Bash and a dedicated user should work with very little effort. Basically, create a user on your VM (maybe called git), set up passwordless (and keyless) ssh for this user but force the command to be the git-shell. Next a simple bash script which iterates directories in this user’s home directory and runs git fetch —all. Set cron to run this script periodically (every hour?). To add a new repository, just ssh as your regular user and su to the git user, then clone the new repository into the home directory. To change the upstream, do the same but simply update the remote.

This could probably be packaged as a dockerfile pretty easily, if you don’t mind either needing to specify the port, or losing the machine’s port 22.

EDIT: I found this after posting, might be the easiest way to serve the repositories, in combination with the update script. There’s a bunch more info in the Git Book too, the next section covers setting up HTTP…

I would probably use ntfy.sh for this purpose. It doesn’t quite meet all your requirements, but you could use a random channel name and get some amount of security…

You can self host it, or use the hosted version. (I know it’s technically not chat, but it works on a series of messages, it just happens to call them notifications.)

I know it’s not ideal, but if you can afford it, you could rent a VPS in a cloud provider for a week or two, and do the download from Google Takeout on that, and then use sync or similar to copy the files to your own server.

If you’re seeing an OOM killer messsage note that it doesn’t necessarily kill the problem process, by default the kernel hands out memory upon requestt, regardless of whether it has ram to back the allocation. When a process then writes to the memory (at some later time) and the kernel determines that there is no physical ram to store that write, it then invokes OOM Killer. This then selects a process and kills it. MySQL (and MariaDB) use large quantities of ram for cache, and by default the kernel lies about how much is available, so they often end up using more than the system can handle.

If you have many databases in containers, set memory limits for those containers, that should make all the databases play nicer together. Additionally , you may want to disable overcommit in the kernel, this will cause the kernel to return out of memory to a process attempting to allocate ram and stop lying about free ram to processes that ask, often greatly increasing stability.

Something that LVM supports but ZFS and BTRFS don’t, is the ability to reduce your storage. (That is, to empty and remove a drive from the array, without having to completely destroy the storage array.) As a home user without sufficient storage to have complete duplicates of everything, I find this an important feature.