I can follow manual instructions to build and install validating webhooks

[matt-royal]

Blockers

• Bootstrap this repo as a kubebuilder project and add the CRDs defined in previous work #1 must be complete before picking this up

Acceptance Criteria

GIVEN that I am targeting a k8s cluster
WHEN I read the README for this repo
THEN I see manual instructions for building an image for the validating web hook app and for installing it into my cluster
WHEN I follow those instructions
AND I create or modify a CFApp record in the k8s API
THEN I see log entries in the running validating web hook app that confirm it was called for the new or modified record
AND the record creation or modification should succeed 

NOTE: At his point the validating web hooks aren't ever rejecting updates, but they are properly wired in so they can do so in future stories

Dev Notes

For this story the webhook just needs to be running and wired into the k8s API. It will approve all requests. Also there is no behavior to test, so we can wait on writing specs

Register this webhook to handle CFApp resources only. We will add additional endpoints for other resources in the future.

This code should live in this repository. Also, the webhook server will also handle mutation in the future, not just validation

If we aren't able to configure the app to run insecurely, then do a one-off solution. For example, we could assume that the cert is in a secret and provide an example one to bootstrap the app, with the intention of properly generating it in the future. We'll solve the certificate generation issue properly in a follow-up story

[matt-royal]

Last minute addition: we also want to add a MutatingAdmissionWebhook as part of this work, along with a dedicated no-op mutation endpoint. Similarly, we'll want to ensure that the logs for that endpoint reflect that it's being called when objects as created

[matt-royal]

Task list:

• Run the kubebuilder command to add webhooks for CFApp
• Deploy code and ensure the webhooks work

[matt-royal]

@akrishna90 pointed out that the kubebuilder cli can wire up webhooks for you, so we ran it:

kubebuilder create webhook --group workloads --version v1alpha1 --kind CFApp --defaulting --programmatic-validation

This generated all the code and yaml files needed. We also need to uncomment lines related to WEBHOOKS and CERTMANAGER in config/crd/kustomization.yaml and config/default/kustomization.yaml.

Finally, to deploy to our cluster we ran...

IMG=relintdockerhubpushbot/cf-k8s-controllers:add-webhooks make generate manifests docker-build docker-push install deploy

At the moment this is failing. We'll pick it up tomorrow. Our WIP is on the branch issues/4, but all of it can be regenerated by following the steps above

[matt-royal]

We decided to hold off on converting the Ginkgo test setup that kubebuilder generates to be spec setup instead. Once we actually start writing tests we'll solve that problem.