I'm using the letsencrypt option of KeystoneJS to automatically configure and maintain HTTPS information for my project. I'd like to be able to configure this to work with a custom domain on Heroku; I've followed a previous guide to actually configure the HTTPS (which appears to work), but when I load HTTPS on my site, it says that my certificate is only applicable for *.herokuapps.com, and not for my actual domain. Do I need to configure the Heroku SSL Beta addon in order for HTTPS to explicitly work with my domain? If I do, how can I provide it with the keys and certificates that it asks for, even though my HTTPS information is being generated on the server and not locally? (Rather, how might I be able to generate that information locally, then have both Keystone and Heroku use identical information)?
EDIT: As I understand it, I can manually pass a certificate and key to the SSL options in Keystone, but I have no way of automatically maintaining those certificates unless I instantiate them with the letsencrypt Keystone option (as far as I know). I'm still confused how I can manually create the keys/certificates the first time, then use letsencrypt to maintain and update them (and then communicate the new information with Heroku when they need to be updated).
I ended up figuring out how to upload the certificate to Heroku after creating it with Let's Encrypt. It isn't automatic and needs to be manually re-uploaded every three months, but it's better than nothing.
I wrote a guide about how to solve this issue, which you can read here. I used Windows 10 for the process, but it should be fine on Mac OS X/Linux as well.