No headers filter for a subrequest

[Maxim Dounin]

Hello!

On Mon, Mar 16, 2015 at 03:14:15PM +0300, Marat Dakota wrote:

> Hi,
> 
> I was digging the reason why add_header in nginx config doesn't work for a
> subrequest and I've found this in ngx_http_headers_filter_module.c:
> 
>     if ((conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL)
>         || r != r->main)
>     {
>         return ngx_http_next_header_filter(r);
>     }
> 
> Is there a particular reason to skip the filter for everything that's not a
> main request?

The main reason is that there are no headers in subrequest 
responses.  Headers are returned by the main request only.

-- 
Maxim Dounin
http://nginx.org/