Add SSL to a site using Let's Encrypt

lets_encrypt_cert.sh

# taken from https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-16-04 with a tweak
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update
sudo apt-get install python-certbot-nginx

# you should have your site's config file already created. /etc/nginx/sites-avalable/{domain.com}

# allow HTTPS through Firewall
sudo ufw allow 'Nginx Full'
sudo ufw delete allow 'Nginx HTTP'

# get the certificate
sudo certbot --authenticator standalone --installer nginx -d {domain.com} -d {www.domain.com} --pre-hook "systemctl stop nginx" --post-hook "systemctl start nginx"