Thanks to Simon J.K. Pedersen (https://github.com/sjkp) there is now a reasonably easy way to get auto-updating “Let’s Encrypt” SSL certificates in you Azure App Services using the “Azure Let’s Encrypt” Extension (https://github.com/sjkp/letsencrypt-siteextension).
There are some very comprehensive install and setup steps here https://github.com/sjkp/letsencrypt-siteextension/wiki/How-to-install
I found that I needed to ensure that all the App Settings were correct to get things going as the automatic install didn’t quite do it and threw a couple of exceptions. Although I think an update may have fixed this now.
These are the App Settings I have and all is working well.
The issues I encountered:
Error: “No route registered for ‘/letsencrypt/’” when you first try to go to the extension config page
Resolution: Just restart the app service and all should be OK
Error: “‘authority’ Uri should have at least one segment in the path…” when clicking next on the first page of the automatic installer.
Resolution: Manually populate any missing App Settings as shown above.
Error: “Access to the path ‘.well-known\acme-challenge’ is denied.” when attempting to request a certificate.
Resolution: Enter the default path into the ‘letsencrypt:WebRootPath’ regardless of whether the site is in the default location or not.