Log response header from upstream

[Maxim Dounin]

Hello!

On Mon, Nov 07, 2011 at 11:57:15AM +0100, Kamil Gorlo wrote:

> OK, thanks - it works.
> 
> One more question: I have to use this variables in quotes because
> sometimes it resolves to just empty string and there is problem with
> parsing such logs.
> 
> Why sometimes empty variables ends in single hyphen ("-", this is what
> I allways want) in access log and sometimes its just empty string
> ("")?

Hyphen is used when variable isn't found.  Empty string - if it's 
found, but empty.

Maxim Dounin

> 
> --
> Kamil Gorlo
> 
> 
> 
> On Mon, Nov 7, 2011 at 11:19 AM, Maxim Dounin <mdounin at mdounin.ru> wrote:
> > Hello!
> >
> > On Mon, Nov 07, 2011 at 06:42:09AM +0100, Kamil Gorlo wrote:
> >
> >> Yeah, I have tried this, but this way non x-accel-redirect requests must be
> >> handled in old way which means I have to use 2 fields in access log. Is
> >> there any way to use only one field?
> >
> > E.g. you may use different log format for internal location.
> >
> > Maxim Dounin
> >
> >> 06-11-2011 22:15 użytkownik "Maxim Dounin" <mdounin at mdounin.ru> napisał:
> >>
> >> > Hello!
> >> >
> >> > On Sun, Nov 06, 2011 at 09:48:08PM +0100, Kamil Gorlo wrote:
> >> >
> >> > > Hi,
> >> > >
> >> > > I have some problem with access log combined with X-Accel-Redirect
> >> > > requests. In my case I have Nginx set up as load-balancer to group of
> >> > > application servers. These servers return some special header in every
> >> > > request - I need to log value of this special header (lets call it
> >> > > 'X-user') in access log - also I do not want to expose this header to
> >> > > the world (proxy_hide_header helps here).
> >> > >
> >> > > Everything seems to work, but when there is X-Accel-Redirect request I
> >> > > have empty field in access log because of subrequest
> >> > > ($upstream_http_x_special is cleared because of subrequest, if I
> >> > > understand this mechanism correctly). How to make this work for every
> >> > > request?
> >> > >
> >> > > Here is my config:
> >> > >
> >> > > http {
> >> > >   log_format extended '$request $upstream_http_x_user';
> >> > >   access_log /var/log/nginx/access.log extended;
> >> > >
> >> > >   ...
> >> > >
> >> > >   server {
> >> > >     listen 80;
> >> > >
> >> > >     location / {
> >> > >       proxy_pass http://backend;
> >> > >       proxy_hide_header X-User;
> >> > >     }
> >> > >
> >> > >     location /files {
> >> > >       internal;
> >> > >       proxy_pass http://filestore;
> >> >
> >> > Workaround is to use
> >> >
> >> >        set $x_user $upstream_http_x_user;
> >> >
> >> > here (and to log $x_user instead).
> >> >
> >> > >     }
> >> > >   }
> >> > > }
> >> >
> >> >
> >> > Maxim Dounin
> >> >
> >> > _______________________________________________
> >> > nginx mailing list
> >> > nginx at nginx.org
> >> > http://mailman.nginx.org/mailman/listinfo/nginx
> >> >
> >
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