From 8d5e27b4807d25308dfe369d5a923d87e7dbfda3 Mon Sep 17 00:00:00 2001
From: midchildan <git@midchildan.org>
Date: Thu, 13 Jun 2024 10:47:38 +0900
Subject: [PATCH] nix: add a declarative alternative to Nix channels (#4031)
* nix: add options 'nixPath' and 'keepOldNixPath'
By default, the system value for $NIX_PATH is kept as a fallback.
To completely override the system value for $NIX_PATH:
nix.keepOldNixPath = false;
* nix: add more tests
* nix: add a declarative alternative to Nix channels
This adds a new option, 'nix.channels'. It's the Nix channels equivalent
of the 'nix.registry' option, and compatible with pre-Flake Nix tooling
including nix-env and nix-shell. Like 'nix.registry', this option is
useful for pinning Nix channels.
Channels defined in the new option can coexist with channels introduced
through the nix-channel command. If the same channel exists in both, the
one from Home Manager will be prioritized.
* nix: add news entry
* nix: make channels respect use-xdg-base-directories
* nix: remove 'with lib;'
---------
Co-authored-by: Michael Hoang <enzime@users.noreply.github.com>
---
modules/misc/news.nix | 11 +++
modules/misc/nix.nix | 83 ++++++++++++++++++-
tests/modules/misc/nix/default.nix | 3 +
tests/modules/misc/nix/empty-settings.nix | 1 +
.../modules/misc/nix/example-channels-xdg.nix | 29 +++++++
tests/modules/misc/nix/example-channels.nix | 26 ++++++
tests/modules/misc/nix/example-settings.nix | 5 ++
tests/modules/misc/nix/keep-old-nix-path.nix | 16 ++++
8 files changed, 172 insertions(+), 2 deletions(-)
create mode 100644 tests/modules/misc/nix/example-channels-xdg.nix
create mode 100644 tests/modules/misc/nix/example-channels.nix
create mode 100644 tests/modules/misc/nix/keep-old-nix-path.nix
diff --git a/modules/misc/news.nix b/modules/misc/news.nix
index 2164d66a5..1242d640b 100644
--- a/modules/misc/news.nix
+++ b/modules/misc/news.nix
@@ -1656,6 +1656,17 @@ in {
See https://codeberg.org/dnkl/yambar for more.
'';
}
+
+ {
+ time = "2024-05-25T14:36:03+00:00";
+ message = ''
+ Multiple new options are available:
+
+ - 'nix.nixPath'
+ - 'nix.keepOldNixPath'
+ - 'nix.channels'
+ '';
+ }
];
};
}
diff --git a/modules/misc/nix.nix b/modules/misc/nix.nix
index a4456946e..2daa56b23 100644
--- a/modules/misc/nix.nix
+++ b/modules/misc/nix.nix
@@ -1,15 +1,40 @@
{ config, lib, pkgs, ... }:
-with lib;
-
let
+ inherit (lib)
+ boolToString concatStringsSep escape floatToString getVersion isBool
+ isConvertibleWithToString isDerivation isFloat isInt isList isString
+ literalExpression maintainers mapAttrsToList mkDefault mkEnableOption mkIf
+ mkMerge mkOption optionalString toPretty types versionAtLeast;
+
cfg = config.nix;
nixPackage = cfg.package;
isNixAtLeast = versionAtLeast (getVersion nixPackage);
+ nixPath = concatStringsSep ":" cfg.nixPath;
+
+ useXdg = config.nix.enable
+ && (config.nix.settings.use-xdg-base-directories or false);
+ defexprDir = if useXdg then
+ "${config.xdg.stateHome}/nix/defexpr"
+ else
+ "${config.home.homeDirectory}/.nix-defexpr";
+
+ # The deploy path for declarative channels. The directory name is prefixed
+ # with a number to make it easier for files in defexprDir to control the order
+ # they'll be read relative to each other.
+ channelPath = "${defexprDir}/50-home-manager";
+
+ channelsDrv = let
+ mkEntry = name: drv: {
+ inherit name;
+ path = toString drv;
+ };
+ in pkgs.linkFarm "channels" (lib.mapAttrsToList mkEntry cfg.channels);
+
nixConf = assert isNixAtLeast "2.2";
let
@@ -102,6 +127,47 @@ in {
'';
};
+ nixPath = mkOption {
+ type = types.listOf types.str;
+ default = [ ];
+ example = [
+ "$HOME/.nix-defexpr/channels"
+ "darwin-config=$HOME/.config/nixpkgs/darwin-configuration.nix"
+ ];
+ description = ''
+ Adds new directories to the Nix expression search path.
+
+ Used by Nix when looking up paths in angular brackets
+ (e.g. `<nixpkgs>`).
+ '';
+ };
+
+ keepOldNixPath = mkOption {
+ type = types.bool;
+ default = true;
+ example = false;
+ description = ''
+ Whether {option}`nix.nixPath` should keep the previously set values in
+ {env}`NIX_PATH`.
+ '';
+ };
+
+ channels = lib.mkOption {
+ type = with lib.types; attrsOf package;
+ default = { };
+ example = lib.literalExpression "{ inherit nixpkgs; }";
+ description = ''
+ A declarative alternative to Nix channels. Whereas with stock channels,
+ you would register URLs and fetch them into the Nix store with
+ {manpage}`nix-channel(1)`, this option allows you to register the store
+ path directly. One particularly useful example is registering flake
+ inputs as channels.
+
+ This option can coexist with stock Nix channels. If the same channel is
+ defined in both, this option takes precedence.
+ '';
+ };
+
registry = mkOption {
type = types.attrsOf (types.submodule (let
inputAttrs = types.attrsOf
@@ -210,6 +276,19 @@ in {
};
config = mkIf cfg.enable (mkMerge [
+ (mkIf (cfg.nixPath != [ ] && !cfg.keepOldNixPath) {
+ home.sessionVariables.NIX_PATH = "${nixPath}";
+ })
+
+ (mkIf (cfg.nixPath != [ ] && cfg.keepOldNixPath) {
+ home.sessionVariables.NIX_PATH = "${nixPath}\${NIX_PATH:+:$NIX_PATH}";
+ })
+
+ (lib.mkIf (cfg.channels != { }) {
+ nix.nixPath = [ channelPath ];
+ home.file."${channelPath}".source = channelsDrv;
+ })
+
(mkIf (cfg.registry != { }) {
xdg.configFile."nix/registry.json".source =
jsonFormat.generate "registry.json" {
diff --git a/tests/modules/misc/nix/default.nix b/tests/modules/misc/nix/default.nix
index b0370c2e4..4c8822bf2 100644
--- a/tests/modules/misc/nix/default.nix
+++ b/tests/modules/misc/nix/default.nix
@@ -2,4 +2,7 @@
nix-empty-settings = ./empty-settings.nix;
nix-example-settings = ./example-settings.nix;
nix-example-registry = ./example-registry.nix;
+ nix-keep-old-nix-path = ./keep-old-nix-path.nix;
+ nix-example-channels = ./example-channels.nix;
+ nix-example-channels-xdg = ./example-channels-xdg.nix;
}
diff --git a/tests/modules/misc/nix/empty-settings.nix b/tests/modules/misc/nix/empty-settings.nix
index 18f1ab430..7e5844742 100644
--- a/tests/modules/misc/nix/empty-settings.nix
+++ b/tests/modules/misc/nix/empty-settings.nix
@@ -8,6 +8,7 @@ with lib;
nmt.script = ''
assertPathNotExists home-files/.config/nix
+ assertPathNotExists home-files/.nix-defexpr/50-home-manager
'';
};
}
diff --git a/tests/modules/misc/nix/example-channels-xdg.nix b/tests/modules/misc/nix/example-channels-xdg.nix
new file mode 100644
index 000000000..8ca1569f3
--- /dev/null
+++ b/tests/modules/misc/nix/example-channels-xdg.nix
@@ -0,0 +1,29 @@
+{ lib, config, pkgs, ... }:
+
+let
+ exampleChannel = pkgs.writeTextDir "default.nix" ''
+ { pkgs ? import <nixpkgs> { } }:
+
+ {
+ example = pkgs.emptyDirectory;
+ }
+ '';
+in {
+ config = {
+ nix = {
+ package = config.lib.test.mkStubPackage {
+ version = lib.getVersion pkgs.nixVersions.stable;
+ };
+ channels.example = exampleChannel;
+ settings.use-xdg-base-directories = true;
+ };
+
+ nmt.script = ''
+ assertFileContains home-path/etc/profile.d/hm-session-vars.sh \
+ 'export NIX_PATH="/home/hm-user/.local/state/nix/defexpr/50-home-manager''${NIX_PATH:+:$NIX_PATH}"'
+ assertFileContent \
+ home-files/.local/state/nix/defexpr/50-home-manager/example/default.nix \
+ ${exampleChannel}/default.nix
+ '';
+ };
+}
diff --git a/tests/modules/misc/nix/example-channels.nix b/tests/modules/misc/nix/example-channels.nix
new file mode 100644
index 000000000..4b98c55d4
--- /dev/null
+++ b/tests/modules/misc/nix/example-channels.nix
@@ -0,0 +1,26 @@
+{ config, pkgs, ... }:
+
+let
+ exampleChannel = pkgs.writeTextDir "default.nix" ''
+ { pkgs ? import <nixpkgs> { } }:
+
+ {
+ example = pkgs.emptyDirectory;
+ }
+ '';
+in {
+ config = {
+ nix = {
+ package = config.lib.test.mkStubPackage { };
+ channels.example = exampleChannel;
+ };
+
+ nmt.script = ''
+ assertFileContains home-path/etc/profile.d/hm-session-vars.sh \
+ 'export NIX_PATH="/home/hm-user/.nix-defexpr/50-home-manager''${NIX_PATH:+:$NIX_PATH}"'
+ assertFileContent \
+ home-files/.nix-defexpr/50-home-manager/example/default.nix \
+ ${exampleChannel}/default.nix
+ '';
+ };
+}
diff --git a/tests/modules/misc/nix/example-settings.nix b/tests/modules/misc/nix/example-settings.nix
index 6cbcd9dfa..df62fe8d1 100644
--- a/tests/modules/misc/nix/example-settings.nix
+++ b/tests/modules/misc/nix/example-settings.nix
@@ -17,6 +17,8 @@ with lib;
'';
};
+ nixPath = [ "/a" "/b/c" ];
+
settings = {
use-sandbox = true;
show-trace = true;
@@ -28,6 +30,9 @@ with lib;
assertFileContent \
home-files/.config/nix/nix.conf \
${./example-settings-expected.conf}
+
+ assertFileContains home-path/etc/profile.d/hm-session-vars.sh \
+ 'export NIX_PATH="/a:/b/c''${NIX_PATH:+:$NIX_PATH}"'
'';
};
}
diff --git a/tests/modules/misc/nix/keep-old-nix-path.nix b/tests/modules/misc/nix/keep-old-nix-path.nix
new file mode 100644
index 000000000..72bd9f164
--- /dev/null
+++ b/tests/modules/misc/nix/keep-old-nix-path.nix
@@ -0,0 +1,16 @@
+{ config, ... }:
+
+{
+ config = {
+ nix = {
+ package = config.lib.test.mkStubPackage { };
+ nixPath = [ "/a" "/b/c" ];
+ keepOldNixPath = false;
+ };
+
+ nmt.script = ''
+ assertFileContains home-path/etc/profile.d/hm-session-vars.sh \
+ 'export NIX_PATH="/a:/b/c"'
+ '';
+ };
+}