Setting up a www subdomain on a self-hosted Ghost blog

Ghost CMS makes it fairly easy to link your blog to your own domain and set up SSL. The ghost setup command in ghost-cli basically does it for you. However, for me it didn't automatically set up a www subdomain. So I could access, say, https://https://myblog.lol, but https://www.myblog.lol would result in a 502. I was thinking of just adding a CNAME or ALIAS record in my providers DNS settings, but that didn't work somehow. So I just set an A record to point from www to the IP of my Ghost blog, which worked fine, but I didn't have any SSL then on my www subdomain. Thus, I had to tinker a bit in the nginx configs of Ghost, so that it automatically redirects all www traffic to the apex. I think that that's a pretty safe solution.

First I would config the www url by changing to /var/www/ghost and run ghost config url https://www.myblog.lol.
Then configure ssl via ghost setup nginx ssl. Set my config again to the apex domain with ghost config url https://myblog.lol. And now you will have to edit the nginx configs in /etc/nginx/sites-available. Go there, and if there are no files called www.myblog.lol-ssl.conf and www.myblog.lol.conf create them. The first one will have to look something like this:

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    server_name www.myblog.lol;
    root /var/www/ghost/system/nginx-root;

    ssl_certificate /etc/letsencrypt/www.myblog.lol/fullchain.cer;
    ssl_certificate_key /etc/letsencrypt/www.myblog.lol/www.myblog.lol.key;
    include /etc/nginx/snippets/ssl-params.conf;

    location / {
        return 301 https://myblog.lol$request_uri;
    }

    location ~ /.well-known {
        allow all;
    }

    client_max_body_size 1g;
}

The latter one should be this:

server {
    listen 80;
    listen [::]:80;

    server_name www.myblog.lol;
    root /var/www/ghost/system/nginx-root; # Used for acme.sh SSL verification (https://acme.sh)

    location / {
       return 301 https://myblog.lol$request_uri;
    }

    location ~ /.well-known {
        allow all;
    }

    client_max_body_size 50m;
}

That's it. Run sudo nginx -t to make sure you don't have any typo in your config files and then source your config files with sudo nginx -s reload. You might have to do ghost restart, if your www subdomain doesn't work immediately.