Using Domain Names in proxy_pass directive

[Ruslan Ermilov]

On Fri, May 23, 2014 at 07:39:36AM -0400, Shobhit Mishra wrote:
> Hi 
> 
> I am using nginx as reverse proxy with FQDN for the backend server .
> 
> My configuration for the location block looks like this :-
> 
> location / {
> 
>   set $ustreamsbc  sbc.example.com ;
>   proxy_pass  HTTPS://$ustreamsbc   ;
> 
>                 proxy_next_upstream error timeout invalid_header http_500
> http_502 http_503 http_504;
> 
>                 proxy_connect_timeout 10s ;
>                 include /usr/local/nginx/conf/proxy.conf ;
> 
> 
> 
>                 proxy_redirect     off;
>       }
> 
> I have a resolver in place for this FQDN  and its running fine.
> 
> 
> My doubt is that if I change the mapped IP for this FQDN in the DNS server ,
> would nginx re-resolve the FQDN to the new IP for all the future requests.
> 
> Also does nginx honor TTL  for all the FQDN stored in variables as shown
> above ??
> 
> Thanks and Regards
> 
> Shobhit Mishra

nginx will re-resolve names as configured by the
http://nginx.org/r/resolver directive.  By default,
the TTL of the response is honored but it can be
overridden.

(Whether the queried server has an up-to-date info
is another question.)