configuration/common: Enable nix flakes

configuration/common/default.nix

@@ -40,7 +40,7 @@
   services.openssh.kbdInteractiveAuthentication = false;
   services.openssh.permitRootLogin = lib.mkDefault "no";
 
-  nix.gc = {
+  nix.gc = lib.mkDefault {
     automatic = true;
     dates = "weekly";
     options = "--delete-older-than 30d";
@@ -76,6 +76,8 @@
     acceptTerms = true;
   };
 
+  nix.settings.experimental-features = [ "nix-command" "flakes" ];
+
   nixpkgs.overlays = [
     (import ../../pkgs/overlay.nix)
   ];

hosts/osmium/configuration.nix

@@ -27,6 +27,12 @@
     git
   ];
 
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 400d";
+  };
+
   clerie.monitoring = {
     enable = true;
     id = "201";