Docker hub image configuration for newbie

Hey guys, I recently started moving from network administrator path to the devops one. For this moment I do it totally for fun.

So, I have created by Kubernetes cluster by loading an image from Docker Hub (Ghost CMS). I’ve set up the ingress on HTTPS. Everything is working perfect and it was fun. The problem is that pods are ephemeral so I can’t really put any data on site because I can loose it in a second. Youjizz Pornhub

So my questions:

How can I reconfigure the existing docker image to change Ghost settings to use independent MySQL/SQLite server for data? Do I have to prepare the new image from scratch? ow do you solve issues like this? I know that I could use Helm + Config Map to setup the whole system but I need to know more about Docker/Kubernetes.