https://github.com/stoatchat/self-hosted

Immich is exactly what you’re looking for. Debugging the installation problem will be a lot less work with a way better result than trying to get Nextcloud to do what you want.

The best practice would be using dev container features. Those are basically install scripts that get layered onto your container. See this list for some available features or write your own.

One nice thing about features is that, in a collaborative environment, you can add required features for everyone directly in the devcontainer.json and personal preferences like a zsh feature in your settings.json (dev.containers.defaultFeatures) so they get installed into every container you open.

Yes. I run Harbor and pull all images through its proxy cache.