How to secure your own server

Hi, there is a problem with some services port all of them (redis, mongo and postgresql) are externally accesibles, I understand this is because is tihinkg about a muliserver instance in a DMZ but if someone has a little size implementation infrastructure (one VPS) is a problem.

There is some documentation to secure this services iin a small server?

Are you looking for commercial solutions around your small servers or you are looking for a solution of securing just the KoboToolBox installed on your server?


Thanks, I’m looking for a solution of securing my server, I try something with IPTABLES to prevent de external access to redis, mongo and postgresql but no luck.