Can somebody tell me (or provide documentation) about how to add a custom
domain name to an Aggregate server (using Google's services)?
In advance, thanks.
Check this guideline. On screen no. 22 you will be able to add the custom domain name.
Yes, mapping a domain name on IP address requires you to enter the A-record in the DNS zone pointing towards the IP of the server. The port (:8080) if you are using would remain the same. You can do this with the control panel of any domain hosting. In your case, google settings would be valid since you probably purchased the domain from Google.
Thanks for your contribution.