tcpproxy | Proxy TCP connections based on static rules | TCP library

You'll need to insert the envoy.filters.network.ext_authz filter into the filter chain before the envoy.filters.network.tcp_proxy and setup a cluster that will actually make the Authz decision.

The envoy docs have a good example to follow.

After getting the message of no matching filter chain, I found the filter chain for the port 31020 with the domain that I have provided in my Gateway config. It looks like while connecting my application(ODBC), the host was not being provided.

The solution is simply to replace the host domain by '*'

I have solved the issue. Browsers use a random port to send http/https requests. As I understand, this can be circumvented by adding a colon and the desired port number to the end of the url.

saw your chat in IRC #netty.

A couple of things here. Your Proxy would need to have a server side that Server 1 connects to. Then the Server 2 and Server 3 need to either except a connection from the Proxy or you could use UDP (depending) to receive data from the Proxy.

Netty has an example of a proxy server. This would work in your case and its really easy for the third part. Simply put you would use the existing example and open a new connection which would be to Server 3. Now what you can do is take both channels from the Proxy (Client Connections to server 2 and 3) Put them in a channel group and write one time to two servers!. My example code that is edit will... allow communications from server 1 to server 2 through the proxy mutually and allow for mutual talk while server 3 only can receive data but if server 3 replies to the proxy, the proxy doesn't do anything. You may want to add a handler to release buffers or handle data written back that shouldn't be from server 3. Also from here this should get you started but check out netty documents, api, examples and ppts they are super helpful!

I will attach some modified code to show you and here is a link to the examples.

Netty Proxy Server Examples

So for the Example you would edit the HexDumpProxyFrontendHandler.class and just add a second Bootstrap for the new client for Server 3.

Current Code

Your script listens on 127.0.0.1, which is your local loopback device. In this case its the loopback device of your container, not 'your' localhost. I am assuming that expose and -p are publishing the port of the ip address of your container to your host. Not its loopback device.

So you need to listen on your external ip address. Try listening to 0.0.0.0