varnish rails devise logout configuration - ruby-on-rails-3

Question

I am using varnish in front end as caching server and apache2 with passenger is running on back-end for my rails3 application.I am using devise gem for my authentication but i am not able to lougout.
I think varnish has a option to clear logged in user session or cookie.I want to know the varnish configuration so that i can logout.
Here is my varnish configuration :
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
if(req.url ~ "my" || req.request == "POST" || req.request == "PUT" || req.request == "DELETE") {
return (pass);
}
return (lookup);
}
sub vcl_fetch {
if(req.url ~ "logout" || req.url ~ "sign_out"){
unset beresp.http.Set-Cookie;
}
if (req.request == "GET") {
unset beresp.http.Set-Cookie;
set beresp.cacheable = true;
set beresp.ttl = 360m;
}
if (req.url ~ "images/" || req.url ~ "javascripts" || req.url ~ "stylesheets"){
set beresp.ttl = 360m;
}
}

Answer 1

I suppose that you have to include the logout urls in tou recv function because otherwise you are not telling rails to kill the session.
i would try with something like:
sub vcl_recv {
if(req.url ~ "logout" ||req.url ~ "my" || req.request == "POST" || req.request == "PUT" || req.request == "DELETE") {
return (pass);
}
return (lookup);
}