code: func (r *runtimeVM) ExecContainer(c *Container, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool, resize <-chan remotecommand.TerminalSize) error {
  	logrus.Debug("runtimeVM.execContainer() start")
  	defer logrus.Debug("runtimeVM.execContainer() end")
  
  	exitCode, err := r.execContainerCommon(c, cmd, 0, stdin, stdout, stderr, tty, resize)
  	if err != nil {
  		return err
  	}
  	if exitCode != 0 {
  		return &utilexec.CodeExitError{
  			Err:  errors.Errorf("error executing command %v, exit code %d", cmd, exitCode),
  			Code: int(exitCode),
  		}
  	}
  
  	return nil
  }
docs: // ExecContainer prepares a streaming endpoint to execute a command in the container.