Test flake templates (#5)

* Test devenv template

* Minor changes to CI workflow

* Fix reference to terraform

* Minor change

* Add devenv template to flake.nix

* Accept flake config

* Add timeout to templates

* Update output reference devShell -> devShells

* Revert renaming devShells -> devShell

* Update README

* Make "Binary Cache" a subsection

* Add Templates section

.github/workflows/ci.yml

@@ -9,6 +9,7 @@ concurrency:
 jobs:
   build:
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -25,3 +26,30 @@ jobs:
         run: nix flake check --impure
         env:
           NIXPKGS_ALLOW_UNFREE: 1
+
+  templates:
+    strategy:
+      matrix:
+        template: [default, devenv]
+      fail-fast: true
+    runs-on: ubuntu-latest
+    timeout-minutes: 2
+    needs: [build]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@v6
+      - name: Replace inputs on templates
+        run: sed -i 's/github:stackbuilders\/nixpkgs-terraform/github:stackbuilders\/nixpkgs-terraform\/${{ github.sha }}/g' templates/*/flake.nix
+      - name: Create a temporary directory
+        run: echo "tmpdir=$(mktemp -d)" >> "$GITHUB_OUTPUT"
+        id: mktemp
+      - name: Scaffold a new project
+        run: nix flake init -t ${{ github.workspace }}#${{ matrix.template }}
+        working-directory: ${{ steps.mktemp.outputs.tmpdir }}
+      - name: Run smoke test
+        run: nix develop --accept-flake-config --impure -c terraform --version
+        env:
+          NIXPKGS_ALLOW_UNFREE: 1
+        working-directory: ${{ steps.mktemp.outputs.tmpdir }}

README.md

@@ -13,15 +13,9 @@ This flake provides a set of Terraform versions in the form of:
 nixpkgs-terraform.packages.${system}.${version}
 ```
 
-Terraform versions >= 1.5.0 are kept up to date via a weekly scheduled [CI
+Terraform versions `>= 1.5.0` are kept up to date via a weekly scheduled [CI
 workflow](.github/workflows/update.yml).
 
-The current project structure as well as some components of the CI workflow are
-heavily inspired by the following projects:
-
-- [nixpkgs-python](https://github.com/cachix/nixpkgs-python)
-- [nixpkgs-ruby](https://github.com/bobvanderlinden/nixpkgs-ruby)
-
 ## Install
 
 The quickest way to get started with an empty project is to scaffold a new
@@ -45,7 +39,7 @@ inputs.flake-utils.url = "github:numtide/flake-utils";
 inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
 ```
 
-**Binary Cache**
+### Binary Cache
 
 It is highly recommended to set up the
 [nixpkgs-terraform](https://nixpkgs-terraform.cachix.org) binary cache to
@@ -90,9 +84,35 @@ env NIXPKGS_ALLOW_UNFREE=1 nix develop --impure
 
 **Note:** Due to Hashicorp’s most recent [license
 change](https://www.hashicorp.com/blog/hashicorp-adopts-business-source-license),
-the `NIXPKGS_ALLOW_UNFREE` flag is required for Terraform versions >= 1.6.0,
+the `NIXPKGS_ALLOW_UNFREE` flag is required for Terraform versions `>= 1.6.0`,
 `nix develop` should work out of the box for older versions.
 
+### Templates
+
+This flake provides the following templates:
+
+- [default](templates/default) - Simple nix-shell with Terraform installed via
+  nixpkgs-terraform.
+- [devenv](templates/devenv) - Using nixpkgs-terraform with devenv.
+
+Run the following command to scaffold a new project using a template:
+
+```sh
+nix flake init -t github:stackbuilders/nixpkgs-terraform#<template>
+```
+
+**Note:** Replace `<template>` with one of the templates listed above.
+
+## Inspired By
+
+The current project structure as well as some components of the CI workflow are
+heavily inspired by the following projects:
+
+- [nixpkgs-python](https://github.com/cachix/nixpkgs-python) - All Python
+  versions, kept up-to-date on hourly basis using Nix.
+- [nixpkgs-ruby](https://github.com/bobvanderlinden/nixpkgs-ruby) - A Nix
+  repository with all Ruby versions being kept up-to-date automatically.
+
 ## License
 
 MIT, see [the LICENSE file](LICENSE).

flake.nix

@@ -61,9 +61,15 @@
             inherit version hash vendorHash;
             patches = [ "${nixpkgs}/pkgs/applications/networking/cluster/terraform/provider-path-0_15.patch" ];
           };
-      templates.default = {
-        description = "Simple nix-shell with Terraform installed via nixpkgs-terraform";
-        path = ./templates/default;
+      templates = {
+        default = {
+          description = "Simple nix-shell with Terraform installed via nixpkgs-terraform";
+          path = ./templates/default;
+        };
+        devenv = {
+          description = "Using nixpkgs-terraform with devenv";
+          path = ./templates/devenv;
+        };
       };
     };
 }

templates/devenv/flake.nix

@@ -0,0 +1,31 @@
+{
+  inputs = {
+    devenv.url = "github:cachix/devenv";
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs-terraform.url = "github:stackbuilders/nixpkgs-terraform";
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  };
+
+  nixConfig = {
+    extra-substituters = "https://nixpkgs-terraform.cachix.org";
+    extra-trusted-public-keys = "nixpkgs-terraform.cachix.org-1:8Sit092rIdAVENA3ZVeH9hzSiqI/jng6JiCrQ1Dmusw=";
+  };
+
+  outputs = inputs@{ self, devenv, flake-utils, nixpkgs-terraform, nixpkgs }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        terraform = nixpkgs-terraform.packages.${system}."1.6.3";
+      in
+      {
+        devShells.default = devenv.lib.mkShell {
+          inherit inputs pkgs;
+          modules = [
+            ({ pkgs, config, ... }: {
+              languages.terraform.enable = true;
+              languages.terraform.package = terraform;
+            })
+          ];
+        };
+      });
+}