initial commit

13 files changed, 698 insertions, 0 deletions

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..1d662ce
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,8 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "actions"
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..a542c01
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,99 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  eval:
+    strategy:
+      matrix:
+        test: [lib, module]
+
+    runs-on: ubuntu-latest
+
+    outputs:
+      lib-matrix: ${{ steps.lib-generate.outputs.matrix }}
+      module-matrix: ${{ steps.module-generate.outputs.matrix }}
+    
+    steps:
+      - uses: actions/checkout@v4
+      - uses: nixbuild/nix-quick-install-action@v26
+
+      - name: generate matrix
+        id: ${{ matrix.test }}-generate
+        run: |
+          cd test/${{ matrix.test }}
+          set -e
+          echo "matrix=$(nix eval --show-trace --json .#githubWorkflow.matrix)" >> "$GITHUB_OUTPUT"
+
+  # would be nice to have another matrix for these but meh
+  test-lib:
+    needs: eval
+
+    strategy:
+      matrix: ${{ fromJSON(needs.eval.outputs.lib-matrix) }}
+
+    runs-on: ${{ matrix.os }}
+
+    name: build (${{ matrix.attr }})
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: setup qemu
+        if: matrix.arch == 'aarch64'
+        run: |
+          sudo apt update -y
+          sudo apt install -y qemu-user-static
+
+      - name: install nix
+        if: matrix.arch != 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+
+      - name: install nix (with aarch64)
+        if: matrix.arch == 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+        with:
+          nix_conf: "extra-platforms = aarch64-linux arm-linux"
+
+      - name: build ${{ matrix.attr }}
+        run: |
+          cd test/lib
+          nix build -L .#${{ matrix.attr }}
+
+  test-module:
+    needs: eval
+
+    strategy:
+      matrix: ${{ fromJSON(needs.eval.outputs.module-matrix) }}
+
+    runs-on: ${{ matrix.os }}
+
+    name: build (${{ matrix.attr }})
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: setup qemu
+        if: matrix.arch == 'aarch64'
+        run: |
+          sudo apt update -y
+          sudo apt install -y qemu-user-static
+
+      - name: install nix
+        if: matrix.arch != 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+
+      - name: install nix (with aarch64)
+        if: matrix.arch == 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+        with:
+          nix_conf: "extra-platforms = aarch64-linux arm-linux"
+
+      - name: build ${{ matrix.attr }}
+        run: |
+          cd test/module
+          nix build -L .#${{ matrix.attr }}
diff --git a/.github/workflows/example.yaml b/.github/workflows/example.yaml
new file mode 100644
index 0000000..5c376c1
--- /dev/null
+++ b/.github/workflows/example.yaml
@@ -0,0 +1,55 @@
+name: Example
+
+on:
+  workflow_dispatch:
+
+jobs:
+  eval:
+    runs-on: ubuntu-latest
+
+    outputs:
+      matrix: ${{ steps.generate.outputs.matrix }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: install nix
+        uses: nixbuild/nix-quick-install-action@v26
+
+      - name: generate matrix
+        id: generate
+        run: |
+          set -Eeu
+          echo "matrix=$(nix eval --show-trace --json .#githubWorkflow.matrix)" >> "$GITHUB_OUTPUT"
+
+  build:
+    needs: eval
+
+    strategy:
+      matrix: ${{ fromJSON(needs.eval.outputs.matrix) }}
+
+    runs-on: ${{ matrix.os }}
+
+    name: build (${{matrix.attr}})
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: setup qemu
+        if: matrix.arch == 'aarch64'
+        run: |
+          sudo apt update -y
+          sudo apt install -y qemu-user-static
+
+      - name: install nix
+        if: matrix.arch != 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+
+      - name: install nix (with aarch64)
+        if: matrix.arch == 'aarch64'
+        uses: nixbuild/nix-quick-install-action@v26
+        with:
+          nix_conf: "extra-platforms = aarch64-linux arm-linux"
+
+      - name: build ${{ matrix.attr }}
+        run: nix build -L --fallback .#${{ matrix.attr }}
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..171b89c
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 seth
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..8f97230
--- /dev/null
+++ b/README.md
@@ -0,0 +1,90 @@
+# nix2workflow
+
+![test status](https://github.com/getchoo/nix2workflow/actions/workflows/ci.yaml/badge.svg)
+
+nix2workflow is a library for generating github matrices from regular nix flake outputs.
+
+## usage
+
+we offer both a standard library for use in any flake, along with
+a [flake-parts](https://flake.parts/) module for easier integration.
+
+you can find an example workflow for use in your own project in
+[./.github/workflows/example.yaml](./.github/workflows/example.yaml).
+
+### flake module
+
+a basic setup might look like this. please see the [module](./module.nix)
+for all options
+
+```nix
+{
+  imports = [nix2workflow.flakeModule];
+
+  githubWorkflowGenerator = {
+    outputs = [
+      "checks"
+      "devShells"
+      "nixosConfigurations"
+      "packages"
+    ];
+
+    overrides = {
+      checks.systems = ["x86_64-linux"];
+    };
+  };
+}
+```
+
+a full example can be found in [./test/module/flake.nix](./test/module/flake.nix)
+
+### library
+
+the regular library will have a more complicated setup, though
+it also allows using lower level functions and has no restrictions on
+what flake outputs are used.
+
+```nix
+{
+  githubworkflow = let
+    workflow = nix2workflow.lib {inherit self;};
+    outputs = [
+      "checks"
+      "devShells"
+      "nixosConfigurations"
+      "packages"
+    ];
+  in {
+    matrix.include = lib.concatLists (
+      map (
+        output:
+          workflow.mkMatrix {
+            inherit output;
+            # you can also specify what systems to build each output for
+            systems = ["x86_64-linux" "aarch64-darwin"];
+          }
+      )
+      outputs
+    );
+  };
+}
+```
+
+you can see a full example in [./test/lib/flake.nix](./test/lib/flake.nix)
+
+### in workflows
+
+when the matrix is imported, a few variables with added to the `matrix` context.
+these can allow you to customize your workflow based on what packages are building
+- such as enabling QEMU when building for aarch64
+
+| name | use |
+| --- | --- |
+| `os` | the operating system of the current output. usually `ubuntu-latest` or `macos-latest` |
+| `arch` | the architecture of the current output. will be `aarch64` or `x64` |
+| `attr` | the flake attribute of the current output (can really be anything) |
+
+## related projects
+  - [nix-community/nix-github-actions](https://github.com/nix-community/nix-github-actions/)
+    - this is the primary inspiration for this project - and i believe also one of the first 
+    projects to attempt this, so kudos! i just wanted a more opionated and expandable approach :)
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..e9a69a9
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1699145078,
+        "narHash": "sha256-OO1b3jiMUGjafD2ErkbTPVgUlhmyWo2Z5i0k2kD1ViU=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "174d7dc67189bc4a53f1bffb4fb9d0f13b79cd3c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..f6d4cd3
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,14 @@
+{
+  description = "generate github matrices with nix!";
+
+  inputs.nixpkgs-lib.url = "github:nix-community/nixpkgs.lib";
+
+  outputs = {
+    self,
+    nixpkgs-lib,
+    ...
+  }: {
+    lib = import ./lib.nix nixpkgs-lib.lib;
+    flakeModule = import ./module.nix self.lib;
+  };
+}
diff --git a/lib.nix b/lib.nix
new file mode 100644
index 0000000..f7f07f3
--- /dev/null
+++ b/lib.nix
@@ -0,0 +1,80 @@
+lib: {
+  self,
+  platforms ? {
+    "x86_64-linux" = {
+      os = "ubuntu-latest";
+      arch = "x64";
+    };
+
+    "aarch64-linux" = {
+      os = "ubuntu-latest";
+      arch = "aarch64";
+    };
+
+    "x86_64-darwin" = {
+      os = "macos-latest";
+      arch = "x64";
+    };
+  },
+  ...
+}: let
+  platforms' =
+    platforms
+    // {
+      fallback = lib.warn "an output in the job matrix is not supported!" {
+        os = null;
+        arch = null;
+      };
+    };
+
+  mkMatrixMulti = systems: output:
+    lib.flatten (
+      lib.mapAttrsToList (
+        system:
+          lib.mapAttrsToList (
+            attr: _: {
+              inherit (platforms'.${system} or platforms'.fallback) arch os;
+              attr = "${output}.${system}.${attr}";
+            }
+          )
+      )
+      (lib.getAttrs systems self.${output})
+    );
+
+  mkMatrixFlat = {
+    output,
+    suffix ? "",
+  }:
+    lib.mapAttrsToList (
+      attr: deriv: {
+        inherit (platforms'.${deriv.pkgs.system} or platforms'.fallback) os arch;
+        attr = "${output}.${attr}${suffix}";
+      }
+    )
+    self.${output};
+in {
+  inherit
+    mkMatrixMulti
+    mkMatrixFlat
+    ;
+
+  mkMatrix = {
+    output,
+    systems ? (builtins.attrNames platforms),
+  }: let
+    systemMatrix = mkMatrixFlat {
+      inherit output;
+      suffix = ".config.system.build.toplevel";
+    };
+  in
+    {
+      "nixosConfigurations" = systemMatrix;
+      "darwinConfigurations" = systemMatrix;
+      "homeConfigurations" = mkMatrixFlat {
+        inherit output;
+        suffix = ".activationPackage";
+      };
+    }
+    .${output}
+    or (mkMatrixMulti systems output);
+}
diff --git a/module.nix b/module.nix
new file mode 100644
index 0000000..189dc69
--- /dev/null
+++ b/module.nix
@@ -0,0 +1,113 @@
+workflowLib': {
+  config,
+  lib,
+  self,
+  ...
+}: let
+  cfg = config.githubWorkflowGenerator;
+
+  inherit
+    (builtins)
+    attrNames
+    elem
+    ;
+
+  inherit
+    (lib)
+    filter
+    getAttrs
+    mapAttrsToList
+    mdDoc
+    mkOption
+    literalExpression
+    types
+    ;
+
+  workflowLib = workflowLib' (
+    {inherit self;}
+    // lib.mkIf (cfg.platforms != {}) {
+      inherit (cfg) platforms;
+    }
+  );
+
+  supportedOutputs = [
+    "apps"
+    "checks"
+    "devShells"
+    "darwinConfigurations"
+    "homeConfigurations"
+    "nixosConfigurations"
+    "packages"
+  ];
+
+  platformMap = {
+    options = {
+      arch = mkOption {
+        description = mdDoc "the architecture of a system";
+        type = types.str;
+        default = null;
+        example = literalExpression "x86_64";
+      };
+
+      os = mkOption {
+        description = mdDoc "the name of an os supported by github runners";
+        type = types.str;
+        default = null;
+        example = literalExpression "ubuntu-latest";
+      };
+    };
+  };
+
+  overrides = {
+    options = {
+      systems = mkOption {
+        description = mdDoc "list of systems to build an output for";
+        type = types.listOf types.str;
+        default = builtins.attrNames cfg.platforms;
+      };
+    };
+  };
+
+  jobs = lib.concatLists (
+    mapAttrsToList (
+      output: _:
+        workflowLib.mkMatrix ({inherit output;} // cfg.overrides.${output} or {})
+    )
+    (getAttrs cfg.outputs self)
+  );
+in {
+  options = {
+    githubWorkflowGenerator = {
+      outputs = mkOption {
+        description = mdDoc "outputs to include in workflow";
+        type = types.listOf types.str;
+        default = filter (output: elem output supportedOutputs) (attrNames self);
+      };
+
+      platforms = mkOption {
+        description = mdDoc ''
+          an attrset that can map a nix system to an architecture and os supported by github
+        '';
+        type = types.attrsOf (types.submodule platformMap);
+        default = {};
+      };
+
+      overrides = mkOption {
+        description = mdDoc "overrides for mkMatrix args";
+        type = types.attrsOf (types.submodule overrides);
+        default = {};
+        example = literalExpression ''
+          {
+            githubWorkflowGenerator.overrides = {
+              checks.systems = [ "x86_64-linux" ];
+            };
+          }
+        '';
+      };
+    };
+  };
+
+  config.flake.githubWorkflow = {
+    matrix.include = jobs;
+  };
+}
diff --git a/test/lib/flake.lock b/test/lib/flake.lock
new file mode 100644
index 0000000..a71eb72
--- /dev/null
+++ b/test/lib/flake.lock
@@ -0,0 +1,42 @@
+{
+  "nodes": {
+    "call-flake": {
+      "locked": {
+        "lastModified": 1699147280,
+        "narHash": "sha256-bmhE1TmrJG4ba93l9WQTLuYM53kwGQAjYHRvHOeuxWU=",
+        "owner": "divnix",
+        "repo": "call-flake",
+        "rev": "7d993ee93bd35a9e6574ec76d54b7d44087495ad",
+        "type": "github"
+      },
+      "original": {
+        "owner": "divnix",
+        "repo": "call-flake",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1699099776,
+        "narHash": "sha256-X09iKJ27mGsGambGfkKzqvw5esP1L/Rf8H3u3fCqIiU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "85f1ba3e51676fa8cc604a3d863d729026a6b8eb",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "call-flake": "call-flake",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/test/lib/flake.nix b/test/lib/flake.nix
new file mode 100644
index 0000000..c4607dc
--- /dev/null
+++ b/test/lib/flake.nix
@@ -0,0 +1,48 @@
+{
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    call-flake.url = "github:divnix/call-flake";
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    call-flake,
+    ...
+  }: let
+    inherit (nixpkgs) lib;
+
+    systems = [
+      "x86_64-linux"
+      "aarch64-linux"
+      "x86_64-darwin"
+      "aarch64-darwin"
+    ];
+
+    forAllSystems = fn: lib.genAttrs systems (sys: fn nixpkgs.legacyPackages.${sys});
+    workflow = (call-flake ../../.).lib {inherit self;};
+  in {
+    devShells = forAllSystems (pkgs: {
+      default = pkgs.mkShell {
+        packages = [pkgs.hello];
+      };
+    });
+
+    packages = forAllSystems (pkgs: {
+      inherit (pkgs) hello;
+      default = pkgs.hello;
+    });
+
+    githubWorkflow = let
+      outputs = ["packages" "devShells"];
+      jobs = lib.concatLists (
+        map (
+          output: workflow.mkMatrix {inherit output;}
+        )
+        outputs
+      );
+    in {
+      matrix.include = jobs;
+    };
+  };
+}
diff --git a/test/module/flake.lock b/test/module/flake.lock
new file mode 100644
index 0000000..c2979aa
--- /dev/null
+++ b/test/module/flake.lock
@@ -0,0 +1,63 @@
+{
+  "nodes": {
+    "call-flake": {
+      "locked": {
+        "lastModified": 1699147280,
+        "narHash": "sha256-bmhE1TmrJG4ba93l9WQTLuYM53kwGQAjYHRvHOeuxWU=",
+        "owner": "divnix",
+        "repo": "call-flake",
+        "rev": "7d993ee93bd35a9e6574ec76d54b7d44087495ad",
+        "type": "github"
+      },
+      "original": {
+        "owner": "divnix",
+        "repo": "call-flake",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1699099776,
+        "narHash": "sha256-X09iKJ27mGsGambGfkKzqvw5esP1L/Rf8H3u3fCqIiU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "85f1ba3e51676fa8cc604a3d863d729026a6b8eb",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "parts": {
+      "inputs": {
+        "nixpkgs-lib": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1698882062,
+        "narHash": "sha256-HkhafUayIqxXyHH1X8d9RDl1M2CkFgZLjKD3MzabiEo=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "8c9fa2545007b49a5db5f650ae91f227672c3877",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "call-flake": "call-flake",
+        "nixpkgs": "nixpkgs",
+        "parts": "parts"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/test/module/flake.nix b/test/module/flake.nix
new file mode 100644
index 0000000..69aa4a2
--- /dev/null
+++ b/test/module/flake.nix
@@ -0,0 +1,39 @@
+{
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+
+    call-flake.url = "github:divnix/call-flake";
+
+    parts = {
+      url = "github:hercules-ci/flake-parts";
+      inputs.nixpkgs-lib.follows = "nixpkgs";
+    };
+  };
+
+  outputs = {
+    parts,
+    call-flake,
+    ...
+  } @ inputs:
+    parts.lib.mkFlake {inherit inputs;} {
+      imports = [(call-flake ../../.).flakeModule];
+
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+
+      perSystem = {pkgs, ...}: {
+        devShells.default = pkgs.mkShell {
+          packages = [pkgs.hello];
+        };
+
+        packages = {
+          inherit (pkgs) hello;
+          default = pkgs.hello;
+        };
+      };
+    };
+}