How to implement a proxy?

Question

proxy

There is such a problem: there are several dozen http proxies, on the server you need to raise a separate proxy, which will scatter requests to higher proxies depending on the port on which it was accessed.
Those. there are groups of servers proxyA, proxyB, proxyC. You need to implement proxy:3128 -> proxyA, proxy:3129 -> proxyB, proxy:3130 -> proxyC.
How can this be done as painlessly as possible? Squid looked, there are groups of upstream proxies and weighted round-robin, but you can only deal with ports by raising one more instance, which is not very convenient if there are more than 3 of them.

Answer 1

Correct answer: haproxy.

Answer 2

If the port mapping to a certain proxy is strict, then you can use port mapping.

Answer 3

squid can do everything