location ^~ /blog/ {
        set $upstream_blog 123.45.67.89;
        proxy_pass  http://$upstream_blog:80$request_uri;
        proxy_set_header    Host                $host;
        proxy_set_header    X-Real-IP           $remote_addr;
        proxy_set_header    X-Forwarded-For     $remote_addr;
        proxy_set_header    X-Forwarded-Host    $host;
        proxy_set_header    X-Forwarded-Server  $host;
        proxy_set_header    X-Forwarded-Proto   https;
        proxy_redirect off;
        proxy_connect_timeout 90s;
        proxy_read_timeout 90s;
        proxy_send_timeout 90s;
        proxy_buffering    off;
        proxy_buffer_size  128k;
        proxy_buffers 100  128k;
    }