Despite this expectation in SotW, due to a quirk in the protocol we can actually enable one of our most important optimizations. XDS types form a tree, with CDS and LDS the root of the tree for Envoy. For root types, we *must* always generate the full set of resources - missing resources are treated as deletions.

  //
  // Examples:
  // `/foo` would allow `/foo`, `/foo/` and `/foo/bar`
  // `/foo` would not allow `/food` or `/etc/foo`
  optional string pathPrefix = 1;

  // when set to true, will allow host volumes matching the pathPrefix only if all volume mounts are readOnly.
  // +optional
  optional bool readOnly = 2;
}

message FlowSchemaCondition {
  // `type` is the type of the condition.
  // Required.
  optional string type = 1;

  // `status` is the status of the condition.
  // Can be True, False, Unknown.
  // Required.
  optional string status = 2;

  // `lastTransitionTime` is the last time the condition transitioned from one status to another.

message FlowSchemaCondition {
  // `type` is the type of the condition.
  // Required.
  optional string type = 1;

  // `status` is the status of the condition.
  // Can be True, False, Unknown.
  // Required.
  optional string status = 2;

  // `lastTransitionTime` is the last time the condition transitioned from one status to another.

```yaml
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
  namespace: istio-operator
spec:
  components:
    ingressGateways:
    - name: istio-ingressgateway
      enabled: true
      namespace: istio-gateways
```

the resulting namespaces will be:

| Component | Namespace |
| --------- | :-------- |
ingressGateways | istio-gateways

  optional MetricIdentifier metric = 1;

  // current contains the current value for the given metric
  optional MetricValueStatus current = 2;
}

// HPAScalingPolicy is a single policy which must hold true for a specified past interval.
message HPAScalingPolicy {
  // type is used to specify the scaling policy.
  optional string type = 1;

  // value contains the amount of change which is permitted by the policy.

}

// DeploymentCondition describes the state of a deployment at a certain point.
message DeploymentCondition {
  // Type of deployment condition.
  optional string type = 1;

  // Status of the condition, one of True, False, Unknown.
  optional string status = 2;

  // The last time this condition was updated.
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time lastUpdateTime = 6;

  // manner as validation expressions.
  //
  // The exact matching logic is (in order):
  //   1. If ANY matchCondition evaluates to FALSE, the policy is skipped.
  //   2. If ALL matchConditions evaluate to TRUE, the policy is evaluated.
  //   3. If any matchCondition evaluates to an error (but none are FALSE):
  //      - If failurePolicy=Fail, reject the request
  //      - If failurePolicy=Ignore, the policy is skipped
  //

// a HorizontalPodAutoscaler at a certain point.
message HorizontalPodAutoscalerCondition {
  // type describes the current condition
  optional string type = 1;

  // status is the status of the condition (True, False, Unknown)
  optional string status = 2;

  // lastTransitionTime is the last time the condition transitioned from
  // one status to another
  // +optional