The reverse proxy is configured to route requests to any container that is currently running. For example, if I have a Jenkins container, as long as it is running, the reverse proxy will send requests to it. In this particular case, I need to proxy a remote host. In order to do that, I have a container running with the appropriate labels, the proxy sees the container running, and it proxies requests to the remote host.
I think I'm being particularly dense here, but do you mean the proxy is proxying to your tiny 1kb container? If so, what happens to the traffic? Or because the tiny container is running the proxy proxies somewhere else? i.e you're using the presence of a container with a label as configuration for the proxy?
I know, it's a bit difficult to explain and a tad confusing. No, the proxy is not sending any traffic to the container. Rather, the container, by simple virtue of being in the running state, tells the proxy to send requests to the domain specified by the label on the container.