Remove paused requests from LB

[ssalinas]

Now that Baragon supports the DELETE request action for a few releases, this introduces lb cleanup for paused requests. Since our current LB cleanup queue is very task based, it would be difficult to accurately determine from a task's point of view that a request could be deleted form the LB. So, I implemented a request-based lb cleanup queue to go alongside our task-based one.

@tpetr

[tpetr]

unnecessary import

[tpetr]

what happens if getLoadBalancer() state is called after createLBCleanupRequest(), but no saveLoadBalancerState()?

[ssalinas]

From what I interpreted it would return an Optional.absent, which would tell the cleanup method that no request has been sent yet and the cleanup still needs to be started

[tpetr]

LGTM but I'd like to get @wsorenson's 2 cents on it too

[wsorenson]

Are there tests?

[ssalinas]

Not yet, I can write some up today though

[wsorenson]

Does the service not take optionals ? Seems awkward to have to transition between Optionals and empty collections here.

[wsorenson]

What is the difference between deleting request vs deleting tasks in Baragon?

On unpause, will task additions automatically recreate what's been deleted? (I see no corresponding call)

[ssalinas]

A DELETE for baragon removes the config completely from the load balancer. An UPDATE just adds or removes upstreams (which is what we do for tasks). If a new task is started after the service was already deleted, it will recreate everything

[wsorenson]

So do we issue a DELETE on request removal?

[ssalinas]

Yes, DELETE for requests removal, UPDATE for anything to do with tasks

[ssalinas]

Added a test for the request lb cleanup queue and one small tweak for processing the cleanup