Forwarding server relay logs to a collector behind a proxy

I would like to forward logs to a centralized collector behind a proxy. The layout would look something like this: client > server relay > proxy server > internet > main collector. I am having trouble finding a destination driver that will work for this. I've exhausted all resources. I've tried the syslog(), network(), and http() drivers. I'm familiar with how to send logs to a main collector and have successfully implemented it in the past, but having the proxy there is what's causing the issue. So basically, the issue is happening between the server relay and the proxy server. 

My proxy is correctly setup and can curl web pages fine through the server relay. I've also tested a dummy page on the collector to see if i can curl the web page on the collector from the server relay. So this means that there is no connection issue between the server relay > proxy > collector.

How i'm testing to see if messages are received: viewing /var/log/messages, using the 'logger' command, checking log file stored from destination driver, and analyzing traffic with tcpdump.

Scenarios of tested destination drivers

  • network() and syslog() drivers: traffic doesn't even reach proxy server. Connection fails to hit the main collector IP through the proxy server. In the configuration for the server relay, the IP address is set to the main collector ip. (See attached photo of configs)

  • http() driver works because i can set the proxy, but obviously the information will be useless as this only returns info on the POST method.
    • Example: 
      destination d_proxy { http( url("collector_ip_here:514") proxy("proxy_server_ip:443") ); };
      log { source(s_client); destination(d_proxy); };

Attached are my config files for syslog-ng PE.

Are there any destination drivers that can send to a collector behind a proxy server? My proxy is tinyproxy