64 lines
1.5 KiB
Markdown
64 lines
1.5 KiB
Markdown
# flake-utils
|
|
|
|
**STATUS: alpha**
|
|
|
|
Pure Nix flake utility functions.
|
|
|
|
The goal of this project is to build a collection of pure Nix functions that don't
|
|
depend on nixpkgs, and that are useful in the context of writing other Nix
|
|
flakes.
|
|
|
|
## Usage
|
|
|
|
### `defaultSystems -> [<system>]`
|
|
|
|
A list of all the systems supported by the nixpkgs project.
|
|
|
|
### `eachSystem -> [<system>] -> (<system> -> attrs)`
|
|
|
|
A common case is to build the same structure for each system. Instead of
|
|
building the hierarchy manually or per prefix, iterate over each systems and
|
|
then re-build the hierarchy.
|
|
|
|
Eg:
|
|
|
|
```nix
|
|
eachSystem ["x86-64-linux"] (system: { hello = 42; })
|
|
# => { hello.x86-64-linux.hello = 42; }
|
|
```
|
|
|
|
### `eachDefaultSystem -> (<system> -> attrs)`
|
|
|
|
`eachSystem` pre-populated with `defaultSystems`.
|
|
|
|
### `mkApp { drv, name ? drv.pname or drv.name, execPath ? drv.passthru.execPath or "/bin/${name}"`
|
|
|
|
A small utility that builds the structure expected by the special `apps` and `defaultApp` prefixes.
|
|
|
|
## Example
|
|
|
|
Here is how it looks like in practice:
|
|
|
|
[$ example/flake.nix](example/flake.nix) as nix
|
|
```nix
|
|
{
|
|
description = "Flake utils demo";
|
|
edition = 201909;
|
|
|
|
inputs.utils = {
|
|
uri = "github:numtide/flake-utils";
|
|
};
|
|
|
|
outputs = { self, nixpkgs, utils }:
|
|
utils.lib.eachDefaultSystem (system:
|
|
let pkgs = nixpkgs.legacyPackages.${system}; in
|
|
rec {
|
|
packages.hello = pkgs.hello;
|
|
defaultPackage = packages.hello;
|
|
apps.hello = utils.lib.mkApp { drv = packages.hello; };
|
|
defaultApp = apps.hello;
|
|
}
|
|
);
|
|
}
|
|
```
|