Modular, context-aware and aspect-oriented dendritic Nix configurations.
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configurations
den
dendritic
nix
aspect
oriented
Example tests and documentation for forwarding classes. (#167)
Related #160
authored by
GitHub
5478f8e9
27899438
+31
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modules/aspects/provides/forward.nix
+31
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modules/aspects/provides/forward.nix
···
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{ lib, ... }:
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{ den, ... }:
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let
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description = ''
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WIP: Creates a class-forwarding aspect.
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'';
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An aspect that imports all modules defined for `from` class
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into a target `into` submodule.
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forward =
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cb:
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{ class, aspect-chain }:
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let
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fwd = cb { inherit class aspect-chain; };
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include =
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item:
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let
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from = fwd.from item;
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into = fwd.into item;
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aspect = fwd.aspect item;
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module = aspect.resolve { class = from; };
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in
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lib.setAttrByPath into { imports = [ module ]; };
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in
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{
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includes = map include fwd.each;
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};
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This can be used to create custom Nix classes that help
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people separating concerns on huge module hierarchies.
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For example, using a new `user` class that forwards all its
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settings into `users.users.<userName>` allows:
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den.aspects.alice.nixos.users.users.alice.isNormalUser = true;
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to become:
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den.aspects.alice.user.isNormalUser = true;
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This is exactly how `homeManager` class support is implemented in Den.
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See home-manager/hm-integration.nix.
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Den also provides the mentioned `user` class (`den._.os-user`) for setting
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NixOS/Darwin options under `users.users.<userName>` at os-level.
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Any other user-environments like `nix-maid` or `hjem` or user-custom classes
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are easily implemented using `den._.forward`.
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Note: `den._.forward` is a high-level aspect, its result
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is another aspect that needs to be included for the new class to exist.
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See templates/ci/modules/forward.nix for usage example.
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See also: https://github.com/vic/den/issues/160, https://github.com/vic/flake-aspects/pull/31
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'';
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in
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{
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den.provides.forward = {
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inherit description;
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__functor = _self: forward;
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__functor = _self: den.lib.aspects.forward;
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};
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}
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modules/aspects/provides/home-manager/hm-integration.nix
+11
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modules/aspects/provides/home-manager/hm-integration.nix
···
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in
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HM { inherit HM-OS-USER; };
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hmUsersAspect = den._.forward (
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hmUsersAspect =
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{ class, aspect-chain }:
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den.lib.take.unused aspect-chain {
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each = hmUsers;
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from = _: hmClass;
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into = user: [
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class
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den._.forward {
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each = lib.optionals (lib.elem class [
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"nixos"
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"darwin"
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]) hmUsers;
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fromClass = _: hmClass;
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fromAspect = den.lib.take.unused aspect-chain hmUserAspect;
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intoClass = _: class;
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intoPath = user: [
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"home-manager"
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"users"
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user.userName
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];
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aspect = hmUserAspect;
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}
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);
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};
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in
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{
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${host.class}.imports = [ hmModule ];
+55
templates/ci/modules/forward.nix
+55
templates/ci/modules/forward.nix
···
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{ lib, den, ... }:
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let
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oneModule.foo = [ "one" ];
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targetSubmodule = lib.mkOption {
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type = lib.types.submoduleWith {
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modules = [
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{
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options.foo = lib.mkOption {
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type = lib.types.listOf lib.types.str;
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};
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}
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];
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};
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};
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forwarded =
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{ class, aspect-chain }:
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den._.forward {
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each = lib.singleton class; # item ignored
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fromClass = _item: "fwd-origin";
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intoClass = _item: "nixos";
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intoPath = _item: [ "fwd-target" ];
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fromAspect = _item: lib.head aspect-chain;
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};
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in
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{
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den.aspects.rockhopper = {
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includes = [ forwarded ];
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nixos = {
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imports = [ { options.fwd-target = targetSubmodule; } ];
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fwd-target = {
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foo = [ "zero" ];
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imports = [ oneModule ];
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};
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};
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fwd-origin.foo = [ "two" ];
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};
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perSystem =
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{ rockhopper, checkCond, ... }:
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{
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checks.forward = checkCond "foo value was forwarded to os-level" (
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rockhopper.config.fwd-target.foo == [
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"two"
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"one"
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"zero"
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]
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);
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};
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}