Removing a request header in an access phase handler

[Maxim Dounin]

Hello!

On Mon, Jul 08, 2013 at 06:45:33PM +0200, Jan Algermissen wrote:

> Hi,
> 
> I developing a handler for the access phase. In this handler I 
> intend to remove a certain header.
> 
> It seems that this is exceptionally hard to do - the only hint I 
> have is how it is done in the headers_more module.
> 
> However, I wonder, whether there is an easier way, given that it 
> is not an unusual operation.

Removing request headers from a request isn't something supported 
by nginx.

What is supported is filtering/modification of headers passed to 
upstream servers with proxy_set_header (fastcgi_param, ...).

E.g., this is how proxy module provies a way to add 
X-Forwarded-For header.  It implements the $proxy_add_x_forward_for 
variable, which is expected to be used in a config like this:

   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

> If not, I'd greatly benefit from a documentation of the list and 
> list-part types. Is that available somewhere? Seems hard to 
> figure out all the bits and pieces that one has to go through to 
> cleanly remove an element from a list.

Try looking into src/core/ngx_list.[ch] for a documentation in C.  
It doesn't really support elements removal though.

-- 
Maxim Dounin
http://nginx.org/en/donation.html