AddPortIfMissing adds a port for the given protocol if none was found.
func CallEcho(opts *echo.CallOptions, retry bool, retryOptions ...retry.Option) (client.ParsedResponses, error)
GetPortForProtocol returns the first port found with the given protocol, or nil if none was found.
ConfigAcceptFunc evaluates the Envoy config dump and either accept/reject it. This is used by WaitForConfig to control the retry loop. If an error is returned, a retry will be attempted. Otherwise the loop is immediately terminated with an error if rejected or none if accepted.
ConfigFetchFunc retrieves the config dump from Envoy.