From 10dbccae97ed1e1ed0cd336b69876fc23c19c6fb Mon Sep 17 00:00:00 2001
From: Pim Kunis <pim@kunis.nl>
Date: Sat, 6 Jan 2024 21:45:18 +0100
Subject: [PATCH] create top-level switch whether a machine holds the
 application data

---
 nixos/machines/default.nix |  4 +---
 nixos/modules/default.nix  | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/nixos/machines/default.nix b/nixos/machines/default.nix
index c161060..572f87f 100644
--- a/nixos/machines/default.nix
+++ b/nixos/machines/default.nix
@@ -38,9 +38,7 @@
 
     nixosModule.lab = {
       disko.osDiskDevice = "/dev/sda";
-      backups.enable = true;
-      networking.allowDMZConnectivity = true;
-      data-sharing.enable = true;
+      dataHost.enable = true;
 
       dataDisk = {
         enable = true;
diff --git a/nixos/modules/default.nix b/nixos/modules/default.nix
index 5762b09..dbd248e 100644
--- a/nixos/modules/default.nix
+++ b/nixos/modules/default.nix
@@ -1,3 +1,7 @@
+{ lib, config, ... }:
+
+let cfg = config.lab.dataHost;
+in
 {
   imports = [
     ./terraform-database
@@ -9,4 +13,20 @@
     ./networking.nix
     ./data-sharing.nix
   ];
+
+  options.lab.dataHost.enable = lib.mkOption {
+    default = false;
+    type = lib.types.bool;
+    description = ''
+      Whether this machine holds application data.
+      This enables NFS and PostgreSQL to serve this data, and sets up backups.
+      Also enables networking on the DMZ to enable serving data.
+    '';
+  };
+
+  config.lab = lib.mkIf cfg.enable {
+    backups.enable = true;
+    data-sharing.enable = true;
+    networking.allowDMZConnectivity = true;
+  };
 }