From ba5fd48569a37e6ec791c78464aab342916d9ac2 Mon Sep 17 00:00:00 2001
From: Julia Lange <public@julialange.org>
Date: Thu, 14 Nov 2024 13:55:47 -0800
Subject: [PATCH] Hosts, Use directory-driven hosts in flake.nix

This adds some code to flake.nix to read the directory of hosts/ and
find all hosts based on their host.nix file, and set the hostname based
on the directory.

I don't know enough about hostnames to know what are valid characters,
but in the future this could allow a hostname such as "servers/madoka"
which may be an issue. For now the structure is simple enough of
"hosts/name" resulting in hostname "name"

Another commit is planned which will do the same thing for users
---
 flake.nix                               | 20 +++++++++++++++-----
 hosts/jibril/{default.nix => host.nix}  |  0
 hosts/onizuka/{default.nix => host.nix} |  0
 3 files changed, 15 insertions(+), 5 deletions(-)
 rename hosts/jibril/{default.nix => host.nix} (100%)
 rename hosts/onizuka/{default.nix => host.nix} (100%)

diff --git a/flake.nix b/flake.nix
index 85c6a1a..7644915 100644
--- a/flake.nix
+++ b/flake.nix
@@ -15,6 +15,8 @@
   outputs = { self, home-manager, nixpkgs, ... }@inputs: let
     system = "x86_64-linux";
     pkgs = nixpkgs.legacyPackages.${system};
+    fs = pkgs.lib.fileset;
+    st = pkgs.lib.strings;
 
     hostConfig = extraModules: nixpkgs.lib.nixosSystem {
       specialArgs = { inherit inputs; };
@@ -23,6 +25,15 @@
         ./nixosModules
       ] ++ extraModules;
     };
+    hostFilter = { name, ...}: name == "host.nix";
+    hostPaths = fs.toList (fs.fileFilter hostFilter ./hosts);
+
+    hosts = builtins.listToAttrs (map (path: {
+      value = hostConfig [ path ];
+      name = builtins.unsafeDiscardStringContext (st.removeSuffix "/host.nix" (
+        builtins.elemAt (st.splitString "/hosts/" path) 1
+      ));
+    }) hostPaths);
 
     userConfig = extraModules: home-manager.lib.homeManagerConfiguration {
       inherit pkgs;
@@ -31,12 +42,11 @@
         ./hmModules
       ] ++ extraModules;
     };
-  in
-  {
-    nixosConfigurations.onizuka = hostConfig [ ./hosts/onizuka ];
-    homeConfigurations."pan@onizuka" = userConfig [ ./hosts/onizuka/users/pan ];
 
-    nixosConfigurations.jibril = hostConfig [ ./hosts/jibril ];
+  in {
+    nixosConfigurations = hosts;
+
+    homeConfigurations."pan@onizuka" = userConfig [ ./hosts/onizuka/users/pan ];
     homeConfigurations."pan@jibril" = userConfig [ ./hosts/jibril/users/pan ];
   };
 }
diff --git a/hosts/jibril/default.nix b/hosts/jibril/host.nix
similarity index 100%
rename from hosts/jibril/default.nix
rename to hosts/jibril/host.nix
diff --git a/hosts/onizuka/default.nix b/hosts/onizuka/host.nix
similarity index 100%
rename from hosts/onizuka/default.nix
rename to hosts/onizuka/host.nix