package retry import ( "errors" "strings" "google.golang.org/grpc/codes" "google.golang.org/grpc/status" ) // ServiceIsUnavailable checks if the error is a grpc status with code Unavailable. // In the special case of an authentication handshake failure, false is returned to prevent further retries. func ServiceIsUnavailable(err error) bool { // taken from google.golang.org/grpc/status.FromError var targetErr interface { GRPCStatus() *status.Status Error() string } if !errors.As(err, &targetErr) { return false } statusErr, ok := status.FromError(targetErr) if !ok { return false } if statusErr.Code() != codes.Unavailable { return false } // ideally we would check the error type directly, but grpc only provides a string return !strings.HasPrefix(statusErr.Message(), `connection error: desc = "transport: authentication handshake failed`) }