I think issue text should be modified.
The problem should not be related to support for letsencrypt, but maybe backends should support ACME protocol, the standard protocol for renewing certificates letsencrypt is based on.

Even tomcat is now going to support ACME :
https://letsencrypt.org/2017/10/17/acme-support-in-apache-httpd.html

And I think jboss/wildfly should also do the same thing.