Init bakke (!87)

New backup server just dropped!
This server is awfully slow, and the mdraid setup is awfully slow, and I doubt that this will be a good experience, but we now have a backup server again?

- Tried Disko and nixos-anywhere
- Tried using mdraid
- Found that md is ancient and bad
- Found that disko is 100% extra steps, and a lot more complicated and noisy than just formatting your disks yourself
- Found that systemd-boot doesn't support mdraid
- Found that we probably don't need to mirror the boot partition :)
- Found that old hardware is slow
- Found that old hardware can have poor support for iPXE with UEFI, and might do weird BIOS stuff on you when you least expect it
- Reaffirmed that zfs is love

Current disk layout:
- mdraid for boot/root disk
    - 4TB WD Red with 500MiB ESP with systemd-boot, Remaining mdraid - Old?
    - 4TB WD Red with 500MiB Unused partition, Remaining mdraid - Old?
- zfs pool "tank" for the actual backup data
    - 8TB Toshiba MG08 - New
    - 8TB Exos 7E10 - New

TODO:

- Document the death of Toriel on the wiki
- Document Bakke on the wiki
  - ... describing the poco loco disk layout
- Start backing stuff up
  - Restic? Borg? Rsync?
  - Make backup retention policy and zfs snapshot system
  - Document backup procedures

Reviewed-on: https://git.pvv.ntnu.no/Drift/pvv-nixos-config/pulls/87
Co-authored-by: Felix Albrigtsen <felix@albrigtsen.it>
Co-committed-by: Felix Albrigtsen <felix@albrigtsen.it>

hosts/bakke/configuration.nix

@@ -0,0 +1,26 @@
+{ config, pkgs, values, ... }:
+{
+  imports = [
+      ./hardware-configuration.nix
+      ../../base
+      ../../misc/metrics-exporters.nix
+      ./filesystems.nix
+    ];
+
+  sops.defaultSopsFile = ../../secrets/bakke/bakke.yaml;
+  sops.age.sshKeyPaths = [ "/etc/ssh/ssh_host_ed25519_key" ];
+  sops.age.keyFile = "/var/lib/sops-nix/key.txt";
+  sops.age.generateKey = true;
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  networking.hostName = "bakke";
+  networking.hostId = "99609ffc";
+  systemd.network.networks."30-enp2s0" = values.defaultNetworkConfig // {
+    matchConfig.Name = "enp2s0";
+    address = with values.hosts.bakke; [ (ipv4 + "/25") (ipv6 + "/64") ];
+  };
+
+  system.stateVersion = "24.05";
+}