initial commit

hosts/example.nix

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+_: {
+  # New host: copy this file to hosts/<name>.nix. Replace fileSystems/boot
+  # below with the real hardware (see hosts/server-n0.nix for a bigger
+  # example). Add a containers/<name>/ directory for its containers.  
+
+  module =
+    { lib, hostInfo, ... }:
+    {
+      networking.hostName = hostInfo.hostname;
+
+      fileSystems."/" = {
+        device = "/dev/disk/by-label/NIXOS_ROOT";
+        fsType = "ext4";
+      };
+
+      fileSystems."/persist" = {
+        device = "/dev/disk/by-label/NIXOS_PERSIST";
+        fsType = "ext4";
+      };
+
+      fileSystems."/nix" = {
+        device = "/dev/disk/by-label/NIXOS_NIX";
+        fsType = "ext4";
+      };
+
+      fileSystems."/var/log" = {
+        device = "/dev/disk/by-label/NIXOS_VARLOG";
+        fsType = "ext4";
+        neededForBoot = true;
+      };
+
+      boot.loader.grub.device = "nodev";
+      boot.loader.grub.efiSupport = true;
+      boot.loader.efi.canTouchEfiVariables = true;
+
+      nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+    };
+}

hosts/server-n0-darling-erasure.sh

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+mkdir -p /mnt
+
+echo "--- erasing system state begin ---"
+# We first mount the btrfs root to /mnt
+# so we can manipulate btrfs subvolumes.
+mount -o subvol=/ /dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820 /mnt
+
+# back up the old root (important!!)
+BOOTID=$(date +"@boot-%Y_%m_%d-%H_%M_%S-%s")
+echo "backing up old root: /mnt/@root/ -> /mnt/@old-roots/$BOOTID..."
+echo "note that the timestamp is of *this* boot, not of the boot that created the old root!"
+mv /mnt/@root /mnt/@old-roots/$BOOTID
+btrfs property set -f -ts /mnt/@old-roots/$BOOTID ro true
+
+echo "restoring blank /@root subvolume..."
+btrfs subvolume snapshot /mnt/@root-blank /mnt/@root
+
+# Once we're done rolling back to a blank snapshot,
+# we can unmount /mnt and continue on the boot process.
+echo "--- erasing system state end ---"
+
+umount /mnt
+

hosts/server-n0.nix

@@ -0,0 +1,109 @@
+_: {
+  module =
+    {
+      config,
+      lib,
+      pkgs,
+      modulesPath,
+      hostInfo,
+      ...
+    }:
+    {
+      imports = [
+        (modulesPath + "/installer/scan/not-detected.nix")
+      ];
+
+      networking.hostName = hostInfo.hostname;
+
+      fileSystems."/" = {
+        device = "/dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820";
+        fsType = "btrfs";
+        options = [
+          "subvol=@root"
+          "noatime"
+          "compress=zstd"
+        ];
+      };
+
+      fileSystems."/nix" = {
+        device = "/dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820";
+        fsType = "btrfs";
+        options = [
+          "subvol=@nix"
+          "noatime"
+          "compress=zstd"
+        ];
+      };
+
+      fileSystems."/persist" = {
+        device = "/dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820";
+        fsType = "btrfs";
+        options = [
+          "subvol=@persist"
+          "noatime"
+          "compress=zstd"
+        ];
+      };
+
+      fileSystems."/btrfs_root" = {
+        device = "/dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820";
+        fsType = "btrfs";
+        options = [
+          "noatime"
+          "ro"
+          "compress=zstd"
+        ];
+      };
+
+      fileSystems."/var/log" = {
+        device = "/dev/disk/by-uuid/5dfd3b74-2162-4167-825b-21259ca48820";
+        fsType = "btrfs";
+        options = [
+          "subvol=@logs"
+          "noatime"
+          "compress=zstd"
+        ];
+        neededForBoot = true;
+      };
+
+      fileSystems."/boot" = {
+        device = "/dev/disk/by-uuid/7155-EF89";
+        fsType = "vfat";
+        options = [
+          "fmask=0022"
+          "dmask=0022"
+        ];
+      };
+
+      boot = {
+        loader.limine.enable = true;
+
+        kernelPackages = pkgs.linuxPackages_latest;
+        kernelModules = [ "kvm-intel" ];
+        extraModprobeConfig = "options kvm_intel nested=1";
+        extraModulePackages = [ ];
+        supportedFilesystems = [ "btrfs" ];
+        initrd = {
+          compressorArgs = [
+            "-22"
+            "-T0"
+            "--long"
+            "--ultra"
+          ];
+          availableKernelModules = [
+            "nvme"
+            "xhci_pci"
+            "ahci"
+            "usbhid"
+          ];
+          kernelModules = [ ];
+          systemd.enable = false;
+          postDeviceCommands = lib.mkBefore (builtins.readFile ./server-n0-darling-erasure.sh);
+        };
+      };
+
+      nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+      hardware.enableRedistributableFirmware = true;
+      hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
+    };
+}