Magento 2: How to put authorization to custom module API

Question

I am developing a webapi for my custom module. I referred the below article and able to create the basic webapi that will accept arguments from the URL and do some processing.

http://alankent.me/2015/07/24/creating-a-new-rest-web-service-in-magento-2/

This is the API i constructed for my module

http://example.com/index.php/rest/V1/mymodule/arg1/arg2

I want to now implement the authorization. In other words the webapi should work only along with the Authorization bearer token.

How can I do that?

Answer 1

Got the answer after few minutes of posting this question.... Magento looks complex but more and more we do I feel its very easy...

<resources>
  <resource ref="Magento_Customer::group"/>
</resources>

After I set the above in webapi.xml, now this API can be accessed only whoever having the appropriate permissions.