118bdf25a6
This makes the following work
disabledModules = [ foo.nixosModules.bar ];
even if `bar` is not a path, but rather a module such as
{ key = "/path/to/foo#nixosModules.bar"; config = ...; }
By supporting this, the user will often be able to use the same syntax
for both importing and disabling a module. This is becoming more relevant
because flakes promote the use of attributes to reference modules. Not
all of these modules in flake attributes will be identifiable, but with
the help of a framework such as flake-parts, these attributes can be
guaranteed to be identifiable (by outPath + attribute path).
71 lines
2.2 KiB
Markdown
71 lines
2.2 KiB
Markdown
# Replace Modules {#sec-replace-modules}
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Modules that are imported can also be disabled. The option declarations,
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config implementation and the imports of a disabled module will be
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ignored, allowing another to take its place. This can be used to
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import a set of modules from another channel while keeping the rest of
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the system on a stable release.
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`disabledModules` is a top level attribute like `imports`, `options` and
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`config`. It contains a list of modules that will be disabled. This can
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either be:
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- the full path to the module,
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- or a string with the filename relative to the modules path (eg. \<nixpkgs/nixos/modules> for nixos),
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- or an attribute set containing a specific `key` attribute.
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The latter allows some modules to be disabled, despite them being distributed
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via attributes instead of file paths. The `key` should be globally unique, so
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it is recommended to include a file path in it, or rely on a framework to do it
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for you.
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This example will replace the existing postgresql module with the
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version defined in the nixos-unstable channel while keeping the rest of
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the modules and packages from the original nixos channel. This only
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overrides the module definition, this won't use postgresql from
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nixos-unstable unless explicitly configured to do so.
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```nix
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{ config, lib, pkgs, ... }:
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{
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disabledModules = [ "services/databases/postgresql.nix" ];
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imports =
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[ # Use postgresql service from nixos-unstable channel.
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# sudo nix-channel --add https://nixos.org/channels/nixos-unstable nixos-unstable
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<nixos-unstable/nixos/modules/services/databases/postgresql.nix>
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];
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services.postgresql.enable = true;
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}
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```
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This example shows how to define a custom module as a replacement for an
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existing module. Importing this module will disable the original module
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without having to know its implementation details.
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```nix
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{ config, lib, pkgs, ... }:
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with lib;
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let
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cfg = config.programs.man;
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in
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{
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disabledModules = [ "services/programs/man.nix" ];
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options = {
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programs.man.enable = mkOption {
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type = types.bool;
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default = true;
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description = "Whether to enable manual pages.";
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};
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};
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config = mkIf cfg.enabled {
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warnings = [ "disabled manpages for production deployments." ];
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};
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}
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```
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