I have two rules for nginx (local):

server_name alocal;
listen 80; 
location / {
    ...
    proxy_pass http://localhost:8081;
}

and

server_name blocal;
listen 80; 
location / {
    ...
    proxy_pass http://localhost:8082;
}

I also changed the "hosts" file.

C:\Windows\System32\Drivers\etc\hosts


127.0.0.1             alocal
127.0.0.1             blocal

Everything works well. When I make a request through the browser, I get the expected behavior.

http://alocal -> http://127.0.0.1:8081
http://blocal -> http://127.0.0.1:8082

But when I specify just "localhost" as a host, nginx still processes my request, and it takes the first rule that comes along (from those that I gave above).

http://localhost -> http://127.0.0.1:8081
or (depends on which rule comes first)
http://localhost -> http://127.0.0.1:8082

1. Why does nginx process localhost if other hosts (alocal, blocal) are specified in server_name?

2. How to make nginx process only the specified host (alocal, blocal), but ignore the "naked" ip address?

CodePudding user response：

Nginx listening to Port 80. If there is a request not matching any server_name the default is taken. Either given by listen 80 default_server; or the first entry if omitted. If you want to block all requests not matching the specified server_name or with empty Host-Header you need a catch all as last block:

server {
    listen      80 default_server;
    server_name "";
    return      444;
}

It will be not really ignored, but rejected. You can't "ignore" something, nginx is blocking port 80 and handling all requests somehow.