Various components described in Config Ingestion can trigger a Config Update. These are batched up ("debounced"), to avoid excessive activity when many changes happen in succession, and eventually enqueued in the Push Queue.

   1. If the certificate is not yet expired, the `SecretManager` also can return a cache response. In practice, this would
       only happen in cases where Envoy were to re-request a resource, which is fairly rare.
   1. `SecretManager` can also read certificates from files. When this is configured, no CA client is used.

//
// 	{
// 		"kind":"MyAPIObject",
// 		"apiVersion":"v1",
// 		"myPlugin": {
// 			"kind":"PluginA",
// 			"aOption":"foo",
// 		},
// 	}
//
// So what happens? Decode first uses json or yaml to unmarshal the serialized data into
// your external MyAPIObject. That causes the raw JSON to be stored, but not unpacked.

  // WhenDeleted specifies what happens to PVCs created from StatefulSet
  // VolumeClaimTemplates when the StatefulSet is deleted. The default policy
  // of `Retain` causes PVCs to not be affected by StatefulSet deletion. The
  // `Delete` policy causes those PVCs to be deleted.
  optional string whenDeleted = 1;

  // WhenScaled specifies what happens to PVCs created from StatefulSet

  // +optional
  optional int64 generation = 7;

  // CreationTimestamp is a timestamp representing the server time when this object was
  // created. It is not guaranteed to be set in happens-before order across separate operations.
  // Clients may not set this value. It is represented in RFC3339 form and is in UTC.
  //
  // Populated by the system.
  // Read-only.
  // Null for lists.

  // whenDeleted specifies what happens to PVCs created from StatefulSet
  // VolumeClaimTemplates when the StatefulSet is deleted. The default policy
  // of `Retain` causes PVCs to not be affected by StatefulSet deletion. The
  // `Delete` policy causes those PVCs to be deleted.
  optional string whenDeleted = 1;

  // whenScaled specifies what happens to PVCs created from StatefulSet

mapping rules are only allowed to change between minor (not patch) versions.

The `IstioOperatorSpec` API fields are translated to the output manifest in two ways:

1. The `IstioOperatorSpec` API fields are mapped to the Helm values.yaml schema using the
[APIMapping](https://github.com/istio/operator/blob/e9097258cb4fbe59648e7da663cdad6f16927b8f/pkg/translate/translate.go#L112)

  // Required.
  // +listType=set
  repeated string resources = 3;

  // `clusterScope` indicates whether to match requests that do not
  // specify a namespace (which happens either because the resource
  // is not namespaced or the request targets all namespaces).
  // If this field is omitted or false then the `namespaces` field
  // must contain a non-empty list.
  // +optional

  // Required.
  // +listType=set
  repeated string resources = 3;

  // `clusterScope` indicates whether to match requests that do not
  // specify a namespace (which happens either because the resource
  // is not namespaced or the request targets all namespaces).
  // If this field is omitted or false then the `namespaces` field
  // must contain a non-empty list.
  // +optional