piku VS kubero

I should add one to https://piku.github.io (spoiler - this doesn't use Docker at all)

I like it. I wrote Piku (https://github.com/piku/piku) with much the same interest in fixing some of my pains, so I get where you're coming from with this. Will drop it into one of my current projects to build ESP32 binaries :)

I never had any serious issue with SD cards since the Pi 2B (and I've kept Pis running for years).

Anyway, for those wanting to deploy more generic apps, that is why I initially wrote https://github.com/piku/piku - you still have to flash the OS (and rpi-imager does that with sane defaults these days), but once you're done you have Heroku-like deployments for any language runtime you install on the Pi.

I also have https://github.com/rcarmo/ground-init, a cloud-init like shim that simplifies setting up machines (I'm a big fan of cloud-init, but since Raspbian doesn't support it and Ubuntu on ARM requires some fiddling to make it work I decided it wasn't too hard to roll my own).

(I probably should look into glueing that into rpi-imager, but there is are only so many hours in the day...)

I automated that away a long time ago: https://github.com/piku/piku/blob/master/piku.py#L814

Piku https://github.com/piku/piku

So, stupid question: why couldn't I just use the 'baremetal' OS provided by Hetzner, install Postgres, Redis & node, create a separate db for each app, and run each app with https://github.com/piku/piku on a different port? For backups, I'll setup crontab to dump dbs locally and to S3.

piku?

For deploying your apps you could use something like Kubero (https://github.com/kubero-dev/kubero)

Repository: https://github.com/kubero-dev/kubero

Are you running Kubero in the background? Zeabur seems to have the same feature set, and Add-ons.

However, because I want to offer an MTA as an add-on for Kubero, my Heroku alternative, I have decided to create one with Haraka. Haraka is a well-known MTA and is used by Craigslist. This MTA is very flexible and can be extended with plugins. It is also highly performant and can run on minimal resources. Another important criterion is that it has been well maintained and developed for a long time.

I'm the maintainer of Kubero, which is pretty similar but requires a Kubernetes cluster, which might be a show-stopper in your case. But apart from that, Kubero would be able to fulfill your requirements:

Probably kubero

I'm self-hosting Heroku with Kubero.