feat: Add a Nix Flake with a devShell, NixOS module, and home-manager module to configure Shell Plugins

.github/workflows/check-flake.yml

@@ -0,0 +1,20 @@
+name: Check Nix flake
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+jobs:
+  check-flake:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - name: Check Nix flake inputs
+        uses: DeterminateSystems/flake-checker-action@v5
+        with:
+          fail-mode: true
+          send-statistics: false
+      - name: Run nix flake check
+        run: nix flake check

.github/workflows/update-flake-dependencies.yml

@@ -0,0 +1,37 @@
+# CI job to periodically (once a week) update flake.lock
+name: Update flake dependencies
+
+on:
+  schedule:
+    - cron: '0 16 * * 5'
+  workflow_dispatch: # for allowing manual triggers of the workflow
+
+jobs:
+  update-dependencies:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: DeterminateSystems/nix-installer-action@main
+    - uses: DeterminateSystems/magic-nix-cache-action@main
+    - name: update flake.lock
+      run: nix flake update
+    - name: Create signed commit with flake.lock changes
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        FILE_TO_COMMIT: flake.lock
+        COMMIT_BRANCH: automation/update-flake-dependencies
+        COMMIT_MESSAGE: "chore(nix): Update Flake dependencies"
+      run: |
+          # make sure something actually changed first, if not, no updates required
+          if [[ `git status --porcelain` ]]; then
+            # create the branch on the remote
+            git branch "$COMMIT_BRANCH"
+            git push -u origin "$COMMIT_BRANCH"
+            # commit via the GitHub API so we get automatic commit signing
+            gh api --method PUT /repos/1Password/shell-plugins/contents/$FILE_TO_COMMIT \
+              --field message="$COMMIT_MESSAGE" \
+              --field content=@<(base64 -i $FILE_TO_COMMIT) \
+              --field branch="$COMMIT_BRANCH" \
+              --field sha="$(git rev-parse $COMMIT_BRANCH:$FILE_TO_COMMIT)"
+            gh pr create --title "[automation]: Update Flake dependencies" --body "This is an automated PR to update \`flake.lock\`" --reviewer mrjones2014 --base main --head $COMMIT_BRANCH
+          fi

.gitignore

@@ -19,3 +19,7 @@ plugins/registry.json
 
 # 1Password
 .op
+
+# direnv
+.direnv
+.envrc

flake.nix

@@ -0,0 +1,18 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-utils = { url = "github:numtide/flake-utils"; };
+  };
+  outputs = { nixpkgs, flake-utils, ... }:
+    (flake-utils.lib.eachDefaultSystem (system:
+      let pkgs = nixpkgs.legacyPackages.${system};
+      in {
+        devShells.default = pkgs.mkShell {
+          name = "Shell with Go toolchain";
+          packages = with pkgs; [ go gopls ];
+        };
+      })) // {
+        nixosModules.default = import ./nix/nixos.nix;
+        hmModules.default = import ./nix/home-manager.nix;
+      };
+}

nix/home-manager.nix

@@ -0,0 +1,7 @@
+{ pkgs, lib, config, ... }:
+import ./shell-plugins.nix {
+  inherit pkgs;
+  inherit lib;
+  inherit config;
+  is-home-manager = true;
+}

nix/nixos.nix

@@ -0,0 +1,7 @@
+{ pkgs, lib, config, ... }:
+import ./shell-plugins.nix {
+  inherit pkgs;
+  inherit lib;
+  inherit config;
+  is-home-manager = false;
+}

nix/shell-plugins.nix

@@ -0,0 +1,85 @@
+{ pkgs, lib, config, is-home-manager, ... }:
+with lib;
+let
+  cfg = config.programs._1password-shell-plugins;
+
+  supported_plugins = splitString "\n" (lib.readFile "${
+    # get the list of supported plugin executable names
+      pkgs.runCommand "op-plugin-list" { }
+      # 1Password CLI tries to create the config directory automatically, so set a temp XDG_CONFIG_HOME
+      # since we don't actually need it for this
+      "mkdir $out && XDG_CONFIG_HOME=$out ${pkgs._1password}/bin/op plugin list | cut -d ' ' -f1 | tail -n +2 > $out/plugins.txt"
+    }/plugins.txt");
+  getExeName = package:
+    # NOTE: SAFETY: This is okay because the `packages` list is also referred
+    # to below as `home.packages = packages;` or `environment.systemPackages = packages;`
+    # depending on if it's using `home-manager` or not; this means that Nix can still
+    # compute the dependency tree, even though we're discarding string context here,
+    # since the packages are still referred to below without discarding string context.
+    strings.unsafeDiscardStringContext (baseNameOf (getExe package));
+in {
+  options = {
+    programs._1password-shell-plugins = {
+      enable = mkEnableOption "1Password Shell Plugins";
+      plugins = mkOption {
+        type = types.listOf types.package;
+        default = [ ];
+        example = literalExpression ''
+          with pkgs; [
+            gh
+            awscli2
+            cachix
+          ]
+        '';
+        description =
+          "CLI Packages to enable 1Password Shell Plugins for; ensure that a Shell Plugin exists by checking the docs: https://developer.1password.com/docs/cli/shell-plugins/";
+        # this is a bit of a hack to do option validation;
+        # ensure that the list of packages include only packages
+        # for which the executable has a supported 1Password Shell Plugin
+        apply = package_list:
+          map (package:
+            if (elem (getExeName package) supported_plugins) then
+              package
+            else
+              abort "${
+                getExeName package
+              } is not a valid 1Password Shell Plugin. A list of supported plugins can be found by running `op plugin list` or at: https://developer.1password.com/docs/cli/shell-plugins/")
+          package_list;
+      };
+    };
+  };
+
+  config = let
+    # executable names as strings, e.g. `pkgs.gh` => `"gh"`, `pkgs.awscli2` => `"aws"`
+    pkg-exe-names = map getExeName cfg.plugins;
+    # Explanation:
+    # Map over `cfg.plugins` (the value of the `plugins` option provided by the user)
+    # and for each package specified, get the executable name, then create a shell alias
+    # of the form:
+    # `alias {pkg}="op plugin run -- {pkg}"`
+    # where `{pkg}` is the executable name of the package
+    aliases = listToAttrs (map (package: {
+      name = package;
+      value = "op plugin run -- ${package}";
+    }) pkg-exe-names);
+    packages = [ pkgs._1password ] ++ cfg.plugins;
+  in mkIf cfg.enable (mkMerge [
+    ({
+      programs = {
+        bash.shellAliases = aliases;
+        zsh.shellAliases = aliases;
+        fish.shellAliases = aliases;
+      };
+    } // optionalAttrs is-home-manager {
+      home = {
+        inherit packages;
+        sessionVariables = { OP_PLUGINS_SOURCED = "1"; };
+      };
+    } // optionalAttrs (!is-home-manager) {
+      environment = {
+        systemPackages = packages;
+        variables = { OP_PLUGINS_SOURCED = "1"; };
+      };
+    })
+  ]);
+}