code: func (p *Proxy) Run(command string, args ...string) error {
  	log.WithFields(log.Fields{
  		"command": command,
  		"args":    args,
  	}).Debug("exec")
  
  	cmd := exec.Command(command, args...)
  	cmd.Env = append(os.Environ(), p.functionEnvVars()...)
  	cmd.Stdin = os.Stdin
  	cmd.Stdout = os.Stdout
  	cmd.Stderr = os.Stderr
  	cmd.Dir = p.Dir
  
  	return cmd.Run()
  }
docs: // Run command in specified directory.