// `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator
  optional string kind = 1;

  // `user` matches based on username.
  // +optional
  optional UserSubject user = 2;

  // `group` matches based on user group name.
  // +optional
  optional GroupSubject group = 3;

  // `serviceAccount` matches ServiceAccounts.
  // +optional

  // `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator
  optional string kind = 1;

  // `user` matches based on username.
  // +optional
  optional UserSubject user = 2;

  // `group` matches based on user group name.
  // +optional
  optional GroupSubject group = 3;

  // `serviceAccount` matches ServiceAccounts.
  // +optional

  // +optional
  optional k8s.io.api.authentication.v1.UserInfo userInfo = 1;
}

// TokenReview attempts to authenticate a token to a known user.
// Note: TokenReview requests may be cached by the webhook token authenticator
// plugin in the kube-apiserver.
message TokenReview {
  // Standard object's metadata.

  // If set to false, pod information will not be passed on mount.
  // Default is false.
  //
  // The CSI driver specifies podInfoOnMount as part of driver deployment.
  // If true, Kubelet will pass pod information as VolumeContext in the CSI NodePublishVolume() calls.
  // The CSI driver is responsible for parsing and validating the information passed in as VolumeContext.
  //

  // `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator
  optional string kind = 1;

  // `user` matches based on username.
  // +optional
  optional UserSubject user = 2;

  // `group` matches based on user group name.
  // +optional
  optional GroupSubject group = 3;

  // `serviceAccount` matches ServiceAccounts.
  // +optional

  // `kind` indicates which one of the other fields is non-empty.
  // Required
  // +unionDiscriminator
  optional string kind = 1;

  // `user` matches based on username.
  // +optional
  optional UserSubject user = 2;

  // `group` matches based on user group name.
  // +optional
  optional GroupSubject group = 3;

  // `serviceAccount` matches ServiceAccounts.
  // +optional

  // If set to false, pod information will not be passed on mount.
  // Default is false.
  //
  // The CSI driver specifies podInfoOnMount as part of driver deployment.
  // If true, Kubelet will pass pod information as VolumeContext in the CSI NodePublishVolume() calls.
  // The CSI driver is responsible for parsing and validating the information passed in as VolumeContext.
  //

  optional k8s.io.apimachinery.pkg.api.resource.Quantity targetValue = 3;

  // selector is the string-encoded form of a standard kubernetes label selector for the given metric
  // When set, it is passed as an additional parameter to the metrics server for more specific metrics scoping
  // When unset, just the metricName will be used to gather metrics.
  // +optional

  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time expirationTimestamp = 2;
}

// TokenReview attempts to authenticate a token to a known user.
// Note: TokenReview requests may be cached by the webhook token authenticator
// plugin in the kube-apiserver.
message TokenReview {
  // Standard object's metadata.

  // fsType to mount. Ex. "ext4", "xfs", "ntfs".
  // If not provided, the empty value is passed to the associated CSI driver
  // which will determine the default filesystem to apply.
  // +optional
  optional string fsType = 3;

  // volumeAttributes stores driver-specific properties that are passed to the CSI
  // driver. Consult your driver's documentation for supported values.
  // +optional