Matching the host header

[Julien Vehent]

Hi there,

I have a quick question for which I haven't found any answer in the 
doc.
I use haproxy as a host balancer: it stands in front of my web 
servers, listening on port 80, and directs incoming requests to the 
good backend depending on the value of the host header (site1, site2, 
and so on...).

I have a frontend section as follow :

###
frontend http-in
       bind *:80
       default_backend siteX

       acl host_hdr_siteA hdr(host) -i sitea.com
       acl host_hdr_siteB hdr(host) -i siteb.org
       acl host_hdr_siteC hdr(host) -i sitec.net

       use_backend siteA if host_hdr_siteA
       use_backend siteB if host_hdr_siteB
       use_backend siteC if host_hdr_siteC
###

The only thing is that the ACLs seem to match only exact value. Thus, 
if somebody tries 'www.sitea.com' instead of 'sitea.com', the acl of 
sitea doesn't match and the visitor is directed to the default backend.

My question is: what is the clean way to do this ? Should I have two 
ACLs for the same site or can I use regex on header matching ?

(or all of this is just simply wrong, in which case how can/should I 
do it :) )

Thanks,
Julien