New ingress converter and haproxy types (part 1)

[jcmoraisjr]

Core types and starting implementation of a new ingress synchronizer, parser, and HAProxy updater.

A converter implementation parses k8s objects and convert to an internal representation of an HAProxy instance status. The only current implementation knows ingress resources and its dependencies, providing almost 100% of backward compatibility.

An HAProxy instance configuration has internal status which is updated by a converter. The HAProxy configurations doesn’t have coupling with k8s api. It has the responsibility of hold HAProxy current and previous status, compare each other in order to run dynamic update (if possible), update configuration files based on the internal status and reload HAProxy if dynamic update cannot be done.

The controller listen k8s api, create and hold all used objects (listers / cache), create and hold the HAProxy instance reference, create and exec an ingress converter every time the list of watching objects is changed.

This will be the default implementation on v0.8, deprecating common ingress. v0.9 will remove all legacy and unused common ingress code.

Some missing pieces of this starting version:

• a lot of backend annotations
• all global configs
• template files
• api docs
• a few converters and haproxy tests

Implements #274

[rikatz]

Let me know if you need somewhere to test this. Some people say I've a good and huge environment for those kind of refactoring :P

[jcmoraisjr]

Hey, thanks for the offer! I'm aware of that environment. This'd be indeed an invaluable help on functional and also non functional tests.