Termux is an option but using pmOS is far from silly.
Android and Termux have their limitations. Granted, I was running a full KDE session in Termux on a 2016 phone, but I saw Android OOM-kill random processes in Termux. You probably don't have a swap partition on your Android phone. Android apps are designed to be killed when in background, and Android avoids killing the app at the foreground, but Android doesn't know some processes running in Termux shouldn't be killed. This could happen if something on your server suddenly uses more RAM than anticipated.
On a regular Linux distro, you can have a swap file and/or teach the OOM to not kill some critically important services, like ssh for instance.
Wakelocks don't answers at all the concerns I raised. And I don't currently use these tools. And I'm not omniscient.
I'm flagging you because you are just introducing aggressity here and this is completely useless. I'm not here for this, I'm here to read and share interesting ideas. Others shared ways to address the concerns I raised in a nice and polite way and didn't need to tell me what I need to do like this. Go spread your disdain elsewhere.
Considering that part of the point is being able to use end-of-life devices, it's doing this in Termux that would be silly, don't run an OS which isn't getting security patches.
https://github.com/cyberkernelofficial/docker-in-termux
I've done it successfully a few times and it works just fine.