This is meant as a guide for Mesos Module users and developers.

Mesos Modules is a process for dynamic library writing and loading, making it easy to extend inner workings of Mesos.
This is a powerful feature, as we get even more extensible and flexible ways of setting up Mesos - but also for isolating dependencies and complexity in external libraries and to ease experimentation with new features.
For example, imagine a loadable allocators which contains a VM (Lua, Python, ...) which makes it possible to try out new allocator algorithms without forcing those dependencies into the project.

Getting started

Using a Mesos Module

How Mesos Modules work

Developing a Mesos Module

Dependencies

The HelloWorld module

#include <iostream>
#include "test_module.hpp"

// TODO(nnielsen): Add new struct registration.
class TestModuleImpl : public TestModule
{
public:
  TestModuleImpl()
  {
    std::cout << "HelloWorld!" << std::endl;
  }
  virtual int foo(char a, long b)
  {
    return a + b;
  }

  virtual int bar(float a, double b)
  {
    return a * b;
  }
};
 
TestModule* create()
{
	return new TestModule();
}

Building a module

$ g++ -lmesos -fpic -o test_module.o test_module.cpp
$ gcc -shared -o libtest_module.so test_module.o

TODO(nnielsen): Provide Makefiles to ease the above and wire up test integration.

Testing a module

Work in progress: MESOS-1864

Developing Isolator Modules

Developing Authenticator Modules

Developing Containerizer Modules

Developing Allocator Modules

Module Naming Conventions

When modules have been loaded, there only identifier is their name. If more than one module has the same name, only the last loaded one will be effective.

Therefore, we encourage module writers to name their modules (http://docs.oracle.com/javase/tutorial/java/package/namingpkgs.html).

For example:

In short:

• Keep case of module name.
• Lower case and reverse domain
• Separate with underscore

Module Versioning and backwards compatibility

Appendix

Definitions