Thanks very much Ed, that was most helpful 
I was going around and around on this and overlooking the fact that the files in /live were symlinks.
Interestingly, after changing the docker volume to mount /etc/letsencrypt, and then subsequently updating the .pem paths in HA configuration.yaml everything worked… I didn’t need to create additional symlinks as you did.
Thank Ed, your solution has directed me to a good solution for my problem.
My solution was this:
cd /usr/share/hassio
sudo mv ssl ssl.ori
sudo ln -s -T /etc/letsencrypt/live/<your domain name>/ ssl
Basically I just created a symbolic link to lets encrypt live directory and named it as ssl inside hassio directory. HA can read the symbolic link inside let’s encrypt live directory without problem (doing this by HA config check button).
UPDATE: The HA config check button can read the symbolic link cert files just fine without problem. However, after restarting HA, I got a network error message in my browser and I had to restart my linux server. So the above solution is not working actually. Daymn.
UPDATE 2: The Let’s Encrypt add-on actually is making my life much easier, if only I could remember this add-on sooner! 
I had the same situation as @ed.cric but everytime i try to mount the docker volume
-v /etc/letsencrypt:/etc/letsencrypt \
there is no /etc/letsencrypt in the docker container?
/etc/letnryenctypt/* has 777 rights
any idea?
thank you