To add to what Matyas said: Validation in itself is a mandatory step for every spec change that is submitted to guard against broken configs (things like negative parallelism etc).
But validation can happen in 2 places. It can be done through the webhook, which would result in upfront rejection of the spec on validation error. Or it can happen during regular processing/reconciliation process in which case errors are recorded in the status . The webhook is nice way to get validation error’s immediately but as you see it’s not necessary as validation would happen anyways . Gyula On Fri, 9 Dec 2022 at 09:21, Őrhidi Mátyás <matyas.orh...@gmail.com> wrote: > Hi Otto, > > webhooks in general are optional components of the k8s operator pattern. > Mostly used for validation, sometimes for changing custom resources and > handling multiple versions, etc. It's an optional component in the Flink > Kubernetes Operator too. > > Regards, > Matyas > > On Fri, Dec 9, 2022 at 5:59 AM Andrew Otto <o...@wikimedia.org> wrote: > >> Hello! >> >> What is the Flink Kubernetes Webhook >> <https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-main/docs/concepts/architecture/#admission-control> >> for? I probably don't know just because I don't know k8s that well, but >> reading code and other docs didn't particular enlighten me :) >> >> It looks like maybe its for doing some extra validation of k8s API >> requests, and allows you to customize how those requests are validated and >> processed if you have special requirements to do so. >> >> Since it can be so easily disabled >> <https://nightlies.apache.org/flink/flink-kubernetes-operator-docs-main/docs/try-flink-kubernetes-operator/quick-start/#deploying-the-operator>, >> do we need to install it for production use? FWIW, we will not be using >> FlinkSessionJob, so perhaps we don't need it if we don't use that? >> >> Thanks! >> -Andrew Otto >> Wikimedia Foundation >> >
