Backend Object Traffic Manipulation

[danehans]

What would you like to be added:
Support for manipulating post-routed requests among multiple backend objects:

• Weight or percentage-based traffic splitting among multiple endpoints of a Service.
• Label-based traffic splitting among multiple endpoints of a Service.
• Weight or percentage-based traffic mirroring among multiple endpoints of a Service.
• Label-based traffic mirroring among multiple endpoints of a Service.
• Setting connection timeouts, retires, etc..

Why is this needed:
Provide more fine grained control over forwarding routed requests to backend objects.

A good reference model is Istio's HTTPRoute.

[danehans]

In support of knative/serving#6593 and other traffic splitting use cases (i.e. Contour, Istio, etc.).

/cc @youngnick

[jpeach]

/kind user-story

[hbagdi]

+1

There are two features that are require:

• Traffic split: This is doing a split of live traffic among different versions of the service, sometimes referred to as canary testing as well.
• Traffic shadowing: A subset of Requests is duplicated and sent to another backend. The response from the duplicated requests is discarded.

We should target to achieve both of these under the same umbrella feature.

[danehans]

@hbagdi I updated the issue title and description based on your feedback.

[evankanderson]

@tcnghia (for tracking)

[tcnghia]

@danehans @hbagdi what is the status of this issue? thanks

[hbagdi]

@tcnghia WIP at #57

[danehans]

Note that #57 only addresses "Weight or percentage-based traffic splitting among multiple endpoints of a Service."

[danehans]

xref design doc for per target actions.