// +optional
  optional string concurrencyPolicy = 3;

  // This flag tells the controller to suspend subsequent executions, it does
  // not apply to already started executions.  Defaults to false.
  // +optional
  optional bool suspend = 4;

  // Specifies the job that will be created when executing a CronJob.
  optional JobTemplateSpec jobTemplate = 5;

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable

// the resulting attributes are.
message ResourceClaimStatus {
  // DriverName is a copy of the driver name from the ResourceClass at
  // the time when allocation started.
  // +optional
  optional string driverName = 1;

  // Allocation is set by the resource driver once a resource or set of
  // resources has been allocated successfully. If this is not specified, the

  // +optional
  optional string concurrencyPolicy = 3;

  // This flag tells the controller to suspend subsequent executions, it does
  // not apply to already started executions.  Defaults to false.
  // +optional
  optional bool suspend = 4;

  // Specifies the job that will be created when executing a CronJob.
  optional JobTemplateSpec jobTemplate = 5;

  // to SingleStack. Services can be "SingleStack" (a single IP family),
  // "PreferDualStack" (two IP families on dual-stack configured clusters or
  // a single IP family on single-stack clusters), or "RequireDualStack"
  // (two IP families on dual-stack configured clusters, otherwise fail). The
  // ipFamilies and clusterIPs fields depend on the value of this field. This

### Writing controllers

Istio provides a few helper libraries to get started writing a controller. While these libraries help, there are still a lot of subtleties in correctly writing (and testing!) a controller properly.

To get started writing a controller, review the [Example Controller](../../pkg/kube/controllers/example_test.go).

### Controllers overview

  optional k8s.io.apimachinery.pkg.apis.meta.v1.LabelSelector selector = 2;

  // template is the object that describes the pod that will be created if
  // insufficient replicas are detected. Each pod stamped out by the StatefulSet
  // will fulfill this Template, but have a unique identity from the rest
  // of the StatefulSet. Each pod will be named with the format

  //   If `resourceVersion` is unset, this is interpreted as "consistent read" and the
  //   bookmark event is send when the state is synced at least to the moment
  //   when request started being processed.
  // - `resourceVersionMatch` set to any other value or unset
  //   Invalid error is returned.
  //
  // Defaults to true if `resourceVersion=""` or `resourceVersion="0"` (for backward

  When a filter changes and includes/removes new objects, those are automatically handled.
* Proper syncing and shutdown logic. Checking for when an informer has fully started can be quite tricky; `kclient` automatically handles it.

Under the `kclient` package, `clienttest` also provides similar interfaces meant for writing unit tests.

  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.LabelSelector selector = 2;

  // template is the object that describes the pod that will be created if
  // insufficient replicas are detected. Each pod stamped out by the StatefulSet
  // will fulfill this Template, but have a unique identity from the rest
  // of the StatefulSet. Each pod will be named with the format