Installing Varnish 3 on CentOS 7
Oddly, there isn’t a lot of information on installing Varnish 3 on CentOS 7. There’s well-written instructions on the official site for CentOS 5/6, but for 7, it seems like you’re stuck with Varnish 4 (from the epel-release repository), especially if you’ve searched around and found forum threads like this one.