Reviving this briefly. I’ve already got Varnish running on my web server, so including Discourse’s static assets in it has basically zero additional cost to me.
On the other hand, I’m running Discourse behind Nginx with Passenger; Nginx is quite good at serving static assets—in fact, under low-to-moderate load, it’s almost always faster than Varnish. Varnish wins as load begins to ramp, though.
Right now (since my Discourse forum is LAN-only and really just for me to play with) I’ve got a statement in vcl_recv to just pass all traffic with my Discourse URL in it, but will it be problematic to enable it? @richp10, have you noticed any cookies placed that you need to strip?