server_name and listen behaviour

[Igor Sysoev]

On Feb 12, 2013, at 23:14 , Ruslan Ermilov wrote:

> On Tue, Feb 12, 2013 at 09:10:17PM +0400, ivan babrou wrote:
>>   Hi, I have a question. It's better to describe with example
>>   I point one.local and two.local to 127.0.0.1 and create following servers
>>   in config for nginx:
>>   server {
>>     listen 80;
>>     server_name one.local;
>>     location / {
>>       return 404;
>>     }
>>   }
>>   server {
>>     listen two.local:80;
>>     server_name two.local;
>>     location / {
>>       return 403;
>>     }
>>   }
>>   If I request one.local then 403 is returned. If i change listen for
>>   one.local to one.local:80 then 404 correctly returned, but only after
>>   restart, reload doesn't help (that's probably bug too).
>>   I expect to get 404 if i request one.local even if I listen on all
>>   addresses. Am I right?
> 
> 127.0.0.1:80 and *:80 are two different socket addresses,
> and when you connect to 127.0.0.1:80, the first one will
> be used (two.local in your case).  This is not specific
> to nginx, it's how sockets work.
> 
> nginx by default optimizes such a config by creating only
> one listening socket [1], and pessimizes by using getsockaddr()
> to differentiate between multiple sockaddrs.  This optimization
> can be turned off by using "bind" parameter (or some other
> parameters, see [1] for details).  Nevertheless, 127.0.0.1:80
> and *:80 are still two different addresses, and 127.0.0.1:80
> is more specific than *:80.
> 
> As to "reload not working", I cannot reproduce this:
> 
> (in my config I always return 200 with "$server_name")
> 
> $ echo 'GET http://one:8000/' | nc 127.0.0.1 8000
> two.local
> 
> # here config was changed to listen on 127.0.0.1:80
> # instead of *:80 for one.local
> 
> # reload (kill -HUP nginx master process)
> 
> $ kill -HUP 33122
> $ echo 'GET http://one:8000/' | nc 127.0.0.1 8000
> one.local
> 
> [1] http://nginx.org/r/listen

I believe on Linux you cannot use

listen  *:80  bind;
listen  127.0.0.1:80  bind;


--
Igor Sysoev
http://nginx.com/support.html