Some more lanzatool refactoring

[nikstur]

Implements some requested changes from #34.

[RaitoBezarius]

@nikstur Do you think we could get the "alternative Nix store" path feature and make it a parameter or something smart?

[nikstur]

@nikstur Do you think we could get the "alternative Nix store" path feature and make it a parameter or something smart?

From some research, I got the impression, that an alternative Nix Store path is not really a well-supported feature of Nix e.g. NixOS/nix#1971. I'd say we just do not explicitly support an alternative path. With the implementation from #42 lanzatool doesn't really know about /nix/store at all anyways, so other store locations should just work. I implemented it that way so I can test with files in a temporary directory instead of /nix/store. (See: https://github.com/nix-community/lanzaboote/blob/master/rust/lanzatool/src/esp.rs#L56)

[RaitoBezarius]

@nikstur Do you think we could get the "alternative Nix store" path feature and make it a parameter or something smart?

From some research, I got the impression, that an alternative Nix Store path is not really a well-supported feature of Nix e.g. NixOS/nix#1971.

It definitely is, the issue you linked is about rewriting the paths which is something different and could be useful to reuse the NixOS cache in an alternative store path.
But, if you do nix-build x --store ~/nix, it will create a new Nix store at this path.

Some people do run Nix store paths at alternative locations, certainly, this is very edgy, but I'm not sure if it cost that much to support it as a flag.

I'd say we just do not explicitly support an alternative path. With the implementation from #42 lanzatool doesn't really know about /nix/store at all anyways, so other store locations should just work.

Hm, that's fair. We can wait for a feature request then.

I implemented it that way so I can test with files in a temporary directory instead of /nix/store. (See: https://github.com/nix-community/lanzaboote/blob/master/rust/lanzatool/src/esp.rs#L56)

Great!

[blitz]

Love the unit tests!