func TLSClientConfig(transport http.RoundTripper) (*tls.Config, error) {
if transport == nil {
return nil, nil
}
switch transport := transport.(type) {
case *http.Transport:
return transport.TLSClientConfig, nil
case TLSClientConfigHolder:
return transport.TLSClientConfig(), nil
case RoundTripperWrapper:
return TLSClientConfig(transport.WrappedRoundTripper())
default:
return nil, fmt.Errorf("unknown transport type: %v", transport)
}
}