View source for Varnish How to redirect non-www URLs to www

==How to redirect non-www URLs to www in Varnish==

If a website's canonical URL has www, it is desirable, as a good SEO practice, to redirect the non-www URLs to www. That is, if the canonical URL is www.briansnelson.com, example.com should be redirected to www.briansnelson.com. How to do this when Varnish is listening on port 80 as a reverse HTTP proxy.

Add the following code in the file, /etc/varnish/default.vcl

===Redirect from non-www to www===

 sub vcl_recv { 
    if (req.http.host == "briansnelson.com") { 
    set req.http.host = "www.briansnelson.com"; 
    error 750 "http://" + req.http.host + req.url; 
    } 
 }

Now you will want to create the redirect

 sub vcl_error { 
    if (obj.status == 750) { 
    set obj.http.Location = obj.response; set obj.status = 301; 
    return(deliver); 
    } 
 }

===Redirect from www to non-www===


 sub vcl_recv { 
    if (req.http.host == "www.briansnelson.com") { 
    set req.http.host = "briansnelson.com"; 
    error 750 "http://" + req.http.host + req.url; 
    } 
 }

Now you will want to create the redirect

 sub vcl_error { 
    if (obj.status == 750) { 
    set obj.http.Location = obj.response; set obj.status = 301; 
    return(deliver); 
    } 
 }