How to proxy Nginx traffic depending on a request from a DNS server?

Question

Nginx

How to pull out a domain from a request and insert it into a proxy.Here is the Nginx proxy config

server {
listen 80;
server_name localhost;
location / {
proxy_pass http://127.0.0.1:80;
}
}

The DNS server sends the user to my server with Nginx, but I can’t figure out how to make Nginx send it to the right place depending on the site that the user entered.
It is necessary that, when requested on google.com, the config becomes

server {
listen 80;
server_name localhost;
location / {
proxy_pass http://google.com:80;
}
}

When requesting yahoo.com

server {
listen 80;
server_name localhost;
location / {
proxy_pass http://yahoo.com:80;
}
}

Something like determining where a person needs and substituting this value in the nginx proxy. Thanks

Answer 1

location / {
    proxy_pass http://$http_host$request_uri;
    proxy_set_header Host $http_host;
    resolver 77.88.8.8;
}

As resolverto specify any DNS server, but not the one that sends everyone to your nginx, otherwise you will get recursion.

Answer 2

If I correctly understood what you need, then you need
server_name localhost;
replace localhost with the name of your server.

Answer 3

Maybe you need $hostname ?

Answer 4

If I do so

server {
listen 80;
server_name localhost;

location / {
proxy_pass http://$hostname:80;

}
}

I get 502 Bad Gateway