Configure multiple sites with Varnish

Question

We have a server which needs to serve multiple domains though varnish e.g. example1.com, example2.com and example3.com

Our current .vcl file looks like this:

Answer 1

unable to add comment so here we go

slight modification for varnish 4

#for www.example.com or example.com
if (req.http.host ~ "^(www\.)?example\.com$") {
        set req.backend_hint = example_com;
        return (lookup);
}

#with any subdomain support
if (req.http.host ~ "^(.*\.)?example2\.com$") {
        set req.backend_hint = example2_com;
        return (lookup);
}

replace backend with backend_hint