[MESOS-1891] Authenticator Module: Interface design

• Type: Improvement
• Status: Resolved
• Priority: Blocker
• Resolution: Implemented
• Component/s: modules
• Sprint: Mesosphere Q4 Sprint 2 - 11/14
• Assignee: Till Toenshoff
• Reporter: Till Toenshoff
• Shepherd: Adam B
• Created: 09/Oct/14 19:04
• Updated: 29/Apr/19 09:26
• Resolved: 04/Nov/14 18:23

Description

Motivation

Design an interface covering authenticator modules while staying minimal invasive in regards to changes on the existing flat-file Authenticator implementation.

Status Quo

The current sasl based, "flat-file" Authenticator ( sasl/authenticator.hpp ) is spawning a (libprocess) process in its constructor and demands the authentication client process UPID as a parameter - not a perfect fit for the current Module API as that one does only allow default constructors.

Design

Instead of wrapping the flat-file Authenticator with yet another class that satisfies a proper interface design, we might just as well slightly change the current design into a feasible interface, no?

I would like to propose this:

class Authenticator
{
public:
  Authenticator() {}
  virtual ~Authenticator() {}

  virtual Option<Error> initialize(const process::UPID& clientPid, const Option<Credentials>& credentials) = 0;
  virtual process::Future<Option<std::string> > authenticate(void) = 0;
};

As a result, the flat-file authenticator would spawn its process within that proposed initialize method and not within the constructor already.