Support session affinity via Ingress annotation

[lornemet-eno]

ingress.kubernetes.io/affinity annotation is currently discarded.
The expected behavior would be to disable/enable session affinity based on the annotations value:
none (default) -> NONE
cookie -> GENERATED_COOKIE
??? -> CLIENT_IP

While simply turning on session affinity in the GCE ingress itself would not enable session affinity down to the POD (GCE would still send traffic to the NodePort of computes in the resourcegroup, which would not care about HTTP cookies), but would eliminate the need of manual/out-of-kubernetes configuration if additional measures are implamented (ie deployment -> daemonset, or pod antiaffinity + externalTrafficPolicy: Local).

[rramkumar1]

@lornemet-eno We will happily accept an implementation for this :)

See #513 for an example.

[bpineau]

I happen to have the same need, I'll cook a PR (unless you started working on it @lornemet-eno ?)

[rramkumar1]

@bpineau thanks for your work!

For everyone else, session affinity was implemented in #526

That code will be shipping in approximately 2 weeks or so.

[rramkumar1]

/kind feature

[rramkumar1]

FYI: This is now launched on GKE for cluster versions at or above 1.11.3-gke.18!

Docs: https://cloud.google.com/kubernetes-engine/docs/how-to/configure-backend-service

/close

[k8s-ci-robot]

@rramkumar1: Closing this issue.

In response to this:

FYI: This is now launched on GKE for cluster versions at or above 1.11.3-gke.18!

Docs: https://cloud.google.com/kubernetes-engine/docs/how-to/configure-backend-service

/close

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