regex matching on a cookie

[Harish Sundararaj]

Hi all,
Sorry that location block should have been:

location ~ ^/cnvpb/(\d+)/ {
set $integer $1;
proxy_pass http://$backend;
}

Thanks
Harish


On Tue, Sep 4, 2012 at 1:22 AM, Harish Sundararaj <tuxtoti at gmail.com> wrote:
> Hi all,
>
> After a bit of head scratching, I came up with this:
>
> 1) Parse $integerA from the URI
> 2) Have two map blocks.
> a) one to get $TermC from the cookie
> b) one to map a backend based on the $TermC
>
> Here is what I have got:
>
>         map $http_cookie $termC {
>                 ~adq_cnv(\d+)=($integer[^;]+#(\w{2}))(?:;|$) $3;
>                 default "WX";
>         }
>
>        map $termC $backend {
>             WX w.x.y.z;
>             AB a.b.c.d;
>        }
>
>
> location ~ ^/cnvpb/(\d+)/ {
> set $cmpid $1;
> proxy_pass http://$backend;
> }
>
>
> But unfortunately it fails saying - "invalid number of map
> parameters". I think its something to do with variable interpolation.
> So a few questions:
> 1) How do I substitute a variable inside a regex ?
> 2) The regex works with a if condition. I kind of extended it from
> here: http://wiki.nginx.org/HttpRewriteModule#if. But there seems to
> be a "space" between "[^;]" and "+" not sure why. Is that right?
> 3) Anything else that can be done better?
>
> Thanks
> Harish
>
>
> On Mon, Sep 3, 2012 at 9:04 PM, Harish Sundararaj <tuxtoti at gmail.com> wrote:
>> Hello,
>>
>> I have a URI like this:
>>
>> example.com/cnvpb/$IntegerA/$TermA
>>
>> eg:
>> example.com/cnvpb/1233/Q4
>>
>> For this request , I might get cookies with names like
>>
>> abc_cnv1, abc_cnv2, abc_cnv3....abc_cnv5
>>
>> all or some of them. The value of these cookies are of the format:
>>
>> $integerB#$TermB#$integerC#$TermC
>>
>> Eg:
>> 1234#blahblah#45#Q1
>>
>> Now this is the requirement:
>>
>> If for any of the cookies in abc_cnv[1-5], $integerA equals $intergerB
>> choose an upstream based on $TermC.
>>
>> I have figured out few of things:
>>
>> 1) Parsing $integerA - Using a regex in the location block
>> 2) Choosing an upstream based on $TermC - using a map block
>>
>> However, I'm stuck at reading cookies (not sure how to read only :
>> abc_cnv[1-5]). I understand it can be done using multiple ifs .
>> But I'm sure there should be a better way than that.
>>
>> Any pointers?
>>
>> Thanks
>> Harish