How to find out by domain name or by ip a request came and for which one specifically?

Question

linux

Good afternoon.
How can you determine the full path of a request?
those. we have one site responsible for IP and for all non-existent subdomains. Accordingly, in the logs of this particular site, I see queries like "/blah-blah-blah/". But I would like to understand the request was on 1.1.1.1/bla-bla-bla/ or site.ru/bla-bla-bla/ or sub.site.ru/bla-bla-bla/
This implies 2 questions:
1. how to determine and log this moment
2. if we have different ip:port services, is it possible to somehow configure it to a non-existing subdomain or only by ip the response is 404 or 503

Answer 1

There is a very simple advice for both of your questions - make virtual hosts, for a site by name, for a site by ip, etc. In virtual hosts, describe the desired behavior of the web server and your logs for each. That is, if the client came to 192.168.1.1 - always get 404 , and if on site.ru - a normal site, etc.
How to do it depends on your web server - both apache and nginx make it easy, it's in all the examples and documentation.

Answer 2

Requests always come to an IP address. The difference is in the header Host, which can be logged at the web server level.