Reverse-Proxy Lösung

server {
    listen 443 http2;
    server_name subdomain.yourdomain.de;

	# SSL Config
	ssl_certificate         /etc/nginx/certs/yourcert.cer;
	ssl_certificate_key     /etc/nginx/certs/yourkey.key;
	ssl_session_timeout 120m;
        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    location / {
        proxy_pass http://yourbackendserver;
        proxy_cookie_path / /;

		proxy_set_header   Host $host;
		proxy_set_header   X-Real-IP $remote_addr;
		proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
		proxy_set_header   X-Forwarded-Proto $scheme;
        }

	# HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
	add_header Strict-Transport-Security max-age=15768000;

	error_log /var/log/nginx/yourdomain-error.log;
        access_log /var/log/nginx/yourdomain-access.log;
}