I was once working on a way to minimize PAC [1] file changes and came up with a hacky way to use DNS for this. The client would use isResolvable(parsedhost.pact

I was once working on a way to minimize PAC [1] file changes and came up with a hacky way to use DNS for this. The client would use isResolvable(parsedhost.pactest.int.domain.com) after some parsing of host, and use the result of the test to return either a PROXY result or DIRECT. It resulted in an extra DNS query for every site being accessed, but because the query is internal and the client caches the result, it didn't add much load but otherwise worked well. Then it was just a matter of automating A record creation. [1] https://en.wikipedia.org/wiki/Proxy_auto-config https://en.wikipedia.org/wiki/Proxy_auto-config