Add flake template

jonringer · Jul 7, 2021 · e3b5bd6 · e3b5bd6
1 parent 4108dcc
commit e3b5bd6
Show file tree

Hide file tree

Showing 4 changed files with 45 additions and 2 deletions.
diff --git a/src/cli.rs b/src/cli.rs
@@ -49,7 +49,8 @@ $ nix-template config nixpkgs-root ~/nixpkgs
         .arg(
             Arg::from_usage("[PATH] 'directory or file to be written. In the case of a directory, a default.nix will be created. When used with --nixpkgs, it will be appended to nixpkgs-root to determine path location.'")
                 .default_value("default.nix")
-                .default_value_if("TEMPLATE", Some("mkshell"), "shell.nix"),
+                .default_value_if("TEMPLATE", Some("mkshell"), "shell.nix")
+                .default_value_if("TEMPLATE", Some("flake"), "flake.nix"),
         )
         .arg(Arg::from_usage(
             "-l,--license [license] 'Set license'",

diff --git a/src/expression.rs b/src/expression.rs
@@ -8,6 +8,7 @@ fn derivation_helper(template: &Template) -> (String, String) {
         Template::qt      => ("mkDerivation", "mkDerivation", None),
         Template::go      => ("buildGoModule", "buildGoModule", None),
         Template::rust    => ("rustPlatform", "rustPlatform.buildRustPackage", None),
+        Template::flake   => ("", "", None) // flakes aren't a normal expression
     };
 
     match documentation_key {
@@ -88,6 +89,45 @@ fn meta() -> &'static str {
 
 pub fn generate_expression(info: &ExpressionInfo) -> String {
     match &info.template {
+        Template::flake   => r#"{
+  description = "CHANGEME";
+
+  inputs = {
+    utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, nixpkgs, utils }:
+    let
+      # put devShell and any other required packages into local overlay
+      localOverlay = import ./nix/overlay.nix;
+
+      pkgsForSystem = system: import nixpkgs {
+        # if you have additional overlays, you may add them here
+        overlays = [
+          localOverlay # this should expose devShell
+        ];
+        inherit system;
+      };
+    # https://github.com/numtide/flake-utils#usage for more examples
+    in utils.lib.eachSystem [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" ] (system: rec {
+      legacyPackages = pkgsForSystem system;
+      packages = utils.lib.flattenTree {
+        inherit (pkgs) devShell myPkg;
+      };
+      defaultPackage = packages.myPkg;
+      apps.<mypkg> = utils.lib.mkApp { drv = packages.myPkg; };  # use as `nix run <mypkg>`
+      hydraJobs = { inherit (legacyPackages) myPkg; };
+      checks = { inherit (legacyPackages) myPkg; };              # items to be ran as part of `nix flake check`
+  }) // {
+    # non-system suffixed items should go here
+    overlay = localOverlay;
+    overlays = []; # list or attr set of overlays
+    nixosModule = { config }: { options = {}; config = {};}; # export single module
+    nixosModules = {}; # attr set or list
+    nixosConfigurations.hostname = { config, pkgs }: {};
+  };
+}"#.to_string(),
         Template::mkshell => "with import <nixpkgs> { };
 
 mkShell rec {

diff --git a/src/main.rs b/src/main.rs
@@ -92,7 +92,8 @@ fn main() {
 
                // ensure directory to file exists
                 if let Some(p) = path.parent() {
-                    if !path.exists() {
+                    // TODO: better way to determine that file will be written PWD
+                    if p.to_str() != Some("") && !p.exists()  {
                         println!("Creating directory: {}", p.display());
                         std::fs::create_dir_all(p)
                             .unwrap_or_else(|_| panic!("Was unable to create directory {}", p.display()));

diff --git a/src/types.rs b/src/types.rs
@@ -19,6 +19,7 @@ arg_enum! {
     #[allow(non_camel_case_types)]
     #[derive(Debug,PartialEq)]
     pub enum Template {
+        flake,
         stdenv,
         python,
         mkshell,