limit_req_zone $binary_remote_addr zone=api_limit:10m rate=20r/s;
server {
    listen 8080;
    server_name ${PUBLIC_HOST};
    if ($host != ${PUBLIC_HOST}) { return 400; }
    # Resolve through Docker's embedded DNS at request time.  This prevents
    # Nginx from exiting during a Swarm rollout when the API task is briefly
    # unavailable or still creating its database schema.
    resolver 127.0.0.11 ipv6=off valid=10s;
    set $api_upstream api:8000;

    # This gateway sits behind the host's reverse proxy, so $remote_addr is that
    # proxy, not the customer. Recover the real address from the header it sets,
    # and only when the connection comes from a private network: a request that
    # reaches the published port directly from the internet is not trusted, so
    # its X-Forwarded-For is ignored and $remote_addr stays the actual peer.
    set_real_ip_from 10.0.0.0/8;
    set_real_ip_from 172.16.0.0/12;
    set_real_ip_from 192.168.0.0/16;
    real_ip_header X-Forwarded-For;
    real_ip_recursive on;
    root /usr/share/nginx/html;
    index ${WEB_INDEX};

    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    add_header X-Content-Type-Options nosniff always;
    add_header Referrer-Policy no-referrer always;
    add_header X-Frame-Options DENY always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' @SCRIPT_HASHES@ ${PAYMENT_CSP_SOURCES}; script-src-attr 'none'; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com; img-src 'self' data: blob: https://cdn.vnda.com.br ${PAYMENT_CSP_SOURCES}; connect-src 'self' ${S3_PUBLIC_ENDPOINT} https://cdn.vnda.com.br ${PAYMENT_CSP_SOURCES}; frame-src 'self' ${PAYMENT_CSP_SOURCES}; worker-src 'self' blob:; object-src 'none'; base-uri 'none'; frame-ancestors 'none'; form-action 'self'" always;

    location = /health { access_log off; return 200 'ok'; }
    location /api/ {
        limit_req zone=api_limit burst=100 nodelay;
        limit_req_status 429;
        proxy_pass http://$api_upstream;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Proto https;
        # Overwrite, never append: $proxy_add_x_forwarded_for keeps any header the
        # client sent, and the leftmost value would then be attacker-controlled.
        # After real_ip above, $remote_addr is the customer even behind the proxy.
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_connect_timeout 5s;
        proxy_read_timeout 30s;
        client_max_body_size 2m;
    }
    # Always revalidate HTML/JS/CSS after a deployment. Without this, a browser
    # can pair a new Kanban page with a cached older script after a rollout.
    location / {
        expires -1;
        try_files $uri $uri/ =404;
    }
}