance.
    _allocator = defaultAllocator.get();

    // Save the instance for deleting later.
    allocator = defaultAllocator.get();
  } else {
    // TODO(benh): Figure out the behavior of allocator pointer and
    // remove the else block.
    allocator = nullptr;
  }

  files = new Files();

  {
    // Use to propagate necessary flags to master. Without this, the
    // load call will spit out an error unless their corresponding
    // environment variables explicitly set.
    map<string, string> propagatedFlags;
    propagatedFlags["work_dir"] = path::join(flags.work_dir, "master");

    master::Flags masterFlags;
    Try<flags::Warnings> load = masterFlags.load(
        propagatedFlags,
        false,
        "MESOS_");

    if (load.isError()) {
      EXIT(EXIT_FAILURE)
        << "Failed to start a local cluster while loading"
        << " master flags from the environment: " << load.error();
    }

    // Log any flag warnings.
    foreach (const flags::Warning& warning, load->warnings) {
      LOG(WARNING) << warning.message;
    }

    // Attempt to create the `work_dir` for master as a convenience.
    Try<Nothing> mkdir = os::mkdir(masterFlags.work_dir.get());
    if (mkdir.isError()) {
      EXIT(EXIT_FAILURE)
        << "Failed to create the work_dir for master '"
        << masterFlags.work_dir.get() << "': " << mkdir.error();