I'm not really sure what your point is, but I'll try to take it in good faith and read it as "why doesn't docker solve the problem for it, since you can also keep those configurations in a git repo?"

If any kind of apt upgrade or similar command is run in a dockerfile, it is no longer reproducible. Because of this it's necessary to keep track of which dockerfiles do that and keep track of when a build was performed; that's more out-of-band logging. With NixOS I will get the exact same system configuration if I build the same commit (barring some very exotic edge cases)

Besides that, docker still needs to run on a system, which must also be maintained, so Docker only partly addresses a subset of the issue

If Docker works for you and you're not facing any issues with such a setup, then that's great. NixOS is the best solution for me

That’s all my point was, yeah. Genuinely no extra snark intended.

> it is no longer reproducible

The problem I have with this is that most of the software I use isn’t reproducible, and reproducible isn’t something that is the be all and end all to me. If you want reproducible then yes nix is the only game in town, but if you want strong versioning with source controlled configuration, containers are 1000x easier and give you 95% of the benefit

> docker still needs to run on a system

This is a fair point but very little of that system impacts the app you’re running in a container, and if you’re regularly breaking running containers due to poking around in the host, you’re likely going to do it by running some similar command whether the OS wants you to do it or not.

> if you want strong versioning with source controlled configuration, containers are 1000x easier and give you 95% of the benefit

For some I'm sure that's the case; it wasn't in my case.

I ran docker for several years before. First docker-compose, then docker swarm, finally Nomad.

Getting things running is pretty fast, but handling volumes, backups, upgrades of anything in the stack (OS, scheduler, containers, etc) broke something almost every time - doing an update to a new release of Ubuntu would pretty much always require backing up all the volumes and local state to external media, wiping the disk, installing the new version, and restoring from the backup

That's not to talk about getting things running after an issue. Because a lot of configuration can't be done through docker envs, it has to be done through the service. As a consequence that config is now state

I had an nvme fail on me six months ago. Recovering was as simple as swapping the drive, booting the install media, install the OS, and transfering the most recent backup before rebooting

Took about 1.5 hours and everything was back up and running without any issues