From 35dcf8940022c269aa39fe13ac07d4d5f6857507 Mon Sep 17 00:00:00 2001
From: tux <t@tux.rs>
Date: Sat, 9 May 2026 05:36:27 +0530
Subject: [PATCH] feat(sirius): enable impermanence

---
 modules/hosts/sirius/config.nix |  1 +
 modules/hosts/sirius/disko.nix  | 82 +++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 modules/hosts/sirius/disko.nix

diff --git a/modules/hosts/sirius/config.nix b/modules/hosts/sirius/config.nix
index 7e0819c..ac28808 100644
--- a/modules/hosts/sirius/config.nix
+++ b/modules/hosts/sirius/config.nix
@@ -18,6 +18,7 @@
 
       tnix = {
         boot.secure-boot.enable = true;
+        boot.impermanence.enable = true;
         networking.openssh.enable = true;
 
         virtualisation = {
diff --git a/modules/hosts/sirius/disko.nix b/modules/hosts/sirius/disko.nix
new file mode 100644
index 0000000..7704fb5
--- /dev/null
+++ b/modules/hosts/sirius/disko.nix
@@ -0,0 +1,82 @@
+{ inputs, ... }:
+{
+  flake.modules.nixos.sirius =
+    { config, lib, ... }:
+    let
+      hasOptinPersistence = config.tnix.boot.impermanence.enable;
+    in
+    {
+      imports = [
+        inputs.disko.nixosModules.disko
+      ];
+
+      disko.devices.disk.primary = {
+        device = "/dev/nvme1n1";
+        type = "disk";
+        content = {
+          type = "gpt";
+          partitions = {
+            ESP = {
+              size = "1G";
+              type = "EF00";
+              content = {
+                type = "filesystem";
+                format = "vfat";
+                mountpoint = "/boot";
+                mountOptions = [
+                  "defaults"
+                  "umask=0077"
+                ];
+              };
+            };
+            swap = {
+              size = "70G";
+              content = {
+                type = "swap";
+                discardPolicy = "both";
+                resumeDevice = true;
+              };
+            };
+            root = {
+              size = "100%";
+              type = "8300";
+              content = {
+                type = "btrfs";
+                # Base subvolumes that always exist
+                subvolumes = {
+                  "/root" = {
+                    mountOptions = [
+                      "compress=zstd"
+                      "noatime"
+                      "space_cache=v2"
+                    ];
+                    mountpoint = "/";
+                  };
+                  "/nix" = {
+                    mountOptions = [
+                      "compress=zstd"
+                      "noatime"
+                      "noacl"
+                      "space_cache=v2"
+                    ];
+                    mountpoint = "/nix";
+                  };
+                }
+                # Conditionally merge /persist only when impermanence is enabled
+                // lib.optionalAttrs hasOptinPersistence {
+                  "/persist" = {
+                    mountOptions = [
+                      "compress=zstd"
+                      "noatime"
+                      "space_cache=v2"
+                    ];
+                    mountpoint = "/persist";
+                  };
+                };
+              };
+            };
+          };
+        };
+      };
+    };
+}