This allow us to use a AEAT valid certificate in a independent server to increment the security.
The webservice clients has to make requests againts the proxy (with a valid SSL client provided by the proxy) and the proxy will resend this request to the AEAT SII system with a valid certificate.
docker run --name sii-proxy -v /path/nginx.conf:/etc/nginx/nginx.conf:ro \
-v /path/ssl:/etc/nginx/ssl:ro -p 4443:443 nginx