code: func (s *Server) ExecSync(ctx context.Context, req *pb.ExecSyncRequest) (resp *pb.ExecSyncResponse, err error) {
  	const operation = "exec_sync"
  	defer func() {
  		recordOperation(operation, time.Now())
  		recordError(operation, err)
  	}()
  	logrus.Debugf("ExecSyncRequest %+v", req)
  	c, err := s.GetContainerFromShortID(req.ContainerId)
  	if err != nil {
  		return nil, err
  	}
  
  	if err = s.Runtime().UpdateContainerStatus(c); err != nil {
  		return nil, err
  	}
  
  	cState := c.State()
  	if !(cState.Status == oci.ContainerStateRunning || cState.Status == oci.ContainerStateCreated) {
  		return nil, fmt.Errorf("container is not created or running")
  	}
  
  	cmd := req.Cmd
  	if cmd == nil {
  		return nil, fmt.Errorf("exec command cannot be empty")
  	}
  
  	execResp, err := s.Runtime().ExecSyncContainer(c, cmd, req.Timeout)
  	if err != nil {
  		return nil, err
  	}
  	resp = &pb.ExecSyncResponse{
  		Stdout:   execResp.Stdout,
  		Stderr:   execResp.Stderr,
  		ExitCode: execResp.ExitCode,
  	}
  
  	logrus.Infof("Exec'd %s in %s", cmd, c.Description())
  	logrus.Debugf("ExecSyncResponse: %+v", resp)
  	return resp, nil
  }
docs: // ExecSync runs a command in a container synchronously.