Varnish and Magento

[Cédric Perronnet]

Hello,

I'm trying to make varnish and magento fits together.

I used some online documentation to create a magento module that will
setup a special cookie when something is added to the cart or wishlist.
This part is working quite well.

Problem is that I have different store inside this magento install.
Some are url related which is solved via varnish hash, using the host.

But some stores only use an url to swith between showing price with VAT
or without per example.
so I must find a way into varnish to make it handle a new cache bucket
and to switch between those buckets whenever an user click on the link (
?__store=de_ht per example ).

I'm thinking about setting a cookie and had the cookie to the varnish
hash to achieve that goal.
Is there any better way to make that? If anybody has some information
about combining varnish and magento, best practice etc , I would truly
appreciate.

Regards
CP