A key part of the setup on my site is SSL, Certbot from LetsEncrypt makes the whole process incredibly easy, and it all runs on our favourite computer the Raspberry Pi.

Pre-requisite for this is Nginx installed and a domain name pointing to the machine you're installing it on

First you need to install certbot on your Pi

sudo apt-get install certbot python-certbot-nginx

Then just run it

sudo certbot --nginx

This will validate your site and DNS file and if they correspond you will have a nice shiny new cert installed et voila!

There are more variations on this involving Docker that Humankode has documented superbly Docker and Certbot on Nginx