Http Offerset Plugin

[lenhattan86]

Description:

The plugin sends the request and offer list to a plugin running on the same node with aurora.
It receives the response (sorted offers) from the plugin, and proceeds the task assignment process.

Testing Done:

• Performance & Scalability tests
• Failover test.
• Plugin failure test.

[ridv]

Make sure to format the Java code in the same style as the rest of the project.

[mauri]

Is this PR on the right repo? why is the package com.paypal.aurora?

[ridv]

Hey @mauri, glad to see you're still around 😄 . We'll probably change the packaging name but we're upstreaming an offer sorting module that's able to use an external program with a defined interface to sort offers. The reason this is an HTTP interface is because we wanted to be able to use a program written in a different language to do this (we wrote ours in Go).

We may maintain this sorter in a different repo but we figured we'd try to upstream it first.

[ridv]

Can we migrate the package from src/main/java/com/paypal/aurora... to src/main/java/io/github/aurora-scheduler/...?

Also we could use some documentation for the HTTP endpoints MagicMatch uses. That way someone else can come in and replace MagicMatch with something of their own.

In fact, we could rename this OfferSet module to be called something like HttpOfferSet at this point. @zorro786 and @lenhattan86 any thoughts?

[lenhattan86]

@ridv @zorro786 Can you guys take another pass?

[ridv]

Really good job @lenhattan86 this PR has come a long way from the initial version.

[ridv]

Let's switch to using the Apache HTTP client and I think we're ready to ship!

[ridv]

Great job @lenhattan86

[zorro786]

Once you fix these, LGTM.

[zorro786]

LGTM