checking headers

[Larry Martell]

On Tue, May 31, 2016 at 11:38 AM, Francis Daly <francis at daoine.org> wrote:
> On Tue, May 31, 2016 at 10:26:26AM -0400, Larry Martell wrote:
>> On Tue, May 31, 2016 at 9:45 AM, Francis Daly <francis at daoine.org> wrote:
>
> Hi there,
>
>> > Possibly one of them covers what you want?
>>
>> There are 2 ways requests get to port 8000, which is the port I want
>> to check headers on.
>>
>> One is via a C++ Qt app, and the other is from a python django app.
>>
>> The C++ app sends the request directly to port 8000. With the django
>> app a request is sent to port 8004 and django sends a 301 redirect to
>> 8000. In both cases the header field X-Capdata-Auth is set. And in
>> neither case does my config pick that up. This is what I have:
>>
>> map $http_x_capdata_auth $not_auth {
>>         default 1;
>>         "authorized" 0;
>> }
>>
>> Is that the correct way to check for that header value?
>
> Yes. That checks for the request header from the client.
>
> It works for me:
>
> ==
> http {
>   map $http_x_capdata_auth $not_auth {
>     default 1;
>     "authorized" 0;
>   }
>
>   server {
>     listen 8080;
>     location / {
>       if ($not_auth) { return 401 "$http_x_capdata_auth, $not_auth\n"; }
>       return 200 "$http_x_capdata_auth, $not_auth\n";
>     }
>   }
> }
> ==
>
> curl -v -H 'X-CapData-Auth: authorized' http://127.0.0.1:8080/test
> --> HTTP/1.1 200 OK; authorized, 0
>
> curl -v  http://127.0.0.1:8080/test
> --> HTTP/1.1 401 Unauthorized: , 1
>
>> Is there a way for me to dump the headers that it sees on requests to port 8000?
>
> Within nginx, probably the debug log is simplest.
>
> Outside nginx: tcpdump, or ask the client what it sends.

Using curl I can see that ngixn is doing the right thing. Looking at
the request coming out of the clients show the header being there.
Using tcpdump I do not see the header. I know this is no longer an
nginx question, but anyone know why that header would get dropped
along the way?