varnish rewrite

https://serverfault.com/questions/858445/varnish-redirect-to-home-web-dir

キャッシュする場合は req.http.host も書き換えたほうがよいはず

sub vcl_hash {
    hash_data(req.url);
    if (req.http.host) {
        hash_data(req.http.host);
    } else {
        hash_data(server.ip);
    }
    return (lookup);
}

https://www.varnish-software.com/developers/tutorials/varnish-builtin-vcl/#4-vcl_hash