nixos/config/nix: Move nixConf

2 files changed, 74 insertions, 54 deletions

diff --git a/nixos/modules/config/nix.nix b/nixos/modules/config/nix.nix
index 78cab3c7f8c..c740f8ccc32 100644
--- a/nixos/modules/config/nix.nix
+++ b/nixos/modules/config/nix.nix
@@ -4,14 +4,33 @@
 { config, lib, pkgs, ... }:
 
 let
-
-  cfg = config.nix;
-
   inherit (lib)
+    concatStringsSep
+    boolToString
+    escape
+    floatToString
+    getVersion
+    isBool
+    isDerivation
+    isFloat
+    isInt
+    isList
+    isString
     mapAttrsToList
+    mkIf
     mkRenamedOptionModuleWith
+    optionalString
+    strings
+    toPretty
+    versionAtLeast
     ;
 
+  cfg = config.nix;
+
+  nixPackage = cfg.package.out;
+
+  isNixAtLeast = versionAtLeast (getVersion nixPackage);
+
   legacyConfMappings = {
     useSandbox = "sandbox";
     buildCores = "cores";
@@ -27,6 +46,54 @@ let
     systemFeatures = "system-features";
   };
 
+  nixConf =
+    assert isNixAtLeast "2.2";
+    let
+
+      mkValueString = v:
+        if v == null then ""
+        else if isInt v then toString v
+        else if isBool v then boolToString v
+        else if isFloat v then floatToString v
+        else if isList v then toString v
+        else if isDerivation v then toString v
+        else if builtins.isPath v then toString v
+        else if isString v then v
+        else if strings.isConvertibleWithToString v then toString v
+        else abort "The nix conf value: ${toPretty {} v} can not be encoded";
+
+      mkKeyValue = k: v: "${escape [ "=" ] k} = ${mkValueString v}";
+
+      mkKeyValuePairs = attrs: concatStringsSep "\n" (mapAttrsToList mkKeyValue attrs);
+
+    in
+    pkgs.writeTextFile {
+      name = "nix.conf";
+      text = ''
+        # WARNING: this file is generated from the nix.* options in
+        # your NixOS configuration, typically
+        # /etc/nixos/configuration.nix.  Do not edit it!
+        ${mkKeyValuePairs cfg.settings}
+        ${cfg.extraOptions}
+      '';
+      checkPhase = lib.optionalString cfg.checkConfig (
+        if pkgs.stdenv.hostPlatform != pkgs.stdenv.buildPlatform then ''
+          echo "Ignoring validation for cross-compilation"
+        ''
+        else ''
+          echo "Validating generated nix.conf"
+          ln -s $out ./nix.conf
+          set -e
+          set +o pipefail
+          NIX_CONF_DIR=$PWD \
+            ${cfg.package}/bin/nix show-config ${optionalString (isNixAtLeast "2.3pre") "--no-net"} \
+              ${optionalString (isNixAtLeast "2.4pre") "--option experimental-features nix-command"} \
+            |& sed -e 's/^warning:/error:/' \
+            | (! grep '${if cfg.checkAllErrors then "^error:" else "^error: unknown setting"}')
+          set -o pipefail
+        '');
+    };
+
 in
 {
   imports =
@@ -39,4 +106,7 @@ in
       })
       legacyConfMappings;
 
+  config = mkIf cfg.enable {
+    environment.etc."nix/nix.conf".source = nixConf;
+  };
 }
diff --git a/nixos/modules/services/misc/nix-daemon.nix b/nixos/modules/services/misc/nix-daemon.nix
index 95ee75922da..b4b909a48d5 100644
--- a/nixos/modules/services/misc/nix-daemon.nix
+++ b/nixos/modules/services/misc/nix-daemon.nix
@@ -29,54 +29,6 @@ let
 
   nixbldUsers = listToAttrs (map makeNixBuildUser (range 1 cfg.nrBuildUsers));
 
-  nixConf =
-    assert isNixAtLeast "2.2";
-    let
-
-      mkValueString = v:
-        if v == null then ""
-        else if isInt v then toString v
-        else if isBool v then boolToString v
-        else if isFloat v then floatToString v
-        else if isList v then toString v
-        else if isDerivation v then toString v
-        else if builtins.isPath v then toString v
-        else if isString v then v
-        else if strings.isConvertibleWithToString v then toString v
-        else abort "The nix conf value: ${toPretty {} v} can not be encoded";
-
-      mkKeyValue = k: v: "${escape [ "=" ] k} = ${mkValueString v}";
-
-      mkKeyValuePairs = attrs: concatStringsSep "\n" (mapAttrsToList mkKeyValue attrs);
-
-    in
-    pkgs.writeTextFile {
-      name = "nix.conf";
-      text = ''
-        # WARNING: this file is generated from the nix.* options in
-        # your NixOS configuration, typically
-        # /etc/nixos/configuration.nix.  Do not edit it!
-        ${mkKeyValuePairs cfg.settings}
-        ${cfg.extraOptions}
-      '';
-      checkPhase = lib.optionalString cfg.checkConfig (
-        if pkgs.stdenv.hostPlatform != pkgs.stdenv.buildPlatform then ''
-          echo "Ignoring validation for cross-compilation"
-        ''
-        else ''
-          echo "Validating generated nix.conf"
-          ln -s $out ./nix.conf
-          set -e
-          set +o pipefail
-          NIX_CONF_DIR=$PWD \
-            ${cfg.package}/bin/nix show-config ${optionalString (isNixAtLeast "2.3pre") "--no-net"} \
-              ${optionalString (isNixAtLeast "2.4pre") "--option experimental-features nix-command"} \
-            |& sed -e 's/^warning:/error:/' \
-            | (! grep '${if cfg.checkAllErrors then "^error:" else "^error: unknown setting"}')
-          set -o pipefail
-        '');
-    };
-
   semanticConfType = with types;
     let
       confAtom = nullOr
@@ -659,8 +611,6 @@ in
       ]
       ++ optional (config.programs.bash.enableCompletion) pkgs.nix-bash-completions;
 
-    environment.etc."nix/nix.conf".source = nixConf;
-
     environment.etc."nix/registry.json".text = builtins.toJSON {
       version = 2;
       flakes = mapAttrsToList (n: v: { inherit (v) from to exact; }) cfg.registry;
@@ -737,7 +687,7 @@ in
             LimitNOFILE = 1048576;
           };
 
-        restartTriggers = [ nixConf ];
+        restartTriggers = [ config.environment.etc."nix/nix.conf".source ];
 
         # `stopIfChanged = false` changes to switch behavior
         # from   stop -> update units -> start