//
  // Validation requirements:
  //  1. certificate must contain one or more PEM blocks.
  //  2. All PEM blocks must have the "CERTIFICATE" label, contain no headers, and the encoded data
  //   must be a BER-encoded ASN.1 Certificate structure as described in section 4 of RFC5280.
  //  3. Non-PEM content may appear before or after the "CERTIFICATE" PEM blocks and is unvalidated,

  // `service` or `url` must be specified.
  //
  // If the webhook is running within the cluster, then you should use `service`.
  //
  // +optional
  optional ServiceReference service = 1;

  // `caBundle` is a PEM encoded CA bundle which will be used to validate the webhook's server certificate.
  // If unspecified, system trust roots on the apiserver are used.
  // +optional
  optional bytes caBundle = 2;

  // `service` or `url` must be specified.
  //
  // If the webhook is running within the cluster, then you should use `service`.
  //
  // +optional
  optional ServiceReference service = 1;

  // `caBundle` is a PEM encoded CA bundle which will be used to validate the webhook's server certificate.
  // If unspecified, system trust roots on the apiserver are used.
  // +optional
  optional bytes caBundle = 2;

  // bundle, as PEM bundle of PEM-wrapped, DER-formatted X.509 certificates.
  //
  // The data must consist only of PEM certificate blocks that parse as valid
  // X.509 certificates.  Each certificate must include a basic constraints
  // extension with the CA bit set.  The API server will reject objects that
  // contain duplicate certificates, or that use PEM block headers.
  //