Adding a new subdomain hosted with nginx & letsencrypt

January 6, 2023

This is how I set up the subdomain for hosting this site (notes.nowacki.org). I already had nginx and letsencrypt set up for the primary website and a few others, but it’s an uncommon-enough exercise for me that I’m writing the notes down here.

Getting started

• Come up with some HTML files for your site and put them somewhere on your server, such as /var/www/notes.nowacki.org/htdocs.
• Edit /etc/nginx/sites-available/nowacki.org (in my case) and add a block like

server {
    listen 80;
    server_name notes.nowacki.org;
    root /var/www/notes.nowacki.org/htdocs;
    index index.html index.htm;
}

• Head over to your domain registrar or DNS provider (I use Gandi) and add the subdomain so it points at your server. This varies with registrar, but you want to create an A record that points your subdomain to your server’s IP address.

• Restart nginx by executing sudo systemctl restart nginx if using an Ubuntu-like system.

• At this point you should have a working website over plain old HTTP.

Enabling HTTPS

• Set up your letsencrypt HTTPS certificate using certbot.

sudo certbot --nginx -d notes.nowacki.org

• With luck, certbot will request the certificate and update your nginx configuration file to handle HTTPS and redirect HTTP traffic to HTTPS.