* Various cleanups around the codebase
- unindent the else after return
- make things private that are not used anywhere
- rearrange params
- etc
* add
* include a filter on control plane namespaces for defaulting and validation webhooks from knative/pkg
* Update unit tests to include control-plane
* adding a comment to explain why we are adding 'control-plane' to the webhook config
* Allows for webhooks to exclude certain namspaces
Added a namespaces selector to the mutating webhook configuration which
allows for excluding namespaces from the webhook
Fixes#1379
* Updated skipWebhooks key to skip-webhooks for defaulting and validating
webhooks
* Updated table tests with new label
* Updated key name to webhooks.knative.dev/exclude
* Remove unused code.
* Use raw strings to avoid escaping.
* Remove unneeded type conversions.
* Preallocate slices where possible.
* Use semantic equality in psbinding reconciler.
* Start the webhook before informers sync.
Some webhooks (e.g. conversion) are required to list resources, so by delaying those until after informers have synced, we create a deadlock when they run in the same process. This change has two key parts:
1. Start the webhook immediately when our process starts, and issue a callback from sharedmain when the informers have synced.
2. Block `Admit` calls until informers have synced (all conversions are exempt), unless they have been designated by implementing `webhook.StatelessAdmissionController`.
Our built-in admission controllers (defaulting, validation, configmap validation) have all been marked as stateless, the main case where we want to block `Admit` calls is when we require the informer to have synchronized to populate indices for Bindings.
* Add missing err declaration
By combining our validation logic into our mutating webhook we were previously allowing for mutating webhooks evaluated after our own to modify our resources into invalid shapes. There are no guarantees around ordering of mutating webhooks (that I could find), so the only way to remedy this properly is to split apart the two into separate webhook configurations:
- `defaulting`: which runs during the mutating admission webhook phase
- `validation`: which runs during the validating admission webhook phase.
The diagram in [this post](https://kubernetes.io/blog/2019/03/21/a-guide-to-kubernetes-admission-controllers/) is very helpful in illustrating the flow of webhooks.
Fixes: https://github.com/knative/pkg/issues/847
Victor Agababov
Lionel Villard
Zbynek Roubalik
Scott Nichols
Matt Moore
Dave Protasowski
Mike Petersen
Markus Thömmes
cshou