xx.com {
    @ws {
        path /ws
        header Connection *Upgrade*
        header Upgrade websocket
    }
    @grpc protocol grpc
    reverse_proxy @ws http://127.0.0.1:2001
    reverse_proxy @grpc h2c://127.0.0.1:2002 {
        transport http {
            versions h2c
        }
    }
    reverse_proxy /h2 h2c://127.0.0.1:2003 {
        transport http {
            versions h2c
        }
    }
    root * /var/www
    file_server
}