From 7918e3d88ed8830f65f8dd2a387ea108d9cdc60f Mon Sep 17 00:00:00 2001 From: Ryan Yin Date: Wed, 4 Oct 2023 15:00:55 +0800 Subject: [PATCH] feat: nix module's default parameters & specialArgs --- .../nixos-with-flakes-enabled.md | 17 +++++++++++++---- .../nixos-with-flakes-enabled.md | 14 +++++++++++--- 2 files changed, 24 insertions(+), 7 deletions(-) diff --git a/docs/nixos-with-flakes/nixos-with-flakes-enabled.md b/docs/nixos-with-flakes/nixos-with-flakes-enabled.md index 921a4b9..92a2299 100644 --- a/docs/nixos-with-flakes/nixos-with-flakes-enabled.md +++ b/docs/nixos-with-flakes/nixos-with-flakes-enabled.md @@ -125,7 +125,7 @@ Note that the copied template cannot be used directly. You need to modify it to # # A Nix Module can be an attribute set, or a function that # returns an attribute set. By default, if a Nix Module is a - # function, this function can only have the following parameters: + # function, this function have the following default parameters: # # lib: the nixpkgs function library, which provides many # useful functions for operating Nix expressions: @@ -143,11 +143,12 @@ Note that the copied template cannot be used directly. You need to modify it to # this parameter is rarely used, # you can ignore it for now. # - # Only these parameters can be passed by default. - # If you need to pass other parameters, + # The default parameters mentioned above are automatically generated by Nixpkgs. + # However, if you need to pass other non-default parameters to the submodules, + # you'll have to manually configure these parameters using `specialArgs`. # you must use `specialArgs` by uncomment the following line: # - # specialArgs = {...} # pass custom arguments into all sub module. + # specialArgs = {...}; # pass custom arguments into all sub module. modules = [ # Import the configuration.nix here, so that the # old configuration file can still take effect. @@ -164,6 +165,14 @@ We defined a NixOS system called `nixos-test` with a configuration file at `./co To apply the configuration to a system with hostname `nixos-test`, run `sudo nixos-rebuild switch --flake /etc/nixos#nixos-test`. No changes will be made to the system because we imported the old configuration file in `/etc/nixos/flake.nix`, so the actual state we declared remains unchanged. +The comments in the above code are already quite detailed, but let's emphasize a few points here: + +1. Default parameters like `lib`, `pkgs`, `config`, and others are automatically generated by Nixpkgs and can be automatically injected into submodules without the need for additional declarations here. + +2. In `specialArgs = {...};`, the content of the attribute set is omitted here. Its contents are automatically injected into submodules through name matching. + + 1. A common usage, for instance, is to directly write `specialArgs = inputs;`, enabling all data sources from the `inputs` attribute set to be used in the submodules. + ## Managing System Packages with Flakes After the switch, we can manage the system using Flakes. One common requirement is installing packages. We have previously seen how to install packages using `environment.systemPackages` from the official `nixpkgs` repository. diff --git a/docs/zh/nixos-with-flakes/nixos-with-flakes-enabled.md b/docs/zh/nixos-with-flakes/nixos-with-flakes-enabled.md index 52c2065..6af42d0 100644 --- a/docs/zh/nixos-with-flakes/nixos-with-flakes-enabled.md +++ b/docs/zh/nixos-with-flakes/nixos-with-flakes-enabled.md @@ -118,7 +118,7 @@ cat flake.nix # 那么它的参数就是当前的 NixOS Module 的参数. # # 根据 Nix Wiki 对 Nix modules 的描述，默认情况下， - # Nix Module 函数的参数可以有这几个： + # Nix Module 函数的默认参数有几个： # # lib: nixpkgs 自带的函数库，提供了许多操作 Nix 表达式的实用函数 # 详见 https://nixos.org/manual/nixpkgs/stable/#id-1.4 @@ -131,8 +131,10 @@ cat flake.nix # 常用于从 nixpkgs 中导入一些额外的模块 # 这个参数通常都用不到，我只在制作 iso 镜像时用到过 # - # 如果需要传其他非默认参数，就得使用 specialArgs，你可以取消注释如下这行来启用该参数 - # specialArgs = inputs # 将 inputs 中的参数传入所有子模块 + # 上述默认参数都由 Nixpkgs 自动生成。而如果你需要将其他非默认参数传递到子模块， + # 就得使用 specialArgs 手动设定这些参数，你可以取消注释如下这行来启用该参数： + # + # specialArgs = {...}; # 将 inputs 中的参数传入所有子模块 modules = [ # 这里导入之前我们使用的 configuration.nix，这样旧的配置文件仍然能生效 # 注: configuration.nix 本身也是一个 Nix Module，因此可以直接在这里导入 @@ -148,6 +150,12 @@ cat flake.nix 现在执行 `sudo nixos-rebuild switch --flake /etc/nixos#nixos-test` 应用配置，系统应该没有任何变化，因为我们仅仅是切换到了 Nix Flakes，配置内容与之前还是一致的。 +上述代码的注释已经非常详细了，这里再着重说明几点： + +1. `lib` `pkgs` `config` 等默认参数都由 Nixpkgs 自动生成，并可被自动注入到子模块，无需在此处额外声明。 +1. `specialArgs = {...};` 这里省略了 attribute set 的内容，其中的内容会被通过名称匹配的方式自动注入到子模块中。 + 1. 常见用法比如直接写 `specialArgs = inputs;`，这样所有 inputs 中的 flake 数据源就都可以在子模块中使用了。 + ## 通过 Flakes 来管理系统软件 {#manage-system-software-with-flakes} 切换完毕后，我们就可以通过 Flakes 来管理系统了。管系统最常见的需求就是装软件，我们在前面已经见识过如何通过 `environment.systemPackages` 来安装 `pkgs` 中的包，这些包都来自官方的 nixpkgs 仓库。