web/src/content/blog/01.md

# Deploying an Astro project on NixOS

[Nix](https://nixos.org) is an incredible project and has completely change the way I think about configuring linux and macOS environments. Recently, I moved my personal server from Ubuntu to NixOS to match my desktop environment. ([dotfiles here!](https://github.com/zackartz/nixos-dots)). In doing so, I realized I needed to move this blog over, too. I could simply deploy a docker container like I did before, but I think it would be interesting and informative to try and build a NixOS module around it. Hopefully you find it useful :)

## The `flake.nix` file.

Nix has a experimental feature called [flakes](https://nixos.wiki/wiki/Flakes), if you've been in the NixOS space long enough you've undoubtably heard of them. Flakes are a new way of writing your package configuration, you expose two objects, `inputs` and `outputs`. Your `inputs` would be things your application depends on, for example, `nixpkgs` (the package repository of Nix). Inputs can be a variety of different things, but typically are git repos. A `flake.lock` file is generated automatically so any consumers of your flake get the exact revisions of each input to guarantee reproducability. The `outputs` section of your flake can contain many things, from `devShells` to entire `nixosConfigurations`, but we are interested in `packages` and `nixosModules` today.

A example for a starter flake for a Astro project may look like this:

```nix
{
nputs = {
 nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
 systems.url = "github:nix-systems/default";
;

utputs = {
 systems,
 nixpkgs,
 ...
 @ inputs: let
 eachSystem = f:
   nixpkgs.lib.genAttrs (import systems) (
     system:
       f nixpkgs.legacyPackages.${system}
   );
n {
 devShells = eachSystem (pkgs: {
   default = pkgs.mkShell {
     buildInputs = [
       pkgs.nodejs

       pkgs.nodePackages.pnpm

       pkgs.nodePackages.typescript
       pkgs.nodePackages.typescript-language-server
       pkgs.nodePackages."@tailwindcss/language-server"
       pkgs.nodePackages."@astrojs/language-server"
     ];
   };
 });
;

```

You can see for my inputs I am taking in `nixpkgs` and `nix-systems`, which I am using to generate a devShell for every system architechture supported by NixOS. The `devShells` all import the following nix packages, `nodejs`, `pnpm`, `typescript`, `typescript-language-server`, `tailwindcss-language-server`, `astrojs-lanaguage-server`. Lets add add a package!

I use [pnpm](https://pnpm.io) as my package manager of choice, and as such we have to add the `pnpm2nix` flake to our inputs, which we can do with the following line.

```nix
 pnpm2nix.url = "github:nzbr/pnpm2nix-nzbr";
```

Now, lets add the package spec:

```nix
...

n {
 # add packages :)
 packages = eachSystem (pkgs: {
   default = inputs.pnpm2nix.packages.${pkgs.system}.mkPnpmPackage {
     name = "zm-blog";
     src = ./.;
     packageJSON = ./package.json;
     pnpmLock = ./pnpm-lock.yaml;
   };
 });

 ...
;
```

Now, when we run `nix build`, everything works as expected, great! But how can we see the outputs of our build? If we run the following command:

```bash
󰘧 | nix eval --raw .#packages.x86_64-linux.default
/nix/store/ik5nmb60qrgib5knp4b538axwdxykc8z-zm-blog
```

Awesome, if we ls this path, we get exactly what we are expecting from the build output.

```bash
󰘧 | ls /nix/store/ik5nmb60qrgib5knp4b538axwdxykc8z-zm-blog                                                                     nix-shell-env
 _astro   fonts                    blog-placeholder-2.jpg   blog-placeholder-5.jpg      󰗀 rss.xml
 about    index.html               blog-placeholder-3.jpg   blog-placeholder-about.jpg  󰗀 sitemap-0.xml
 blog     blog-placeholder-1.jpg   blog-placeholder-4.jpg  󰕙 favicon.svg                 󰗀 sitemap-index.xml
```

At this point, we could add this repo as a input to the flake configuring our server, add a new `virtualHost` for the domain we want this to run on, point the root at this package and call it a day, but I want to take it one step further. I want to write a NixOS module to make the configuration server side even easier.

Add the following code to the outputs section of your `flake.nix`.

```nix
nixosModule = {
   config,
   lib,
   pkgs,
   ...
 }:
   with lib; let
     cfg = config.zmio.blog;
   in {
     options.zmio.blog = {
       enable = mkEnableOption "Enables the Blog Site";

       domain = mkOption rec {
         type = type.str;
         default = "zackmyers.io";
         example = default;
         description = "The domain name for the website";
       };

       ssl = mkOption rec {
         type = type.bool;
         default = true;
         example = default;
         description = "Whether to enable SSL on the domain or not";
       };
     };

     config = mkIf cfg.enable {
       services.nginx.virtualHosts.${cfg.domain} = {
         forceSSL = cfg.ssl;
         enableACME = cfg.ssl;
         root = "${packages.${pkgs.system}.default}";
       };
     };
   };
```