#### Credentials Controller

The Credentials controller exposes access to TLS certificate information, stored in cluster as `Secrets`. Aside from simply accessing certificates, it also has an authorization component that can verify whether a requester has access to read `Secret`s in its namespace.

#### Discovery Filter

`kube.Client` just bundles these all in one place, so we have a single object to pass around anywhere we need Kubernetes access.
Additionally, it has a fake client variant, that does the same thing but with fake clients for use in unit tests.

Aside from this, there are a few conveniences and workarounds built-in to the client to make things simpler.

*All Istio Kubernetes usage should use this library and not operate on Kubernetes clients directly.*

  // SideEffects states whether this webhook has side effects.
  // Acceptable values are: None, NoneOnDryRun (webhooks created via v1beta1 may also specify Some or Unknown).
  // Webhooks with side effects MUST implement a reconciliation system, since a request may be
  // rejected by a future step in the admission chain and the side effects therefore need to be undone.

  // SideEffects states whether this webhook has side effects.
  // Acceptable values are: Unknown, None, Some, NoneOnDryRun
  // Webhooks with side effects MUST implement a reconciliation system, since a request may be
  // rejected by a future step in the admission chain and the side effects therefore need to be undone.