On Apr 9, 2014, at 05:05 , Thierry FOURNIER <tfourn...@exceliance.fr> wrote:
> On Tue, 8 Apr 2014 11:02:42 -0700
> Marc Fournier <scra...@hub.org> wrote:
>
>>
>> as per the subject, has anyone done something like this?
>>
>> we’re setting up two backend pools, one geared to RTL languages, one to LTR
>> … I’d like to set it up so that its transparent to the end user, so that if
>> they come in requesting, for instance, Arabic, they get directed to the RTL
>> pool, and if they come in requesting English, they go to the LTR …
>>
>> I’ve searched for examples of doing this (figure I can use req.hdr() for
>> this), but have drawn a blank …
>>
>> Before I try and do it from scratch, just figured I’d see if I wasn’t
>> re-creating the wheel first …
>>
>> Thanks ...
>
>
> Hello,
>
> I understand your need, but the header accept-language is a little bit
> complicated to understand. How do you known the language required by
> the browser if the accept-language header contain data like this ("ar"
> is arabic, RTL language):
>
> ar,vi;q=0.8,fr-FR;q=0.6,fr;q=0.4,en-US;q=0.2,en;q=0.2
> vi-vn,vi;q=0.8,ar;q=0.5,en;q=0.3
> zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4,ar
> zh-TW,ar;q=0.8,ja;q=0.6,en-US;q=0.4,en;q=0.2
>
> In second time, if you find a solution to the first issue, you can use
> the acl file. This file can contain all RTL language, if the acl is
> true you can send the request.
>
> This is the file (list from wikipedia
> http://en.wikipedia.org/wiki/Right-to-left):
>
> mycomputer:~$ cat rtl_languages
> ar
> arc
> bcc
> bqi
> ckb
> dv
> fa
> glk
> he
> ku
> mzn
> pnb
> ps
> sd
> ug
> ur
> yi
>
> Haproxy config:
>
> use_backend rtl if {
> req.hdr(accept-language),<unknown-process-that-return-language> -m str -f
> rtl_languages }
nginx has a module for doing this (http://wiki.nginx.org/AcceptLanguageModule)
that appears to work on a ‘first match’ basis:
==
set_from_accept_language $lang en ja pl;
==
so site supports en/ja/pl … $lang variable set based on the first
Accept-Languages value that matches that list … if no match, default to the
first one (en) …
This might be more then could be done in the config file though, if you want to
honor the q= prioritizer, but that is just a method of grouping, from what I’ve
read in RFC2616 … your examples above, for instance, would translate as:
> zh-TW,zh;q=0.8,en-US;q=0.6,en;q=0.4,ar
zh-TW;q=1,zh;q=0.8,en-US;q=0.6,en;q=0.4,ar;q=1
which would then sort out to:
zh-TW,ar,zh,en-US,en
Of course, that assumes I’m reading how it works from RFC2616 correctly …
without any q= value, everything defaults to 1 and is parsed “in hte order
presented” … the q= modifier provides a sort order by weighting everything from
‘most desired’ to ‘least desired’ …
Hrmmm … a bit messy, but what I could probably do is use nginx in front of
haproxy to set a cookie that I could read in haproxy and redirect accordingly …
which I may need to do anyway, to support https:// …
And yes, I could use nginx to do the load balancing too, but I’m using
haproxy’s stats interface for load monitoring / alerting … I’d rather avoid
using nginx if I can, since it just adds one more layer ...
