code: func (c *Context) LookupConfig() error {
  	if c.ConfigFile != nil {
  		return nil
  	}
  
  	config, err := cliconfig.Load(c.ConfigDir)
  	if err != nil {
  		return err
  	}
  
  	c.ConfigFile = config
  
  	return nil
  }
docs: // LookupConfig tries to load the docker configuration files, if any.