nginx transparent reverse proxy for denonavr debug - replace $avr with the avr ip

interface

auto lo:192
iface lo:192 inet static
	address 192.168.123.45/32

nft-ruleset

table ip nat {
	chain denon-intercept {
		ip saddr 192.168.123.45 ip daddr $avr dnat to $avr
		ip daddr $avr tcp dport 80 dnat to 192.168.123.45:8001
		ip daddr $avr tcp dport 8080 dnat to 192.168.123.45:8002
		ip daddr $avr tcp dport 60006 dnat to 192.168.123.45:8003
	}

	chain denon-intercept-remote {
		type nat hook prerouting priority -101; policy accept;
		jump denon-intercept
	}

	chain denon-intercept-local {
		type nat hook output priority -101; policy accept;
		jump denon-intercept
	}

	chain denon-forward {
		type nat hook postrouting priority 99; policy accept;
		ip saddr 192.168.123.45 oif "bond0" masquerade
	}
}

nginx-site

    log_format bodylog '$remote_addr - $remote_user [$time_local] '
        '"$request" $status $body_bytes_sent '
        '"$http_referer" "$http_user_agent" $request_time '
        'REQUEST:"$request_body" RESPONSE:"$resp_body"';

    server {
        listen       192.168.123.45:8001;
        server_name  localhost;

        # http://serverfault.com/questions/361556/is-it-possible-to-log-the-response-data-in-nginx-access-log
        access_log  /var/log/nginx/avr.80.access.log  bodylog;

        lua_need_request_body on;

        set $resp_body "";
        body_filter_by_lua '
          local resp_body = string.sub(ngx.arg[1], 1, 100000)
          ngx.ctx.buffered = (ngx.ctx.buffered or "") .. resp_body
          if ngx.arg[2] then
            ngx.var.resp_body = ngx.ctx.buffered
          end
        ';

        location / {
            proxy_pass   http://$avr:80;
            proxy_bind   192.168.123.45;
        }
    }

    server {
        listen       192.168.123.45:8002;
        server_name  localhost;

        # http://serverfault.com/questions/361556/is-it-possible-to-log-the-response-data-in-nginx-access-log
        access_log  /var/log/nginx/avr.8080.access.log  bodylog;

        lua_need_request_body on;

        set $resp_body "";
        body_filter_by_lua '
          local resp_body = string.sub(ngx.arg[1], 1, 100000)
          ngx.ctx.buffered = (ngx.ctx.buffered or "") .. resp_body
          if ngx.arg[2] then
            ngx.var.resp_body = ngx.ctx.buffered
          end
        ';

        location / {
            proxy_pass   http://$avr:8080;
            proxy_bind   192.168.123.45;
        }
    }

    server {
        listen       192.168.123.45:8003;
        server_name  localhost;

        # http://serverfault.com/questions/361556/is-it-possible-to-log-the-response-data-in-nginx-access-log
        access_log  /var/log/nginx/avr.60006.access.log  bodylog;

        lua_need_request_body on;

        set $resp_body "";
        body_filter_by_lua '
          local resp_body = string.sub(ngx.arg[1], 1, 100000)
          ngx.ctx.buffered = (ngx.ctx.buffered or "") .. resp_body
          if ngx.arg[2] then
            ngx.var.resp_body = ngx.ctx.buffered
          end
        ';

        location / {
            proxy_pass   http://$avr:60006;
            proxy_bind   192.168.123.45;
        }
    }