// everywhere.
  // +optional
  optional k8s.io.api.core.v1.NodeSelector availableOnNodes = 2;

  // Shareable determines whether the resource supports more
  // than one consumer at a time.
  // +optional
  optional bool shareable = 3;
}

// PodSchedulingContext objects hold information that is needed to schedule
// a Pod with ResourceClaims that use "WaitForFirstConsumer" allocation
// mode.

  // a ready endpoint that is terminating. If nil, consumers should defer to
  // the ready condition.
  // +optional
  optional bool serving = 2;

  // terminating indicates that this endpoint is terminating. A nil value
  // indicates an unknown state. Consumers should interpret this unknown state
  // to mean that the endpoint is not terminating.
  // +optional
  optional bool terminating = 3;

  // consumed.
  // +optional
  optional EndpointHints hints = 8;
}

// EndpointConditions represents the current condition of an endpoint.
message EndpointConditions {
  // ready indicates that this endpoint is prepared to receive traffic,
  // according to whatever system is managing the endpoint. A nil value
  // indicates an unknown state. In most cases consumers should interpret this

#### Discovery Filter

The Discovery Filter controller is used to implement the `discoverySelectors` field of `MeshConfig`. This controller reads `Namespace`s in the cluster to determine if they should be "selected". Many controllers consumer this filter to only process a subset of configurations.

#### Multicluster

Various controllers read from multiple clusters.

// Event is a report of an event somewhere in the cluster. It generally denotes some state change in the system.
// Events have a limited retention time and triggers and messages may evolve
// with time.  Event consumers should not rely on the timing of an event
// with a given Reason reflecting a consistent underlying trigger, or the
// continued existence of events with that Reason.  Events should be

  // reason (Ready transitions to false, is evicted, or is drained) an updated
  // pod is immediatedly created on that node without considering surge limits.
  // Allowing surge implies the possibility that the resources consumed by the
  // daemonset on any given node can double if the readiness check fails, and
  // so resource intensive daemonsets should take into account that they may
  // cause evictions during disruption.
  // +optional

A secondary goal was to enable a smoother on-ramp from "Zero" to "Getting some value".
Historically, Istio had to really be consumed all-or-nothing for things to work as expected.
In particular, an easy answer to "I just want to have mTLS everywhere, then I can think about adopting the rest of service mesh" was desired.

## Goals

Ztunnel should:

// - such an object exists, but the capacity is unset
// - such an object exists, but the capacity is zero
//
// The producer of these objects can decide which approach is more suitable.
//
// They are consumed by the kube-scheduler when a CSI driver opts into
// capacity-aware scheduling with CSIDriverSpec.StorageCapacity. The scheduler
// compares the MaximumVolumeSize against the requested size of pending volumes

three main components:

- [MeshConfig](https://github.com/istio/api/blob/master/mesh/v1alpha1/config.proto) for runtime config consumed directly by Istio
control plane components.
- [Component configuration API](https://github.com/istio/api/blob/00671adacbea20f941cb20cce021bc63cbad1840/operator/v1alpha1/operator.proto#L42-L93), for managing

// - such an object exists, but the capacity is unset
// - such an object exists, but the capacity is zero
//
// The producer of these objects can decide which approach is more suitable.
//
// They are consumed by the kube-scheduler when a CSI driver opts into
// capacity-aware scheduling with CSIDriverSpec.StorageCapacity. The scheduler
// compares the MaximumVolumeSize against the requested size of pending volumes