Use attic as nixos binary cache and update CI accordingly

common/server/atticd.nix

@@ -0,0 +1,37 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.services.atticd;
+in
+{
+  config = lib.mkIf cfg.enable {
+    services.atticd = {
+      credentialsFile = "/run/agenix/atticd-credentials";
+
+      settings = {
+        listen = "[::]:28338";
+
+        chunking = {
+          # Disable chunking for performance (I have plenty of space)
+          nar-size-threshold = 0;
+
+          # Chunking is disabled due to poor performance so these values don't matter but are required anyway.
+          # One day, when I move away from ZFS maybe this will perform well enough.
+          # nar-size-threshold = 64 * 1024; # 64 KiB
+          min-size = 16 * 1024; # 16 KiB
+          avg-size = 64 * 1024; # 64 KiB
+          max-size = 256 * 1024; # 256 KiB
+        };
+
+        # Disable compression for performance (I have plenty of space)
+        compression.type = "none";
+
+        garbage-collection = {
+          default-retention-period = "6 months";
+        };
+      };
+    };
+
+    age.secrets.atticd-credentials.file = ../../secrets/atticd-credentials.age;
+  };
+}

common/server/default.nix

@@ -22,5 +22,6 @@
     ./dashy.nix
     ./librechat.nix
     ./actualbudget.nix
+    ./atticd.nix
   ];
 }