Our loadbalancers TMM has gone up quite a bit lately, so I started looking into how to move some of the workload to Varnish instead. I came across this configexample and pulled out the mobile redirects part. It’s a rather dirty hack, but it works. Varnish does not have support of HTTP redirects, so you have to trigger an error and then pick it up in the vcl_error subroutine later.
This is what the redirect-config looks like on my test-system :
sub vcl_recv {
if ( req.http.user-agent ~ "(.*Blackberry.*|.*BlackBerry.*|.*Blazer.*|.*Ericsson.*|.*htc.*
|.*Huawei.*|.*iPhone.*|.*iPod.*|.*MobilePhone.*|.*Motorola.*|.*nokia.*
|.*Novarra.*|.*O2.*|.*Palm.*|.*Samsung.*|.*Sanyo.*|.*Smartphone.*
|.*SonyEricsson.*|.*Symbian.*|.*Toshiba.*|.*Treo.*|.*vodafone.*
|.*Xda.*|^Alcatel.*|^Amoi.*|^ASUS.*
|^Audiovox.*|^AU-MIC.*|^BenQ.*|^Bird.*|^CDM.*|^DoCoMo.*|^dopod.*
|^Fly.*|^Haier.*|^HP.*iPAQ.*|^imobile.*|^KDDI.*|^KONKA.*|^KWC.*
|^Lenovo.*|^LG.*|^NEWGEN.*|^Panasonic.*|^PANTECH.*|^PG.*|^Philips.*
|^portalmmm.*|^PPC.*|^PT.*|^Qtek.*|^Sagem.*|^SCH.*|^SEC.*|^Sendo.*
|^SGH.*|^Sharp.*|^SIE.*|^SoftBank.*|^SPH.*|^UTS.*|^Vertu.*
|.*Opera.Mobi.*|.*Windows.CE.*|^ZTE.*)"
&& req.http.host ~ "(www.somehost.com)"
&& req.url == "/") {
set req.http.newhost = regsub(req.http.host, "(www)?\.(.*)", "http://m.\2");
error 750 req.http.newhost;
}
sub vcl_error {
if (obj.status == 750) {
set obj.http.Location = obj.response;
set obj.status = 302;
deliver;
}
}