nginx.conf

# Serves the Astro Starlight static build.
#
# Plain HTTP on port 80, on purpose. Traefik terminates TLS: the browser
# connects to Traefik over 443, and Traefik forwards a plain request to this
# container over the private Docker network. The certificate, its renewal and
# the public hostname all live in Traefik, so this server needs no 443
# listener and no certificate of its own.
#
# Astro writes each page as `<page>/index.html`, which the `index` directive
# resolves, so no rewrite rules are needed.

server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    location / {
        try_files $uri $uri/ =404;
    }

    # Asset filenames contain a content hash, so a given URL never changes.
    location /_astro/ {
        access_log off;
        add_header Cache-Control "public, max-age=31536000, immutable";
        try_files $uri =404;
    }

    # Starlight generates this page as part of every build.
    error_page 404 /404.html;

    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types
        text/plain
        text/css
        text/xml
        application/javascript
        application/json
        application/xml
        image/svg+xml;
}