feat: use disko for disk management

[realeinherjar]

disko is an automated disk partitioning and formatting for NixOS.

Install via flakes:

{
  inputs.disko.url = "github:nix-community/disko";
  inputs.disko.inputs.nixpkgs.follows = "nixpkgs";

  outputs = { self, nixpkgs, disko }: {
    # change `yourhostname` to your actual hostname
    nixosConfigurations.yourhostname = nixpkgs.lib.nixosSystem {
      # change to your system:
      system = "x86_64-linux";
      modules = [
        ./configuration.nix
        disko.nixosModules.disko
      ];
    };
  };
}

Then add the following:

{ disks ? [ "/dev/vda" ], ... }: {
  # checkout the example folder for how to configure different disko layouts
  disko.devices = {
    disk = {
      vbd = {
        device = builtins.elemAt disks 0;
        type = "disk";
        content = {
          type = "table";
          format = "gpt";
          partitions = [
            {
              name = "ESP";
              start = "1MiB";
              end = "512MiB";
              type = "EF00";
              bootable = true;
              content = {
                type = "filesystem";
                format = "vfat";
                mountpoint = "/boot";
                mountOptions = [
                  "defaults"
                ];
              };
            }
            {
              name = "luks";
              start = "512MiB";
              end = "100%";
              part-type = "primary";
              bootable = true;
              content = {
                type = "luks";
                name = "crypted";
                type = "btrfs";
                extraOpenArgs = [ "-f" "--allow-discards" ];
                passwordFile = config.age.secrets.luks.path;
                subvolumes = {
                  "/nix" = {
                    mountOptions = [ "compress=zstd" "noatime" ];
                    mountpoint = "/nix";
                  };
                };
              };
            }
          ];
        };
      };
    };
    nodev = {
      "/" = {
        fsType = "tmpfs";
        mountOptions = [
          "defaults"
          "size=12G"
          "mode=755"
        ];
      };
    };
  };
}

secrets.nix add an entry:

"luks.age".publicKeys = [ einherjar ];

hosts/laptop/wayland/default.nix:

age.secrets = {
  ...
  luks.file = ../../../secrets/luks.age;
};

Additionally this script might help you: https://github.com/Ruixi-rebirth/flakes/blob/main/scripts/disko.sh