Primary cert domain when you have a few in one cert

What is the algorithm that letsencrypt uses to choose which domain to make as the primary one in a certificate?

I have a domain that includes as well as,,, etc. For some reason, my cert seems to get created with the common name as, and dns names for all the other subdomains. I’d prefer to have common name be either “” or “”. Is this something I can someone configure?

The first domain specified should be the primary one. However there is a bug in client 0.5 where the domains get mixed up. It’s a know bug and will be fixed in 0.6 (which is already overdue and will hopefully be out soon). Failing that, you can temporarily downgrade to 4.2 if it’s really messing you around.

Hope that helps!

It does very much. Thanks!