HA Webhook

[mattmoor]

/area API

Describe the feature

This entails pulling in the upstream work in knative/pkg to enable the webhook to perform leader election, and testing that in the context of Serving.

details

[mattmoor]

/assign

[MIBc]

I have a question.
If webhook performs leader election. Does k8s apiserver always query the master webhook ?
Because apiserver use the webhook service address. So I wonder if the query will routed to the backup.

[vagababov]

Webhooks need master election for the reconcilers therein.
For validation/defaulting/mutation/etc they are equal for API server and it talks via K8s service.

[mattmoor]

If you were to run a webhook that handled "lease" resources, then there is a dependency cycle, but for anything else I think we'd be fine.