From 7d0b7575657aabdf58307e7e6c0cc037d2c14147 Mon Sep 17 00:00:00 2001
From: Caroline Larimore <caroline@larimo.re>
Date: Tue, 4 Feb 2025 22:15:16 -0800
Subject: migration: root impermanence

---
 hosts/c-pc/configuration.nix                   | 16 ----------------
 snowfall/modules/nixos/system/default.nix      | 20 ++++++++++++++++++++
 snowfall/systems/x86_64-linux/c-pc/default.nix |  1 +
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/hosts/c-pc/configuration.nix b/hosts/c-pc/configuration.nix
index df060d0..eabe18a 100644
--- a/hosts/c-pc/configuration.nix
+++ b/hosts/c-pc/configuration.nix
@@ -10,22 +10,6 @@
 
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
-  environment.persistence."/persist/system" = {
-    hideMounts = true;
-
-    directories = [
-      "/etc/nixos"
-      "/var/log"
-      "/var/lib/nixos"
-      "/var/lib/systemd/coredump"
-      #"/var/lib/bluetooth"
-    ];
-    
-    files = [
-      "/etc/machine-id"
-    ];
-  };
-
   programs.fuse.userAllowOther = true;
 
   time.timeZone = "America/Los_Angeles";
diff --git a/snowfall/modules/nixos/system/default.nix b/snowfall/modules/nixos/system/default.nix
index 9fa3902..dc790bd 100644
--- a/snowfall/modules/nixos/system/default.nix
+++ b/snowfall/modules/nixos/system/default.nix
@@ -12,10 +12,30 @@ in {
       default = null;
       type = nullOr str;
     };
+
+    impermanent = mkEnableOption "root impermanence";
   };
 
   config = {
     networking.hostName = cfg.hostname;
     networking.hostId = cfg.id;
+
+    environment = mkIf cfg.impermanent {
+      persistence."/persist/system" = {
+        hideMounts = true;
+
+        directories = [
+          "/etc/nixos"
+          "/var/log"
+          "/var/lib/nixos"
+          "/var/lib/systemd/coredump"
+          # "/var/lib/bluetooth"
+        ];
+        
+        files = [
+          "/etc/machine-id"
+        ];
+      };
+    };
   };
 }
diff --git a/snowfall/systems/x86_64-linux/c-pc/default.nix b/snowfall/systems/x86_64-linux/c-pc/default.nix
index 8d80b9a..5301ed8 100644
--- a/snowfall/systems/x86_64-linux/c-pc/default.nix
+++ b/snowfall/systems/x86_64-linux/c-pc/default.nix
@@ -10,6 +10,7 @@ with lib; with lib.${namespace}; {
     system = {
       hostname = "c-pc";
       id = "23ce94ff";
+      impermanent = true;
     };
 
     suites = {
-- 
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