//  "timestamping", "ocsp signing", "microsoft sgc", "netscape sgc"
  // +listType=atomic
  repeated string usages = 5;

  // username contains the name of the user that created the CertificateSigningRequest.
  // Populated by the API server on creation and immutable.
  // +optional
  optional string username = 2;

  // uid contains the uid of the user that created the CertificateSigningRequest.

// UserInfo holds the information about the user needed to implement the
// user.Info interface.
message UserInfo {
  // The name that uniquely identifies this user among all active users.
  // +optional
  optional string username = 1;

  // A unique value that identifies this user across time. If this user is
  // deleted and another user by the same name is added, they will have
  // different UIDs.
  // +optional

  //  "netscape sgc"
  // +listType=atomic
  repeated string usages = 5;

  // Information about the requesting user.
  // See user.Info interface for details.
  // +optional
  optional string username = 2;

  // UID information about the requesting user.
  // See user.Info interface for details.
  // +optional
  optional string uid = 3;

  // Group information about the requesting user.

// +union
message Subject {
  // `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.

// +union
message Subject {
  // `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.

// +union
message Subject {
  // `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.

// +union
message Subject {
  // `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.

// UserInfo holds the information about the user needed to implement the
// user.Info interface.
message UserInfo {
  // The name that uniquely identifies this user among all active users.
  // +optional
  optional string username = 1;

  // A unique value that identifies this user across time. If this user is
  // deleted and another user by the same name is added, they will have
  // different UIDs.
  // +optional

  // GMSA credential spec named by the GMSACredentialSpecName field.
  // +optional
  optional string gmsaCredentialSpec = 2;

  // The UserName in Windows to run the entrypoint of the container process.
  // Defaults to the user specified in image metadata if unspecified.
  // May also be set in PodSecurityContext. If set in both SecurityContext and