From a29b1ee5e0c59db135723fe08159aa7554a54c0e Mon Sep 17 00:00:00 2001
From: Gabriel Arazas <foodogsquared@foodogsquared.one>
Date: Mon, 25 Dec 2023 19:54:54 +0800
Subject: [PATCH] flake.nix: filter NixOS config as images and deployments

Though there are systems that can be used for both. For now, we'll use
the deploy key as a surefire attribute that it is used for deployment
while having an intended output image format. The best solution is
simply have a conditional config for certain output formats.
---
 flake.nix        | 37 ++++++++++++++++++++-----------------
 setups/nixos.nix |  6 +++---
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/flake.nix b/flake.nix
index 949e3e3a..98070011 100644
--- a/flake.nix
+++ b/flake.nix
@@ -82,6 +82,7 @@
       # purposes. The format used here is whatever formats nixos-generators
       # support.
       images = import ./setups/nixos.nix { inherit lib inputs; };
+      images' = listImagesWithSystems images;
 
       # A set of users with their metadata to be deployed with home-manager.
       users = import ./setups/home-manager.nix { inherit lib inputs; };
@@ -370,14 +371,17 @@
 
       # A list of NixOS configurations from the `./hosts` folder. It also has
       # some sensible default configurations.
-      nixosConfigurations =
+      nixosConfigurations = let
+        validImages = lib.filterAttrs (name: metadata:
+          metadata.format == null || metadata ? deploy) images;
+      in
         lib.mapAttrs
           (host: metadata:
             mkHost {
               extraModules = [ (hostSpecificModule host metadata) ];
               nixpkgs-channel = metadata.nixpkgs-channel or "nixpkgs";
             })
-          (listImagesWithSystems images);
+          (listImagesWithSystems validImages);
 
       # We're going to make our custom modules available for our flake. Whether
       # or not this is a good thing is debatable, I just want to test it.
@@ -419,23 +423,22 @@
       # This contains images that are meant to be built and distributed
       # somewhere else including those NixOS configurations that are built as
       # an ISO.
-      images =
-        forAllSystems (system:
+      images = forAllSystems (system: let
+        validImages = lib.filterAttrs (host: metadata:
+          system == metadata._system && metadata.format != null) images';
+      in
+      lib.mapAttrs'
+        (host: metadata:
           let
-            images' = lib.filterAttrs (host: metadata: (system == metadata._system) && (metadata.format != null)) (listImagesWithSystems images);
+            name = metadata._name;
+            nixpkgs-channel = metadata.nixpkgs-channel or "nixpkgs";
+            format = metadata.format or "iso";
           in
-          lib.mapAttrs'
-            (host: metadata:
-              let
-                name = metadata._name;
-                nixpkgs-channel = metadata.nixpkgs-channel or "nixpkgs";
-                format = metadata.format or "iso";
-              in
-              lib.nameValuePair name (mkImage {
-                inherit nixpkgs-channel format;
-                extraModules = [ (hostSpecificModule host metadata) ];
-              }))
-            images');
+          lib.nameValuePair name (mkImage {
+            inherit nixpkgs-channel format;
+            extraModules = [ (hostSpecificModule host metadata) ];
+          }))
+        validImages);
 
       # My several development shells for usual type of projects. This is much
       # more preferable than installing all of the packages at the system
diff --git a/setups/nixos.nix b/setups/nixos.nix
index 965c0a50..467f38f2 100644
--- a/setups/nixos.nix
+++ b/setups/nixos.nix
@@ -10,7 +10,7 @@
 {
   ni = {
     systems = [ "x86_64-linux" ];
-    format = "iso";
+    format = null;
     modules = [
       inputs.nur.nixosModules.nur
       inputs.nix-index-database.nixosModules.nix-index
@@ -35,7 +35,7 @@
 
   plover = {
     systems = [ "x86_64-linux" ];
-    format = "iso";
+    format = null;
     domain = "foodogsquared.one";
     deploy = {
       hostname = "plover.foodogsquared.one";
@@ -62,7 +62,7 @@
 
   winnowing = {
     systems = [ "x86_64-linux" ];
-    format = "iso";
+    format = null;
     modules = [
       inputs.nixos-wsl.nixosModules.default
     ];