default.vcl

 # handle vhosts here
 if (req.http.host ~ "^(www.)?staging-seriouseats.com$") { 
    set req.http.host = "www.staging-seriouseats.com";
    set req.backend = staging; 
 } 
 else if (req.http.host ~ "^newyork.staging-seriouseats.com$") { 
     set req.backend = staging; 
 }
 else { 
    set req.backend = apache; 
 }