I need to generate a number of scripts in my configuration and make them into a single package (for ease of reference, because there are a lot of them).
So far, I’m creating the scripts via writeShellApplication
, making them into packages via an overlay
, merging them with buildEnv
and then adding the resulting package to `systemPackages.
Something like:
nixpkgs.overlays = [ (final: prev: {
my-hello-1 = final.writeShellApplication {
name = "my-hello-1-script";
text = "echo my hello wolrd 1";
};
my-hello-2 = final.writeShellApplication {
name = "my-hello-2-script";
text = "echo my hello wolrd 1";
};
my-hello-scripts = final.buildEnv {
name = "my-hello-scripts";
paths = [ final.my-hello-1 final.my-hello-2 ];
};
}) ];
environment.systemPackages = [ pkgs.my-hello-scripts ];
This works, but I don’t really need the my-hello-1
and my-hello-2
packages… can you think of a way to make do without needing them?
Why the overlay? If you just want to give the drvs names (good practice IMO), simply use a let binding.
The buildEnv is unnecessary: systemPackages does the same with all the derivations in the list in the end anyways.
If you just want to give the drvs names […], simply use a let binding.
I must be missing something here… my first idea was to put all the
writeShellApplication
s insidesystemPackages
(with no let bindings: the scripts are generated from config anyway), but it resulted in nixos complaining that it was expecting actual packages.Edit: scratch that - I was being stupid :)
Don’t worry about the extra derivations. Nix is full of them.
Well, it does work as-is, and it’s not like I’m worried how many symlinks need to be dereerenced… the point is mainly that my nix code could be much simpler if I didn’t have to build the overlay attrset like that from a list.
You might simplify it a bit with something like,
let my-hello-scripts = [ (writeShellApplication { name = "my-hello-1-script"; text = "echo my hello world 1"; }) (writeShellApplication { name = "my-hello-2-script"; text = "echo my hello world 2"; }) ]; in { environment.systemPackages = my-hello-scripts ++ [ pkgs.whatever-else-you-want ]; }
That was my first idea (well, I say “my”… but it was really suggested by yourself in the question I posted the other day), but it results in nixos complaining that
error: A definition for option 'environment.systemPackages."[definition 1-entry 1]"' is not of type 'package'.
It might very well be that I’m doing some stupid mistake here (or maybe it’s something that used to work and doesn’t anymore?)… here’s what I used to test it out:
environment.systemPackages = [ pkgs.writeShellApplication { name = "some-script"; text = "echo hello wolrd"; } ];
Edit:
And indeed I was the one doing stupid things: it must be
environment.systemPackages = [ (pkgs.writeShellApplication { name = "some-script"; text = "echo hello wolrd"; }) ];
with the parentheses, or it’s a list with two elements (a function and an attrset)…
Oh yeah, the need for parenthesis often has me scratching my head for a bit
There’s probably a cleaner way to do this, but you can look at abstractions as a way to reduce all that code repetiton.