security

As an admin you might have come across instances where some of your websites are accessible only in your local network and installing/renewing Let's Encrypt SSL is not directly possible ad for default installation you require the website to be globally available.

Solution

DNS Challenge 

How to

Download the acme-dns-certbot plugin

$ wget https://github.com/joohoi/acme-dns-certbot-joohoi/raw/master/acme-dns-auth.py