location ~ ^/foo(/?)(.*)$ {
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_redirect ~^http://backend/(.*)$ https://$host/$1;
    proxy_pass http://backend;
    location ~ ^/foo(/?)(special.*)$ {
        proxy_read_timeout 600s;
    }
}