Add garnix build config.

garnix.yaml

@@ -0,0 +1,8 @@
+---
+# Config for garnix.io builds & caching
+builds:
+  include:
+    - homeConfigurations.*
+    - nixosConfigurations.*
+    - packages.x86_64-linux.*
+    - packages.aarch64-linux.*

nixos/common.nix

@@ -20,8 +20,12 @@
     options = [ "x-systemd.automount" "noauto" ];
   };
 
-  nix.settings.experimental-features = [ "nix-command" "flakes" ];
-  nix.settings.trusted-users = [ "root" "jahanson" ];
+  nix.settings = {
+    experimental-features = [ "nix-command" "flakes" ];
+    trusted-users = [ "root" "jahanson" ];
+    extra-substituters = "https://cache.garnix.io";
+    extra-trusted-public-keys = "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g=";
+  };
 
   # Enable fish
   programs.fish.enable = true;