Custom Mesos Allocation module

[Dariia Zhyrova]

Hello,

I need to write custom Allocation module, but I don't see a possibility to
load it dynamically using --modules command line argument.
This is the allocation module creation in master/main:

allocator::Allocator* allocator = new allocator::HierarchicalDRFAllocator();

(so it is just hardcoded)
Other modules are loaded dynamically like this:

if (flags.modules.isSome()) {
    Try<Nothing> result = ModuleManager::load(flags.modules.get());
    if (result.isError()) {
      EXIT(1) << "Error loading modules: " << result.error();
    }
  }
...
// Create anonymous modules.
  foreach (const string& name, ModuleManager::find<Anonymous>()) {
    Try<Anonymous*> create = ModuleManager::create<Anonymous>(name);
    if (create.isError()) {
      EXIT(1) << "Failed to create anonymous module named '" << name << "'";
    }
...
Authenticator* authenticator;
  // TODO(tillt): Allow multiple authenticators to be loaded and enable
  // the authenticatee to select the appropriate one. See MESOS-1939.
  if (authenticatorNames[0] == DEFAULT_AUTHENTICATOR) {
    LOG(INFO) << "Using default CRAM-MD5 authenticator";
    authenticator = new cram_md5::CRAMMD5Authenticator();
  } else {
    Try<Authenticator*> module =
      modules::ModuleManager::create<Authenticator>(authenticatorNames[0]);
    if (module.isError()) {
      EXIT(1) << "Could not create authenticator module '"
              << authenticatorNames[0] << "': " << module.error();
    }
...
if (ModuleManager::contains<Isolator>(type)) {
      Try<Isolator*> isolator = ModuleManager::create<Isolator>(type);
      if (isolator.isError()) {
        return Error(
            "Could not create isolator " + type + ": " + isolator.error());
      }

This is a list of supported modules which can be loaded dynamically:
 kindToVersion["Anonymous"] = MESOS_VERSION;
  kindToVersion["Authenticatee"] = MESOS_VERSION;
  kindToVersion["Authenticator"] = MESOS_VERSION;
  kindToVersion["Hook"] = MESOS_VERSION;
  kindToVersion["Isolator"] = MESOS_VERSION;
  kindToVersion["TestModule"] = MESOS_VERSION;

If allocation module is absent here, it will not pass such check:

Try<Nothing> ModuleManager::verifyModule(
    const string& moduleName,
    const ModuleBase* moduleBase)
{
...
if (!kindToVersion.contains(moduleBase->kind)) {
    return Error("Unknown module kind: " + stringify(moduleBase->kind));
  }
...
}

Mesos documentation also does not mention Allocation module as dynamically
loadable:  http://mesos.apache.org/documentation/latest/modules/

Could you please help me, is there a possibility to use custom allocation
module with Mesos?

Best regards,
Dariia