I have a php-application which connects to another app called Solr (database search engine). I can via this php app add/remove documents (records) from the Solr index.

However, the Solr security is low, and anybody with the right port nr can access Solr and remove documents (records).

I wonder, is it possible to ONLY allow my own php-app to have access to Solr somehow? Prefferably via Iptables. I am thinking I can only allow my own servers IP to that port, and it would solve my problem, because PHP is a server-side code. But I am not sure.

About the Php-app:
The website is a classifieds website, and when users wants to add or remove classifieds, they do so through a php app, which is this one. The app has a function which connects to solr and updates the database (index).

I appreciate detailed answers...

Thanks