Redirect HTTP to HTTPS using Varnish

I recently enabled HTTPS on this site and wanted to use a 301 redirect in order to correctly re-route guests from HTTP to HTTPS (HTTP to SSL/TLS). I originally performed all of my rewrites in Apache which acts as my backend. While Apache handled the typical non-www to www redirects with ease, it created a redirect loop when attempting to redirect users from HTTP to HTTPS. I decided to let Varnish Cache 4 rather than the Apache backend handle the redirect.

The documentation on the Varnish site is for Varnish 3 which is not compatible for Varnish 4 as of this writing:

sub vcl_recv { if ( (req.http.host ~ "^(?i)somesite.org" || req.http.host ~ "^(?i)www.somesite.org") && req.http.X-Forwarded-Proto !~ "(?i)https") { set req.http.x-Redir-Url = "https://www.somesite.org" + req.url; error 750 req.http.x-Redir-Url; }
} sub vcl_error { if (obj.status == 750) { set obj.http.Location = obj.response; set obj.status = 302; return (deliver); }

After some research, I found a redirect example that was similar to what I was trying to achieve in Varnish 4:

sub vcl_recv { if ( (req.http.host ~ "^(?i)www.domain.com" || req.http.host ~ "^(?i)domain.com") && req.http.X-Forwarded-Proto !~ "(?i)https") { return (synth(750, "")); }
} sub vcl_synth { if (resp.status == 750) { set resp.status = 301; set resp.http.Location = "https://www.domain.com" + req.url; return(deliver); }
}

Now non-HTTPS requests to domains listed in the vcl_recv should redirect to the respective HTTPS version of your site.