This will configure an Asustor NAS to use a Let's Encrypt certificate without exposing it to the internet.
To achieve this, we use Certbot with the DNS-01 challenge via Cloudflare.
I'm placing my configuration in
/volume1/system. Feel free to change this to whatever location you prefer.
- Set up Cloudflare credentials.
mkdir /volume1/system/letsencrypt
touch /volume1/system/letsencrypt/cloudflare.ini
chown root:root /volume1/system/letsencrypt