Thanks to your comment I gave termux another try and finally figured out what I was doing wrong (pgk updates never working). DO NOT install termux from the Play Store, use FDROID. If you use the play store version you have an old and outdated version with old and broken package repos.
If you haven’t already, check out Proxmox. It’s an operating system that specializes in running Virtual Machines. If you run Proxmox at home you can have all the features that you just mentioned and more.
I ran one for a few months until I woke up one morning and it wasn’t working. As I was the only person using it, I didn’t bother to troubleshoot and just signed up for an account at lemmy.world.
If you want to run your own I recommend you check out the ansible install route. It’s really simple and straightforward once you wrap your head around ansible.
What’s the point of renting a VPS if you only access it from your own network? I understand why a large company would do it (risk mitigation) but I don’t understand why a self-hoster wouldn’t just use an old computer at home. Your costs would be reduced and you could more easily control access.
Now that being said, most Cloud VPS providers have a firewall that you can configure from their web portal. If you whitelist your home network public IP then you can be sure that anyone connecting to your VPS will have to be doing so from your home network. You could do the same thing with UFW or Iptables on the VPS but I recommend using the external firewall because it won’t take resources from your VPS while defending against a DDOS.
Just a little nitpicking, the words you want to be using are “offSITE” and “onSITE” not “offSIDE” or “onSIDE” (this isn’t a football match).
Same, IONOS is cheap and I had no issues when requesting they open port 25 for my mail relay server.