nginx.conf

server {
    listen       3000;
    listen  [::]:3000;
    server_name  _;

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

    # ---------- Security headers ----------
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), interest-cohort=()" always;
    add_header Cross-Origin-Opener-Policy "same-origin" always;
    add_header Cross-Origin-Resource-Policy "same-origin" always;
    # HSTS only takes effect when served over HTTPS at the edge (ingress / LB).
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    # ---------- Gzip compression ----------
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/javascript
        application/x-javascript
        application/json
        application/xml
        application/xml+rss
        application/wasm
        image/svg+xml;

    # ---------- Long-term cache for hashed assets ----------
    location /assets/ {
        access_log off;
        expires 1y;
        add_header Cache-Control "public, max-age=31536000, immutable" always;
        add_header X-Content-Type-Options "nosniff" always;
        try_files $uri =404;
    }

    # Hashed static files (favicon, fonts, etc.) get a shorter cache
    location ~* \.(?:ico|svg|png|jpg|jpeg|gif|webp|woff2?|ttf|otf|eot)$ {
        access_log off;
        expires 7d;
        add_header Cache-Control "public, max-age=604800" always;
        try_files $uri =404;
    }

    # ---------- Never cache the entry HTML ----------
    location = /index.html {
        add_header Cache-Control "no-store, no-cache, must-revalidate" always;
        add_header X-Content-Type-Options "nosniff" always;
        expires 0;
    }

    # robots.txt and version.json are always-fresh
    location = /robots.txt {
        access_log off;
        add_header Cache-Control "public, max-age=3600" always;
    }

    location = /version.json {
        access_log off;
        add_header Cache-Control "no-store" always;
    }

    # ---------- SPA fallback ----------
    location / {
        try_files $uri $uri/ /index.html;
    }

    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        internal;
    }
}